Physics
drorzel | May 6, 2014We had a couple of weeks of unplanned hiatus due to sick kids and day care closures, so the superstitious among you might've thought we would never get to the 13th episode of Encertain Dots. Rhett and I are scientists, though, so we powered through:
Given the time of year, this is mostly about end-of-academic-year stuff: exams, intro course curricula, and undergrad research. The undergraduate research symposium I mention a few times is the Steinmetz Symposium, a Union tradition that will happen for the 24th time this Friday. This cancels a day of classes, which is a little annoying, but it's…
esiegel | May 6, 2014“He who loves practice without theory is like the sailor who boards ship without a rudder and compass and never knows where he may cast.” -Leonardo Da Vinci
One of the great tools that theorists use in their arsenal is the reductio ad absurdum, or the notion that if you can prove that the acceptance of a scientific theory leads to an unacceptable prediction known to conflict with experiment. But there's a catch.
Image credit: University of Iowa.
You see, if it's an experiment that hasn't been rigorously performed before, you must actually perform it, no matter how ridiculous the…
drorzel | May 6, 2014Last week's talks were using sci-fi space travel as a hook to talk about relativity, and my original idea for the talk was to explain how faster-than-light travel ultimately ends up violating causality. Some observers will see effects happening before the events that cause them, and that's just weird. In How to Teach Relativity to Your Dog, the illustration I use is a stationary dog watching a cat moving by at half the speed of light and a space alien zipping past at four times the speed of light. In that scenario, the dog can hand a water balloon to the passing alien to soak the cat, and…
drorzel | May 3, 2014Below you'll find the slides from my Physics Day presentations at Space Center Houston, embedded via SlideShare. I was doing the TED-style minimal text thing, so they're probably not all that comprehensible on their own.
The event was supposed to have a pop-culture connection, so I decided to use space travel and extrasolar planets as a hook for talking about relativity, thus all the movie images near the beginning. The original idea I had was to look at different fictional ways of evading the ban on faster-than-light travel, but they wanted something more in the half-hour range than the hour…
esiegel | May 2, 2014“The atoms become like a moth, seeking out the region of higher laser intensity.” -Steven Chu
Sure, lasers are fascinating entities. By stimulating the right medium with the right conditions, you can induce the stimulated emission of radiation of the same exact wavelength in the same exact direction over and over again.
Image credit: Q-LINE Laser pointers, via Wikimedia Commons user Netweb01, under a c.c.-by-3.0 license.
But is there a limit to the amount of energy that can be produced by a laser? And if so, what is that limit, and might it be overcome by future technological advances, or…
drorzel | May 2, 2014My Thursday presentation here in Houston went well, though it was a pretty small crowd. I'll be doing it again today before running to the airport to get home. I didn't really have an opportunity to do shameless self-promotion regarding the new book, but I did get a copy of the official cover for it, which you'll see above if you're looking at this on the blog, or below if you're reading via RSS.
I don't have a very detailed schedule for the rest of the process, but the target on-sale date is in early January 2015. Which probably dashes my dream of getting on the Colbert Report, but I'll…
drorzel | May 1, 2014One of the pop-physics books I've read recently was Amanda Gefter's much-discussed Trespassing on Einstein's Lawn. I was going to post a review of it back in March, but literally the day I was planning to write it, I got email from an editor at Physics Today asking if I had any books I'd like to review for them. So it ended up there instead of here:
Amanda Gefter’s Trespassing on Einstein’s Lawn comes with a super-sized subtitle: “A Father, a Daughter, the Meaning of Nothing, and the Beginning of Everything.” It’s a mouthful, but also rather fitting for a book that manages to be many things…
drorzel | April 30, 2014I had hoped to have another post or two scheduled for the end of this week, but The Pip got some kind of stomach bug, and threw everything into disarray. And tonight, I'm flying to Houston to give a couple of talks as part of Physics Day at Space Center Houston. Life being what it is these days, I'm still fiddling with the talk, so I don't have time to get any more big blog posts done.
If you're in the Houston area and free in the middle of the day Thursday or Friday, come by the Space Center-- I'm talking at noon both days. If you're not in Houston, or not free at lunchtime, well, I'll…
drorzel | April 29, 2014Before going to the playground Saturday to investigate non-intertial frames, SteelyKid and I went over to campus to do some experiments in relativity. Galileian relativity, that is:
What you see here is SteelyKid sitting on a rolling lab cart with a camera bolted to it. She throws a ball up in the air a couple of times with the cart at rest, then I start pushing it across the room, and she tosses the ball a few more times. You can see from the video that, other than the motion of the background, the two cases look very similar.
This is a demonstration of the principle of relativity, which…
drorzel | April 28, 2014The Schenectady JCC, where SteelyKid and The Pip go to day care, has a playground with a merry-go-round on it. How this hasn't been sued out of existence, I have no idea, but it's a great boon to a physics professor. I've used it before to talk about angular momentum, but this weekend I enlisted SteelyKid's help to make a video illustrating a different sort of physics with the merry-go-round, a camera, and a tennis ball:
As you can see in the video, when the merry-go-round isn't moving, the ball rolls straight, but when it's spinning, the ball follows a curved path. This is a striking…
drorzel | April 28, 2014Back when the first episode of the Cosmos reboot aired, somebody put together a composite of the cartoon people who flashed on screen, and we played a guessing game on Twitter. The image above is from a blog post by Meg at True Anomalies, and I think it was probably her, but the ephemeral nature of Twitter makes it annoying to track down the original discussion.
Anyway, we collectively got four of the five right: ibn al-Haytham in the upper left, Annie Jump Cannon in the middle top, Isaac Newton on the lower left, and William Herschel on the lower right. Well, five of six, if you include…
drorzel | April 26, 2014While I'm complaining about statisticulation in social media, I was puzzled by the graph in Kevin Drum's recent post about college wage gaps, which is reproduced as the "featured image" above, and also copied below for those reading via RSS. I don't dispute the general phenomenon this is describing-- that the top 10% of college grads earn way more than the average, and the bottom 10% way less, and somewhat less than high school grads-- but I'm baffled about what was done to generate this graph.
Specifically, I'm puzzled by the vertical axis, which is labeled "Real hourly wage (natural log)."…
carlyo | April 25, 2014
Guest Blog By Lek KadeliActing Assistant Administrator in the U.S. Environmental Protection Agency's (EPA) Office of Research and Development (ORD)
Each spring around the same time that so much of the country is swept up in the “madness” of amateur basketball tournaments, a dedicated team of employees at the U.S. Environmental Protection Agency are finishing up preparations to host student teams for another hard-fought college challenge: EPA’s P3 student design competition for sustainability.
While participants may not grab national headlines, the long-term benefits of their efforts have the…
drorzel | April 24, 2014The finalists for the 2014 "Flame Challenge" have been selected, three written entries and three visual entries. None of these is my entry, alas, but it was worth a shot.
I watched the videos last night, and it was sort of interesting to compare what ended up working well with the test audience of 11-year-olds to the comments that I got. The main difference between what I did and what got picked wasn't so much in the use of unfamiliar words (the thing that generated comments on my post), but in the use of 11-year-old humor. (To be honest, I kind of hate one of them, because it overdoes the…
esiegel | April 23, 2014“Don’t gain the world and lose your soul;
wisdom is better than silver or gold.” -Bob Marley
Going back to ancient times, it's hard to think of a more commonly coveted element than gold. In fact, trying to transmute other elements into it was perhaps the holy grail of the pseudoscience of alchemy, the forerunner of modern chemistry.
Image credit: National Etruscan Museum at Villa Giulia, of Etruscan Gold, via flickr user HEN-Magonza, at http://www.flickr.com/photos/hen-magonza/4256649637/.
Yet, when was the last time you thought about where elements like gold actually came from? It's true…
catdynamics | April 21, 2014Julia is a nifty new language being developed at MIT
I stole this plot from github, it shows Julia's current performance on some standard benchmarks compared to a number of favourite tools like Python, Java and R. Normalized to optimized C code.
And, there, in a single plot, is why Real Programmers still use Fortran...!
esiegel | April 17, 2014“Other than the laws of physics, rules have never really worked out for me.” -Craig Ferguson
When you think about the Standard Model of particle physics, you very likely think about all the matter, energy, particles, antiparticles, forces and interactions of the Universe. And you might legitimately worry that this is all there is.
Image credit: Fermilab, modified by me.
Never fear; it can't be! The Standard Model may be wonderful for what it does predict, but we know with absolute certainty that it can't be everything.
Image credit:the BICEP2 collaboration, via http://www.cfa.harvard.edu/…
drorzel | April 17, 2014As I've mentioned here before, I do a lot of work these days in my local Starbucks. This is slightly ironic, as I don't like coffee-- instead, I order tea, which I put in an insulated travel mug. I tend to get the tea, carry the mug back to the table, and let it steep while I boot up the laptop, then pull the teabags out. I get a hot water refill after I finish the first mug, and take it over to campus if I'm going in that day, and those generally carries me through the morning.
At some point, I noticed that when I had the cap on, I tended to end up with a small puddle of liquid next to the…
esiegel | April 16, 2014“Mr. Burns: Smithers, hand me that ice-cream scoop.
Smithers: Ice-cream scoop?
Mr. Burns: Damn it, Smithers! This isn’t rocket science, it’s brain surgery!” -The Simpsons
I bet you're one of those people who hears a term like "nuclear physics" and thinks that's hard stuff, way over your head. But in many ways, it's the easiest of all physics branches: if you can count protons and neutrons, you can do nuclear physics!
Image credit: Plasma Physics at University of Helsinki, via http://theory.physics.helsinki.fi/~plasma/lect09/12_Fusion.pdf.
Well, nuclear fusion is the process that powers…
drorzel | April 16, 2014The last couple of days have been ridiculously hectic, but Rhett and I did manage to record another episode of Uncertain Dots, our twelfth:
This time out, we talk about labs, undergrad research, kids doing chores, weather, student course evaluations, and I didn't really rant about superheroes. Relevant to the weather thing, I offer the "featured image" up top, showing last night's snow at Chateau Steelypips. Spring in New England, baby!