02/26/2004
A Constant Constant?
A few days ago I saw a news item stating that NASA has found the cause of the detached foam that resulted in the Columbia shuttle disaster. It seems there were voids between the foam and the rocket body to which it was attached. Leakage of either liquid nitrogen or hydrogen, I forget which, into these voids, and the subsequent expansion of the liquefied gas, is thought to have led to an explosive detachment of the foam. Let’s hope that the process for applying the foam can be improved and the shuttle flights resumed. One future flight that has been canceled was to have serviced the Hubble Space Telescope in 2006.
After President Bush announced the proposed manned mission to Mars, NASA decided to cancel the servicing flight and sacrifice the Hubble. Like many others, I’m very disappointed that the quest for Mars has doomed the Hubble Space Telescope to an early demise. However, I was heartened to read in a news item by Andrew Lawler in the February 6 issue of Science that Senator Barbara Mikulski has won a review of the decision. Harold Gehman, leader of the investigation into the Columbia Space shuttle disaster, will carry out the review.
Our editor, Brian Trumbore, sent me a couple of items from the February 21 editions of the Washington Post and the New York Times on some very important recent results reported by workers employing the Hubble telescope. The Hubble data seem to confirm once again that Albert Einstein, even when he “blundered”, was right on the money. We’ve talked before about his so-called “cosmological constant” but let’s revisit it to set the stage for these recent findings. When Einstein proposed this cosmological constant, it was thought that the universe was a static place. Einstein was concerned that, with all those stars out there, gravity should take over and the attraction among all the celestial bodies should result in the collapse of the universe.
So, what was keeping these bodies apart? Einstein’s reasoned that since the universe was not collapsing, there must be some kind of force pushing it apart just enough to keep it stable. Therefore, he introduced into his equations a fudge factor, his cosmological constant, which represented a force that pushes against the gravitational force pulling things together. Einstein suggested that this cosmological force was essentially unchanged throughout the history of the universe. This was back in 1917 when the universe was a static place.
But in 1929 Edwin Hubble showed that, far from being static, the universe was expanding and the Big Bang explanation followed. Einstein decided that his cosmological constant was not needed and called it his greatest blunder. Then, just a few years ago, came evidence that not only is the universe expanding but also that the expansion is speeding up. We began hearing about “dark energy”, something working against gravity pushing things apart. The cosmological constant was back and Einstein’s “blunder” was far from a blunder. We’ve been over this road before, so what’s new that requires further consideration?
Remember that Einstein suggested that the cosmological constant was unchanged throughout the history of the universe. Now, with the rebirth of the constant, the question became “Was Einstein right, has the cosmological constant been truly constant or is it changing?” The recent work of Adam Reiss and his coworkers at the Space Telescope Science Institute in Baltimore and at the University of California at Berkeley provides data related to this question. They used the Hubble Space Telescope to look for supernovae, exploding stars. According to the Times article, by James Glanz, they found 42 new supernovae. Some of these were among the most distant supernovae ever seen, dating two-thirds of the way back to the Big Bang.
According to the Post article, by Rob Stein, 16 of these supernovae were studied in detail insofar as the properties of the light they emitted is concerned. It is from such studies that the existence of dark energy was found. Since the light emitted by these supernovae originated over a wide range of times in the past, it is possible to calculate whether the cosmological constant varied over billions of light years. Why concern ourselves with how this cosmological constant varies?
It makes a big difference in our future, or at least the future of our universe. If the cosmological constant is increasing over time, it might become so strong that we have a “Big Rip”, in which galaxies and stars and maybe even atoms are eventually ripped apart. On the other hand, if the cosmological constant is decreasing, the universe may stop expanding and end up collapsing in a “Big Crunch”.
Einstein’s hunch was that the constant was indeed constant. Sure enough, the Hubble telescope data gathered so far makes it look like Einstein was right. The cosmological constant seems not to have varied much if at all over time. If this conclusion is correct, it looks like our universe will just keep expanding forever. If there is still an Earth, its sky will grow darker and darker until nothing is visible. It will be a cold and lonely place.
Naturally, astronomers will be anxiously searching for more supernovae to check these first results. Obviously, the demise of the Hubble telescope clouds the outlook for any prolonged effort along these lines. It’s no wonder that Senator Mikulski got a standing ovation when she appeared in Baltimore at the aforementioned Space Telescope Science Institute after the decision to reevaluate the Hubble situation. Considering the terrible start of the Hubble mission caused by the improper grinding of the telescopes lens and then the Shuttle mission to correct the problem, it’s amazing how that instrument has changed our view of our universe.
As I’m typing this I look out on our little bay and the fishermen going out in their boats. Fishing requires a lot of patience. Perhaps we should be more patient in our quest for a manned trip to Mars and allow the Hubble to continue to fish the universe for supernovae and all sorts of other oddities that will amaze and confound us.
Totally unrelated to science, patience is something that our nephew Bob needed recently when we went out to a nearby golf course. It was the first time I’ve been golfing since my kidney surgery last September. Bob had to bide his time while I plunked no fewer than a dozen golf balls in the numerous bodies of water that decorated the course. My score was indeterminate, what with picking up on a hole or two and finding it difficult to remember the large number of strokes on any given hole.
Later, my wife and I joined Bob and his wife Brenda on a trip up to what must be the biggest flea market in the world in Ft. Myers. Normally, I detest any kind of shopping. However, I managed to purchase 50 pre-owned golf balls for the paltry sum of $7.55 and a 2-metal for $25. I figure that the 2-metal might replace my borrowed driver, the face of which seems to have a negative slope based on the trajectory of my drives into the water. And 50 golf balls should suffice for at least a couple of rounds. If not, I will probably give up the game forever!
Finally, a few words about birds of the non-golfing variety. Yesterday, I counted no less than 26 pelicans gathered around a fisherman cleaning his catch on the marina outside our condo. I can report that the pelican is not an endangered species. I’m not sure about the status of the muscovy duck but it seems to have an appreciation for Cole Porter. The Naples Concert Band gave a concert in the park here on Marco Island and during a melody of Cole Porter tunes, this quite large duck flies up on the basket (basketball) bordering the covered shelter housing the band and audience. The duck, silhouetted against the sky, stayed for the Porter medley, swaying its head in time with the music. It joins the heron that I’ve reported standing at the water’s edge at 6 AM looking at the moon as one of those birds that I fantasize appreciates the finer things in life.
Allen F. Bortrum
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