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David Darling's Newsletter #26


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November 13, 2004


Contents

1. Meanderings
2. Teleportation
3. Bookends



1. Meanderings


This newsletter is coming to you from a different continent than the last. Our relocation from Minnesota to the UK went successfully and we're now temporarily based near Penrith in northern England before moving to a more permanent base in the Dundee area of Scotland. As with all such moves there was a certain amount of disruption - most of our belongings are still in storage in the States, including my precious books and guitar - but by far the most difficult hurdle to overcome was importing our small, black 12-year-old mongrel, Cookie. Try going through the rigmarole of getting a dog into Britain and you'll learn the true meaning of bureaucracy. Anyhow, in the end, we managed to avoid the 6-month period of quarantine that previously had been mandatory but only after numerous visits to the vet for various jabs, checkups, microchip implant, etc., and a $1,000 bill from Northwest Airlines for the gross inconvenience of carrying a 25-pound dog as cargo!

Work continues on expanding my website. The latest addition, about to be unveiled, is the Encyclopedia of Alternative Energy and Sustainable Living, which will have exactly the same format as the existing 5,500-page Encyclopedia of Astrobiology, Astronomy, and Spaceflight. I've long wanted to write a reference book on sustainable living but publishers keep telling me there isn't a big enough market for eco- issues. (Sad, since these are the most urgent issues on the planet!) Fortunately, thanks to the Internet, writers like myself can now reach a large audience without always having to go the conventional publishing route. So, keep an eye out in the coming days for this latest resource, linked to from my home page.

Exciting news continues to pour in from our robot probes in various parts of the solar system. Cassini is the big star at the moment, sending back pictures fast and furious from its orbit around Saturn. Among some of the latest discoveries from Saturn: the little moon Prometheus has been seen plundering material from one of Saturn's rings (the so-called F-ring, which Prometheus "shepherds"); the rings themselves have been found to make a strange kind of music in the form of a melodic series of radio waves (researchers have listened to the music by shifting the frequency); and something very interesting has happened recently on the surface of Titan. Saturn's giant moon Titan, second largest in the solar system after Jupiter's Ganymede, has always been a enigma because its thick, opaque atmosphere blocks our view of the surface. Astrobiologists have been intrigued by Titan ever since the finding of organic material in its atmosphere and the possibility that early steps may have taken place on the moon toward life. There's even a very remote chance of finding life itself if parts of Titan can occasionally get warm enough to melt ice and so provide that most basic ingredient of life-as-we-know-it: liquid water. (Of course, there's always the chance too of life-as-we-don't-know-it based on other elements and solvents.) Now comes the discovery from radar observations by Cassini, during its latest flyby of Titan on October 26, of what looks very much like a flow of some kind across the moon's surface. One promising explanation is that Titan has cryovolcanoes — structures that pour out not hot lava but cool, slushy ice. If this is the case it makes Titan even more potentially important as a natural laboratory for prebiological synthesis. Geological activity of this kind, which might provide local oases of warmth and water, could have enabled the moon to push further along the road to life. Might there even be extreme low-temperature microbes —"hyperpsychrophiles" — eking out a living in the shelter of Titan's ice volcanoes? More data will surely come from future flybys of Cassini and, most importantly, during the descent of the Huygens probe to the surface of Titan in a few weeks' time.

The latest signals from Mars are equally tantalizing in the quest to find the first incontrovertible evidence of life beyond Earth. Several independent teams of researchers, one involved with the Mars Express probe and two using ground-based telescopes, have now reported finding methane in the atmosphere of Mars, as well as localized regions on the surface, especially near the equator, from which the methane seems to be coming. Methane on Earth stems primarily from biological sources. It can also be produced geothermally. But despite repeated attempts to identify hot spots on Mars associated with low-level volcanic or tectonic activity, nothing has shown up. It's therefore getting increasingly hard to avoid the conclusion that the Martian methane is coming from methanogenic microbes below the surface. The exciting thing is that either discovery - of a geothermally active or a biologically active Mars — is huge news. If life turns out to be the correct explanation, it raises a number of further fascinating questions. How similar are these Red Planet bugs to our own microbes? If they're very similar, are they directly related or is this an example of biological convergence - separate life-forms evolving independently along more or less parallel tracks? Also, if the Martian methane is biogenic it may leave astrobiologists scratching their heads for another reason. A popular paradigm is that once life gets started on a planet it will eventually alter the global environment, including the make-up of the atmosphere, so as to make the whole world inhabitable to a greater or lesser degree. Obviously, this has happened on Earth because we find life wherever we look — even at the polar caps and deep underground. Many astrobiologists incline to the view that where life takes hold it will, in time, take over. But the indications from Mars are that if the methane is biological, it's being produced in restricted regions of the planet — small biological oases separated by great tracts of lifelessness. It seems surprising that life could continue to survive in such limited refuges over periods of many millions of years. You'd think it might either spread or die out, not just keep hanging on. Maybe Mars — and even Titan — will force a rethink and show us that refugial life, far from being unlikely, is in fact the norm. We'll see!

Congratulations to Burt Rutan and his team who have now been rewarded with a check for $10 million having claimed the X-Prize of reaching the edge of space twice in two weeks in a privately-built manned rocket. It will be interesting to see how far such projects go over the next few years in forging a new, commercial frontier in space. Meanwhile, NASA is moving ahead with its plans for JIMO — the Jupiter Icy Moons Orbiter, the first mission in its Project Prometheus that will rely heavily on nuclear technology. Also, the world's first spacecraft to use a solar sail for propulsion is slated for launch from a submerged Russian sub on March 1, 2005. Cosmos-1 is sponsored by The Planetary Society and will deploy eight triangular sail blades once it has arrived safely in orbit. Plenty to look forward to, then, in space over the next few months.



2. Teleportation

Of course, we're still a long way from living in the Star Trek universe with its starships effortlessly hopping from star to star via warp drive. But at least one of the seemingly far-fetched technologies in Star Trek has already become a reality. This is teleportation, the subject of my next book "Teleportation: The Impossible Leap," to be published by John Wiley & Sons in April 2005.

True, we're not yet beaming people, or even pineapples, from one place to another. But the trick is now being done routinely with quanta of light and other subatomic particles in laboratories around the world. In one of the latest breakthroughs, photons were teleported 600 meters from a laboratory on one side of the Danube River to a lab on the opposite bank along a fiber optic cable passed through a public sewer tunnel. This demonstration, by Austrian scientists, was important because it shows the viability of using teleportation to transmit encoded data across ordinary communications links. Pretty soon it will be commonplace for banks, government offices, and other institutions dealing with private data to use teleportation for establishing secret codes. Further down the road, teleported particles will be put to work in quantum computers and quantum computer networks. And then, in the more distant future, who knows? We may beaming bigger objects from one place to another in the wink of an eye.

How does this nifty trick of dematerializing something at one point and then rematerializing it, an instant later, at some other point, work? The key is a bizarre property of the quantum mechanical world known as entanglement.

But let's start our story at the very beginning. The word "teleportation" was coined back in 1931 by none other than that collector of curiosities and archiver of strange tales, Charles Hoy Fort, after whom the term "Fortean" derives. In his third published anthology of the weird and mysterious ("Lo!"), he wrote: "Mostly in this book I shall specialize upon indications that there exists a transportory force that I shall call Teleportation."

About the same time, scientists pioneering the new field of quantum mechanics were cottoning on to the fact that the physics of the very small allows what Einstein derisively called "spooky action at a distance." In 1935, Erwin Schrodinger, who hatched a mathematical form of quantum physics known as wave mechanics, used the German word verschrankung, which can be translated as "entanglement," to describe how subatomic particles can become linked in a way that seems to go beyond the bounds of space and time. Entangled particles, even when widely separated (possibly by light-years), appear to be connected by an instantaneous invisible bond, so that observing one has an immediate effect on determining the properties of the other. Einstein couldn't stomach the idea of this "spooky" link, which seemed to fly in the face of commonsense and violate the spirit if not the law of special relativity. Yet, over the past couple of decades, experiments have shown beyond doubt that entanglement is real. Then, in 1992 at the University of Montreal, a group of computer scientists and physicists met after a seminar and effectively drew up the plans for how entanglement could be used as the basis for teleportation.

In a nutshell, this is how it works. Say you want to teleport a photon — a particle of light — which is in a certain quantum state. You can't simply measure this state and then send on the details so that a second photon can be put into the same state somewhere else. The reason is that a measurement on a quantum system causes unknowable changes that prevent you from learning what the state was before the measurement. Entanglement, however, provides a way around this problem. You create two entangled photons, A and B, and send B to the destination — the place where you want the teleported particle to appear. The other entangled photon, A, is combined with the photon to be teleported, X. To be precise, A and X are combined in a special way called a Bell state measurement. This measurement does two things: it causes X to lose its original quantum state identity, and it also forces an instantaneous change in B (along what's called a quantum channel). Photon B alters to correlate with a combination of the result of the Bell state measurement and the original state of X. In fact, what was B is now in either exactly the same state as the original photon X or in a state that's closely related to it. The final step is for a message to be sent to the destination (along a normal "classical" channel) giving the result of the Bell state measurement. Using this information, the photon at the destination can be transformed so that, if it isn't already, it becomes an exact replica of the original photon X. Effectively, photon X has been teleported from one place to another. I say "effectively" because what's really happened is that the original has been destroyed and a perfect copy made elsewhere. One of the catches of quantum teleportation is that you can't keep the original (making it useless for Star Trek-style replicators) because of the so-called "no-cloning theorem." This might be a problem if and when it comes to teleporting humans. Would you feel happy about being disassembled and all your old atoms thrown away, then a particle-perfect copy of you formed an instant later? If not, why not? Let me know what you think and I'll include some of the answers next time.




3. Bookends

Find out more about all my books, including the latest one - the Universal Book of Mathematics, here.



Until next time,
All the best,
David Darling