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Battle of Analogue Vs Digital technology

Dr Vidhura Mahendra

In this 21st century how many times have we encountered the word 'digital' over its predecessor 'analogue' in terms of modern technology? It is amazing the magnitude that digital technology has taken over from its forebear in the recent history especially in the audio visual industry.

The terms such as CD (Compact Disc), DVD (Digital Video Disc), VCD (Video Compact Disc) and digital camera are some of the day to day words in our modern day conversations irrespective of the culture or tradition behind them.

In a world dominated by digital technology it is worth looking at how it unfolded or the cause of the nature. Whether this can be attributed to a battle against each other is certainly debatable.

Firstly it is significant whether we really prefer digital technology to analogue. The answer is still not clear according to various researches that were carried out among different countries and certain groups of audio engineers.

So do we have a 'digimania' (digital mania) of some sort or is it just a contemporary trend in the 21st century of getting things easy? Yet again it's a debatable query. But according to modern day audio engineers the 'digital' term is dubbed mainly due to its compact and easy to handle approach rather than any significant quality it possesses.

Is digital always superior to old-fashioned analogue? Samara Mitchell of Australian Broadcasting Corporation explains how they are different and lets you make up your own mind.

"Imagine that you're at a garage sale and you strike upon a bunch of CD's and records going cheap. So you're flipping through the CD's and "get out of town!" You find a rare album that will complete your entire collection. Not only do you have a special edition CD in your hands, but by freaky coincidence, you find a re-release of the same album on vinyl.

It's got a tiny scratch on it, but otherwise it's in pretty good condition! But you only have enough money on you to buy one item. As a collector, you know that they are worth about the same amount. So which is it going to be, the CD or the record? In some ways we have learnt to assume that if something is digital, like a CD, that it's higher in quality. But just because something is digital, does that mean it's always the best technology for the job?"

Many more of the audio engineers have the same query to that of Samara. So what is so good about 'analogue' technology?

The term analogue refers to the recording or transmission of information in a continuous way. In the past, most audio recordings were analogue. Vinyl records (gramophones and record players) and magnetic tapes [tape recorders or reel to reel machines, SLBC still uses the sturdily built Otari reel to reel machines and records programs at 7 1/2 inches per second (ips) speed for high quality in their recording studios] are good examples.

In fact on the surface of a vinyl record, one can see that it holds one unbroken analogue signal (a constant groove) and similarly the magnetic tape consists of iron (ferrous) or chromium particles to facilitate the same feat.

What is the difference then between an analogue recording and a digital recording?

An analogue event remains constant and unbroken. During the process of recording music digitally, digital recording device takes a momentary bite at the signal, a certain number of times per second (often termed as Kbps or Kilo bytes per second, a term very much associates with computers/internet etc.). But in the analogue technology there is no break in signals or else no measure of times per second units (constant and unbroken).

So we now have a very reasonable theory to define the two terms. But apart from the sonic frequency effect do we really feel the difference in quality when we hear the two sounds from the respective audio machines.

For an example a magnetic tape and a CD that have the same sound with the similar conditions and environment. In fact the answer is 'Yes'. Yes in terms of the comprehensive reproduction of the sound. The sound produced by the magnetic tape has a profound effect than to the machine of the CD. This is the result of the continuity of the analogue reproduction which lacks in the CD player.

But the maintenance is something that need be looked at the former (especially the different climatic conditions in various countries i.e. high relative humidity etc). In Sri Lanka humidity has been one of the biggest problems to keep such machines in tidy conditions (SLBC keep them in air-conditioned studios to prevent them from oxidising/rusting).

However, there are other reasons that the digital technology has superseded its analogue mode and that's mainly due to the convenience of storage especially with the modern day computers and internet facilities. The term, 'files' has often been given for storage of such recordings, voice cuts and other important material.

Analogue technology has been employed by human civilisations for thousands of years, from tick-tock of the clocks, to radio, television and early computing. Digital technology has also been in use for thousands of years, but because it is marketed as the tool of the future, it's easy to overlook the fact that its use well and truly predates modern computer technology.

As the world embraces the 'digital' technology, the BBC has planned to set out its own agenda of total digitalisation of the BBC television by the year 2010-11. This has created some sort of controversy among the general public especially those who are among the low income bracket and depend on national TV. But it is imperative that these changes take place irrespective of for better or worse before staging the London Olympics by 2012.

On contrary to the digitalisation different sectors of people who believe in professional audio recording still opt for the old analogue machines. Since digital consumer electronics are readily available in the local retail outlets for a reasonably low price a demand for analogue machines such as reel to reel tape recorders and LP turn tables have raised markedly.

Former audio engineers believe that there is still a considerable market for the analogue lover hence the good old analogue machines can survive for some time despite the digital invasion of the technology.

A fine example for this phenomenon is the price hike of good quality Akai and other professional/semi professional reel to reel tape recorders. These machines can now be purchased only from certain dealers. During the 1970s and early 80s due to these fabulous machines there were huge number of audiophiles in the UK and the world as a result of a growing pop music culture which also prompted Japan as the leading country to manufacture these machines and for their very own economic development.

Now in the UK there is a growing phrase of humour among the slightly older young people; that if you are 20 years of age you may hardly know about reel to reel machines but if you are 30 you are just old enough to buy one. Well, it certainly sums up where we heading to in a world of digitalisation.

Nature encourages diversity

An analysis of seven tropical forests around the world has found that nature encourages species diversity by selecting for less common trees as the trees mature. The landmark study, which was conducted by 33 ecologists from 12 countries and published in this week's issue of the journal Science, conclusively demonstrates that diversity matters and has ecological importance to tropical forests.

"Ecologists have debated for decades whether there is ecological value to species diversity," says Christopher Wills, a biologist at the University of California, San Diego, who led the study. "We found that in forests throughout the New and Old World tropics, older trees are more diverse than younger ones.

In other words, diversity is actually selected for as each of the forests matures. This means diversity does indeed matter and is an essential property of these complex ecosystems."

The study was conducted on seven undisturbed forest plots, or "tropical forest observatories," maintained and studied by research institutions in Borneo, India, Malaysia, Panama, Puerto Rico and Thailand, under the coordination of the Center for Tropical Forest Science of the Smithsonian Tropical Research Institute, based in Panama.

"Each forest in our study is a highly dynamic community," says Kyle Harms, a biologist at Louisiana State University (LSU) and a collaborator on the project. "We found that the diversity of each local area increased regardless of the species that were present.

This is because trees that were locally common tended to die more often than those that were locally rare, giving a survival advantage to rare species." The effect was even seen within species, he adds. "If a species was common in one part of a plot and rare in another, its death rate was higher where it was common."

The forest plots, two from the Americas and five from Asia, are themselves diverse. They range from dense and species-rich wet rainforest to drier and more open forest that is often swept by fires. Even so, all the forests show the same pattern of increasing local diversity as trees age.

"The great scientific value of these tropical forest observatories is that each of them has undergone a complete census more than once, so that the researchers know what has happened to hundreds of thousands of trees from one census to the next," says Stuart Davies, director of the Center for Tropical Forest Science. "These tropical forest observatories, along with others in our network, represent some of the most important, detailed and long-running ecological studies in the world today."

In addition to the Smithsonian Tropical Research Institute, the institutions that manage the tropical forest observatories included in this study are the Indian Institute of Science, Royal Forest Department of Thailand, University of Peradeniya of Sri Lanka, University of Puerto Rico, and the Forest Research Institutes in Peninsular Malaysia and Sarawak.

The study was funded by grants from the National Science Foundation and the Center for Tropical Forest Science of the Smithsonian Tropical Research Institute.

Scientists are unsure what is responsible for the increases in diversity, but it seems to exert its effects in all seven of the research forests.

"This study addresses a fundamental question in tropical ecology," said Jess Zimmerman, co-author of the paper. Zimmerman is on leave from the University of Puerto Rico at Rio Piedras and is currently a program director in the National Science Foundation (NSF)'s Division of Environmental Biology.

"In a snapshot of time, are rare species rare because they are on the brink of local extinction, or because they are on their way to becoming more common? This long-term study shows that there is an advantage to being rare, and that this advantage causes rare species to become more common."

The authors cite three possibilities, all of which, they say, are likely to play a role. First, rare species may be at an advantage because the animals, fungi, bacteria and viruses that prey on them are less likely to cause damage when their hosts are rare.

Second, the rare species may be at an advantage in competition for certain physical resources, because individuals of the same species tend to share more similar resource requirements than individuals of different species.

And third, rare species would be at an advantage when tree species have direct, positive influences on one another, because trees of rare species are on average surrounded by a high proportion of trees that are different from themselves. The scientists point out that none of these processes can operate in forests where the individual trees are all of one species.

Such forests are highly susceptible to diseases, and individuals are in direct competition with others like themselves.

The three diversity enhancing processes are also likely to be absent from badly damaged forests. When forests are clear-cut, the soil is rapidly eroded, depleted of nutrients and the "invisible world" of insects, bacteria and fungi that help to sustain diversity largely disappears.

But the authors believe that their study suggests that tropical forests that have been damaged slightly, by carefully managed selective logging for example, should soon regain their former levels of diversity, provided the damage has not been severe or long-continued.

"If you damage a forest a little bit, the forest can recover," says Wills. "Even damaged ecosystems can be restored to their former diversity through natural processes if they are allowed to do so." Wills says the new study points the way towards further detailed investigations of the processes by which forest diversity is maintained and raises new questions and lines of research for ecologists, and forest managers, to pursue.

"Are the same processes operating in temperate forests?" he asks. "How much damage can a forest sustain before its diversity begins to decline? Are other complex ecosystems, like coral reefs, also selected for increased diversity? This paper provides insights into a dynamic and evolving natural world and shows that diversity is not just an esthetic ideal, but is also an important property of natural ecosystems." (Courtesy: Sciencedaily.com)

Milky Way brims with singleton stars

Most of the stars in the Milky Way are born alone and live out their lives without partners, a new analysis suggests. If true, the work overturns standard theories that stars are born in broods and also suggests planets - and potentially life - may be more common in the galaxy than thought.

Observations show that stars are born in nurseries of gas and dust that typically contain several hundred stars in a region 3 light years wide. According to most models, they are born there in clutches, with several stars condensing from each of many large, dense clouds of matter.

Now, astronomer Charles Lada of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, US, is challenging that notion notion and says most stars are born one by one in the nurseries.

He says those models are based on early stellar surveys that focused on bright, relatively massive stars like the Sun. The surveys found that about 60% of these bright stars are found in pairs.

But in the last 15 years or so, astronomers have used more sensitive telescopes to survey smaller, dimmer stars called red dwarfs, which are between 10% and 50% the mass of the Sun. "The faint stars are harder to see, but they make up 85% of all stars in the galaxy, and three quarters of those are single," Lada told New Scientist. "I think the result strongly favours the idea that most stars form initially as single objects, not in multiple systems."

That goes against current models, which explain the existence of single stars by arguing they are born with siblings and are then separated after a gravitational interaction with another star. "You can certainly form a lot of stars that way, but with so many single red dwarfs, there's no simple way" to explain them all, says Lada.

Cloud turbulence

Frank Shu, an astronomer and president of the National Tsinghua University in Taiwan, agrees. In order to explain the fact that red dwarfs are vastly more common than any other type of star, "the mechanism doesn't work unless one always breaks apart a pair of red dwarfs," he told New Scientist.

But he says that scenario is unlikely, as stellar home-wreckers are most likely to break up pairs of stars that orbit each other at relatively large distances. And observations show that such "wide binaries" are usually made up of stars of different masses.

Lada argues that whether a star forms alone or with a sibling depends on its mass, which in turn depends on the mass of its parent cloud. Observations show that the gas in large, star-forming clouds is more turbulent than the gas in small ones. Shu has done previous theoretical work suggesting this turbulence may cause large clouds to separate into groups of massive stars. "Turbulence becomes relatively unimportant" for clouds that form small stars, he adds.

"It means the majority of stars in the galaxy and the universe forms under considerably more quiescent conditions than have been promoted in some quarters," Shu says. "If Lada's results hold up, a lot of people who have made rash claims in the past will have to re-evaluate their positions."

Planets and life

If most red dwarfs form without a sibling, extrasolar planetary systems similar to our solar system may be common, says Lada. Kevin Luhman, an astronomer at Pennsylvania State University in University Park, US, agrees. He says planets would probably have a more difficult time forming around a star in a binary system because the other star's gravity would disturb them.

He adds that red dwarfs can live as long as a trillion years - 100 times longer than the Sun, which will heat and bloat up as a red giant in several billion years.

"Those factors together make the stars very likely sites for the formation of planets and life," Luhman says.

The stars' longevity may make them ideal destinations when the Sun becomes a red giant and "makes life on Earth a living hell", says Shu. "In that case, travelling to a habitable planet (or making one by terraforming) around a red dwarf star could extend the lifetime of the human race by many, many billions of years." (Courtesy: New Scientist)

St. Jude Conducts Large-scale Bird Flu Genome Study

Unique resources at St. Jude Children's Research Hospital let researchers generate a "gold mine" of data to track evolution of bird flu virus genes and understand how they cooperate to cause disease Investigators at St. Jude Children's Research Hospital have completed the first large-scale study of bird flu virus genomes, thereby doubling the amount of genetic information available on the genes and proteins of these viruses.

The results of the project could lead to major insights into the bird flu virus known as H5N1, the researchers said. H5N1 is the bird flu virus currently infecting humans in Asia and Eastern Europe, and flu experts fear it could mutate in a way that would allow it to cause a worldwide pandemic in humans.

"These studies provide the first fundamental insight into the evolution of influenza viruses in nature the source of all influenza viruses that affect humans, domestic animals and birds," said Robert G. Webster, Ph.D., a member of the Infectious Diseases department and holder of the Rose Marie Thomas Chair at St. Jude. "This information is a true gold mine, and we are inviting all of the miners to help us unlock the secrets of influenza."

Webster is an internationally renowned expert on bird flu viruses and a co-author of the report that appears in the January 27 issue of Science.

St. Jude was uniquely positioned to conduct these studies because it houses Webster's large collection of bird flu viruses collected over several decades. The hospital is also home to St. Jude's Hartwell Center for Bioinformatics and Biotechnology, which provided the necessary expertise and biotechnology resources; and its supercomputer has the horsepower needed to conduct these studies.

"Despite the major threat to human health posed by these viruses, there was very little information available on the entire genomes of bird flu viruses," said Clayton Naeve, Ph.D., director of St. Jude's Hartwell Center. "The St. Jude Influenza Virus Genome project provides a major contribution to our understanding of H5N1 and other bird flu viruses.

Now we're in a much better position to understand what makes these viruses tick. And that could help us learn how to control the avian influenza viruses that threaten humans."

Naeve is senior author of the report in Science. The project produced 70 million bases of sequence information leading to DNA sequences for 2,196 genes and 169 complete bird flu genomes from the St. Jude collection, including representatives of all known subtypes of the virus including H5 bird flu.

Preliminary analysis of these data and development of new analysis software has led to the discovery of new forms of bird flu genes, how these viruses evolve through time and the identification of genes that travel together through evolution.

The St. Jude research also made an intriguing discovery that avian influenza viruses have a particular molecular feature that human influenza viruses do not have, which may cause them to be more toxic when infecting human cells.

"The major accomplishment of this project is that it gives the scientific community significantly more new data and analytical tools to use in the study of these potentially very dangerous viruses," said John C. Obenauer, Ph.D., a Bioinformatics associate research scientist at St. Jude's Hartwell Center. "In the future, that might lead to effective strategies for controlling outbreaks of these viruses in birds and humans." Obenauer is first author of the paper.

Other authors of the paper include Jackie Denson, Perdeep K. Mehta, Xiaoping Su, Suraj Mukatira, David B. Finkelstein, Xiequn Xu, Jinhua Wang, Jing Ma, Yiping Fan, Karen M. Rakestraw; Erich Hoffmann, Scott Krauss, Jie Zheng and Ziwei Zhang. (ScienceDaily.com)

Why is oil usually found in deserts and arctic areas?

Roger N. Anderson, a professor at the Lamont-Doherty Earth Observatory at Columbia University, explains.

Plate tectonics determines the location of oil and gas reservoirs and is the best key we have to understanding why deserts and arctic areas seem to hold the largest hydrocarbon reserves on earth. But there are other important locations of large reserves: river deltas and continental margins offshore. Together, these four types of areas hold most of the oil and gas in the world today.

Oil and gas result mostly from the rapid burial of dead microorganisms in environments where oxygen is so scarce that they do not decompose.

This lack of oxygen enables them to maintain their hydrogen-carbon bonds, a necessary ingredient for the production of oil and gas. Newly developing ocean basins, formed by plate tectonics and continental rifting, provide just the right conditions for rapid burial in anoxic waters.

Rivers rapidly fill these basins with sediments carrying abundant organic remains. Because the basins have constricted water circulation, they also have lower oxygen levels than the open ocean. For instance, the Gulf of California, an ocean basin in development, is making new oil and gas in real time today. The Gulf of Mexico is also a great example of new oil and gas formation in a restricted circulation environment (see image at right above).

The same plate tectonics that provides the locations and conditions for anoxic burial is also responsible for the geologic paths that these sedimentary basins subsequently take. Continental drift, subduction and collision with other continents provide the movement from swamps, river deltas and mild climates where most organics are deposited to the poles and deserts, where they have ended up today by coincidence.

In fact, the Libyan Sahara Desert contains unmistakable glacial scars and Antarctica has extensive coal deposits-and very likely abundant oil and gas that establish that their plates were once at the other ends of the earth (see image at right).

Plate tectonics is also responsible for creating the "pressure cooker" that slowly matures the organics into oil and gas. This process usually takes millions of years, giving the oil and gas deposits plenty of time to migrate around the globe on the back of plate movements. Because these hydrocarbons are much more buoyant than water, they eventually force their way to the surface.

Alternatively, rifting, collisions between land masses, and other tectonic forces can free the mature oil and gas from deep within sedimentary basins and then trap these organic fluids in reservoirs before they escape to the earth's surface. We know these reservoirs as oil and gas fields.

(Courtesy: Scientific American)

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