Astronomy
drorzel | March 15, 2008Paul Krugman is now a famour economist, but many years ago, he was "an oppressed assistant professor, caught up in the academic rat race." So, he did what any good academic would do in that situation: he wrote a silly paper to cheer himself up. In this case, a paper discussing the issues that arise in interstellar trade because of realtivistic effects.
It's a brilliant bit of silliness. It's hard to pick a favorite bit, but this is pretty good:
To conclude this section, we should say something about the assumption that the trading planets lie in the same inertial frame. This will turn out to…
drorzel | December 4, 2007Physics World has an interview with Alastair Reynolds, who was trained as an astrophysicist but is now a full-time SF author:
How does your physics training help with your writing?
Less than people imagine. I think the most important attribute for a science-fiction writer is to be fascinated by science -- in all its manifestations. It's not necessary to be able to understand all the details, but just to be inspired and stimulated. Most of the ideas that have fed into my writing have come from reading popular articles on subjects far away from my own very limited specialization, such as…
drorzel | November 15, 2007Via email, a plug for the newish site 60 Second Science, which is a project from Scientific American built around a podcast featuring one-minute explanations of, well, science.
The email was specifically highlighting their new project, a set of video podcasts going by the name of Instant Egghead. The first video (also the only one so far) is a one-minute explanation of how we know there's dark matter using items found in editor George Musser's office.
It's a well-done video, and a nice explanation of galaxy rotation curves using coffee, crumbs, and a CD. I do have one quibble about the…
drorzel | November 9, 2007 I have a bunch of science news sources in my RSS feeds, and every evening, I scan through the accumulated articles to try to figure out what physics-related stories there are to talk about. Sometimes, it's hard to find anything, but other days, you get stories that lead to four press releases at EurekAlert (one, two, three, four), a write-up at Backreaction, a Physics World news story, and a Dennis Overbye piece in the New York Times. I guess I really ought to say something about the new results from the Pierre Auger Observatory, published this week in Science (Science 318, 938 (2007), if…
drorzel | September 27, 2007The New York Times is commemorating the 50th anniversary of Sputnik with a huge clump of articles about, well, space. I'm a little surprised that I haven't seen more said about these-- they turned up in my RSS feeds on Tuesday, but I've been both busy and slightly ill, and haven't gotten around to blogging them until now. I guess it's further evidence that space is no longer inherently cool. That, or there are just too many damn biologists on my blogroll.
Anyway, there's a bunch of retrospective material that I didn't really bother with, along with four pieces with more of a current…
drorzel | September 26, 2007Physics World has a somewhat puzzling news article about the solar system:
Physicists have known for some time that the motions of Pluto and the inner planets are chaotic. This means that a small external force on a planet could, over time, cause a major change in the position of the planet within its orbit. Although no planets are likely to collide or be ejected from the Solar System anytime soon, the chaos means that the orbits of these planets cannot be forecasted with any long-term reliability.
Whether the orbits of the gas giants are chaotic, however, is less certain -- some computer…
drorzel | September 20, 2007I'm in a Department of Physics and Astronomy, so several of my colleagues are astronomers. We also have a rather nice on-campus observatory, used for student research projects.
Unfortunately, the combination means that we have a running argument with the rest of the campus regarding lights. The rather nice observatory is basically useless if there are big bright lights on all around it all the time, but various other groups want to have bright lights on all the time: Athletics wants the lights on the football field on so they can run night practices and intramurals; Campus Safety wants more…
drorzel | September 15, 2007Speaking of science explanations in SF, or at least science explained by SF authors, there's a very nice history of dark matter at SFNovelists.com by Mark Brotherton (via Tobias Buckell):
The story of dark matter starts back in the 1930s with Fritz Zwicky, a brilliant but difficult Caltech astronomer, who was studying galaxy clustering. Galaxies group together, apparently under the force of gravity, and between Newton and Einstein, humans seem to have a pretty good idea of how gravity works. There's a very general relationship between gravity, speed, and size, that governs everything from the…
bergman | September 8, 2007I remember the last time I saw the milky way. I was at my aunt's house in the foothills of the Sierras, and late at night the dense river of stars emerges. But that is still not the true milky way, or so I hear. And, in more urban areas, the detritus of our incandescent society reduces the night sky to an inchoate glow. This article in the New Yorker talks about the poorly designed night time illumination that has resulted in our current situation, and what can be and is being done about it.
(via Slashdot)
bergman | August 31, 2007If you're on the west coast tonight and are willing to stay up late or wake up early, you have the chance to see the Aurigid meteor shower. This shower is fairly unique because it arises from a comet with a period of around 900 years. Some people have even claimed that there's a chance this could be spectacular, but these predictions are often wrong. After the disappointing Perseids, I'd love to be able to stay up for this one, but I'm still on the east coast. Ah well. Maybe some other shower.
bergman | August 25, 2007For those of you willing to stay up late, there will be a total eclipse of the moon on August 28 visible to various extents over most of the western hemisphere and some of east Asia. The show is a little late for me (some might call it early) as I'm on the east coast right now, but if you're up for it, enjoy. After the jump are two photos I took of a total lunar eclipse on 10/27/04:
drorzel | August 13, 2007I am sorry to report the passing of Ralph Alpher, of the famous "Alpher-Bethe-Gamow" paper. I don't know many details, but he's been in poor health for some time, so this is sad but not surprising news.
Ralph Alpher was an astrophysicist and cosmologist whose thesis work with George Gamow on the origin of the universe was a critical early step in the development of the "Big Bang" theory. Alpher predicted the existence of the cosmic microwave background, and estimated its temperature (at 5K, not far from the correct value of 2.7 K) in 1948, nearly two decades before it was detected by Penzias…
drorzel | July 12, 2007There's a new paper in Nature announcing the detection of water vapor in the atmosphere of a "hot Jupiter" orbiting a distant star. There's also a story on Physics Web and a press release from the Spitzer Telescope group, if you'd like some stuff you can read without a subscription to Nature.
The idea here is that the planet passes between its star and Earth every couple of days, causing a dimming of the light from the star. The researchers looked at the first part of that dimming, which is when the light is passing through the edge of the atmosphere, and measured the amount of light in a few…
drorzel | July 3, 2007There have been a number of true and non-silly stories about astronomy and cosmology recently, which I'll collect here as penance for the earlier silly post:
Some theorists at Penn State have constructed a Loop Quantum Gravity model that they claim allows for an oscillating universe with no singularities. In one of those psychology-of-the-press moments, the PSU press release accentuates the positive, with the headline "What happened before the Big Bang?" Meanwhile, the IOP Physics Web news item goes negative: "'Cosmic forgetfulness' shrouds time before the Big Bang" (referring to the model…
drorzel | July 3, 2007WASHINGTON, DC (UP News Service)-- In a move that supporters say shows sensitivity and compassion, President Bush today commuted the sentence of the planet Pluto, which was demoted to a "dwarf planet" by the International Astronomical Union in August of 2006. Under the President's new order, Pluto will once more be regarded as a full-fledged planet, though he left unchanged the part of the decision in which the astronomical object must share its name with a cartoon dog.
"Pluto's crimes have been well-documented," said the President in a short statement from the Oval Office, citing in…
drorzel | June 29, 2007Steinn checks in from his Mediterranean vacation with not one, not two, but three reports from the conference on Extreme Solar Systems, and a hint of maybe more to come.
The big news here, as far as I can see, is that they're starting to find more low mass planets, and more planets with long orbital periods. These are both the result of technical improvements-- the sensitivity of the planet-finding techniques has improved as people get more practice, enabling more low-mass detections, and as Steinn puts it, "things are piling up at multi-year periods as the searches go on for long enough to…
drorzel | June 12, 2007Clifford Johnson is pointing to a pair of stories about extrasolar planets. One is a news piece about the "flood" of new discoveries, and the other is a Top 10 list from space.com (warning: irritating web design).
This provides a good excuse to roll out a blog suggestion from Ron Walsworth, who pointed out a possible connection to the ultra-stable lasers that Jun Ye and Jim Bergquist talked about on the first day of last week's conference. He suggested that, in the future, these ultra-stable lasers may be useful not only for comparing clocks on Earth, but as a crucial reference to help detect…
drorzel | May 25, 2007Courtesy of EurekAlert:
physicists Lawrence Krauss from Case Western Reserve University and Robert J. Scherrer from Vanderbilt University predict that trillions of years into the future, the information that currently allows us to understand how the universe expands will have disappeared over the visible horizon. What remains will be "an island universe" made from the Milky Way and its nearby galactic Local Group neighbors in an overwhelmingly dark void.
You can always count on astrophysics to brighten your day.
Or, if you'd prefer something actually amusing for your Friday blog-reading, you…
drorzel | May 16, 2007One of the fun things about EurekAlert is that it allows you to trace the full life cycle of the publicization of science in a way that used to be impossible for a regular person. For example, take the recent "Ring of Dark Matter" story.
First, there's a rumor of a result. This first stage lasts about a week, and if all goes well, it manages to generate a little buzz, and maybe even some divination.
The rumor, warmed by the buzz, will then hatch, giving rise to a press release. Dependning on the species, you may get two, and for highly collaborative research, you can generate even more.
In…
drorzel | May 7, 2007Over in LiveJournal Land, James Nicoll is pining for the good old days:
I'm going through one of my "I would kill for some new SF" phases, SF in this case being defined in a narrow and idiosyncratic way. In particular, I want the modern version of those old SF stories where SF writers, having just read some startling New Fact [Black holes could be very small! Mercury isn't tide-locked! The Galilean moons are far more interesting than we thought!], would craft some thrilling tale intended to highlight whatever it was that the author had just learned.
I suspect this is mostly due to James's…