Bruce Lahn, geneticist at the University of Chicago
Will we evolve to resist major diseases?
Sarah Tishkoff, human geneticist at the University of Pennsylvania
10,000 YEARS: HOW DO MASSIVE STARS BLOW UP?
Cole Miller, astronomer at the University of Maryland
Supernovae are rare, occurring perhaps once every several decades in a large spiral galaxy such as ours. The last time one was seen here was A.D. 1604: Johannes Kepler described it as outshining everything in the night sky but Venus. All supernovae recorded in more recent times took place in other galaxies that are millions, if not billions, of light-years away. When we finally see a supernova up close, we will be able to study it not only with ordinary telescopes but also with two new kinds of observatories—one detecting neutrinos and the other, gravitational waves—which will tell us what actually goes on inside the exploding star. If you could wait 10,000 years, you would be virtually guaranteed to get 100 or 200 of these events—enough to distinguish their subtle variations.
The explosion of a star could happen in our galaxy at any time. When it starts, the screens of computers at a handful of gravitational-wave observatories around the world will begin to flash, signaling the passage of ripples in the fabric of space. These so-called gravitational waves are a key prediction of Einstein's general theory of relativity but have so far eluded direct detection. The waves will signal that the star's core has begun to collapse under its own gravitational pull. The compressed matter turns into neutrons and releases neutrinos—particles that can zip through matter and thus escape through the star's outer layers and into space (and reach observatories on Earth). The energy released by the collapse, mostly carried by neutrinos, could blow off the outer layers of the star, making it stupendously bright. In some cases, however, the shock wave might fizzle, yielding gravitational waves but no light. We do not know for sure, because so far we have only seen the final, visible stage (with the exception of a handful of neutrinos from a supernova in 1987). Having thousands of years to observe would make all the difference. The new tools could also let us solve another open question—namely, in what conditions a dying star leaves behind a black hole or a neutron star.
100,000 YEARS: HOW DO MATERIALS DECAY?
Kristin Persson, theoretical physicist and materials scientist at Lawrence Berkeley National Laboratory
We build things all the time, but how do we know how long they will last? If we are going to build storage for nuclear waste, we need to be sure that the containers will last until the material inside is no longer dangerous. And if we are not going to fill the planet up with trash, it would help to know how much time it takes plastics and other materials to degrade.
The only way to be sure is to put these materials under stress tests for 100,000 years or so and see how they hold up. Then we could learn to build things that truly last—or that degrade in a “green” way.
We could, for example, test such materials as the copper-based alloys and glasses typically used for encasing nuclear waste. (Repositories are supposed to go deep underground in carefully chosen locations. But geologic conditions may change in unpredictable ways within a few thousand years.) Such experiments would expose the materials to accelerated wear and tear and to chemical abuse—say, varying pH. They would dial temperature up and down to simulate the cycles of day and night and of the seasons.
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Reply | Report Abuse | Link to thisIf someone could live forever, there would be no question worth to ask
Reply | Report Abuse | Link to thisThey could fail time after time after time.Blowing up or poisoning everyone around themselves and keep coming back to try,try again. Never the need of finally admitting to failure.What a exciting life after life after life to lead forever.And It would never be necessary to find a answer.
Reply | Report Abuse | Link to thisI would like to suggest that SciAm use notation such as 10^43 to indicate powers of ten. In the Mac/Safari browser, at least, the currently used notation shows up as "1043". It's very amusing to read that the lifetime of a proton might be 1043 years.
Reply | Report Abuse | Link to thisWe wish you could have measured the electric charges of protons and neutrons. According to our theory, the present value of the charge of quarks contain an error element of 3%. In stead of 2/3 and 1/3, they are 7/11 and 4/11. This makes the charge of protons +10/11 and that of neutrons -1/11. The net charge is not perceptible as it is a negative charge directed towards the nucleus. This theory also predicts the value of fine structure constant alpha as 7/960 and zero energy level and 7/900 at the weak interaction level, which fairly matches with the measured value. This shows that our understanding of atomic shells itself is too primitive. It may take a 1000 years to get a complete picture.
Reply | Report Abuse | Link to thisIt's amazing to think that anything would take us this long to understand. Looking at the technological innovations of the last 150 years, and the decreasing time between major breakthroughs, to think that *anything* is out of reach within a relatively short timeframe is mindboggling.
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