Today, thanks to some very beautiful cosmology, we think we know quite a bit about the matter content of our universe. The observed universe is, according to these studies, 1 part ordinary matter, 5 parts dark matter, and 14 parts dark energy. One of the interesting gaps in our understanding of this picture, however, is that when we add up all the numbers, we find that we are missing between 30 to 40 percent of the ordinary matter. One possibility for where this matter may be found is in hot (10^6 K) low density gas in the intergalactic medium. At these high temperatures, atoms like oxygen and nitrogen retain a few bound electrons. But because these are heavy elements with a few bound electrons they will absorb only at very high energies. In order to see this absorbtion, you need to look in the ultraviolet or X-ray regime of the spectrum. Since it’s impossible to test this theory from ground-based instruments, this idea has floated around, but never really been verified.
Now there is news today, published in Nature by Nicastro et. a (vol. 433, p.493), that the Chandra space telescope has indeed detected evidence of this absorption and, with admittedly still large uncertainty, the calculations suggest that indeed this indeed makes the calculations for ordinary matter add up.
Nature Discovers Physics
The journal Nature has finally discovered physics! For a while now there have been specialized Nature journals for different disciplines. Now, starting in October 2005, they’ve discovered physics: Nature Physics.
Oh and look what at the list of what they will cover:
* quantum physics
* atomic and molecular physics
* statistical physics, thermodynamics and nonlinear dynamics
* condensed-matter physics
* fluid dynamics
* optical physics
* chemical physics
* information theory and computation
* electronics, photonics and device physics
* nanotechnology
* nuclear physics
* plasma physics
* high-energy particle physics
* astrophysics and cosmology
* biophysics
* geophysics
Clearly not alphabetical and quantum physics is number one!
Four More Pages
Ken Brown suggests the following solution to the Physical Review Letters “problem”:
I think a possibl[ity] is to make it so no one can submit to PRL. Instead the editors/refs can choose to bump your paper up from PRX. Then the PRX paper would be published in full and the PRL would be a short summary(intro and conclusions) with the details left in PRX.
This is a really intriguing idea. There must be something wrong with it, but I can’t see it right now. One small problem, I think, is that as the system is currently set up, when I submit a paper to Phys. Rev. A, there is usually only one referee for the paper and it seems a bit much to put all of the discission making in two peoples hands (one ref, one editor.)
But a Patent Clerk
Yes, as many will have noticed, I’ve gotten a little bit of the Einstein bug lately. Then, on the APS jobs listing the following listing appeared:
Physics Patent Prosecutor
Berkeley Law & Technology Group, LLC
Salary: Open
Location: Bellevue, Washington
Type: Full Time – Experienced
Physics Patent Prosecutor to join a small group of prosecutors in a well-funded, non-firm environment. PhD preferred, though others could be considered. Work activity will involve preparation and prosecution of patent applications in a variety of technology areas, many of which involve emerging areas of physics. The environment is challenging, unstructured and interesting. You will work directly with inventors from conception through issuance. You should have strong fundamentals and enjoy working in a variety of areas, including quantum mechanics, waves and wave propagation, photonics, optics and other related areas. A good portion of the technology involves working with, applying, or developing cutting edge approaches. Emphasis on quality, productivity and training. Minimum of 1+ years of prosecution experience. Send your response and attach a resume’ to . E-mail queries only. No phone calls please.
As many of you may know, recent events in my family have made getting to the great state of Washington a high priority on my list of priorities (hard to imagine that a postdoc has any other priority than getting a tenure track position wherever he or she can possibly get a position, no?) And most times, when I think that this might mean leaving the tenure track bandwagon of physics, I feel rather sad (better to admit your emotions, than to ever become bitter.) But then I see a posting like this, and I remember Einstein, nothing more than a patent clerk, and I think, well anything is possible.
The Happy Physicist
Many have pictures of Einstein on their wall. And rightly so, for the patent clerk who sparked revolutions. Since I’m in quantum computing, I think Einstein might not be the most appropriate person to have on my wall. Indeed, to hear the historians, Einstein wouldn’t even believe in the basics of what I work on (somehow I really doubt this.) So instead, I think I should put a picture of John Bell on my wall. I went looking for a suitable picture and found this article, with a very happy John Bell:
Look how happy he is! Yes, Gloria, being a physicist is glorious.
Got Textbook?
Wikipedia, the open source encyclopedia is a resource I really love. Mostly it’s just hard to avoid letting it take you to a random page and reading. Actually I think encyclopedias are one of the great self-teaching tools for young kids. I recall stories from both Borges and Feynman about devouring encyclopedias as small children.
Now, via Michael Nielsen’s blog, I learn that in addition to all the other wiki(insert word here) there is Wikibooks a collection of free open-content textbooks. So far some of the textbooks are pretty incomplete, but definitely a cool site to watch grow.
Whatcha Wearing Under There?
From a L.A. Times story about how people who fidget a lot are leaner:
Each participant wore a special, high-tech set of underwear, which were rigged with sensors and data loggers originally designed to monitor jet fighter motion. The underwear could track most body movements.
It’s great to see what some people will do all for the love of science!
Emergence
One question people spend a lot of blood, sweat, and tears thinking about is the emergence of the classical world from the quantum world. The real question all these studies must grope with is what is special about the classical world. But what if we ask the following question: what other types of worlds can emerge from the quantum world? Is it possible to think of some artificial setting where a totally bizarre world emerges from the quantum world? I don’t know if I’ve ever seen this: it seems like everything I do gets me to something which is either classical or quantum or in the convex sum of these two theories.
The Wonders Never Cease
Right now I’m at my office, but I’m also vacuuming my home. How am I doing this, you ask? My new Roomba – the robotic vacuum! Already I am thinking of new names for my new robotic friend. This will be needed especially when the Roomba accidentally (can a robot do someting “on accident?”) chews up something it wasn’t supposed to chew up. The coolest thing about the Roomba right now is that when it gets low on power, it returns to its charging station. Now if only it could reproduce…
Four Pages
Recently I have been debating in my head the following question: Does the four page limit for papers in Physical Review Letters squash physics?
Benefits of the four page limit: (1) brevity enforces a focused article, (2) experiemental results can often be described in four pages, (3) you can tell when a paper is submitted to PRL on the preprint server by counting the number of pages.
Problems with the four page limit: (1) brevity means much is left out or compressed to near unreadability, (2) experimental techniques are rarely described in enough detail, (3) the compression to unreadibility means that general readership across the different sections of PRL, one of the supposed goals of the journal, is difficult if not impossible, (4) the papers are often light on citations since it is easier to cut citations to get to the page limits than to cut the content, (5) theories of any complexity are impossible to present in four pages without obmitting or skimming major portions of the work.