by Paul Gilster | Feb 14, 2007 | Culture and Society |
Centauri Dreams has little use for pessimism. The operative assumption in these precincts is that humanity will muddle through somehow and eventually get to the stars, whether in a matter of centuries or millennia. But it’s always good to have a backup plan in the event of catastrophe, which is what the Norwegian government has been working on. Who knows when some rogue asteroid like 99942 Apophis may beat the odds and fall, with shattering results, to Earth?
The Svalbard International Seed Vault has the aim of protecting the world’s agriculture in a vast seed bank, one that would house three million seed samples. Collecting and maintaining the seeds is the Global Crop Diversity Trust, whose executive director, Cary Fowler, likened the vault to a safety net in a recent BBC story, saying “Can you imagine an effective, efficient, sustainable response to climate change, water shortages, food security issues without what is going to go in the vault – it is the raw material of agriculture.”
And if you drill 120 meters into a mountainside on Spitsbergen, you’ve found a place so remote and geologically stable that such a seed bank should survive a variety of catastrophes, including climate change that would raise the local sea level. Seeds are to be stored at -18 degrees Celsius, the beauty of the location also being that the permafrost that surrounds this site near the North Pole provides natural refrigeration in the event of power failure.
The facility is designed to operate autonomously, with no full-time staff. All of which gives me eerie reminiscences of Wells’ Time Machine, in the passage where the Time Traveller enters what is obviously the ruins of a huge museum. Here there are exhibits on chemistry, minerology, even the broken remains of a great library, but what left its mark on my imagination was the natural history exhibit Wells describes:
Within the big valves of the door–which were open and broken–we found, instead of the customary hall, a long gallery lit by many side windows. At the first glance I was reminded of a museum. The tiled floor was thick with dust, and a remarkable array of miscellaneous objects was shrouded in the same grey covering. Then I perceived, standing strange and gaunt in the centre of the hall, what was clearly the lower part of a huge skeleton. I recognized by the oblique feet that it was some extinct creature after the fashion of the Megatherium. The skull and the upper bones lay beside it in the thick dust, and in one place, where rain-water had dropped through a leak in the roof, the thing itself had been worn away. Further in the gallery was the huge skeleton barrel of a Brontosaurus. My museum hypothesis was confirmed. Going towards the side I found what appeared to be sloping shelves, and clearing away the thick dust, I found the old familiar glass cases of our own time. But they must have been air-tight to judge from the fair preservation of some of their contents.
Svalbard’s installation will, we hope, stay in better shape, though who knows what can happen at the time scales Wells talks about? And, of course, a vault like this one needs constant replenishment, depending on the species being preserved — some seeds simply won’t survive more than a few decades in their frozen state. Nonetheless, the concept of hoarding away life’s treasures to ensure their survival has a deep resonance, and we can hope to do better than the museum builders Wells writes about if we plan intelligently and think long-term.
And just in from the New York Times:
Bent Skovmand, a plant scientist who helped to create the “doomsday vault,” a massively fortified cavern to safeguard three million kinds of unique crop seeds against catastrophe, died Tuesday in Kavlinge, Sweden. He was 61.
A notable fact from the story: “…of an estimated 7,100 types of apples grown in the United States in the 1800s, more than 6,800 no longer exist.” Skovmand’s career was dedicated in part to ensuring against that kind of loss, his work on the Svalbard International Seed Vault just the capstone to a remarkable career. The entire article is worth reading.
by Paul Gilster | Feb 13, 2007 | Culture and Society |
It’s hard to believe that Sir Patrick Moore started his astronomy program The Sky at Night fifty years ago. Since then, BBC viewers have known where to turn for a view of things celestial, one with that particular Moore mix of savvy and amiable, eccentric enthusiasm that comes across so well in his many books. So what a pleasure to see that a set of stamps has now gone on sale honoring his work. How else would you see interstellar scenery on an postal envelope?
A news account in the Telegraph quotes Sir Patrick thus:
“I feel deeply honoured. I would like to think that we have played a part in introducing astronomy to people who would otherwise have paid no real attention to the heavens. Many years hence, philatelists will still be admiring these stamps paying tribute, not to me, but to The Sky At Night.”
Can you imagine a show running for fifty years with the same host? I hate to disagree with the gentleman, having grown up reading his books, but the tribute future stamp admirers pay will be very much directed to him. Moore is a legendary figure in making our society aware of the sky, and these stamps are hardly the last honor in line for him. Kudos to the Royal Mail for extending this recognition. More on Moore here.
by Paul Gilster | Feb 13, 2007 | Exoplanetary Science |
Our Solar System in the distant future may look something like the Helix nebula today. That’s because in about five billion years, the Sun will have become a white dwarf, its inner planets swallowed up by its earlier expansion, its outer planets, asteroids and comets surviving in distant orbits and colliding with each other to form a ring of dusty debris. The Sun will undergo, in other words, a kind of rejuvenation, experiencing what scientists call ‘late bombardment’ in a system that has become dynamically young again.
Such a disk has now been found in the Helix nebula, some 700 light years away in Aquarius. It took the infrared tools of the Spitzer Space Telescope to sort out the glow of the dusty disk that circles the remnant white dwarf between 35 and 150 AU out. The assumption is that the disk is the result of smashups in the outer system, presumably involving objects like those in our Kuiper Belt or comets from an Oort-like cloud.
Image: Spitzer’s infrared view of the Helix nebula. Infrared light from the outer gaseous layers is represented in blues and greens. The white dwarf is visible as a tiny white dot in the center of the picture. The red color in the middle of the eye denotes the final layers of gas blown out when the star died. The brighter red circle in the very center is the glow of a dusty disk circling the white dwarf (the disk itself is too small to be resolved). Credit: NASA/JPL-Caltech/K. Su (Univ. of Arizona).
A dusty disk found last year around the white dwarf G29-38 had shown that objects like these could survive around dead stars, though the disk around G29-38 was much closer to its star. We obviously have much to learn about debris disks in such settings. And what exactly does happen when a Sol-like star becomes a red giant? Here’s a snippet from the paper on this work (references edited out; see the preprint):
It has been established that any planet closer than ~1 AU will be engulfed by an expanding red giant…, while planets outside ~5 AU from the Sun will survive post-main-sequence evolution…, and the orbits of surviving planets and most of the Kuiper Belt objects (KBOs) and Oort Cloud comets will expand adiabatically and remain bound to the solar system… The re-stabilized KBOs and Oort Cloud can later become the source of objects that go into the inner part of the system, either plunging into the white dwarf or breaking up due to tidal destruction, and they can populate the inner system with dust.
The newfound debris disk may be solving a different mystery as well. The Helix nebula’s white dwarf is known to be emitting highly energetic x-rays, leading some astronomers to believe it was accreting matter from a hidden companion star. But disk material falling onto the star and triggering the outbursts seems to be a more satisfactory answer. “The high-energy X-rays were an unsolved mystery, said You-Hua Chu (UIUC). “Now, we might have found an answer in the infrared.”
The paper on this work is Su et al., “A Debris Disk around the Central Star of the Helix Nebula?,” which will appear in Astrophysical Journal Letters. The preprint is already available online.
by Paul Gilster | Feb 13, 2007 | Culture and Society
Centennaries are worth celebrating, especially when they involve people whose work advanced our understanding of reality. A big one comes up in 2008, about which this clue:
“The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.”
The speaker is Hermann Minkowski (1864-1909), the German scientist and mathematician who didn’t survive the 1908 presentation he began with these words by more than a few months (he died of appendicitis the following January). The talk, entitled Raum und Zeit, contains Minkowski’s view that time and space must be understood together as a four dimensional concept called spacetime.
That idea played a material role in furthering Einstein’s later development of General Relativity. Indeed, Einstein would later write of Minkowski’s views that “Without them…the General Theory of Relativity would probably have remained stuck in its swaddling-clothes.”
Honoring the centennary will be Third International Conference on the Nature and Ontology of Spacetime, to be held in June of 2008 in Montreal. Its purpose: “…to bring together physicists and philosophers and to provide a forum where different aspects of the nature and ontology of spacetime can be discussed.” The call for papers remains open until November. Papers on Minkowski’s legacy are especially sought.
by Paul Gilster | Feb 12, 2007 | Exoplanetary Science
It’s good to see that Greg Laughlin’s systemic project is getting some public attention. This article in the Santa Cruz Sentinel goes through the basics, explaining how amateurs can use the systemic console to identify possible planets around other stars. “We want to demonstrate that it’s not just public outreach, it’s a way of carrying out research,” Laughlin adds, and that fusion is what the Net is bringing to exoplanetary studies.
