Physics

As previously mentioned, I'm watching a little bit of Fringe in order to be able to talk sensibly about it later this week. I watch the Season 1 finale last night, and its treatment of parallel universes is about what I'd expect for tv, but being the obsessive dork I am, I got distracted from the big picture by a silly side issue. There's a running joke for the first bit of the episodes about Walter trying to find various pieces of scientific equipment, only to find that Peter has appropriated them for some sort of personal project. One of these items is an electron microscope (presumably an…

"It has been rightly said that nothing is unimportant, nothing powerless in the universe; a single atom can dissolve everything, and save everything! What terror! There lies the eternal distinction between good and evil." -Gerard De Nerval (For Rich C. and Sili, for their questions on this post.) The humble hydrogen atom -- one proton and one electron, bound together -- is the most common form of normal matter in the entire Universe. When you look out at all the galaxies in the Universe, what you're seeing is predominantly light coming from those simple hydrogen atoms fusing together at the…

We're having a birthday party for SteelyKid tomorrow, so I have a ton of stuff to do today. I may have something more substantive later, but for the moment, here are a couple of videos to enjoy. First, from the Minute Physics set of videos at YouTube, an explanation of why you have quantum physics to thank for sunny days: There's a bunch of good stuff in the Minute Physics channel, so if you're looking for a way to kill time in small chunks, have at it. And if you prefer your physics to be classical, this demo from Harvard has been making the rounds: Isn't physics awesome? Of course it is.

"To correct a natural indifference I was placed half-way between misery and the sun. Misery kept me from believing that all was well under the sun, and the sun taught me that history wasn't everything." -Albert Camus Our Sun has been shining brightly for over four billion years now, giving light, heat, and energy to our entire Solar System. But -- like every other star -- it won't continue to burn forever. In an estimated five-to-seven billion years, the Sun will cease its nuclear fusion reactions, and eventually contract down into a white dwarf star, losing a good fraction of its mass and…

Unlike the previous post, this is not a rhetorical question that I will ask and then answer. I genuinely do not know the answer. I could Google it, of course, but I'd like to see if somebody reading this is able to deduce the correct answer from the available evidence. So, here's the deal: as an attempt to recover from a rather sedentary couple of months due to computer-based work and some plantar fascitis kind of problem in my foot that's keeping me from playing hoops as much as I'd like, I'm spending a while each day on the exercise bike we have upstairs. While I do a bunch of reading of…

A while back, I explained how polarized sunglasses work, the short version of which is that light reflected off the ground in front of you tends to be polarized, and by blocking that light, they reduce the effects of glare. This is why fishermen wear polarized sunglasses (they make it easier to see through the surface of water) and why they're good for driving (they cut down on glare off the road ahead). I almost exclusively buy polarized sunglasses, because I like this feature. But let's say you have a pair of polarized sunglasses that broke, because they were cheap to begin with (such as…

There's a lot of stuff in the news lately about asteroids, what with the Dawn mission orbiting Vesta, and the talk of a manned asteroid mission as a possible future step for NASA. Prompted by this, I'm going to dip into the territory usually occupied by Matt and Rhett, and ask a somewhat silly question: What size asteroid would you be able to throw a baseball into orbit, a la Bugs Bunny? (Sadly, probably for copyright reasons, I couldn't quickly find a YouTube video of the cartoon where Bugs throws a baseball all the way around the world. But you can probably picture it, even if you're too…

For the past few years, astronomer and SF author Mike Brotherton has been running the Launch Pad Workshop, a program bringing interested SF authors to Wyoming (where he's on the faculty) to learn about modern astronomy. The idea is to teach writers the real facts about the weird and wonderful things going on in astronomy these days, so they can write better stories about astronomical objects and ideas, and reach a wider audience through fiction. This year's workshop just ended, and Brotherton has links to some of the presentations, and blogs about it from the attendees. I really like this…

"Birth and death; we all move between these two unknowns." -Bryant H. McGill One of the most remarkable consequences of the Big Bang is that the Universe as we know it -- full of planets, stars, galaxies and life -- hasn't been around forever! Because the Universe is expanding and cooling, it was hotter, denser, and more compact in the past. Image credit: SciencePhotoLibrary. But these things that fill the Universe today weren't there in the very early stages of the Universe; they took time. Gravity needed many millions of years to collapse these slightly overdense regions to a point where…

One of the benefits of having joined AAAS in order to get a reduced registration fee at their meeting is that I now have online access to Science at home. Including the Science Express advance online papers, which I don't usually get on campus. Which means that I get the chance to talk about the few cool physics things they post when they first become available, without having to beg for a PDF on Twitter. This week's advance online publication list includes a good example of the sort of cool ultra-cold atom physics that I talked about at and after DAMOP, so let's take a look at this paper in…

Via Bee, we have the BlaBlaMeter, a website that purports to "unmask without mercy how much bullshit hides in any text." Like Bee, I couldn't resist throwing it some scientific text, but rather than pulling stuff off the arxiv, I went with the abstracts of the papers I published as a grad student, which I wrote up on the blog as part of the Metastable Xenone Project a few years ago. The abstracts, their scores, and some comments below: Paper 1: Optical Control of Ultracold Collisions: Near-resonant light is used to modify the collision dynamics of magneto-optically trapped metastable xenon…

I've got a ton of stuff to do this morning that will keep me from more substantive blogging, so here's a cute toddler picture: This is SteelyKid playing with the giant magnet in the MRI exhibit at the Schenectady Museum, trying to see how big a tower she could make out of steel washers and hex nuts (answer: 11 hex nuts before it fell over). She also greatly enjoyed tossing washers at the magnet and seeing them snap to it (I was more interested in tossing them so they got deflected but missed the magnet body, and shot off into the wider room. I doubt the other patrons would've guessed…

It's really frickin' hot in much of the US. Fortunately, we have central air at home, A/C in the car, and convenient local businesses with air conditioning and free wi-fi. The inadequate HVAC systems in the Science and Engineering building on campus aren't anywhere near being able to cope with this, so I'm working from home or a cafe until the weather breaks. I will, however, use this as a shameless plug to re-link a post from last year, where we scientifically tested whether it's better to leave your car windows open or closed on a hot day. The answer: if it's a short stop, closing the…

"Almost every way we make electricity today, except for the emerging renewables and nuclear, puts out CO2. And so, what we're going to have to do at a global scale, is create a new system. And so, we need energy miracles." -Bill Gates Energy is one of the most important topics facing our modern, industrialized civilization. What sources we get it from, what we use it for, and how we deal with the waste from its production are paramount to the future of our species on Earth. Yet in many ways, energy is one of the most poorly understood quantities in all of physics. To help you better…

I've been going through the manuscript for the book making up a list of glossary words (a frighteningly long list), and also noting miscellaneous pop-cultural references-- quotes, direct mentions, paraphrases, etc. I'm sure I've missed a few-- many of them occur in section titles, which my eyes tend to slide right over as I read (in the previous book, one section was titled "Clever Section Title Here" until distressingly late in the process)-- but for your amusement, here's what I have at the moment, in approximately the order in which they appear in the book: Star Wars The Adventures of…

"We all want progress, but if you're on the wrong road, progress means doing an about-turn and walking back to the right road; in that case, the man who turns back soonest is the most progressive." -C. S. Lewis Many of you are a little bit skeptical that I talk about things like the History of the Universe, Inflation, Dark Matter and Dark Energy like they are absolute certainties. After all, isn't it true that there are an awful lot of assumptions that we make in order for these things to be true? Image credit: NASA. Absolutely! That's right, I admit it. We make assumptions when we come up…

As many a thoughtless person has observed when learning what I do for a living, physics is really hard. But you may have wondered just how much harder is physics than other subjects? Well, now, we have a quantitative answer: This is a shelf of books at the Burlington, MA Barnes and Noble, clearly showing that while it is possible to learn all about politics and philosophy in thirty seconds, understanding Einstein takes three whole minutes. So, relativity is at least six times more difficult than philosophy. (This presumably explains why there are so many physicists who dabble in philosophy,…

I really ought to be doing other things, but this roller slide business kept nagging at me, and I eventually realized I could mock up a crude simulation of the results. This led to the production of this graph: This looks pretty similar to the Tracker Video data from the previous post, which I'll reproduce below the fold, along with an explanation of the math that went into the model: The two graphs are qualitatively similar, other than, you know, the godawful Excel aesthetic of the simulation results graph. One line looks relatively straight, like motion at constant speed, while the others…

On Monday, I posted a short video and asked about the underlying physics. Here's the clip again, showing SteelyKid and then me going down a slide made up of a whole bunch of rollers at a local playground: The notable thing about this is that SteelyKid takes a much, much longer time to get down the slide than I do. This is very different than an ordinary smooth slide, where elementary physics says we should go down the slide at the same rate, and empirically I tend to be a little slower than she is. So what's the difference? First of all, let's be a little more quantitative about this. Here's…

Last week Doug Natelson noted a drop-off in active physics blogs. This had not gone unnoticed hereabouts, though I couldn't immediately think of what to say about that. Yesterday, though, former ScienceBlogs wrangler Christopher Mims provided a possible answer: Google+ has destroyed blogging completely. I would've liked to find a way to tie all this together into a deep and meditative blog post about the nature of blogging and the reasons for the decline of physics blogging specifically (to the extent that this is a decline, which is somewhat debatable). I have a faculty meeting to go to this…