Physics
pontiff | October 20, 2009Two notes on chairs. Michael Green is the new Lucasian chair of Mathematics replacing the esteemed Stephen Hawking. Green helped sparked the great optimism in string theory by discovering with John Schwarz the Green-Schwarz anomaly cancellation mechanism.
Elsewhere, the Perimeter Institute has named ten new distinguished research chairs, among them a host of the quantum computing afflicted:
Dorit Aharonov is a Professor in the Department of Computer Science and Engineering at Hebrew University in Jerusalem. She has made major contributions to the theoretical foundations of quantum…
jstemwedel | October 19, 2009Over at Starts with a Bang, Ethan Siegel expressed exasperation that Nature and New Scientist are paying attention to (and lending too much credibility to) an astronomical theory Ethan views as a non-starter, Modified Netwonian Dynamics (or MOND):
[W]hy is Nature making a big deal out of a paper like this? Why are magazines like New Scientist declaring that there are cracks in dark matter theories?
Because someone (my guess is HongSheng Zhao, one of the authors of this paper who's fond of press releases and modifying gravity) is pimping this piece of evidence like it tells us something.…
esiegel | October 19, 2009If people around you aren't going anywhere, if their dreams are no bigger than hanging out on the corner, or if they're dragging you down, get rid of them. Negative people can sap your energy so fast, and they can take your dreams from you, too.
--Earvin "Magic" Johnson
As far as science goes, we all have our own dreams. For me, it's to understand the largest scales in the Universe: the most massive structures, the highest energies, and the earliest times of existence.
Particle physicists are also after understanding the Universe at its highest energies, and that's one of the primary goals…
esiegel | October 15, 2009
All of this has happened before, and it will all happen again. --Peter Pan
Much like any new venture where the outcome is uncertain, there are a lot of fears surrounding the LHC. And I know, because it occasionally shows up in my comment threads, in my inbox, or in my office.
Could it form a black hole and destroy Earth? Could we somehow do something in the future that would destroy the past? Or is it just generally unsafe?
The answers to these questions are no, no, and no. The first question -- about creating a black hole and destroying Earth -- requires that we apply the laws of…
drorzel | October 15, 2009I gave a guest lecture this morning in a colleague's sophomore seminar class about time. She's having them look at time from a variety of perspectives, and they just finished reading Longitude, so she asked me to talk about the physics of clocks and the measurement of time.
I've long considered using "A Brief History of Timekeeping" as the theme for a general education course-- there's a ton of interesting science in the notion of time and timekeeping. This was just a single class, though, so I didn't go into too much detail:
A Brief History of Timekeeping
View more presentations from Chad…
drorzel | October 15, 2009I was surprised to see Tom linking to a site claiming a superconductor at 254K. Not because the figure isn't newsworthy, but because somebody sent me this about a week ago, and I decided not to link to it. It's absolutely dripping with kook signifiers.
The two biggest things tripping my kook alarm are:
1) I've clicked around a bit, and there don't seem to be any links on the site to any external page. They have a whole set of claims of dramatic breakthroughs in the transition temperature for their superconducting materials, a new one every couple of months, but no links to research papers, or…
drorzel | October 14, 2009In the time that I've been at Union, I have suffered a number of lab disasters. I've had lasers killed in freak power outages. I've had lasers die because of odd electrical issues. My lab has flooded not once, not twice, but three different times. I've had equipment damaged by idiot contractors, and I've had week-long setbacks because the temperature of the room slews by ten degrees or more when they switch the heat on in the fall and off in the spring. I had a diode laser system trashed because of a crack in the insulation on a water pipe, that exposed the pipe to moist room air, leading to…
pontiff | October 14, 2009You all scoff at me for subscribing to the RSS feed http://www.hasthelhcdestroyedtheearth.com/rss.xml but on Oct. 12 it told me
NO AND NOR WILL IT IN 2012
Aha! What will this do to the sales of 2012 end of world books? (Crap, yeah you're right it will probably make them go up.)
drorzel | October 14, 2009Both Physics Buzz and the X-Change Files are noting the Imagine Science Film Festival starting tomorrow in New York City. As the Buzz notes:
This is only the film festival's second year, but it's already attracted the attention of major sponsors. Last year the journal Nature co-sponsored the festival, and this year the American Association for the Advancement of Science, publisher of rival journal Science, has taken the helm. Maybe it's because of the festival's unique approach to the genre of science film.
Unlike what you can expect to see on PBS NOVA or the Discovery Channel, these films…
rallain | October 13, 2009The last time I looked at this projectile motion lab, I was confused. My different methods for measuring the launch speed of the ball were not even close to being consistent. So, I am bringing out the big guns - video. I made a video of the ball shot both horizontally off the table and vertically. No point posting the whole video (unless you really need it), but here is a screen shot of what the setup looked like.
These videos were made with my flip video camera, it doesn't have adjustable shutter speed so that there is some blur. Also, notice the carbon paper on the floor. This is so…
drorzel | October 13, 2009The abbreviation here has a double meaning-- both "Open Access" and "Operator Algebra." In my Quantum Optics class yesterday, I was talking about how to describe "coherent states" in the photon number state formalism. Coherent states are the best quantum description of a classical light field-- something like a laser, which behaves very much as if it were a smoothly oscillating electromagnetic field with a well-defined frequency and phase.
Mathematically, one of the important features of a coherent state is that it is unchanged by the photon annihilation operator (in formal terms, it's an "…
grrlscientist | October 12, 2009tags: soap bubble science, physics, science, surface tension, Keith Johnson, streaming video
This is a really interesting video about soap bubbles -- how they work and what we can do with them. The slow motion footage of a bursting bubble is especially interesting to watch.
rallain | October 12, 2009I put together this short presentation on fake videos for a class. What the heck, I will also put it online so that maybe some other people can use it. So, here it is. I have it in many forms. First, a video of me going through the talk. Then I have the keynote and PowerPoint files with the movies. Feel free to use it as you see fit. You might want to modify some of the files, I have no problem with that.
How to spot a fake video from Rhett Allain on Vimeo.
And the other versions:
Keynote (fakevideos.key - 46.1 MB) - this has the movies embedded
PowerPoint (fakevideos.ppt - 2.6 MB) -…
drorzel | October 12, 2009It's Adopt-a-Physicist time again, and I've been "adopted" by three classes: Susan Kelly's class at Blind Brook High School in Rye, NY; Lisa Edwards's class at Hickory High School in Hickory, NC (insert your own Hoosiers joke); and Suprit Dharmi's class at Terrill Middle School in Scotch Plains, NJ. So here's a shout-out to all of them, and their students.
Amusingly, my fellow adoptees include at least one occasional commenter on this blog, and somebody I know from NIST. Small world.
drorzel | October 12, 2009The Digital Cuttlefish looks at the Archie comics, and waxes poetic:
Two paths play out in a comic book,
When Archie walks down memory lane
"The road not taken" is the hook;
So now, the writers take a look
And re-write Archie's life again,
This time with Betty as his bride;
Veronica the woman spurned,
Who once upon a time, with pride,
Was wed to Archie. Thus allied,
They lived while many seasons turned.
Why am I commenting on this, given that what little I know about Archie I learned from The Comics Curmudgeon and Chasing Amy? Because he goes on to talk about the Many-Worlds Interpretation…
rallain | October 11, 2009The other myth the MythBusters looked at last week was the phrase "knock your socks off" (along with the dropping and shooting a bullet myth). But before that, let me complain.
Maybe it is just me, but I totally cringe when these guys use the word 'force'. Force probably isn't the best term to use to describe a collision especially when you are talking about one of the objects. "oh, we will just give this object some more force to impact with that other object". Force is not a property of an object, but rather an interaction between two objects. When two things collide, you really need…
drorzel | October 10, 2009In the last couple of weeks, I have suddenly acquired a rather full travel schedule for the coming months. The odd thing is that none of these trips are book-publicity junkets-- they're all basically professional-type appearances, several of them taking place before How to Teach Physics to Your Dog hits stores on December 22. My schedule so far:
October 24, Waterloo, Ontario: I'm a late addition the Quantum to Cosmos Festival, as a panelist for a discussion on "Communicating Science in the 21st Century." This will also be webcast and recorded for television (my itinerary includes a "Speaker…
rallain | October 9, 2009If you didn't catch the latest MythBusters (yeah! new episodes), they did something straight from the physics textbooks. Just about every text has this example of shooting a bullet horizontally and dropping a bullet from the same height. The idea is that they should hit the ground at the same time. No one but the MythBusters could actually show this demo with a real gun.
The Physics
I am going to do some calculations, but I want to first write about the physics that accompanies this idea (and you can actually do it your self without the gun). What physics principle does this demo show?…
pontiff | October 9, 2009A physicist at CERN has been arrested for suspicions of ties to Al Qaeda. Don't worry I already checked www.hasthelhcdestoryedtheearth.com and www.hasthelargehadroncolliderdestroyedtheworldyet.com and both assured me that, so far, Al Qaeda has not managed to generate black holes that would consume the planet.
But what a great opportunity to muse along with a New York Times article..
"His work did not bring him into contact with anything that could be used for terrorism," said the statement from the center, whose formal name is the European Organization for Nuclear Research.
Like, what…
pontiff | October 9, 2009James Simons, he of the Chern-Simons form, and also, of late, from the hedge fund Renaissance Technologies Corporation, is retiring. The infamous Medallion fund was up last year, apparently, only a mere 80 percent.
Quite a feat, turning
into