Physics
grrlscientist | May 16, 2009tags: science, physics, boiling water into ice, streaming video
This should go into the category: What scientists do when the boss is out of town: This video shows a couple scientists who are "boiling water into ice." Can you describe how they do this? [5:02]
drorzel | May 15, 2009Speaking of conferences (as we were a little while ago), the Female Science Professor has a post on the phenomenon of logos in talk slides:
Do you put your institution's logo in your talks and on your posters at conferences? If you put a logo in your talk, do you put the logo on every slide or just on the title slide? Is institutional logo-ing more common on some continents than on others?
Logos on slides are one of those things that in principle, ought to be annoying. In practice, I'm usually just grateful that they're not using one of the godawful default slide layouts that come in…
rallain | May 14, 2009I think the Mythbusters have a wonderful opportunity for educational outreach. Take this week's episode. One myth was to see if arrows fired from a moving horse penetrated more than arrows fired from a standing position. They first did this with real horses, but they said the data was not convincing.
I am pretty sure they had more than 10 trials recorded (there was a glimpse of the notebook). I would love to see this data and find (or let students find) the standard error of these measurements. This would be a great exercise to see how this whole uncertainty thing works.
As long as I am…
rallain | May 14, 2009Last night was Wednesday, so of course I watched Mythbusters. You never know when a good blogging opportunity will come up. I could talk about the kinetic energy of arrows, but instead let me talk about their episode for next week. I only caught a glimpse of it in the preview. It looks like they are doing something about jumping on a see-saw and launching the other person. It could be this video they are looking at:
EMBED-Extreme Catapulting - Watch more free videos
From my analysis of this video, I found that the likely outcome was a broken board (if it were not fake). Also, if the…
drorzel | May 14, 2009I'm a little surprised that I haven't seen bloggers commenting on Tom Hanks's appearance on The Daily Show, in which he talks about CERN:
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Everything he says is pretty much true, but garbled and exaggerated for comic effect. People at CERN have to be shaking their heads, though. Or maybe they don't bother watching the interview segments...
At any rate, it's not nearly as good as their earlier segment with John Oliver at CERN
The Daily Show…
drorzel | May 13, 2009An example problem from today's lecture:
A sleep-deprived parent is warming a bottle for a midnight feeding. He places a bottle containing 250 ml of infant formula at 275K into 300 ml of water at 320 K. When the two liquids reach equilibrium, what is the temperature of the formula?
Answer: Trick question! While the bottle is warming, he dozes off holding the baby, and by the time they wake up, both bottle and water have cooled to only 288K.
rallain | May 12, 2009Maybe you have seen this trick. Basically, you hold by supporting it with two fingers from the bottom. You then move your hand around to keep it balanced while the stick is vertical. It is really not as hard as it looks. Also, there are two things that can make your job easier. Use a longer stick, or add an extra mass at the end of the stick. Here is a video of me demonstrating this. (I forgot, this also an event in the show Unbeatable Banzuke)
Balancing a Stick Demo from Rhett Allain on Vimeo.
So, how does this work? Let me start with a stick that is mostly vertical and supported by…
grrlscientist | May 11, 2009
What: A public presentation, "Not Even Wrong: The Failure of String Theory & the Continuing Challenge to Unify the Laws of Physics"
Where: Brooklyn Society for Ethical Culture, 53 Prospect Park West (corner of Prospect Park West and 1st Street), Brooklyn, NY [map]
When: Monday, May 18, 7:30 p.m.
Cost: free and open to the public.
Peter Woit is a mathematician and physicist at Columbia University who will discuss string theory and why it is controversial, as well as prospects for new experiments and a better understanding of the mathematical theories used to describe the physical world…
esiegel | May 8, 2009Let's get something out in the open: not all science fiction is scientifically possible. Some of it is possible, but the laws of nature are pretty strict, and they prevent us from doing a number of things that -- in principle -- would be incredible to do. Examples on both sides, please?
You got it. Wall-crawling like Spider-Man? Totally possible. Just graft enough gecko fibers onto a person and not only will you be climbing walls, but also ice, oily surfaces, and even teflon!
Shrink rays? A la Fantastic Voyage? Completely impossible, unfortunately. Protons, neutrons, and electrons are stuck…
drorzel | May 8, 2009It's a nice demonstration of the oddity of the blogosphere that a libertarian political blog has become my go-to-source for thoughtful blogging about physics education. Thoreau had two good posts yesterday at Unqualified Offerings, one on the problems created by breaking down incorrect intuition, and another on the lack of calculus in calculus-based physics texts:
The ostensibly calculus-based introductory physics book by Knight is not really a calculus-based book. Sure, integrals and derivatives pop up here and there, but the vast majority of the problems can be solved without them, and…
drorzel | May 8, 2009Via Michael Nielsen, a page documenting what I really hope is the dorkiest family vacation ever: Project GREAT: General Relativity Einstein/Essen Anniversary Test Clocks, Kids, and General Relativity on Mt Rainier:
In September 2005 (for the 50th anniversary of the atomic clock and 100th anniversary of the theory of relativity) we took several cesium clocks on a road trip to Mt Rainier; a family science experiment unlike anything you've seen before.
By keeping the clocks at altitude for a weekend we were able to detect and measure the effects of relativistic time dilation compared to atomic…
drorzel | May 8, 2009I get sent a lot of publicity material by people hoping I'll mention it on the blog, but because I'm a terrible person, very little of it actually gets used. One thing that shouldn't be allowed to slip through the cracks, though, is the announcement of the program for the 2009 World Science Festival, June 11-14 in New York City.
There's a lot of interesting stuff there. The emails I got specifically mentioned the Opening Gala, which I suspect is likely to be a little more expensive than I'd like. Unless some New York based science magazine were willing to cough up some, let's call it "seed…
esiegel | May 7, 2009I recently got this comment of incredulity on my article about what wiped out the dinosaurs?
I´m sorry. But i don´t believe this. In my opinion they were wiped out by a climatic changing.
And I think it's worth -- with the help of a little math and physics -- looking at what this asteroid impact might have done.
First off, we need to know how massive this asteroid was. This asteroid was about 10 to 12 km in diameter, which is large, but less than 0.2% the diameter of the Earth. It's pretty unremarkable, and makes it a pretty typical minor asteroid. For comparison, this makes it about half…
drorzel | May 7, 2009You might think that Monday's discourse on thermodynamics in the Goldilocks story was the only children's story in which physics plays a role, but that's not true. Physics is everywhere in fairy tales.
Take, for example, the story of Rumpelstiltskin, in which a mysterious little man demands a terrible price for helping a miller's daughter spin straw into gold. This raises the obvious question of exactly how one would go about extracting gold from straw.
The use of the term "spin" might suggest the use of rotational motion-- if the straw were ground up very fine, and mixed with water, it might…
rallain | May 7, 2009Time Warp is this Discovery channel show that makes slow motion videos of stuff. Not too bad of a show (although I already talked about the samurai guy and "waves of energy").
Professor splash is this guy that jumps from really high positions and lands in 1 foot of water (and doesn't die). He was on Time Warp last night. If you are interested in this, I did an explanation of how it works in a previous post.
The Physics of Professor Splash's Jump into 1 foot of water
I haven't watched the whole show yet - but I did TiVo it. If there is any thing interesting to analyze, I will post that…
drorzel | May 7, 2009I was surprised, a few days ago, to see a post from ZapperZ recommending a Wall Street Journal article on quantum entanglement. It was surprising not only because it's weird to see anything in the WSJ that doesn't have an immediate financial connection, but more than that, I was surprised because the article contains a lot of statements that are the sort of thing ZapperZ usually denounces as unforgivable ignorance by journalists who shouldn't be allowed to write about science.
Happily, by sitting on the article for a couple of days, Tom said most of what I would've said, and I was saved…
rallain | May 6, 2009I probably should have included this idea on my "All about science" blog post. Maybe I didn't put it in there because if I talk about what science is you can figure out what it is not.
Science is not math
Science is all about making models. It is true that many current models are mathematical models, but it doesn't have to be that way, and it hasn't always been that way. Think about rubbing a piece of metal with a magnet. It gets magnetized - right? What if you then cut that magnet in half? Then you have two smaller magnets. How can you make a model that explains this phenomena? Yes…
thusspakezuska | May 5, 2009Over at Uncertain Principles, Chad frets about committing physics heresy via a reading of Goldilocks and the Three Bears to his young offspring.
The story may convey a useful moral message, but it's way off base on the physics.
After all, the Papa Bear, being the biggest, presumably has the largest bowl of porridge. Here, the story fits what we know about thermodynamics, as the largest bowl should take the longest time to cool, and thus should be the hottest at any time before the porridge bowls reach thermal equilibrium with their environment.
The description provided of the other two bowls…
rallain | May 5, 2009I just realized that something has been bothering me. It is this KillaCycle - the electric zoom-fast motorcycle that I posted about previously. It clearly is super fast. However there are two claims that seem iffy.
It can be recharged in 4 minutes.
It is recharged by wind power.
It may be possible that these individually could be true - but could it be recharged in 4 minutes by the wind? I am not sure. Let me do some estimations to see if this is possible. What am I starting with:
From the review on gas2.org, uses cordless drill batteries.
Uses 1200 batteries
Produces 500 bhp - not…
drorzel | May 5, 2009As I understand it, the Physics ArXiv Blog is not affiliated with the people who actually run the Arxiv (Paul Ginsparg et al.). Which is probably good, as I'm never entirely sure how seriously to take the papers they highlight.
Take yesterday's post, Diamond Challenges for Quantum-Computing Crown, which is about a paper that asks the question Could one make a diamond-based quantum computer?. It's an interesting idea, and something I wrote about last year, so it seems like a promising topic.
The preprint in question, though, is a little dodgy. It's indifferently proofread, with all sorts of…