The Origin of Life on Earth

There are two basic ideas about how life on Earth originated. The first is that life (or at least the chemical precursors of life) arose on other planets followed by a diaspora (migration) to various parts of the galaxy including Earth. This idea is know as panspermia (see BP p. 398-399). Recent support for this idea comes from Mars rocks found in the Antarctic that appear to contain fossilized organisms resembling bacteria. There is also some evidence from Martian probes suggesting the possibility of life existing either in the past or even currently on Mars or Europa.

The alternate hypothesis about how life arose on Earth is that of Spontaneous Generation. Not the spontaneous generation of the17th century that Reddi, Leeuwenhoek, Spallanzalli, Tyndall, and Pasteur put to rest, but the 1936 spontaneous generation of Oparin, a Russian biochemist, that non-cellular macromolecular precursors developed into cells.
Oparin's argument goes something like this:
1. The Universe formed approximately 20 billion years ago, followed by our solar system (the Sun and planets) about 4-5 billion years ago. Our solar system formed from a cloud of dust and gas which condensed into a single compact mass resulting in tremendous heat and pressure. Because of the heat and pressure, thermonuclear reactions were initiated creating the Sun. Lesser centers of condensation occurred to the Earth and other planets.
Earth's condensation (and other terrestrial plants too) resulted in stratification of the components giving rise to Fe + Ni at the Earth's center (the heavy metals) and H2 + He + other gases (the lighter elements) as the primordial atmosphere. But, because of the size of the Earth and its weak gravitational field, these gases escaped nearly immediately. As a result the Earth became a bare, rocky globe with no oceans or atmosphere.
Time passes and gravity compresses the earth more. Radioactive decay occurs to produce heat and create a molten interior. More stratification occurs to produce a core of molten Fe + Ni and a mantel of Fe and magnesium silicates. The heat of the core forces gases and water out by volcanic action. These gases formed a second atmosphere, the evolutionary atmosphere.

As the Earth cooled, water vapor would have condensed and torrential rains would have fallen. The rain would have dissolved minerals (i.e., mineral weathering would have occurred) and the run-off from topographic highs would have collected in topographic lows to form oceans. If CH4 and NH3 were present in the atmosphere, then they would have also dissolved to some extent in the rain and ended up in the forming oceans.
2. The next step in the evolution of life would have been the formation of small organic molecules. The combination of minerals, NH4+, CH4 , H2, and H2O that formed the oceans is a very stable mixture so how could the building blocks of life arise? Some sort of energy source was necessary. An abundance of energy sources was available on early Earth in the form of solar radiation (visible light, ultra-violet light, x-rays), lightning, heat, cosmic rays, radioactive decay, or volcanic explosions.
In 1953, Stanley Miller did an experiment in which he combined an atmosphere containing CH4 , H2, H2O, and NH3 in a reaction vessel. Using an electrical spark, he was able to generate several small organic molecules including urea (CO(NH2)2), hydrogen cyanide (CHN), acetic acid (CH3COOH), and lactic acid (CH3COH2COOH). To eliminate the criticism that microbial activity was the source of the organic compounds, Miller ran the experiment under sterile conditions and without an electrical spark. When no spark was used, no organic compounds were formed. When the experiment was conducted under sterile conditions, no organic compounds were formed.
Since Miller's experiment many other similar experiments have been done with various atmospheric component combinations with similar results. All 20 of the most common amino acids have been produced by these types of experiments. In fact the experiments have been so successful under so many conditions that it is unlikely that organic compounds weren't formed in this manner!!!!
Some have argued that the organic compounds formed by these means would have been destroyed as fast as they formed. It has been suggested the small organic compounds would have oxidized, but there was no O2 in the early atmosphere for this to happen. It has been suggested that the small organic compounds would have decayed, but there were no microorganisms to decay them. It has been suggested that the high levels of UV light would have destroyed the small organic compounds. This is true to some extent, but because UV doesn't penetrate water very well, small organic molecules formed in water would have been shielded from UV destruction by the water. Soooo, it seems highly likely that small organic molecules would have formed and survived on early Earth. But is the formation of small organic molecules sufficient for the beginning of life? NO!
3. The next step in evolution of life on Earth would have been the formation of macromolecules or polymers. It is unlikely that sufficient concentrations of small organic molecules would have formed in the early oceans. A concentration process would have been necessary to encourage formation of polymers like polypeptides (precursors of proteins) or polynucleotides (precursors of DNA and RNA). Several processes easily could have occurred on early Earth to allow for polymer formation. For example, small organic molecules could have been concentrated by adsorption on clay particles or adsorption on pyrites in black smokers (see BP p. 398). Another concentration mechanism would have been evaporation in small pools or puddles on beaches or in lagoons. Additionally, UV light could have served as an energy source to produced polymers. To demonstrate that these mechanisms have the potential to produce polymers from small organic molecules, Sidney Fox heated dry mixtures of amino acids to produce a variety of polypeptides in the laboratory.
4. Once polymers were formed the next step in creating life on Earth would have been the formation of molecular aggregates and primitive "cells". The term cells is used very loosely here. When polypeptides or polynucleotides are combined in solution they form one of two types of complex units: one that Oparin called coacervate droplets and the other that Stanley Fox called proteinoid microspheres. Coacervate droplets are macromolecules that are surrounded by a shell of water molecules which are rigidly oriented relative to the macromolecule forming a "membrane". The coacervate droplets will adsorb and absorb chemicals from the surrounding medium and can se highly selective (lets only certain things in and certain things out) like a cell membrane. The coacervate droplets can become complex and show internal structure which becomes more and more pronounced as more materials pass the "membrane" and are incorporated into the droplet.
Proteinoid microspheres form when hot aqueous solutions of polypeptides are cooled. Proteinoid microspheres are much more stable than coacervate droplets and have the following characteristics: swell in a high salt solution, shrink in a low salt solution, have a double-layered outer boundary which is very similar to a cell membrane, show internal movement similar to cytoplasmic streaming "grow" in size and complexity, "bud" in a manner superficially similar to yeast cell reproduction, have electrical potential differences across the outer boundary which is necessary for cell membranes to generate ATP, and aggregate into clusters.
In either case (coacervate droplets or proteinoid microspheres) these "prebionts" are structurally complex and sharply separated from their environment creating a situation in which chemical reactions can take place inside the prebionts that would not happen in the surrounding medium.
On early Earth, many types of prebionts would have formed. Some would have been unstable. Others may have contained especially favorable combinations of chemicals. If they were to continue to exist, they must have had synthetic ability and thus a mechanism for handling energy. Energy demands probably would have been handled through ATP since all living things use ATP as their energy currency. Sidney Fox showed that proteinoid microspheres can use ATP to make polypeptides and nucleic acids. As a result proteinoid microspheres can increase in size. They are also susceptible to fragmentation to produce smaller droplets of similar composition - or they demonstrate a kind of reproduction.
There is a third hypothesis about formation of prebionts called the naked gene hypothesis. The basis for this hypothesis is the observation that self-replicating macromolecules (nucleotides) can accumulate a shell of other substances in a manner analogous to a modern day virus. Modern day viruses contain either DNA or RNA and are surrounded by a protein shell. BUT, modern day viruses are parasites that require living cells to reproduce and so are thought to be recent evolutionary products. Evidence for the naked gene hypothesis comes from discovery of prions, which are naked pieces of DNA that have been associated with cancer.
The difference between the naked gene hypothesis and the coacervate droplet or proteinoid microsphere hypotheses is that the later two prebionts showed primitive reproduction first followed by development of a genetic control system while the naked gene prebiont evolved a genetic control system first followed by cytoplasm and a membrane. Regardless of which hypothesis is correct, CELLS HAPPEN HERE!!!!
The oldest cell fossils are all procaryotic (bacterial) and are 3.5 billion years old. Procaryotes (lacking a "true" nucleus) are cells in which the chromosome is not surrounded by a nuclear membrane. They also lack the specialized cellular organelles that other types of cells have with the exception of ribosomes. There are many other distinguishing characteristics of procaryotic cells but these characteristics, while fascinating, are outside the scope of EVSC 101.
5. Once cells arrived on the scene, they would have had to evolve biochemical pathways. The oceans of early Earth would have been a soup that contained lots of energy rich organic matter the first cells could have used to produce ATP. However, as the number of organisms increased the supply of organic compounds would have decreased, becoming limiting, because the natural rate of organic matter formation is very slow. Thus, these early organisms were faced with a minor crisis - limited energy sources. To overcome this, some organisms began to use alternate forms of organic matter, converting it to chemical compounds similar to those they used previously to generate energy. As the process continued, the chain of reactions cells were capable of carrying out would have become longer and longer leading to the very complex series of chemical reactions all cells carry out today. Because these early cells all used pre-formed organic materials, they were all heterotrophs.
As the number of cells increased even further, the demand for abiotically formed organic materials would have out striped the rate at which they could be formed leading to a major crisis in the evolution of life on Earth - the first famine.
5. By the time the first famine occurred, cells had evolved very complex biochemical pathways. The lack of available energy sources to these early organisms would have created selective pressure for evolution of an alternative to small organic molecules as a way to obtain energy. That alternative was to capture light energy and convert it to chemical energy in the form of ATP. This process is what we know as photosynthesis, but not the type of photosynthesis that green plants carry out. The first photosynthetic organisms were bacteria that used H2S instead of H2O as a source of reducing power or H+. As a result, the end products of bacterial photosynthesis were organic matter and sulfide, not O2 like green plants produce. However, because the supply of H2S on early Earth would have also been limited, selective pressure would have existed for the evolution of an alternative to H2S. That alternative was H2O, which was very abundant and serves as an excellent source of H+ for photosynthesis. The first organisms to make the leap from using H2S to H2O were the blue-green bacteria or the Cyanobacteria (you will often hear these organisms referred to incorrectly as the blue-green algae).
This new type of photosynthesis (based on H2O) created the second major crisis for life on Earth. One of the products of H2O-dependent photosynthesis is O2 - a highly toxic gas. Oxygen is toxic to many critical biochemicals in cells and as a result early organisms had to either avoid O2 or evolve mechanisms to detoxify or protect the cell biochemicals from O2. In addition to the affect on cells, accumulation of O2 in the atmosphere lead to the formation of the ozone (O3) layer, which reduced the rate of mutation and significantly slowed the rate of evolution. Development of oxygenic photosynthesis is an excellent example of organisms altering their environment.
6. The accumulation of O2 in the atmosphere forced the next major evolutionary step - the evolution of aerobic organisms. The procaryotic organisms that evolved prior to this were all anaerobes - that is they didn't require O2 for cellular respiration or were fermentors. Aerobes require O2 for cellular respiration. The advantage of respiration using O2 is that it is very efficient compared to fermentation and somewhat more efficient than anaerobic respiration. Consequently aerobic organisms had a selective advantage over organisms that ferment or respire anaerobically.
So at this point, after about 3 billion years in the story of evolution of life on Earth the organisms that have evolved are all procaryotic (bacteria) and are:
A. anaerobes
i. fermentors
ii. respirers
iii. photosynthesizers
B. aerobes
i. photosynthesizers
ii. respirers
7. The rest of evolution on Earth is simple - the eucaryotes evolve. The first eucaryotic fossils are 1.5 billion years old. From these very first eucaryotes (cells with a "true" nucleus - or one enclosed in a nuclear membrane) all other eucaryotes (protozoa, fungi, plants, and animals) evolved. Several hypotheses have been proposed to explain how eucaryotic cells arose: the invagination hypothesis and the symbiont hypothesis (see BP figure on p. 402). The invagination hypothesis proposes that a procaryotic cell enclosed a portion of itself to become an organelle to form either a mitochondrion or a chloroplast like those typical of eucaryotic cells. The symbiont hypothesis suggests that independent, free-living procaryote cells formed a symbiotic relationship with one another in which one of the procaryotes was resident inside the other procaryotic. As the relationship evolved the "invader" lost its ability to live independently and became either a mitochondrion ("invader" was a heterotroph) or a chloroplast ("invader" was a photosynthetic autotroph).

what is plasma tv

Plasma televisions are much thinner than traditional TV sets (usually no more than 4 inches thick). The diminutive size necessitates a special stand to display the TV. There are several different types and an almost endless array of styles of plasma television stands. Plasma TV owners should choose a style that is compatible for their TV and complements their décor.
Modern Plasma Television Stands for Modern Plasma Televisions
Because plasma televisions are the highest end home entertainment piece currently available, they are rightfully viewed as high tech and ultra-modern. Plasma television stand designs reflect this focus. Most stands are made of metal or plastic and feature bare bones styles and modernistic lines.
A focus on geometric shapes and a tendency to provide platforms or shelves but not necessarily cabinets on which the TV rests is also common. Often these types of plasma television stands are no more than a series of platforms, the highest of which holds the television, and lower ones that hold other home entertainment components. Modernistic plasma television stands tend to complement the TV very well, but may not mesh with the style of every home in which they are placed.
Not to fear, other options do exist. A Google search for “plasma television stand” reveals an impressively long list of about 13,000 sites, most of which feature plasma television stands for sale. More traditional styles, made of hardwood or veneer, are available, as are cabinet style stands.
With the latter type of stand, a basic TV cabinet, similar to those used with traditional televisions is outfitted with a special mount to base to hold the plasma television. These plasma television stands make a good for choice for more traditionally decorated homes, or for owners who need storage for videotapes, DVDs and other peripherals. In contrast to more modernistic styles, cabinet type stands tend to enclose peripherals, videos, etc. and hide them from view.
Regardless of the style of plasma television stand chosen, it’s very important to make sure the stand is compatible with the owner’s particular model of plasma TV. Some brands produce custom plasma television stands that are designed to work with specific models; in fact, during some promotional events, plasma televisions come with complementary stands.
Should you fail to find any plasma television stand that meets your needs, you could always consider another option – wall mounting your plasma television. Although many people associate this idea with more contemporary décor, the wall-mounted plasma television would be relatively attractive in any environment

Upcoming PS3 Games

PS3 game fans are some of the most devoted fans in the world. They take their games seriously and follow the characters and story lines of their favorite franchises closely. These are the fans who are in line at the store the moment a new release hits the shelves.
Click Here For Upcoming PS3 Games!
Whether you are a passionate PS3 fan or a casual one, we've got information you can use right here. Our gaming channel has the current scoop on all the upcoming PS3 games on the market. You can find out plot details, read reviews and get spoilers galore all in one convenient online location

Get Inside Information on Upcoming PS3 Games

For a PS3 gaming fan, coming to CraveOnline.com's gaming channel is like visiting Disney World. Our information on upcoming PS3 games includes some of the truest reviews you'll find anywhere. Our reviewers are all PS3 game fans themselves and have no problem telling it like it is about new games. We always have a new and extensive supply of PS3 game reviews on our site. We also offer strategy guides and preview clips for upcoming and existing games. We even have periodic interviews with professionals in the gaming world.
Explore our gaming channel while you're here. The channel has several subsections, as well, including one on strategy and one on role-playing video games. If you find something really thought-provoking or just feel like talking to someone about a game, head to our message boards. There are always lots of people just like you waiting to discuss all the latest info on upcoming and old-school PS3 games

does cats have emotions and feelings

Cats do not experience anything like people do. They do not have the brain capacity to do so. They are not cognitively self aware (sentient). Only humans and a handful other species have been demonstrated to be cognitively self aware. However, 'emotions' as we experience them, are the closest that humans may get to feeling like animals. This is because the brain areas that are most active during emotional situations are located in the basal ganglia, or lower brain. We have a vastly larger cortex (the grey matter) than most other animals, and this adds an entire new level of processing that is absent in non sentient organisms.The basic instinctive behaviors that interact with emotions are highly conserved between species, so for instance the joy of 'winning' at anything probably 'feels' similar to what a cat may 'feel' when it catches a bird, or a Gazelle. This also applies to love, fear, and anger. The difference lies in the fact that you are aware that you exist and that you are angry. The cat is not aware of itself, or its anger, it only responds to the anger and expresses it in its behavior. It cannot ponder upon its own existance, like you can. Cats do have emotion, but the experience of it from the perspective of the cat is nothing like it is from your perspective.What you are doing is called Anthropomorphism. You are interpreting the behavior of another organism in light of human traits. The behavior of a cat as it interacts with you is not sentient (self aware). They DO NOT have the brain capacity to interpret the world in the way that you do

While cats are different in physiology and feelings, they display enough of what we consider to be emotion. They wouldn't have made it into so many homes and hearts if they didn't. People may choose to read into the emotion displayed. Doesn't hurt anyone. Bob Blaylock Nov, 21 2006 at 03:05 AM
setTimeout('Comment.clearEdit(83044);', (120 - 56636173) * 1000);

Anyone who's ever really known any cat knows how wrong this answer is. science_geek Nov, 21 2006 at 05:09 PM
setTimeout('Comment.clearEdit(83761);', (120 - 56585577) * 1000);

Yes, Bob, don't you have anything better to do than run around and follow me? If you have ever studied neuronal function, had any basic idea of how the human body and mind function other than from your subjective experience, as well as having an understanding of human and animal physiology, you would realize how ridiculous your statement is. We have a cat. I know animal behavior quite well. I perform research on animals. Look at the question I answered. Cats do not experience anything like people do!

Mammals like cats and dogs are selm aware and do show emotion one standard used for there self awarness is the mirror test. Cats and Dogs know there own reflection and thus know who they are and what they look like. As for emotions cats show a wide number of emotions they are one of the most bonding mammals on the planet to humans even Charles Darwin said this in his accounts when he studied mammals such as cats, They are not just a Flesh,blood and bone with Electroic impulses like some of you are making them out to be !!! More scientist will agree that house hold animals started out with only limited emotions to survive but over thousands of years being domesticated there brains have picked up emotions and thus feelings for there human companion/owner !!!!

Why I don’t like chocolate....???

the reasons given by some people during our survey.....

It gives me a headache. I got one today for the first time in a while. In preparation for my trip to the grocery store tomorrow, I decided to clean out the cupboards and had to finish off the last couple segments of a dark chocolate bar. But then I got a headache.
Chocolate started hurting me years ago. The last time I ate a piece of chocolate cake with chocolate frosting I got a bad headache. I think that was back in 1996. I stopped eating chocolate a lot because I was trying to have a healthier diet. And, after learning that there was a correlation between caffeine and miscarriage, I also avoided chocolate for years during pregnancies and infertility treatment. So I lost a lot of tolerance. Brownies, chocolate cake, anything with cocoa powder is bad news for this head. Chocolate candy is okay, as long as it is not too much, mostly milk chocolate. It was only recently that I dared to eat dark chocolate again. A friend of mine who was in medical school back then, when I last ate cake, tried to explain my headaches to me, but I’ve forgotten it - I think she said caffeine dilates the blood vessels (?). I think sometimes people have a hard time believing me but it’s true - I can’t eat chocolate cake!
Maybe though tonight it was the wine. By dinner I really had a headache. And I only took a small sip or two of wine from my glass. I bought the Jacob’s Creek Shiraz Cabernet because it was on sale at Safeway, and because it had some medal stickers on the bottle - great way to pick a wine, huh?! Also too, since I had not yet liked a shiraz, based on what we had at the winetasting party , I was afraid to choose a pure one - the combination cabernet sounded better to me. Ted and I both liked it a lot!
Maybe though too it was the Matrix movie…..a bit intense!Or the fact that I didn’t get much sleep last night, interrupted at least once by a child who couldn’t find her blankets…
Anyway I’m feeling a bit better now And off to bed….

Agriculture tips

Agriculture has possibly the biggest environmental impact of any human activity. Key consequences include the pollution of water, soil and air; land and habitat conversion; soil degradation; and the huge demand for water.
For example, agriculture draws 70 per cent of the world's freshwater - more than 90 per cent in some countries - and this contributes to the massive degradation that has taken place in the world's freshwater ecosystems

Agriculture tips
Sustainable agriculture
Permaculture
Pest management
Hydroponics
Planting tips
Fertilizer Storage and Handling Practices on the Farm
Agricultural Pollution Prevention

Other agriculture tips
Reduce soil erosion by using conservation practices and other applicable best management practices.
Use planned grazing systems on pasture and rangeland.

What is Dark Matter?

The story of dark matter is best divided into two parts. First we have the reasons that we know that it exists. Second is the collection of possible explanations as to what it is.

Why the Universe Needs Dark Matter

We believe that that the Universe is critically balanced between being open and closed. We derive this fact from the observation of the large scale structure of the Universe. It requires a certain amount of matter to accomplish this result. Call it M.
We can estimate the total baryonic matter of the universe by studying Big Bang nucleosynthesis. This is done by connecting the observed He/H ratio of the Universe today to the amount of baryonic matter present during the early hot phase when most of the helium was produced. Once the temperature of the Universe dropped below the neutron-proton mass difference, neutrons began decaying into protons. If the early baryon density was low, then it was hard for a proton to find a neutron with which to make helium before too many of the neutrons decayed away to account for the amount of helium we see today. So by measuring the He/H ratio today, we can estimate the necessary baryon density shortly after the Big Bang, and, consequently, the total number of baryons today. It turns out that you need about 0.05 M total baryonic matter to account for the known ratio of light isotopes. So only 1/20 of the total mass of the Universe is baryonic matter.
Unfortunately, the best estimates of the total mass of everything that we can see with our telescopes is roughly 0.01 M. Where is the other 99% of the stuff of the Universe? Dark Matter!
So there are two conclusions. We only see 0.01 M out of 0.05 M baryonic matter in the Universe. The rest must be in baryonic dark matter halos surrounding galaxies. And there must be some non-baryonic dark matter to account for the remaining 95% of the matter required to give Ω, the mass of the Universe, in units of critical mass, equal to unity.
For those who distrust the conventional Big Bang models, and don't want to rely upon fancy cosmology to derive the presence of dark matter, there are other more direct means. It has been observed in clusters of galaxies that the motion of galaxies within a cluster suggests that they are bound by a total gravitational force due to about 5-10 times as much matter as can be accounted for from luminous matter in said galaxies. And within an individual galaxy, you can measure the rate of rotation of the stars about the galactic center of rotation. The resultant "rotation curve" is simply related to the distribution of matter in the galaxy. The outer stars in galaxies seem to rotate too fast for the amount of matter that we see in the galaxy. Again, we need about 5 times more matter than we can see via electromagnetic radiation. These results can be explained by assuming that there is a "dark matter halo" surrounding every galaxy.

What is Dark Matter?

This is the open question. There are many possibilities, and nobody really knows much about this yet. Here are a few of the many published suggestions, which are being currently hunted for by experimentalists all over the world. Remember, you need at least one baryonic candidate and one non-baryonic candidate to make everything work out, so there there may be more than one correct choice among the possibilities given here.
Normal matter which has so far eluded our gaze, such as:
dark galaxies
brown dwarfs
planetary material (rock, dust, etc.)
Massive Standard Model neutrinos. If any of the neutrinos are massive, then this could be the missing mass. On the other hand, if they are too heavy, as the purported 17 keV neutrino would have been, massive neutrinos create almost as many problems as they solve in this regard.
Exotica (See the Particle Zoo FAQ entry for some details.)
Massive exotica would provide the missing mass. For our purposes, these fall into two classes: those which have been proposed for other reasons but happen to solve the dark matter problem, and those which have been proposed specifically to provide the missing dark matter.
Examples of objects in the first class are axions, additional neutrinos, supersymmetric particles, and a host of others. Their properties are constrained by the theory which predicts them, but by virtue of their mass, they solve the dark matter problem if they exist in the correct abundance.
Particles in the second class are generally classed in loose groups. Their properties are not specified, but they are merely required to be massive and have other properties such that they would so far have eluded discovery in the many experiments which have looked for new particles. These include WIMPS (Weakly Interacting Massive Particles), CHAMPS, and a host of others.

References: Dark Matter in the Universe (Jerusalem Winter School for Theoretical Physics, 1986-7), J.N. Bahcall, T. Piran, & S. Weinberg editors.
Dark Matter (Proceedings of the XXIIIrd Recontre de Moriond), J. Audouze and J. Tran Thanh Van. editors.

hair growth

Growth of healthy hair largely depends on its normal healthy functioning and structure. The hair structure is divided into two parts - the non living part that is projected out of the skin of the scalp and the other living part, that remains buried inside the scalp skin. Both hair parts have various functions to perform, besides being an integral component of the hair growth cycles.Alteration in the normal cyclical process of hair growth is one of the main causes of hair loss. The factors that affect the normal hair growth cycle are hormonal imbalance and genetics.Though it is hard to take care of the above two factors of hair loss, it is essential for you to keep your hair clean and healthy with the use of well-formulated cleansers and conditioners. To ensure faster hair growth proper intake of nutritional supplements and natural hair care is essential.Healthy and faster hair growth not only helps you to look beautiful, it helps you to tie them to good hair styling. Here is an interesting opportunity for trying the hair styling tips. You can also imitate the hair styles of some famous Hollywood celebrities.Apart from imitating the hair styles of celebrities follow the natural hair care tips and discover the secrets of faster hair growth for beautifully shining hair. The hair information presented in the web pages is sure to help you in taking proper care of your hair, promote faster hair growth and also give you the opportunity to the follow the trendy hair style.See what useful information the following sections have to offer you to help you in hair care and hair maintenance:Variations in hair-growth and typesKnow about the various hair types and the suitability of special hair care products for different ethnic hair types.Hair PhysiologyRead about structure and functions of the hair and how find how it helps you in taking better care of your hair.Hair Loss CausesSee whether you are able to find out the reason for your hair loss among the various causes discussed in this section.Hair NutritionBe informed about the importance of proper nutrition for enhancing your hair growthHair CareFind out exclusive information on natural hair care for colored and normal hair.Hair StylesHere is a chance for you to imitate the hair styles of famous Hollywood celebrities or choose the best hair style that brings out the best from you.

what is bermuda triangle

The Bermuda Triangle has a reputation for being an area where ships and airplanes dissappear, often under mysterious circumstances. This reputation came to public awareness in the 1950s and became a household name in the 1970s, mostly due to "The Bermuda Triangle", a bestselling book written by Charles Berlitz.Various explanations for the apparent high number of dissapperances have been put forward, ranging from the mundane to the hyper-fantastic.Skeptics contend that this region has a comparable rate of maritime and aerial incidents as any other similar sized region of the ocean. They point out that Lloyd's of London, a world-reknowned insurer of maritime vessels, does not charge a higher insurance premium for ships that regularly traverse the triangle.Scientific considerations for an increased dissaperance rate take into acount that this region experiences severe tropical storms and is the source of many hurricanes. These storms create an increased danger to both ship and air traffic.Rougue waves have also been put forward as a possible cause. These rare waves can reach heights of as much as 100 feet (30 meters), easily swamping most ships. Rouge waves, however, would have no effect on air travel.A third scientific explanation is methane hydrates. Methane deposits on the ocean floor may release bursts of methane gas that reduces the density of the water it permeates. Since ships rely on displacement to stay afloat, a reduction of density in the water would cause a ship to immediately sink. As the methane leaves the water and rises into the air, it would reduce the density of the air as well, thus reducing lift on aircraft, causing them to descend rapidly. In addition, the methane would change the air mixture taken into the engines of the aircraft, causing the engine to stall. While these events have not been witnessed in nature, they have been proven in lab experiments.More exotic explanations for the Bermuda Triangle include it being an area of magnetic disturbance, temporal (or time) holes, the location of the lost city of Atlantis, or extra-terrestrial abduction.

Zenith EcoStyle: Low-Cost PC & Laptop

Zenith has announced the launch of a new laptop and desktop series, EcoStyle, in the Indian market. The series is expected to be available across the country this festive season.
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Zenith has announced the launch of a new laptop and desktop under brand name EcoStyle in the Indian market. With an aesthetic design, the EcoStyle laptop comes preloaded with the Microsoft productivity suite, which includes Windows XP Home Edition, Microsoft Office, and Microsoft Windows Live Suite.
Meanwhile, the EcoStyle PC offers customers an option to choose between Windows Vista Starter or Microsoft Windows XP Home. It weighs just 2.2 kg and has dimensions of 185mm x 250 mm x 70 mm. It will also come preloaded with the Microsoft productivity suite. The Zenith EcoStyle laptop is priced at Rs 14,999; while the desktop PC is priced at Rs 11,999. Both models will be available across the country this festive season.

Alien Abductions

Alien abduction stories have spread widely over the last hundred years, though they did not truly hit their stride until the 1961 Barney and Betty Hill abduction. Some abductees report their abductions as warm, pleasant experiences with intense psychic contact. Other abductees have reported that aliens conducted scientific experiments or operations on their unwilling patients. How can these vastly different experiences be explained?
After the Hill abduction, investigators collected more and more accounts, usually, though not always, elicited through hypnosis. In most cases witnesses told of seeing a UFO or even humanoid beings, then suffering amnesia for a period of anywhere from a few minutes to a few hours. Some witnesses claimed repeated experiences that started when they were children.
Mary Evans Picture LibraryOne morning in July 1965 Maurice Masse of Valensole, France, encountered figures and a UFO in a field.
The clear implication was that UFO beings (typically described in these instances as little gray humanoids with oversize heads, slanted eyes, two holes for a nose, and a slit for a mouth) had a long-term interest in certain human beings. Some abductees even reported that the abductors had put small implants -- usually said to be tiny balls inserted through the nose and (apparently) into the brain via a long needle-inside their bodies.
In time new and even more unsettling dimensions to the abduction experience came to light. Some female abductees reported sexual experiences followed by pregnancies that would be terminated in a follow-up abduction some months later. During later abductions the UFO entities would show the women strange-looking children, apparently human/alien hybrids, whom they would sense were their own.
Not surprisingly, such reports gave rise to furious controversy. Even many ufologists rejected them, preferring, in common with UFO skeptics, to believe "abductions" were fantasies generated by the process of hypnosis itself. Contrary to popular understanding, hypnosis is no royal road to the truth. Hypnotic subjects are in a highly suggestible state and may seek to please the hypnotist. Thus, if the hypnotist asks leading questions, the subject will be led to provide the desired answers. Moreover, purely imaginary events can seem real under hypnosis (confabulation), as testified to in the phenomenon of "past lives" recounted while in a hypnotic state.
To test the confabulation hypothesis, folklorist Thomas E. Bullard collected all available abduction accounts. He found that as many as one-third of the informants had full conscious recall of their experiences and had never resorted to hypnosis to elicit the details. These non-hypnotic reports proved identical in all significant particulars to those told under hypnosis. Bullard also learned that the identity of the individual hypnotist made no difference. The stories remained consistent down to details that even those most familiar with the phenomenon had failed to notice. In short, Bullard concluded, whatever its ultimate cause, the abduction phenomenon was not the product of hypnosis. "The skeptical argument needs rebuilding from the ground up," he wrote.
A growing number of mental-health professionals have conducted their own investigations of the abduction phenomenon. In the early 1980s psychological testing of a small group of abductees in New York indicated that they suffered from post-traumatic stress disorder (PTSD). Dr. Elizabeth Slater, a psychologist with a private practice in New York City, remarked that these findings are "not inconsistent with the possibility that reported UFO abductions have, in fact, occurred." Other studies since then have come to similar conclusions, and the scientific investigation of the abduction phenomenon continues.

How Near-death Experiences Work

Near-death experiences (NDEs) are common enough that they have entered our everyday language. Phrases like "my whole life flashed before my eyes" and "go to the light" come from decades of research into these strange, seemingly supernatural experiences that some people have when they're at the brink of death. But what exactly are NDEs? Are they hallucinations? Spiritual experiences? Proof of life after death? Or are they simply chemical changes in the brain and sensory organs in the moments prior to death?
In this article, we'll discuss what makes an experience an NDE and who typically has them. We'll also explore spiritual, philosophical and scientific theories for why they happen.

Dr. Raymond Moody coined the term "near-death experience" in his 1975 book, "Life After Life." Many credit Moody's work with bringing the concept of the near-death experience to the public's attention, but reports of such experiences have occurred throughout history. Plato's "Republic," written in 360 B.C.E., contains the tale of a soldier named Er who had an NDE after being killed in battle. Er described his soul leaving his body, being judged along with other souls and seeing heaven [ref].
For the purposes of this article, a near-death experience is any experience in which someone close to death or suffering from some trauma or disease that might lead to death perceives events that seem to be impossible, unusual or supernatural. While there are many questions about NDEs, one thing is certain -- they do exist. Thousands of people have actually perceived similar sensations while close to death. The debate is over whether or not they actually experienced what they perceived.
Most NDEs share certain common traits, but not all NDEs have every trait and some NDEs don't follow a pattern at all. Here are the traits that "typical" NDEs share:
Feelings of calmness - These feelings may include peacefulness, acceptance of death, emotional and physical comfort.
Intense, pure bright light - Sometimes this intense (but not painful) light fills the room. In other cases, the subject sees a light that they feel represents either Heaven or God.
Out-of-body experiences (OBE) - The subject feels that he has left his body. He can look down and see it, often describing the sight of doctors working on him. In some cases, the subject's "spirit" then flies out of the room, into the sky and sometimes into space.
Entering into another realm or dimension - Depending on the subject's religious beliefs and the nature of the experience, he may perceive this realm as Heaven or, in rare cases, as Hell.
Spirit beings - During the OBE, the subject encounters "beings of light," or other representations of spiritual entities. He may perceive these as deceased loved ones, angels, saints or God.The tunnel - Many NDE subjects find themselves in a tunnel with a light at its end. They may encounter spirit beings as they pass through the tunnel.
Communication with spirits - Before the NDE ends, many subjects report some form of communication with a spirit being. This is often expressed a "strong male voice" telling them that it is not their time and to go back to their body. Some subjects report being told to choose between going into the light or returning to their earthly body. Others feel they have been compelled to return to their body by a voiceless command, possibly coming from God.
Life review - This trait is also called "the panoramic life review." The subject sees his entire life in a flashback. These can be very detailed or very brief. The subject may also perceive some form of judgment by nearby spirit entities. Near-death experiences and out-of-body experiences are sometimes grouped together, but there are key differences. An OBE can be a component of an NDE, but some people experience OBEs in circumstances that have nothing to do with death or dying. They may still have spiritual elements or feelings of calm. OBEs can happen spontaneously, or drugs or meditation can induce them.
In the next section, we'll take a look at who typically has NDEs and how they're affected

Some NDEs have elements that bear little resemblance to the "typical" near-death experience. Anywhere from one percent (according to a 1982 Gallup poll) to 25 percent (according to some researchers) of subjects do not experience feelings of peace, nor do they visit Heaven or meet friendly spirits. Instead, they feel terrified and are accosted by demons or malicious imps. They may visit places that fit Biblical descriptions of Hell, including lakes of fire, tormented souls and a general feeling of oppressive heat.
There have been a few reports of shared NDEs, in which someone connected to the dying person accompanies them on their out-of-body journey. This might take the form of a dream that occurs at the same time that the subject was near death. Children have also been the subjects of NDEs. Very young children tend to report surreal experiences that have some common NDE elements. As children get older, their religious teachings often color their NDEs with more spiritual connotations, such as meeting God or Jesus.
A small percentage of NDE subjects report a prophetic vision that reveals to them the fate of earth and humanity. This is generally an apocalyptic vision showing the end times, but some report visions of humanity evolving into higher beings. One group of subjects, unknown to each other, reported that the world would end in 1988

WHAT IS HYPNOTISM........?

When you hear the word hypnosis, you may picture the mysterious hypnotist figure popularized in movies, comic books and television. This ominous, goateed man waves a pocket watch back and forth, guiding his subject into a semi-sleep, zombie-like state. Once hypnotized, the subject is compelled to obey, no matter how strange or immoral the request. Muttering "Yes, master," the subject does the hypnotist's evil bidding.
This popular representation bears little resemblance to actual hypnotism, of course. In fact, modern understanding of hypnosis contradicts this conception on several key points. Subjects in a hypnotic trance are not slaves to their "masters" -- they have absolute free will. And they're not really in a semi-sleep state -- they're actually hyperattentive.
Our understanding of hypnosis has advanced a great deal in the past century, but the phenomenon is still a mystery of sorts. In this article, we'll look at some popular theories of hypnosis and explore the various ways hypnotists put their art to work.

What is Hypnosis?

People have been pondering and arguing over hypnosis for more than 200 years, but science has yet to fully explain how it actually happens. We see what a person does under hypnosis, but it isn't clear why he or she does it. This puzzle is really a small piece in a much bigger puzzle: how the human mind works. It's unlikely that scientists will arrive at a definitive explanation of the mind in the foreseeable future, so it's a good bet hypnosis will remain something of a mystery as well.
But psychiatrists do understand the general characteristics of hypnosis, and they have some model of how it works. It is a trance state characterized by extreme suggestibility, relaxation and heightened imagination. It's not really like sleep, because the subject is alert the whole time. It is most often compared to daydreaming, or the feeling of "losing yourself" in a book or movie. You are fully conscious, but you tune out most of the stimuli around you. You focus intently on the subject at hand, to the near exclusion of any other thought.
In the everyday trance of a daydream or movie, an imaginary world seems somewhat real to you, in the sense that it fully engages your emotions. Imaginary events can cause real fear, sadness or happiness, and you may even jolt in your seat if you are surprised by something (a monster leaping from the shadows, for example). Some researchers categorize all such trances as forms of self-hypnosis. Milton Erickson, the premier hypnotism expert of the 20th century, contended that people hypnotize themselves on a daily basis. But most psychiatrists focus on the trance state brought on by intentional relaxation and focusing exercises. This deep hypnosis is often compared to the relaxed mental state between wakefulness and sleep.

In conventional hypnosis, you approach the suggestions of the hypnotist, or your own ideas, as if they were reality. If the hypnotist suggests that your tongue has swollen up to twice its size, you'll feel a sensation in your mouth and you may have trouble talking. If the hypnotist suggests that you are drinking a chocolate milkshake, you'll taste the milkshake and feel it cooling your mouth and throat. If the hypnotist suggests that you are afraid, you may feel panicky or start to sweat. But the entire time, you are aware that it's all imaginary. Essentially, you're "playing pretend" on an intense level, as kids do.
In this special mental state, people feel uninhibited and relaxed. Presumably, this is because they tune out the worries and doubts that normally keep their actions in check. You might experience the same feeling while watching a movie: As you get engrossed in the plot, worries about your job, family, etc. fade away, until all you're thinking about is what's up on the screen.
In this state, you are also highly suggestible. That is, when the hypnotist tells you do something, you'll probably embrace the idea completely. This is what makes stage hypnotist shows so entertaining. Normally reserved, sensible adults are suddenly walking around the stage clucking like chickens or singing at the top of their lungs. Fear of embarrassment seems to fly out the window. The subject's sense of safety and morality remain entrenched throughout the experience, however. A hypnotist can't get you to do anything you don't want to do.
But what is it that makes this happen? In the next section, we'll look at the most widely accepted theory of what's going on when you become hypnotized.

Early Hypnohistory

People have been entering hypnotic-type trances for thousands and thousands of years; various forms of meditation play an important role in many cultures' religions. But the scientific conception of hypnotism wasn't born until the late 1700s.
The father of modern hypnotism is Franz Mesmer, an Austrian physician. Mesmer believed hypnosis to be a mystical force flowing from the hypnotist into the subject (he called it "animal magnetism"). Although critics quickly dismissed the magical element of his theory, Mesmer's assumption, that the power behind hypnosis came from the hypnotist and was in some way inflicted upon the subject, took hold for some time. Hypnosis was originally known as mesmerism, after Mesmer, and we still use its derivative, "mesmerize," today.

WHAT IS JOKES......???

Jokes have a generic meaning of verbal humor, including one-liners, riddles, and other things that make us laugh; but the joke is also a form, a funny, made-up story with a punchline told by one person. A joke is distinguished from an anecdote, which may be a funny story and have a punchline, but is about a real or true incident. Because it is a form of story, the joke has some of the attributes of a story, such as a beginning, middle, and end. The beginning is the set-up for the joke. While the setting, mood, and tone of, say, a short story or novel are established over time, these elements are often compressed into as little as a single sentence in a joke.
There were two truck drivers at a rest stop.
A lawyer died and went to heaven.
Did you hear about the _____ who _____?
Some jokes, like the type invoked by the last set-up sentence above, are only two sentences – the first sets up the joke, and the second delivers the punch line. This is the most compact kind of joke. Notice that the question is only formal here – a real answer is not expected, and in most cases, cannot be given.
This distinguishes the joke from a riddle in two ways. First, the input of another person is crucial to the riddle form, while it is not in this kind of joke. Second, in a riddle, the question is specifically constructed to be answerable by a clever guesser, but in a joke of this sort, the question is functioning as the joke set-up and not intended to give too many clues to what is to come. Here’s an example:
What's the latest crime wave in New York City?
Drive-by viola recitals.
Notice that there is not sufficient information in the question for anybody to guess the response. Instead, the question sets the scene and mood: it creates tension by suggesting a dramatic and dangerous topic, and then undermines the tension with a ridiculous response. This helps us to understand this example as a joke, rather than as a riddle.
There are certain categories of jokes that have many, many examples. Violist jokes are among these. Other such categories include computer jokes, blonde jokes, lawyer jokes, army jokes, off-color jokes, and jokes about certain instrumentalists – notably violists, banjo players, and drummers.

The mobile phone (also called a wireless phone or cellular phone)[1] is a short-range, portable electronic device used for mobile voice or data communication over a network of specialized base stations known as cell sites. In addition to the standard voice function of a telephone, current mobile phones may support many additional services, and accessories, such as SMS for text messaging, email, packet switching for access to the Internet, gaming, bluetooth, infrared, camera with video recorder and MMS for sending and receiving photos and video. Most current mobile phones connect to a cellular network of base stations (cell sites), which is in turn interconnected to the public switched telephone network (PSTN) (the exception is satellite phones).

Overview
According to internal memos, American Telephone & Telegraph discussed developing a wireless phone in 1915, but were afraid deployment of the technology could undermine its monopoly on wired service in the U.S.[2]
The first commercial mobile phone service was launched in Japan by NTT in 1978. By November 2007, the total number of mobile phone subscriptions in the world had reached 3.3 billion, or half of the human population (although some users have multiple subscriptions, or inactive subscriptions), which also makes the mobile phone the most widely spread technology and the most common electronic device in the world.[3]
The first mobile phone to enable internet connectivity and wireless email, the Nokia Communicator, was released in 1996, creating a new category of expensive phones called smartphones. In 1999 the first mobile internet service was launched by NTT DoCoMo in Japan under the i-Mode service. By 2007 over 798 million people around the world accessed the internet or equivalent mobile internet services such as WAP and i-Mode at least occasionally using a mobile phone rather than a personal computer.

Cellular systems
See also: Cellular frequencies

Mobile phone tower
Mobile phones send and receive radio signals with any number of cell site base stations fitted with microwave antennas. These sites are usually mounted on a tower, pole or building, located throughout populated areas, then connected to a cabled communication network and switching system. The phones have a low-power transceiver that transmits voice and data to the nearest cell sites, normally not more than 8 to 13 km (approximately 5 to 8 miles) away.
When the mobile phone or data device is turned on, it registers with the mobile telephone exchange, or switch, with its unique identifiers, and can then be alerted by the mobile switch when there is an incoming telephone call. The handset constantly listens for the strongest signal being received from the surrounding base stations, and is able to switch seamlessly between sites. As the user moves around the network, the "handoffs" are performed to allow the device to switch sites without interrupting the call.
Cell sites have relatively low-power (often only one or two watts) radio transmitters which broadcast their presence and relay communications between the mobile handsets and the switch. The switch in turn connects the call to another subscriber of the same wireless service provider or to the public telephone network, which includes the networks of other wireless carriers. Many of these sites are camouflaged to blend with existing environments, particularly in scenic areas.
The dialogue between the handset and the cell site is a stream of digital data that includes digitized audio (except for the first generation analog networks). The technology that achieves this depends on the system which the mobile phone operator has adopted. The technologies are grouped by generation. The first-generation systems started in 1979 with Japan, are all analog and include AMPS and NMT. Second-generation systems, started in 1991 in Finland, are all digital and include GSM, CDMA and TDMA.
The nature of cellular technology renders many phones vulnerable to 'cloning': anytime a cell phone moves out of coverage (for example, in a road tunnel), when the signal is re-established, the phone sends out a 're-connect' signal to the nearest cell-tower, identifying itself and signalling that it is again ready to transmit. With the proper equipment, it's possible to intercept the re-connect signal and encode the data it contains into a 'blank' phone -- in all respects, the 'blank' is then an exact duplicate of the real phone and any calls made on the 'clone' will be charged to the original account.
Third-generation (3G) networks, which are still being deployed, began in Japan in 2001. They are all digital, and offer high-speed data access in addition to voice services and include W-CDMA (known also as UMTS), and CDMA2000 EV-DO. China will launch a third generation technology on the TD-SCDMA standard. Operators use a mix of predesignated frequency bands determined by the network requirements and local regulations.
In an effort to limit the potential harm from having a transmitter close to the user's body, the first fixed/mobile cellular phones that had a separate transmitter, vehicle-mounted antenna, and handset (known as car phones and bag phones) were limited to a maximum 3 watts Effective Radiated Power. Modern handheld cellphones which must have the transmission antenna held inches from the user's skull are limited to a maximum transmission power of 0.6 watts ERP. Regardless of the potential biological effects, the reduced transmission range of modern handheld phones limits their usefulness in rural locations as compared to car/bag phones, and handhelds require that cell towers be spaced much closer together to compensate for their lack of transmission power.
Some handhelds include an optional auxiliary antenna port on the back of the phone, which allows it to be connected to a large external antenna and a 3 watt cellular booster. Alternately in fringe-reception areas, a cellular repeater may be used, which uses a long distance high-gain dish antenna or yagi antenna to communicate with a cell tower far outside of normal range, and a repeater to rebroadcast on a small short-range local antenna that allows any cellphone within a few meters to function properly.

Handsets
Nokia is currently the world's largest manufacturer of mobile phones, with a global device market share of approximately 40% in 2008. Other major mobile phone manufacturers (in order of market share) include Samsung (14%), Motorola (14%), Sony Ericsson (9%) and LG (7%).[4] These manufacturers account for over 80% of all mobile phones sold and produce phones for sale in most countries.
Other manufacturers include Apple Inc., Audiovox (now UTStarcom), Benefon, BenQ-Siemens, CECT, High Tech Computer Corporation (HTC), Fujitsu, Kyocera, Mitsubishi Electric, NEC, Neonode, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Sanyo, Sharp, Siemens, Sendo, Sierra Wireless, SK Teletech, Sonim Technologies, T&A Alcatel, Huawei, Trium and Toshiba. There are also specialist communication systems related to (but distinct from) mobile phones.
There are several categories of mobile phones, from basic phones to feature phones such as musicphones and cameraphones, to smartphones. The first smartphone was the Nokia 9000 Communicator in 1996 which incorporated PDA functionality to the basic mobile phone at the time. As miniaturization and increased processing power of microchips has enabled ever more features to be added to phones, the concept of the smartphone has evolved, and what was a high-end smartphone five years ago, is a standard phone today. Several phone series have been introduced to address a given market segment, such as the RIM Blackberry focusing on enterprise/corporate customer email needs; the SonyEricsson Walkman series of musicphones and Cybershot series of cameraphones; the Nokia N-Series of multimedia phones; and the Apple iPhone which provides full-featured web access and multimedia capabilities.
Main article: Mobile phone features
Mobile phones often have features beyond sending text messages and making voice calls, including Internet browsing, music (MP3) playback, memo recording, personal organizer functions, e-mail, instant messaging, built-in cameras and camcorders, ringtones, games, radio, Push-to-Talk (PTT), infrared and Bluetooth connectivity, call registers, ability to watch streaming video or download video for later viewing, video calling and serve as a wireless modem for a PC, and soon will also serve as a console of sorts to online games and other high quality games. The total value of mobile data services exceeds the value of paid services on the Internet, and was worth 31 billion dollars in 2006 (source Informa).[citation needed] The largest categories of mobile services are music, picture downloads, videogaming, adult entertainment, gambling, video/TV.

Applications
The most commonly used data application on mobile phones is SMS text messaging, with 74% of all mobile phone users as active users (over 2.4 billion out of 3.3 billion total subscribers at the end of 2007). SMS text messaging was worth over 100 billion dollars in annual revenues in 2007 and the worldwide average of messaging use is 2.6 SMS sent per day per person across the whole mobile phone subscriber base. (source Informa 2007). The first SMS text message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.
The other non-SMS data services used by mobile phones were worth 31 Billion dollars in 2007, and were led by mobile music, downloadable logos and pictures, gaming, gambling, adult entertainment and advertising (source: Informa 2007). The first downloadable mobile content was sold to a mobile phone in Finland in 1998, when Radiolinja (now Elisa) introduced the downloadable ringing tone service. In 1999 Japanese mobile operator NTT DoCoMo introduced its mobile internet service, i-Mode, which today is the world's largest mobile internet service and roughly the same size as Google in annual revenues.
The first mobile news service, delivered via SMS, was launched in Finland in 2000. Mobile news services are expanding with many organizations providing "on-demand" news services by SMS. Some also provide "instant" news pushed out by SMS. Mobile telephony also facilitates activism and public journalism being explored by Reuters and Yahoo![5] and small independent news companies such as Jasmine News in Sri Lanka.
Companies like Monster are starting to offer mobile services such as job search and career advice. Consumer applications are on the rise and include everything from information guides on local activities and events to mobile coupons and discount offers one can use to save money on purchases. Even tools for creating websites for mobile phones are increasingly becoming available, e.g. Mobilemo.
Mobile payments were first trialled in Finland in 1998 when two coca cola machines in Espoo were enabled to work with SMS payments. Eventually the idea spread and in 1999 the Philippines launched the first commercial mobile payments systems, on the mobile operators Globe and Smart. Today mobile payments ranging from mobile banking to mobile credit cards to mobile commerce are very widely used in Asia and Africa, and in selected European markets. For example in the Philippines it is not unusual to have your whole paycheck paid to the mobile account. In Kenya the limit of money transfers from one mobile banking account to another is one million US dollars. In India paying utility bills with mobile gains a 5% discount. In Estonia the government found criminals collecting cash parking fees, so the government declared that only mobile payments via SMS were valid for parking and today all parking fees in Estonia are handled via mobile and the crime involved in the activity has vanished.
Mobile Applications are developed using the Six M's (previously Five M's) service-development theory created by the author Tomi Ahonen with Joe Barrett of Nokia and Paul Golding of Motorola. The Six M's are Movement (location), Moment (time), Me (personalization), Multi-user (community), Money (payments) and Machines (automation). The Six M's / Five M's theory is widely referenced in the telecoms applications literature and used by most major industry players. The first book to discuss the theory was Services for UMTS by Ahonen & Barrett in 2002.
The availability of mobile phone backup applications is growing with the increasing amount of mobile phone data being stored on mobile phones today. With mobile phone manufacturers producing mobile handsets with more and more memory storage capabilities the awareness of the importance in backing up mobile phone data is increasing. Corporate mobile phone users today keep very important company information on their mobiles, information if lost then not easily replaced. Wireless backup applications like SC BackUp offer users the chance to backup mobile phone data using advanced wireless technology. Users can backup, restore or transfer mobile data anytime, anywhere all over the world, to a secured server.

Media
The mobile phone became a mass media channel in 1998 when the first ringing tones were sold to mobile phones by Radiolinja in Finland. Soon other media content appeared such as news, videogames, jokes, horoscopes, TV content and advertising. In 2006 the total value of mobile phone paid media content exceeded internet paid media content and was worth 31 Billion dollars (source Informa 2007). The value of music on phones was worth 9.3 Billion dollars in 2007 and gaming was worth over 5 billion dollars in 2007 (source Netsize Guide 2008 [1]).
The mobile phone is often called the Fourth Screen (if counting cinema, TV and PC screens as the first three) or Third Screen (counting only TV and PC screens). It is also called the Seventh of the Mass Media (with Print, Recordings, Cinema, Radio, TV and Internet the first six). Most early content for mobile tended to be copies of legacy media, such as the banner advertisement or the TV news highlight video clip. Recently unique content for mobile has been emerging, from the ringing tones and ringback tones in music to "mobisodes," video content that has been produced exclusively for mobile phones.
The advent of media on the mobile phone has also produced the opportunity to identify and track Alpha Users or Hubs, the most influential members of any social community. AMF Ventures measured in 2007 the relative accuracy of three mass media, and found that audience measures on mobile were nine times more accurate than on the internet and 90 times more accurate than on TV.

Power supply
Mobile phones generally obtain power from batteries, which can be recharged from a USB port, from portable batteries, from mains power or a cigarette lighter socket in a car using an adapter (often called battery charger or wall wart) or from a solar panel o a dynamo (that can also use a USB port to plug the phone).
Formerly, the most common form of mobile phone batteries were nickel metal-hydride, as they have a low size and weight. Lithium-Ion batteries are sometimes used, as they are lighter and do not have the voltage depression that nickel metal-hydride batteries do. Many mobile phone manufacturers have now switched to using lithium-Polymer batteries as opposed to the older Lithium-Ion, the main advantages of this being even lower weight and the possibility to make the battery a shape other than strict cuboid. Mobile phone manufacturers have been experimenting with alternate power sources, including solar cells.

SIM card
In addition to the battery, most cellphones require a small microchip, called a Subscriber Identity Module or SIM Card, to function. Approximately the size of a one-cent postage stamp, the SIM Card is usually placed underneath the battery in the rear of the unit, and (when properly activated) stores the phone's configuration data, and information about the phone itself, such as which calling plan the subscriber is using. When the subscriber removes the SIM Card, it can be re-inserted into another phone and used as normal.
Each SIM Card is activated by use of a unique numerical identifier; once activated, the identifier is locked down and the card is permanently locked in to the activating network. For this reason, most retailers refuse to accept the return of an activated SIM Card.
Those cell phones that do not use a SIM Card have the data programmed in to their memory. This data is accessed by using a special digit sequence to access the "NAM" as in "Name" or number programming menu. From here, one can add information such as a new number for your phone, new Service Provider numbers, new emergency numbers, change their Authentication Key or A-Key code, and update their Preferred Roaming List or PRL. However, to prevent the average Joe from totally disabling their phone or removing it from the network, the Service Provider puts a lock on this data called a Master Subsidiary Lock or MSL.
The MSL also ensures that the Service Provider gets payment for the phone that was purchased or "leased". For example, the Motorola Razr V9C costs upwards of CAD $500. You can get one from Bell Mobility for approximately $200. The difference is paid by the customer in the form of a monthly bill. If, in this case, Bell Mobility did not use a MSL, then they may lose the $300–$400 difference that is paid in the monthly bill, since some customers would cancel their service and take the phone to another carrier such as Telus, or Verizon. This would eventually put the carrier or in this case, Bell Mobility out of business.

Usage

By civilians

This Railfone found on some Amtrak trains in North America uses cellular technology.
See also: List of mobile network operators
An increasing number of countries, particularly in Europe, now have more mobile phones than people. According to the figures from Eurostat, the European Union's in-house statistical office, Luxembourg had the highest mobile phone penetration rate at 158 mobile subscriptions per 100 people (158%), closely followed by Lithuania and Italy.[6] In Hong Kong the penetration rate reached 139.8% of the population in July 2007.[7] Over 50 countries have mobile phone subscription penetration rates higher than that of the population and the Western European average penetration rate was 110% in 2007 (source Informa 2007). The U.S. currently has one of the lowest rates of mobile phone penetrations in the industrialized world at 85%.
There are over five hundred million active mobile phone accounts in China, as of 2007, but the total penetration rate there still stands below 50%.[8] The total number of mobile phone subscribers in the world was estimated at 2.14 billion in 2005.[9] The subscriber count reached 2.7 billion by end of 2006 according to Informa[citation needed], and 3.3 billion by November, 2007[3], thus reaching an equivalent of over half the planet's population. Around 80% of the world's population has access to mobile phone coverage, as of 2006. This figure is expected to increase to 90% by the year 2010.[10]
In some developing countries with little "landline" telephone infrastructure, mobile phone use has quadrupled in the last decade.[11] The rise of mobile phone technology in developing countries is often cited as an example of the leapfrog effect. In many remote regions in the third world went literally from having no telecommunications infrastructure to having satellite based communications systems. At present, Africa has the largest growth rate of cellular subscribers in the world,[12] its markets expanding nearly twice as fast as Asian markets.[13] The availability of prepaid or 'pay-as-you-go' services, where the subscriber is not committed to a long term contract, has helped fuel this growth in Africa as well as in other continents.
On a numerical basis, India is the largest growth market, adding about 6 million mobile phones every month.[14] With 256.55 million mobile phones, market penetration in the country is still low at 22.52%. India expects to reach 500 million subscribers by end of 2010.
There are three major technical standards for the current generation of mobile phones and networks, and two major standards for the next generation 3G phones and networks. All European, African and many Asian countries have adopted a single system, GSM, which is the only technology available on all continents and in most countries and covers over 74% of all subscribers on mobile networks. In many countries, such as the United States, Australia, Brazil, Canada, Costa Rica, India, and South Korea and Vietnam GSM co-exists with other internationally adopted standards such as CDMA and TDMA, as well as national standards such as iDEN in the USA and PDC in Japan. Over the past five years several dozen mobile operators (carriers) have abandoned networks on TDMA and CDMA technologies, switching over to GSM.
With third generation (3G) networks, which are also known as IMT-2000 networks, about three out of four networks are on the W-CDMA (also known as UMTS) standard, usually seen as the natural evolution path for GSM and TDMA networks. One in four 3G networks is on the CDMA2000 1x EV-DO technology. Some analysts count a previous stage in CDMA evolution, CDMA2000 1x RTT, as a 3G technology whereas most standardization experts count only CDMA2000 1x EV-DO as a true 3G technology. Because of this difference in interpreting what is 3G, there is a wide variety in subscriber counts. As of June 2007, on the narrow definition there are 200 million subscribers on 3G networks. By using the more broad definition, the total subscriber count of 3G phone users is 475 million.

Culture and customs
Between the 1980s and the 2000s, the mobile phone has gone from being an expensive item used by the business elite to a pervasive, personal communications tool for the general population to where specific styles of phones are often seen as a regular fashion statements (much to the lament of some). In most countries, mobile phones outnumber land-line phones, with fixed landlines numbering 1.3 Billion but mobile subscriptions 3.3 Billion at the end of 2007.
In many markets from Japan and South Korea, to Scandinavia, to Israel, Singapore, Taiwan and Hong Kong, most children age 8-9 have mobile phones and the new accounts are now opened for customers aged 6 and 7. Where mostly parents tend to give hand-me-down used phones to their youngest children, in Japan already new cameraphones are on the market whose target age group is under 10 years of age, introduced by KDDI in February 2007. The USA also lags on this measure, as in the US so far, about half of all children have mobile phones.[15] In many young adults' households it has supplanted the land-line phone. Mobile phone usage is banned in some countries, such as North Korea and restricted in some other countries such as Burma.[16]
Given the high levels of societal mobile phone service penetration, it is a key means for people to communicate with each other. The SMS feature spawned the "texting" sub-culture amongst younger users. In December 1993, the first person-to-person SMS text message was transmitted in Finland. Currently, texting is the most widely-used data service; 1.8 billion users generated $80 billion of revenue in 2006 (source ITU). Many phones offer Instant Messenger services for simple, easy texting. Mobile phones have Internet service (e.g. NTT DoCoMo's i-mode), offering text messaging via e-mail in Japan, South Korea, China, and India. Most mobile internet access is much different from computer access, featuring alerts, weather data, e-mail, search engines, instant messages, and game and music downloading; most mobile internet access is hurried and short.
The mobile phone can be a fashion totem custom-decorated to reflect the owner's personality.[17] This aspect of the mobile telephony business is, in itself, an industry, e.g. ringtone sales amounted to $3.5 billion in 2005.[18]

The use of a mobile phone is prohibited in some train company carriages
Mobile phone use can be an important matter of social discourtesy: phones ringing during funerals or weddings; in toilets, cinemas and theatres. Some book shops, libraries, bathrooms, cinemas, doctors' offices and places of worship prohibit their use, so that other patrons will not be disturbed by conversations. Some facilities install signal-jamming equipment to prevent their use, although in many countries, including the US, such equipment is illegal. Some new auditoriums have installed wire mesh in the walls to make a Faraday cage, which prevents signal penetration without violating signal jamming laws.
Trains, particularly those involving long-distance services, often offer a "quiet carriage" where phone use is prohibited, much like the designated non-smoking carriage of the past. In the UK however many users tend to ignore this as it is rarely enforced, especially if the other carriages are crowded and they have no choice but to go in the "quiet carriage".[citation needed] In Japan, it is generally considered impolite to talk using a phone on any train -- texting is generally the mode of mobile communication. Mobile phone usage on local public transport is also increasingly seen as a nuisance; the city of Graz, for instance, has mandated a total ban of mobile phones on its tram and bus network in 2008 (though texting is still allowed).[19][20]
Mobile phone use on aircraft is also prohibited and many airlines claim in their in-plane announcements that this prohibition is due to possible interference with aircraft radio communications. Shut-off mobile phones do not interfere with aircraft avionics; the concern is partially based on the crash of Crossair Flight 498.

By government agencies

Law enforcement
Main article: Lawful interception
Law enforcement have used mobile phone evidence in a number of different ways. In the EU the "communications of every mobile telephone user are recorded".[21] In other countries, evidence about the physical location of an individual at a given time has been introduced by triangulating the individual's cellphone between several cellphone towers. This triangulation technique can be used to show that an individual's cellphone was at a certain location at a certain time. The concerns over terrorism and terrorist use of technology prompted an inquiry by the British House of Commons Home Affairs Select Committee into the use of evidence from mobile phone devices, prompting leading mobile telephone forensic specialists to identify forensic techniques available in this area.[22] NIST have published guidelines and procedures for the preservation, acquisition, examination, analysis, and reporting of digital information present on mobile phones can be found under the NIST Publication SP800-101.[23]
In the UK in 2000 it was claimed that recordings of mobile phone conversations made on the day of the Omagh bombing were crucial to the police investigation. In particular, calls made on two mobile phones which were tracked from south of the Irish border to Omagh and back on the day of the bombing, were considered of vital importance.[24]
Further example of criminal investigations using mobile phones is the initial location and ultimate identification of the terrorists of the 2004 Madrid train bombings. In the attacks, mobile phones had been used to detonate the bombs. However, one of the bombs failed to detonate, and the SIM card in the corresponding mobile phone gave the first serious lead about the terrorists to investigators. By tracking the whereabouts of the SIM card and correlating other mobile phones that had been registered in those areas, police were able to locate the terrorists.[25]

Disaster response
The Finnish government decided in 2005 that the fastest way to warn citizens of disasters was the mobile phone network. In Japan, mobile phone companies provide immediate notification of earthquakes and other natural disasters to their customers free of charge [26]. In the event of an emergency, disaster response crews can locate trapped or injured people using the signals from their mobile phones. An interactive menu accessible through the phone's Internet browser notifies the company if the user is safe or in distress.[citation needed] In Finland rescue services suggest hikers carry mobile phones in case of emergency even when deep in the forests beyond cellular coverage, as the radio signal of a cellphone attempting to connect to a base station can be detected by overflying rescue aircraft with special detection gear. Also, users in the United States can sign up through their provider for free text messages when an AMBER Alert goes out for a missing person in their area.
However, most mobile phone networks operate close to capacity during normal times and spikes in call volumes caused by widespread emergencies often overload the system just when it is needed the most. Examples reported in the media where this have occurred include the September 11, 2001 attacks, the Hawaiian earthquake, the 2003 Northeast blackouts, the 2005 London Tube bombings, Hurricane Katrina, and the 2007 Minnesota bridge collapse. Thus mobile phones are better for isolated emergencies such as vehicle accidents.
Under FCC regulations, all mobile telephones must be capable of dialing emergency services, regardless of the presence of a SIM card or the payment status of the account.

Business models

Tariff models
See also: GSM services#Voice charges
When cellular telecoms services were launched, phones and calls were very expensive and early mobile operators (carriers) decided to charge for all air time consumed by the mobile phone user. This resulted in the concept of charging callers for outbound calls and also for receiving calls. As mobile phone call charges diminished and phone adoption rates skyrocketed, more modern operators decided not to charge for incoming calls. Thus some markets have "Receiving Party Pays" models (also known as "Mobile Party Pays"), in which both outbound and received calls are charged, and other markets have "Calling Party Pays" models, by which only making calls produces costs, and receiving calls is free. An exception to this is international roaming tariffs, by which receiving calls are normally also charged.[citation needed]
The European market adopted a "Calling Party Pays" model throughout the GSM environment and soon various other GSM markets also started to emulate this model. As Receiving Party Pays systems have the undesired effect of phone owners keeping their phones turned off to avoid receiving unwanted calls, the total voice usage rates (and profits) in Calling Party Pays countries outperform those in Receiving Party Pays countries. Consequently, most countries previously with Receiving Party Pays models have either abandoned them or employed alternative marketing methods, such as massive voice call buckets, to avoid the problem of phone users keeping phones turned off.[citation needed]
In most countries today, the person receiving a mobile phone call pays nothing. However, in Hong Kong, Canada, and the United States, one can be charged per minute, for incoming as well as outgoing calls. In the United States and Canada, a few carriers are beginning to offer unlimited received phone calls. For the Chinese mainland, it was reported that both of its two operators will adopt the caller-pays approach as early as January 2007.[27]
While some systems of payment are 'pay-as-you-go' where conversation time is purchased and added to a phone unit via an Internet account or in shops or ATMs, other systems are more traditional ones where bills are paid by regular intervals. Pay as you go (also known as "pre-pay") accounts were invented simultaneously in Portugal and Italy and today form more than half of all mobile phone subscriptions. USA, Canada, Costa Rica, Japan and Finland are among the rare countries left where most phones are still contract-based.
One possible alternative is a sim-lock free mobile phone. Sim-lock free mobile phones allow portability between networks so users can use sim cards from various networks and not need to have their phone unlocked.

Impacts

Human health and behaviour
Main article: Mobile phone radiation and health
Since the introduction of mobile phones, concerns (both scientific and public) have been raised about the potential health impacts from regular use.[28] Numerous studies have reported no significant relationship between mobile phone use and health, but the effect of mobile phone usage on health continues to be an area of public concern.

Safety concerns
As of 2007, several airlines are experimenting with base station and antenna systems installed to the aeroplane, allowing low power, short-range connection of any phones aboard to remain connected to the aircraft's base station.[29] Thus, they would not attempt connection to the ground base stations as during take off and landing.[citation needed] Simultaneously, airlines may offer phone services to their travelling passengers either as full voice and data services, or initially only as SMS text messaging and similar services. Qantas, the Australian airline, is the first airline to run a test aeroplane in this configuration in the autumn of 2007.[citation needed] Emirates has announced plans to allow limited mobile phone usage on some flights.[citation needed] However, in the past, commercial airlines have prevented the use of cell phones and laptops, due to the assertion that the frequencies emitted from these devices may disturb the radio waves contact of the airplane.
On 20 March 2008, an Emirates flight was the first time voice calls have been allowed in-flight on commercial airline flights. The breakthrough came after the European Aviation Safety Agency (EASA) and the United Arab Emirates-based General Civil Aviation Authority (GCAA) granted full approval for the AeroMobile system to be used on Emirates. Passengers were able to make and receive voice calls as well as use text messaging. The system automatically came into operation as the Airbus A340-300 reached cruise altitude. Passengers wanting to use the service received a text message welcoming them to the AeroMobile system when they first switched their phones on. The approval by EASA has established that GSM phones are safe to use on airplanes, as the AeroMobile system does not require the modification of aircraft components deemed "sensitive," nor does it require the use of modified phones.
In any case, there are inconsistencies between practices allowed by different airlines and even on the same airline in different countries. For example, Northwest Airlines may allow the use of mobile phones immediately after landing on a domestic flight within the US, whereas they may state "not until the doors are open" on an international flight arriving in the Netherlands. In April 2007 the US Federal Communications Commission officially prohibited passengers' use of cell phones during a flight.[30]
In a similar vein, signs are put up in many countries, such as Canada, the U.K. and the U.S., at petrol stations prohibiting the use of mobile phones, due to possible safety issues.[citation needed]

Etiquette
Most schools in the United States have prohibited mobile phones in the classroom, due to the large number of class disruptions that result from their use, and the potential for cheating via text messaging[citation needed]. In the UK, possession of a mobile phone in an examination can result in immediate disqualification from that subject or from all that student's subjects.[31]
A working group made up of Finnish telephone companies, public transport operators and communications authorities has launched a campaign to remind mobile phone users of courtesy, especially when using mass transit—what to talk about on the phone, and how to. In particular, the campaign wants to impact loud mobile phone usage as well as calls regarding sensitive matters.[32]
Many US cities with subway transit systems underground are studying or have implemented mobile phone reception in their underground tunnels for their riders. Boston, Massachusetts has investigated such usage in their tunnels, although there is a question of usage etiquette and also how to fairly award contracts to carriers.[33][34]
The issue of mobile communication and etiquette has also become an issue of academic interest. The rapid adoption of the device has resulted in the intrusion of telephony into situations where this was previously not known. This has exposed the implicit rules of courtesy and opened them to reevaluation.[35]

Use by drivers

This driver is using two phones at once
Main article: Mobile phones and driving safety
The use of mobile phones by people who are driving has become increasingly common, either as part of their job, as in the case of delivery drivers who are calling a client, or by commuters who are chatting with a friend. While many drivers have embraced the convenience of using their cellphone while driving, some jurisdictions have made the practice against the law, such as the Canadian provinces of Quebec, Nova Scotia, and Newfoundland and Labrador as well as the United Kingdom, consisting of a zero-tolerance system operated in Scotland and a warning system operated in England, Wales, and Northern Ireland. Officials from these jurisdictions argue that using a mobile phone while driving is an impediment to vehicle operation that can increase the risk of road traffic accidents.
Studies have found vastly different relative risks (RR). Two separate studies using case-crossover analysis each calculated RR at 4,[36][37] while an epidemiological cohort study found RR, when adjusted for crash-risk exposure, of 1.11 for men and 1.21 for women.[38]
A simulation study from the University of Utah Professor David Strayer compared drivers with a blood alcohol content of 0.08% to those conversing on a cell phone, and after controlling for driving difficulty and time on task, the study concluded that cell phone drivers exhibited greater impairment than intoxicated drivers. [39] Meta-analysis by The Canadian Automobile Association[40] and The University of Illinois[41] found that response time while using both hands-free and hand-held phones was approximately 0.5 standard deviations higher than normal driving (i.e., an average driver, while talking on a cell phone, has response times of a driver in roughly the 40th percentile).
Driving while using a hands-free device is not safer than driving while using a hand-held phone, as concluded by case-crossover studies.[36][37] epidemiological studies,[38] simulation studies,[39] and meta-analysis[40][41]. Even with this information, California recently passed a cell phone law that requires drivers who are 18 years of age or older to use a hands-free device while using the phone in the vehicle. Moreover, this law also restricts drivers under the age of 18 from using a mobile phone. This law goes into effect on July 1, 2008 with a $20 fine for the first offense and $50 fines for each subsequent conviction. The consistency of increased crash risk between hands-free and hand-held phone use is at odds with legislation in over 30 countries that prohibit hand-held phone use but allow hands-free. Scientific literature is mixed on the dangers of talking on a phone versus those of talking with a passenger, with the Accident Research Unit at the University of Nottingham finding that the number of utterances was usually higher for mobile calls when compared to blindfolded and non-blindfolded passengers,[42] but the University of Illinois meta-analysis concluding that passenger conversations were just as costly to driving performance as cell phone ones.[41]

Environmental impacts
Like all high structures, cellular antenna masts pose a hazard to low flying aircraft. Towers over a certain height or towers that are close to airports or heliports are normally required to have warning lights. There have been reports that warning lights on cellular masts, TV-towers and other high structures can attract and confuse birds. US authorities estimate that millions of birds are killed near communication towers in the country each year.[43]
An example of the way mobile phones and mobile networks have sometimes been perceived as a threat is the widely reported and later discredited claim that mobile phone masts are associated with the Colony Collapse Disorder (CCD) which has reduced bee hive numbers by up to 75% in many areas, especially near cities in the US. The Independent newspaper cited a scientific study claiming it provided evidence for the theory that mobile phone masts are a major cause in the collapse of bee populations, with controlled experiments demonstrating a rapid and catastrophic effect on individual hives near masts.[44] Mobile phones were in fact not covered in the study, and the original researchers have since emphatically disavowed any connection between their research, mobile phones, and CCD, specifically indicating that the Independent article had misinterpreted their results and created "a horror story".[45][46][47] While the initial claim of damage to bees was widely reported, the corrections to the story were almost non-existent in the media.
See also: Electronic waste
There are more than 500 million used mobile phones in the US sitting on shelves or in landfills [2], and it is estimated that over 125 million will be discarded this year alone. [3] The problem is growing at a rate of more than two million phones per week, putting tons of toxic waste into landfills daily. Several sites including PaceButler Corporation, TradeMyCell.com, ReCellular, and MyGreenElectronics offer to buy back and recycle mobile phones from users.

History
Main article: History of mobile phones
In 1908, U.S. Patent 887,357 for a wireless telephone was issued in to Nathan B. Stubblefield of Murray, Kentucky. He applied this patent to "cave radio" telephones and not directly to cellular telephony as the term is currently understood.[48] Cells for mobile phone base stations were invented in 1947 by Bell Labs engineers at AT&T and further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been available since 1973. Due to their low establishment costs and rapid deployment, mobile phone networks have since spread rapidly throughout the world, outstripping the growth of fixed telephony.[citation needed]
In 1945, the zero generation (0G) of mobile telephones was introduced. 0G mobile phones, such as Mobile Telephone Service, were not cellular, and so did not feature "handover" from one base station to the next and reuse of radio frequency channels.[citation needed] Like other technologies of the time, it involved a single, powerful base station covering a wide area, and each telephone would effectively monopolize a channel over that whole area while in use. The concepts of frequency reuse and handoff as well as a number of other concepts that formed the basis of modern cell phone technology are first described in U.S. Patent 4,152,647 , issued May 1, 1979 to Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada and assigned by them to the United States Government.
This is the first embodiment of all the concepts that formed the basis of the next major step in mobile telephony, the Analog cellular telephone. Concepts covered in this patent (cited in at least 34 other patents) also were later extended to several satellite communication systems. Later updating of the cellular system to a digital system credits this patent.
Martin Cooper, a Motorola researcher and executive is widely considered to be the inventor of the first practical mobile phone for handheld use in a non-vehicle setting. Using a modern, if somewhat heavy portable handset, Cooper made the first call on a handheld mobile phone on April 3, 1973.[49]
The first commercial citywide cellular network was launched in Japan by NTT in 1979. Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G generation). The Nordic Mobile Telephone (NMT) system went online in Denmark, Finland, Norway and Sweden in 1981.[50] NMT was the first mobile phone system that enabled international use of the phone, or "roaming" on other networks in other countries. This was followed by a boom in mobile phone usage, particularly in Northern Europe.[citation needed]
In 1983, Motorola DynaTAC was the first approved mobile phone by FCC in the United States. In 1984, Bell Labs developed modern commercial cellular technology (based, to a large extent, on the Gladden, Parelman Patent), which employed multiple, centrally-controlled base stations (cell sites), each providing service to a small area (a cell). The cell sites would be set up such that cells partially overlapped. In a cellular system, a signal between a base station (cell site) and a terminal (phone) only need be strong enough to reach between the two, so the same channel can be used simultaneously for separate conversations in different cells.
Cellular systems required several leaps of technology, including handover, which allowed a conversation to continue as a mobile phone traveled from cell to cell. This system included variable transmission power in both the base stations and the telephones (controlled by the base stations), which allowed range and cell size to vary. As the system expanded and neared capacity, the ability to reduce transmission power allowed new cells to be added, resulting in more, smaller cells and thus more capacity. The evidence of this growth can still be seen in the many older, tall cell site towers with no antennae on the upper parts of their towers. These sites originally created large cells, and so had their antennae mounted atop high towers; the towers were designed so that as the system expanded—and cell sizes shrank—the antennae could be lowered on their original masts to reduce range.
The first "modern" network technology on digital 2G (second generation) cellular technology was launched by Radiolinja (now part of Elisa Group) in 1991 in Finland on the GSM standard which also marked the introduction of competition in mobile telecoms when Radiolinja challenged incumbent Telecom Finland (now part of TeliaSonera) who ran a 1G NMT network.
The first data services appeared on mobile phones starting with person-to-person SMS text messaging in Finland in 1993. First trial payments using a mobile phone to pay for a Coca Cola vending machine were set in Finland in 1998. The first commercial payments were mobile parking trialled in Sweden but first commercially launched in Norway in 1999. The first commercial payment system to mimick banks and credit cards was launched in the Philippines in 1999 simultaneously by mobile operators Globe and Smart. The first content sold to mobile phones was the ringing tone, first launched in 1998 in Finland. The first full internet service on mobile phones was i-Mode introduced by NTT DoCoMo in Japan in 1999.
In 2001 the first commercial launch of 3G (Third Generation) was again in Japan by NTT DoCoMo on the WCDMA standard.[citation needed][51]
Until the early 1990s, most mobile phones were too large to be carried in a jacket pocket, so they were typically installed in vehicles as car phones. With the miniaturization of digital components and the development of more sophisticated batteries, mobile phones have become smaller and lighter.
In the 2000s, video and TV services are driving forward third generation (3G) deployment. In the future, low cost, high speed data may drive forward the fourth generation (4G) as short-range communication emerges. Service and application ubiquity, low cost data delivery, and a high degree of personalization and synchronization between various user appliances will be drivers. At the same time, the radio access network may evolve from a centralized architecture to a distributed one.[citation needed]

Terminology

Related non-mobile-phone systems
Car phone
A type of telephone permanently mounted in a vehicle, these often have more powerful transmitters, an external antenna and loudspeaker for handsfree use. They usually connect to the same networks as regular mobile phones.
Cordless telephone (portable phone)
Cordless phones are telephones which use one or more radio handsets in place of a wired handset. The handsets connect wirelessly to a base station, which in turn connects to a conventional land line for calling. Unlike mobile phones, cordless phones use private base stations (belonging to the land-line subscriber), and which are not shared.
Professional Mobile Radio
Advanced professional mobile radio systems can be very similar to mobile phone systems. Notably, the IDEN standard has been used as both a private trunked radio system as well as the technology for several large public providers. Similar attempts have even been made to use TETRA, the European digital PMR standard, to implement public mobile networks.
Radio phone
This is a term which covers radios which could connect into the telephone network. These phones may not be mobile; for example, they may require a mains power supply, they may require the assistance of a human operator to set up a PSTN phone call.
Satellite phone
This type of phone communicates directly with an artificial satellite, which in turn relays calls to a base station or another satellite phone. A single satellite can provide coverage to a much greater area than terrestrial base stations. Since satellite phones are costly, their use is typically limited to people in remote areas where no mobile phone coverage exists, such as mountain climbers and mariners in the open sea.