Physics
esiegel | May 4, 2011"You still don't get it, do you? He'll find her! That's what he does! That's ALL he does! You can't stop him!" -Kyle Reese, the Terminator
Now that we've all survived Judgment Day, we can stop looking for ways to stop the Terminators, and go back to the search for dark matter. Let's back up a bit, though, and take a look at normal matter first.
As you well know, normal matter here on Earth is always subjected to the force of gravity. You throw something up into the air, and the Earth's gravity always works to pull it back down. In general, something moving under only the influence of the…
drorzel | May 4, 2011It's been a hectic day here, so I haven't had time to do any substantive blogging. I did want to quickly note a couple of stories presenting marked improvements in experiments I've written up here in the past:
1) In the "self-evident title" category, there's Confinement of antihydrogen for 1000 seconds, which extends last year's antihydrogen trapping to times a factor of 6000 longer than the previous record. That's very good, and a good sign for plans to do precision spectroscopy and other such experiments. As always, Physics World offers a nice write-up.
2) As noted in the comments of Monday…
esiegel | May 2, 2011"I have departed from this planet and I have left behind my poor earthly ones with their occupations which are as many as they are useless; at last I am living in the scintillating splendor of the stars, each of which used to seem to me as large as millions of suns." -Jules Massenet
Each star in the night sky, just a distant, shining point of light, holds the same potential as our Sun. The potential for other worlds, for life, for civilization both as we know it and as we can only imagine it. On a clear, dark night, the possibilities seem almost limitless.
Image credit: ForestWander, Summit…
drorzel | May 2, 2011Over in Scientopia, Janet notes an interesting mis-statement from NPR, where Dina Temple-Raston said of the now-dead terrorist:
[O]ne intelligence officials told us that nothing with an electron actually passed close to him, which in a way is one of the ways they actually caught him.
As Janet notes, this would be quite a feat, given that electrons are a key component of ordinary matter. But for the sake of silly physics blogging, let's take this seriously for a moment. Suppose that Osama bin Laden really could make himself utterly devoid of electrons: would that be a good way to hide?
To…
drorzel | May 2, 2011Last summer, there was a fair bit of hype about a paper from Mark Raizen's group at Texas which was mostly reported with an "Einstein proven wrong" slant, probably due to this press release. While it is technically true that they measured something Einstein said would be impossible to measure, that framing is a little unfair to Einstein. It does draw media attention, though...
The experiment in question involves Brownian motion, and since I had to read up on that anyway for something else, I thought I might as well look up this paper, and write it up for the blog.
OK, so what did they do that…
esiegel | April 28, 2011"Listen; there's a hell of a good universe next door: let's go." -e. e. cummings
Sometimes, you just need to take stock of what we know, and appreciate how far we've come. A hundred years ago, we thought the Universe consisted of the stars and nebulae in our Milky Way. We thought Newton's Law of Gravity governed it all, and that the other forces -- electromagnetism and a few weird quantum things -- were all there was.
So why not -- all in one article -- go through the entire history of the Universe, from as early as we can say anything sensible to as late as we can say anything sensible? Let'…
esiegel | April 26, 2011"Science for me is very close to art. Scientific discovery is an irrational act. It's an intuition which turns out to be reality at the end of it -- and I see no difference between a scientist developing a marvelous discovery and an artist making a painting." -Carlo Rubbia, famous and infamous Nobel Prize-winning physicist
Unless you've been living under a rock for the last few years, you're aware that the largest, most powerful physics experiment in the history of the world is currently going on at CERN: the Large Hadron Collider (LHC).
Image credit: CERN.
Colliding protons with other…
drorzel | April 26, 2011This paper made a big splash back in November, with lots of news stories talking about it; it even made the #6 spot on Physics World's list of breakthroughs of the year. I didn't write it up then because I was hellishly busy, and couldn't take time away from working on the book-in-progress to figure out exactly what they did and why it mattered. I've got a little space now between handing the manuscript in last week and starting to revise it (probably next week), so while it's a bit late, here's an attempt at an explanation of what all the excitement was about.
So, what's this about, anyway?…
drorzel | April 22, 2011A few months ago-- just before the paperback release of How to Teach Physics to Your Dog-- Amazon started providing not only their Sales Rank data, but also sales data from Nielsen BookScan. Of course, the BookScan data is very limited, giving you only four weeks, and the Sales Rank data, while available over the full published life of any given book, are presented as a graph only with no way to extract them as a data table. You'd have to be some sort of obsessive nerd to make a quantitative comparison between them.
So, anyway, here's the data I got for How to Teach Physics to Your Dog:
This…
drorzel | April 21, 2011Several people blogged about a new measurement of gravitational states of neutrons done by physicists using ultracold neutrons from the Institut Laue-Langevin in France. I had to resort to Twitter to get access to the paper (we don't get Nature Physics here, and it's way faster than Inter-Library Loan), but this is a nice topic for a ResearchBlogging post, in the now-standard Q&A form:
OK, why was this worth begging people on Twitter to send you a copy? The paper is a demonstration of a sort of spectroscopy of neutrons bouncing in a gravitational field. They showed they could drive…
esiegel | April 20, 2011"You may hate gravity, but gravity doesn't care." -Clayton Christensen
What's the deal with gravity, dark matter, and this whole "lensing" business anyway? You've probably heard that energy -- most commonly mass -- bends light. And perhaps you've seen an image or two like this one to illustrate that.
Image credit: ESA, NASA, J.-P. Kneib and Richard Ellis.
Above is the great galaxy cluster Abell Cluster 2218. But those giant, stretched arcs you see? Those are actually background galaxies that get distorted and magnified by the giant cluster.
As the light leaves its source, the mighty gravity…
drorzel | April 18, 2011 It's been a while since I wrote up a ResearchBlogging post, but since a recent paper forced me to update my "What Every Dog Should Know About Quantum Physics" slides with new pictures, I thought I should highlight the work on the blog as well. Not that you could've missed it, if you follow physics-y news-- it's been all over, getting almost as much press as rumors that some people whose funding will run out soon saw something intriguing in their data. So, in the usual Q&A format:
OK, what's this about? Well, the paper title, "Quantum interference of large organic molecules" pretty well…
jdupuis | April 17, 2011I have a whole pile of science-y book reviews on two of my older blogs, here and here. Both of those blogs have now been largely superseded by or merged into this one. So I'm going to be slowly moving the relevant reviews over here. I'll mostly be doing the posts one or two per weekend and I'll occasionally be merging two or more shorter reviews into one post here.
This one, of Einstein: His Life and Universe, is from March 24, 2008.
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Walter Issacson's 2007 biography of Albert Einstein was one of the best reviewed books of that year, appearing on nearly all the year end lists of…
drorzel | April 15, 2011Regular blogging has been interrupted this week not only because I jetted off to southern MD but because this week was the due date for the manuscript of the book-in-progress. It's now been sent off to my editor, and thus begins my favorite part of the process, the waiting-to-see-what-other-people-think part.
I'm pretty happy with it, though it's a bit longer than it was originally supposed to be. This is no doubt partly due to the fact that I'm too close to the thing at the moment, and can't see the obvious places where I could cut material, but that's why professional editors get the big…
esiegel | April 14, 2011"All of nature begins to whisper its secrets to us through its sounds. Sounds that were previously incomprehensible to our soul now become the meaningful language of nature." -Rudolf Steiner
For millenia, humans have looked to the heavens for answers about the cosmos.
Image credit: ESO/S. Guisard.
And one of the main reasons I write what I do for all of you is to help give you -- as I've said many times -- is an awareness and an appreciation for what we've learned, what we think we know, and how we think we know it.
Which is why I was a little bit confused when I read this article from…
drorzel | April 12, 2011I'm in last-minute-revision mode here, made mroe frantic by the fact that SteelyKid developed a fever yesterday, and had to be kept home from day care. I did want to pop in to note that I will be giving the Natural Science and Mathematics Colloquium at St. Mary's College in Maryland tomorrow, Wednesday the 13th. This will be the "What Every Dog Should Know About Quantum Physics" talk, described for the colloquium announcement as:
Quantum physics, the science of extremely small things like atoms and subatomic particles, is one of the best tested theories in the history of science, and also one…
drorzel | April 8, 2011It's college admissions season, which means a steady influx of high-school seniors thinking about coming here next year, making campus visits. Most of these students sit in on at least one class, to get an idea of what it's like. Which occasionally leads to odd things, but nothing stranger than what just happened: a prospective student just sat in on my junior/senior level elective class on quantum mechanics in the state-vector formalism. I suspect he didn't get a whole lot out of today's lecture, on changing state vectors and operators from one basis to another. In fact, I suspect this might…
drorzel | April 7, 2011A few weeks ago, I gave a talk based on How to Teach Physics to Your Dog for the University of Toledo's Saturday Morning Science program. At that time, their local PBS affiliate recorded the talk, for use on their very nice streaming video site, Knowledgestream.org. My talk is now up, and the video is hopefully embedded below:
I haven't listened to the entire thing, but I watched the first 10-15 minutes, and it's pretty good. the sound is coming from a microphone on my shirt, so you can't really hear any of the audience reaction (I got some good laughs in appropriate places), and in places…
esiegel | April 6, 2011"Although important nuclear physics work was to go on in laboratories such as ours had become - and we had to cut down to a lower energy group - it was not fundamentally opening up new insights on the structure of matter. That required you to be in a higher league." -John Henry Carver
Okay, before we get into speculating, the short answer is maybe. And that's amazing! Let's recap the basics, and bring you up to speed of what could be the Tevatron's last -- and possibly greatest -- hurrah.
Image credit: Fermi National Accelerator Laboratory, a.k.a. Fermilab.
This is the Tevatron. For decades…
drorzel | April 2, 2011Thursday's post about the troubles of biomedical scientists drew a response from Mad Mike saying that, no, biomedical science Ph.D.'s really don't have any career options outside of academia, and pointing to Jessica Palmer's post on the same subject for corroboration. Jessica writes:
This is something I've tried to explain many times to nonscientists: most of the esoteric techniques I mastered during my thesis aren't useful outside a Drosophila lab. They're not transferable to any other field of biology, let alone any other scientific or nonscientific profession. Those skills I picked up on…