Physics

tags: Richard Feynman Explains Rubber Bands, science, physics, imagination, hot, offbeat, rubber bands, jiggling atoms, physical laws, Richard Feynman, streaming video Physicist Richard Feynman thinks more about the 'jiggling' of atoms, and about rubber bands and how they 'work'. "The world is a dynamic mess of jiggling things, if you look at it right", says Richard Feynman.

It's been a very long day, so I'm lying on the couch watching "Pardon the Interruption" on ESPN. They're having a boring conversation about baseball, and I'm just drifting off into a pleasant doze when: "Fear! Fire! Foes! Awake! Fear! Fire! Foes! Awake!" I jolt awake. "What are you barking at?!?" I yell at the dog, who is standing in the middle of the living room, baying at nothing. She stops. "Scary things!" The room is empty. "There's nothing here," I say, and then hear a car door slam. I look outside, and see the mathematician next door heading into his house. "Were you barking at Bill? He…

There's a Dennis Overbye article in the Times today with the Web headline "From Fermilab, a New Clue to Explain Human Existence?" which I like to think of as a back-handed tribute to the person who linked to an interview with Sean Carroll by calling him "The cosmologist, not the scientist." This is the secret of human existence explained by science, not biology. The physics issue in question is why we have more matter than antimatter in the universe, as symmetry would seem to demand they be created in equal amounts in the Big Bang. Had that happened, though, all of the matter should've…

tags: Richard Feynman Explains Jiggling Atoms, science, physics, imagination, hot, offbeat, fire, jiggling atoms, physical laws, Richard Feynman, streaming video Physicist Richard Feynman talks more about jiggling atoms and heat, and about what fire is. From the BBC TV series 'Fun to Imagine' (1983).

"From the intrinsic evidence of his creation, the Great Architect of the Universe now begins to appear as a pure mathematician." -Sir James Jeans Last time we met, I posed a mystery to you: why are globular clusters the smallest in the Universe? And what's more than that, we never find them in isolation! We always find them bound to galaxies (or, if not bound to a galaxy, then within a cluster of galaxies; thanks Steinn), but never just off in deep space, floating on their own like some lone Death Star. Like all structures in the Universe, everything we're talking about here -- stars,…

Grades are in. So, let me just say a couple of trends that I saw on the physical science final exam. Gravity on the moon I asked the question: "why is the gravitational force on an astronaut less on the moon than on Earth?" The simplest answer is that the gravitational field on the moon is smaller than on Earth (I would accept that answer). Why is this? It is because the moon as a much smaller mass even though it also has a smaller radius (that idea is rather complicated for this class - that gravitational force depends on both mass and radius). I would also take "the mass is smaller" as…

And lo and behold. Another semester has ended. I was going to post about somethings from my physical science course (for non-science) majors. Then I noticed that both Ethan at Starts With a Bang! and Farady's Cage posted about their semester reflections. I vote that the academic blogging community make this a tradition. This semester, I had 3 courses. Here is a brief overview of what I learned. Physics for Scientists and Engineers II This is the electricity and magnetism part of the intro physics course. As I said before, I used Matter and Interactions (Chabay and Sherwood). I am not…

You may have noticed things look a little different around here. We’ve gussied up for the 2010 iteration of our flagship festival, which officially went on sale last week. There are still a few bugs we’re ironing out on the site (please bear with us!) and a couple of exciting programs yet to be announced, but the important thing is that tickets are now on sale. And if previous years are any indication (2008 and 2009), you may want to hurry to reserve your seats. Tickets tend to sell out very quickly. There’s a LOT to be excited about this year. Let's see, where to begin... Legendary…

Matt's Sunday Function this week is a weird one, a series that is only conditionally convergent: So the sum of the infinite series, by inexorable logic, is both ln(2) and ln(2)/2. How is this possible? Of course it isn't. The flaw in our logic is the assumption that the series has a definite sum - in the mathematical parlance, that it's absolutely convergent. This series is not, it's only conditionally convergent. In fact you can show (the great G.F.B. Riemann was the first) that with judicious rearrangement, you can get this series to converge to anything at all. As such it's only…

SteelyKid's every-so-often bath was last night, and as always, she was fascinated by scooping up water in a hexagonal cup thing that's part of one of her bath toys, and watching it drain out. Which is completely understandable-- not just because she's a baby, but because there's a bunch of physics at work, here. I realize this is trampling on Rhett's territory, but I made a little video showing the physics part (in the sink, not the tub, because I don't want to have the pay the therapy bills that would come from posting video of SteelyKid in the tub): The explanation is laid out in the video…

Galactic Binder (a Star Wars fan site) invited me to write an article for them. Obviously, I said "yes". But what to write about? I decided to write a different version of my flying R2-D2 post. What is different? In my original post, I go into a lot of details. Essentially, that post is like most of my other ones where I am thinking out loud. I used to work out the answer and then write the post, but I like it this way better. Here is the Galactic Binder post: Aristotle, Newton, and R2-D2 So, in this Galactic Binder post, I don't go into the details. Basically, I just use the flying…

tags: Richard Feynman Explains Jiggling Atoms, science, physics, imagination, hot, offbeat, cold, jiggling atoms, physical laws, Richard Feynman, streaming video Physicist Richard Feynman thinks aloud about atoms and how they jiggle, and how we perceive that jiggling as 'hot' and 'cold'. From the BBC TV series 'Fun to Imagine' (1983).

I am excited. This Wednesday, the MythBusters are doing the giant water slide jump. Maybe you are new to the internet and you haven't seen this video. Here it is: And since it is as old as the hills, of course I have already analyzed it - actually twice. First, the video is fake - but it is an excellent fake. Here is another site with details on how this was created. What did I look at in my previous posts? Here is a summary. The video is difficult to analyze because of perspective changes. Even with these problems, nothing says it has to be fake. The vertical acceleration during the…

A few upcoming events related to How to Teach Physics to Your Dog: The big one is that I'll be aprt of the "Author's Alley" portion of the World Science Festival Street Fair in New York City on Sunday, June 6th. The last couple of these have coincided with out-of-town trips for me, so I'm glad to get to go to this year's World Science Festival, which includes a whole bunch of cool-sounding stuff. The Street Fair is an eight-hour affair, while I'll only be signing books for an hour or so during that span; I'll post a more specific time when I get it. On Sunday, June 19th, I'll be signing…

I was going to just leave the oil spill in the gulf topic alone. Not because it isn't important, obviously it is. Rather, I wasn't going to do anything because I didn't really have anything to add to the topic. After a couple of readers requested it, I think I do have something to add. How exactly do you estimate the amount of oil flowing into the gulf? What do I have to start with? A video. Here is a video of the undersea oil leak. Now, I am not the first to estimate the oil flow rate (NPR on Purdue Prof's estimation and here a commenter make a quick calculation). Like I said, I am…

"I may be an old lion, but if someone puts his hand in my mouth, I can still bite it off." -Wilhelm Steinitz When you look at a typical galaxy, you usually find a disk, a bulge, and a few dots diffusely strewn about the exterior. Like an old lion, these dots have been around for a very long time: often for longer than the galactic disk itself! Just what are these things? Well, we can learn a little more if we look in the X-ray (with Chandra) and the infrared (with Spitzer), in addition to a visible light image (from Hubble). Let's take a look at a composite: Just what are these dots that…

Blame Bryan O'Sullivan for this-- after his comment about misreading "Bohmian Mechanics" as "Bohemian Mechanics," I couldn't get this silly idea out of my head. And this is the result. I like to think that this was Brian May's first draft (he does have a Ph.D. in astrophysics, after all), before Freddie Mercury got hold of it: Is this the real life? Is this just fantasy? Do objects have real states Or just probabilities? Open your eyes Look up to the skies and see Studying quantum (poor boy), I need no sympathy Because I'm easy come, easy go A little psi, little rho No interpretation ever…

I'm a great believer in luck and I find the harder I work, the more I have of it. -Thomas Jefferson It's the end of the semester at my college as well as at many schools across the world, and I've spent the last week or so grading final exams. And while I was doing it, I noticed something astonishing. But let me start at the beginning. Introductory physics -- without calculus -- is one of the most notoriously challenging and rigorous classes that students pursuing a career in health, including doctors, nurses, pharmacists, veterinarians, and physical therapists, face in their college career…

Yes, green laser pointers are cool. Especially when you use them to make stuff fluoresce. Ok, what about a blue laser pointer? They are getting surprisingly cheap (Amazon has a 10 mW for pretty cheap). Still not cheap enough for me. But, you know what? Some of the physics majors here at Southeastern Louisiana University purchased a couple of these. Physics major Daniel let me borrow his. First, they don't look too bright. This is probably because our eyes are not too sensitive to this wavelength. The blue 10 mW does not look anywhere near as bright as the 5 mW green that I used in…

I get asked my opinion of Bohmian mechanics a fair bit, despite the fact that I know very little about it. This came up again recently, so I got some suggested reading from Matt Leifer, on the grounds that I ought to learn something about it if I'm going to keep being asked about it. One of his links led to the Bohmian Mechanics collaboration, where they helpfully provide a page of pre-prints that you can download. Among these was a link to the Bohmian Mechanics entry in the Stanford Encyclopedia of Philosophy, which seemed like a good place to start as it would be a) free, and b) aimed at a…