Monday, February 25, 2008

In the distant future, Mankind sleeps for eternity


So, what if nothing really happens? What if the world isn't struck by meteors, destroyed by divine hand or blown to bits by scientists? Well, in the long run, we might sleep. Not just for the nights, but also during the day. We might even sleep our entire lives, from birth to death, without ever waking up. What's more: the survival of our species may depend on it.

Luckily, it will take some time before it gets that far. Something like one hundred trillion years, to be precise.

Our Universe expands. Ever since the Big Bang blew all matter, space and time into existence, the Universe grows. The Universe expands and cools, much like the fire cloud after an explosion gets bigger and colder. And that's exactly what astronomers see as they study the sky: all stars we see rush away from us and from each other at tremendous speeds.

But time is ticking. According to the latest insights, the expanding and cooling of the cosmos will go on and on and on. Galaxies and stars will be further and further apart. Stars will slowly become dimmer, as they move out of sight. The night sky will become darker and darker. And darker still, until there's absolutely nothing to be seen.

What's more, stars die. After a lifecycle of several to many millions of years (depending on their size), every star is destined to spew out its last bit of energy and collapse, becoming a cold `neutron star', a `white dwarf', or a black hole. As time passes, this will happen to more and more stars, creating a Universe full of burnt out dead stars and black holes.

And black holes `eat' other stars. A black hole has such immense gravity, that no star or planet can resist it. The increasing number of black holes will sweep the Universe clean, much like the devil in St. John's biblical vision of the Apocalypse sweeps the stars from the sky with its tail. It will become even darker still. And oh, by the way, our own Sun will die too, about 5,000 million years from now.

So what about us? Suppose man somehow finds a way to survive all these cataclysmic events.

Suppose humanity colonizes other, `safer' planets. And, for argument's sake, just suppose humanity is somehow able to dodge all those mean, black holes that scavenge the cosmos. What would life be like?

First, we would find ourselves in an increasingly cold, numbingly dark surrounding. We would be truly alone in the Universe.

But that's not the biggest problem. With the stars and the Sun long gone, we'll find ourselves in the midst of an energy crisis of unimaginable proportions. And terrible enough, in all the dark and the cold, we need energy more than ever.

Just hack up some atoms in a nuclear power plant, you might say. But that's not a good solution. By physical law, the energy within atoms decreases as the Universe expands.

And, bizarre as it may sound, the supply of atoms is ultimately limited. The matter on our planet is, of course, finite. And in the nothingness of the faded-out Universe, matter is hard to get at. It's either beyond reach or eaten up by black holes. And there's no more particles raining down on our planet from solar radiation, meteors or cosmic dust.

In the long run, we have to come up with something to adapt to our new environment. And `adapting' means more than getting used to cold feet and being able to see in total darkness: it means cutting drastically on our energy bill.

First, we'll have to get rid of our bodies. No, really! Our carbon-based bodies are very vulnerable to cold. They get damaged even when temperatures drop only a few degrees. It's absolutely certain there's no way life as we know it can survive for a substantial period of time in an expanded Universe.

But that's no big deal, Princeton physicist Freeman Dyson and many others suggest. We `only' have to transport our consciousness into something else. A cyborg, an interstellar cloud of particles maybe -- with one hundred trillion years ahead, we have plenty of time to come up with something.

So okay. Grudgingly, you've turned yourself into a cyborg. But in the long run, even that isn't enough. For one thing, thought itself costs energy. Just think of your computer doing its calcu­lations: the thing simply wouldn't run if you didn't have it connected to a power source.

And what's worse, the universe gets colder still. This brings out other, very weird physical problems of its own. The speed of thought will drastically decline in extreme cold, Dyson demonstrated. So there you are, you've decided to become a cyborg, and now you find out you're sooooo slooow-witted.

And when temperatures drop even further, there's more trouble facing us poor former humans. It'll be so cold, even a cyborg would get into trouble. A point comes when organisms cannot lower their temperatures any further without becoming less complex -- in effect, dumbing down. Before long, life could no longer be regarded as intelligent.

It's here where sleep comes into play. As Dyson calculates, there's only one possibility to survive. We'd hibernate. By sleeping, our metabolic rates will drop, and we will be able to achieve an ever-lower body temperature. In fact, by spending an increasing fraction of our time asleep, eternal life would indeed be possible.

So you've become a slow-thinking robot that's asleep most of the time. Still, even that may not be enough. For example, what kind of alarm clock would you set to wake you up? Your alarm clock would have to operate reliably for a long, long time, using less and less energy. A curious but, scientifically speaking, dead serious problem, that no physicist has been able to answer yet.

And then there's the problem of thought. In the early 1980s, computer researchers realized that in principle it's possible to design a computer that doesn't dissipate energy while processing information. Isn't that great news for all those dormant cyborgs to come?

No, it isn't. To function, this computer -- that only is a theoretical possibility so far -- must never, NEVER discard any information. If it does discard only one bit of information, it will be like pulling the plug out of a bath tub: it would use up energy while calculating for ever more.

But thoughts are finite. Information is by definition stored in a finite amount of particles. Even in your cyborg brain, there will come a point where you would have to discard old information in order to store something new. And that IS a problem.

'All organisms would ever do is relive the past, having the same thoughts over and over again,' cosmologists Lawrence M. Krauss and Glenn D. Starkman estimate. 'Eternity would become a prison, rather than an endlessly receding horizon of creativity and exploration. It might be nirvana, but would it be living?'

Nope. Probably not. There you go, Mr. Cyborg: constantly asleep, and when awake only rethinking old thoughts.

Perhaps it's best our world is swallowed by one of those big, mean Black Holes after all.

Friday, February 8, 2008

Implants create computer-controlled insect cyborgs

Cornell University researchers have succeeded in implanting electronic circuit probes into tobacco hornworms as early pupae.

The hornworms pass through the chrysalis stage to mature into long-lived moths whose muscles can be controlled with the implanted electronics.

The research was showcased at MEMS 2008, an international academic conference on Micro-Electrico-Mechanical Systems that took place from January 13-17 in Tucson, AZ. The pupae insertion state was found to yield the best results.

The resulting moth, a microsystem-controlled insect, has a circuit board protruding from the top of its midsection. Probes are inserted into the dorsoventral and dorsolongitudinal flight muscles.

CT images show components of high absorbance indicating tissue growth around the probe. The research also indicated the most favorable and least favorable times for insertion of control devices.

The overall size of the circuit board is just 8x7mm, with a total weight of about 500 mg. The capacity of the battery is 16 mAh, and weighs 240 mg. A driving voltage of 5 volts causes the tobacco hornworm blade muscles (two pairs) to move for flight and maneuvering.

The insect cyborgs are part of a program called HI-MEMS (Hybrid Insect MEMS), a DARPA program initiated by Program Manager Dr. Amit Lal.

The ultimate goal of the HI-MEMS program is to provide insect cyborgs that can demonstrate controlled flight; the insects would be used in a variety of military and homeland security applications. HI-MEMS program director Amit Lal credits science fiction writer Thomas Easton with the idea.

Lal read Easton's 1990 novel Sparrowhawk, in which animals enlarged by genetic engineering (called Roachsters) were outfitted with implanted control systems. Dr. Easton, a professor of science at Thomas College, sees a number of applications for HI-MEMS insects.

Moths are extraordinarily sensitive to sex attractants, so instead of giving bank robbers money treated with dye, they could use sex attractants instead. Then, a moth-based HI-MEMS could find the robber by following the scent."

"[Also,] with genetic engineering Darpa could replace the sex attractant receptor on the moth antennae with receptors for other things, like explosives, drugs or toxins," said Easton.

DARPA had better be careful with its insect army; in Easton's novel, hackers are able to gain control of genetically engineered animals by hacking the controller chips used in their implanted control structures.

Saturday, February 2, 2008

One Common Ancestor Behind Blue Eyes

People with blue eyes have a single, common ancestor, according to new research.

A team of scientists has tracked down a genetic mutation that leads to blue eyes. The mutation occurred between 6,000 and 10,000 years ago. Before then, there were no blue eyes.

"Originally, we all had brown eyes," said Hans Eiberg from the Department of Cellular and Molecular Medicine at the University of Copenhagen.

The mutation affected the so-called OCA2 gene, which is involved in the production of melanin, the pigment that gives color to our hair, eyes and skin.

"A genetic mutation affecting the OCA2 gene in our chromosomes resulted in the creation of a 'switch,' which literally 'turned off' the ability to produce brown eyes," Eiberg said.

The genetic switch is located in the gene adjacent to OCA2 and rather than completely turning off the gene, the switch limits its action, which reduces the production of melanin in the iris. In effect, the turned-down switch diluted brown eyes to blue.

If the OCA2 gene had been completely shut down, our hair, eyes and skin would be melanin-less, a condition known as albinism.

"It's exactly what I sort of expected to see from what we know about selection around this area," said John Hawks of the University of Wisconsin-Madison, referring to the study results regarding the OCA2 gene. Hawks was not involved in the current study.

Baby blues

Eiberg and his team examined DNA from mitochondria, the cells' energy-making structures, of blue-eyed individuals in countries including Jordan, Denmark and Turkey. This genetic material comes from females, so it can trace maternal lineages.

They specifically looked at sequences of DNA on the OCA2 gene and the genetic mutation associated with turning down melanin production.

Over the course of several generations, segments of ancestral DNA get shuffled so that individuals have varying sequences. Some of these segments, however, that haven't been reshuffled are called haplotypes. If a group of individuals shares long haplotypes, that means the sequence arose relatively recently in our human ancestors. The DNA sequence didn't have enough time to get mixed up.

"What they were able to show is that the people who have blue eyes in Denmark, as far as Jordan, these people all have this same haplotype, they all have exactly the same gene changes that are all linked to this one mutation that makes eyes blue," Hawks said in a telephone interview.

Melanin switch

The mutation is what regulates the OCA2 switch for melanin production. And depending on the amount of melanin in the iris, a person can end up with eye color ranging from brown to green. Brown-eyed individuals have considerable individual variation in the area of their DNA that controls melanin production. But they found that blue-eyed individuals only have a small degree of variation in the amount of melanin in their eyes.

"Out of 800 persons we have only found one person which didn't fit — but his eye color was blue with a single brown spot," Eiberg told LiveScience, referring to the finding that blue-eyed individuals all had the same sequence of DNA linked with melanin production.

"From this we can conclude that all blue-eyed individuals are linked to the same ancestor," Eiberg said. "They have all inherited the same switch at exactly the same spot in their DNA." Eiberg and his colleagues detailed their study in the Jan. 3 online edition of the journal Human Genetics.

That genetic switch somehow spread throughout Europe and now other parts of the world.
"The question really is, 'Why did we go from having nobody on Earth with blue eyes 10,000 years ago to having 20 or 40 percent of Europeans having blue eyes now?" Hawks said. "This gene does something good for people. It makes them have more kids."