Physics
drorzel | December 30, 2009Today is Question Day when it comes to post topics, I guess. Over at Fine Structure, Nick asks about the effect of spotlighting brilliant scientists:
I can't help but think about the repercussions of looking at his clearly above average career as something that's normal in physics. It's a deterrent, I think, for all those students that aren't so completely brilliant that they do Nobel winning physics by 21. And it's not exactly uncommon to hear about these minds anymore. Is it a function of community density when we funnel all the supremely smart people towards math and science? What does it…
drorzel | December 30, 2009 I should probably start date-tagging these updates about miscellaneous How to Teach Physics to Your Dog news. I don't really mean this to become a second daily links dump, but it's kind of looking that way...
-- As a general matter, it's dangerous for authors to acknowledge the existence of Amazon customer reviews (acknowledgment leads to responding, responding leads to madness), but the half-dozen customer reviews already posted are really good. These three especially. There are also a couple that aren't much more coherent than comment spam, so go figure.
-- At the risk of setting up a…
rallain | December 30, 2009Some time ago, I wrote about the awesome things the Greeks did in astronomy. Basically they calculated the size of the Earth, distance and size of the moon and distance and size of the sun. The value obtained for the distance to the sun was a bit off, but still a bang up job if you ask me. (where bang-up is meant as a good thing) If the greeks were in my introductory physics lab, they would need to include uncertainties with their measurements. What would the uncertainty in the final value look like?
In my introductory physics lab course, I have students measure things and estimate the…
rallain | December 29, 2009I saw this post about Panasonic's home battery. The claim is that this will lead a battery that can power a house for a week. I wonder if I can estimate how big this battery would be.
First - to estimate the energy a house consumes. My first approximation is that you could probably run a house off of a 5000 Watt generator, but this probably isn't the average power use for a house. It is probably lower. I am going to go with an estimate of 2000 Watts as the average power over 1 day. How much energy would this be for 1 week?
The article above claims that it is a lithium ion battery.…
drorzel | December 29, 2009If you're still not sure whether you should be teaching physics to your dog, here's another good reason: Superconductors.
The "super" in "superconductor" refers to the fact that these materials conduct electric current with absolutely zero resistance, better than the best ordinary metals. This has obvious applications in the green technology field (which dogs should definitely be interested in, as discussed in a previous installment)-- if you could remove the resistance of power lines, you would lose less energy on the way from the generating plant to your home, increasing the energy…
rallain | December 28, 2009What happens when your kids won't give you a turn on the Wii? Simple. You take their LEGO bricks and their slinky and do some physics. I will keep this simple. Basically, I created a slinky holder out of LEGO pieces and added LEGO bricks to the end to stretch it. Here is the video.
Lego + Slinky = Physics from Rhett Allain on Vimeo.
Maybe in an un-Dot Physics fashion, I am not going to analyze this data. I am not going to even describe the physics. Instead, I will leave this as a What Can You Do With This in the style of Dan Meyer.
I will give a couple of hints. First, I put this on…
drorzel | December 28, 2009When I saw the data generated by the sales rank tracker Matthew Beckler was kind enough to put together, I joked that I hoped to someday need a logarithmic scale to display the sales rank history of How to Teach Physics to Your Dog. Thanks to links from Boing Boing, John Scalzi, and Kevin Drum, I got my wish:
For those not familiar with the concept, a log scale plots values on a scale that represents each order of magnitude as a fixed distance. So, the top horizontal line on that plot represents a sales rank of a million, the line below that a hundred thousand, the line below that ten…
rallain | December 28, 2009One of things I like to think about in science is "how do we know that?" It is interesting how one thing builds on another. This is a story of how the Greeks estimated the distance from the Earth to the Sun (an important idea in the development of the model of the solar system). I like this story because it is not too complicated. In fact, one could easily reproduce these measurements themselves. So, here is what I will talk about:
Measuring the size of the Earth.
Determining the distance from the Earth to the moon and the size of the moon.
Calculating the distance (and size) to the Sun…
rallain | December 27, 2009In part I of this post, I talked about the basics of projectile motion with no air resistance. Also in that post, I showed that (without air resistance) the angle to throw a ball for maximum range is 45 degrees. When throwing a football, there is some air resistance this means that 45 degree is not necessarily the angle for the greatest range. Well, can't I just do the same thing as before? It turns out that it is a significantly different problem when air resistance is added. Without air resistance, the acceleration was constant. Not so now, my friend.
The problem is that air…
rallain | December 26, 2009On a previous episode of The MythBusters, Adam and Jamie made a lead balloon float. I was impressed. Anyway, I decided to give a more detailed explanation on how this happens. Using the thickness of foil they had, what is the smallest balloon that would float? If the one they created were filled all the way, how much could it lift?
First, how does stuff float at all? There are many levels that this question could be answered. I could start with the nature of pressure, but maybe I will save that for another day. So, let me start with pressure. The reason a balloon floats is because the air…
drorzel | December 24, 2009A couple of quick book-related items that I can't resist posting, even while on vacation:
First, the sales rank cracked the top 500 on Amazon last night, peaking at 396. I don't know if this is just a matter of relative sales volume being low, or what, but it's a huge kick all the same. For the moment, it's the top seller in the Physics category, and #35 in Science as a whole. Statistical fluctuation or not, that's very cool.
Even better is this excellent online review from New Scientist:
Talking quantum physics with a dog may seem a tad eccentric, but Orzel's new book is a true delight to…
rallain | December 24, 2009Which wastes more fuel? (and thus produces more carbon dioxide). This is a difficult to question to answer for a variety of reasons. The main reason is that a speed change from 71 mph to 70 mph is different than a reduction from 56 to 55 mph.
First, let me be clear that the question of how much fuel is wasted using daytime running lights (or DRL as they are called) has already been addressed. The first source I found was howstuffworks.com
Assumptions
The daytime running lights on a car run at about 100 watts (for the pair)
The energy density of gasoline is 1.21 x 108 Joules/gallon.
A car is…
esiegel | December 23, 2009089:32:50 Mattingly: Apollo 8, Houston. [No answer.]
089:33:38 Mattingly: Apollo 8, Houston.
089:34:16 Lovell: Houston, Apollo 8, over.
089:34:19 Mattingly: Hello, Apollo 8. Loud and clear.
089:34:25 Lovell: Roger. Please be informed there is a Santa Claus.
089:34:31 Mattingly: That's affirmative. You're the best ones to know. -NASA
The world is an awfully big place now. Santa's job has to be tougher than its ever been before. And yet, across the world, every year without fail at this time, children delight with joy at the presents brought to them by Santa Claus. So, how does he do it?
Santa…
milhayser | December 23, 2009
Yesterday was the winter solstice, meaning the sun concluded its six-month southward course and seemed to "stand still" before beginning its journey north. Of course, this being a heliocentric neighborhood, the tilt, orbit, and rotation of Earth are what really move the sun through the sky. But don't let that stop you from appreciating colorful crayon diagrams of the ancient "two-sphere" model of the heavens with Dr. Free-Ride on Adventure in Ethics and Science. If that's not a useful enough approximation, you can get a modern understanding of solstices and seasonal dynamics from Anne…
grrlscientist | December 23, 2009tags: The Known Universe, education, AMNH, American Museum of Natural History, NYC, streaming video
The Known Universe is an educational video about the new exhibit at AMNH that takes viewers from the Himalayas through our atmosphere and the inky black of space to the afterglow of the Big Bang. Every star, planet, and quasar seen in the film is possible because of the world's most complete four-dimensional map of the universe, the Digital Universe Atlas that is maintained and updated by astrophysicists at the American Museum of Natural History. The new film, created by the Museum, is part of…
rallain | December 23, 2009One of my students showed me this game, Fantastic Contraption. The basic idea is to use a couple of different "machine" parts to build something that will move an object into a target area. Not a bad game. But what do I do when I look at a game? I think - hey! I wonder what kind of physics this "world" uses. This is very similar to my analysis of the game Line Rider except completely different.
Fantastic Contraption gives the unique opportunity to build whatever you want. This is great for creating "experiments" in this world.
The first step is to "measure" some stuff. The game…
drorzel | December 22, 2009Not that I'm obsessed, or anything (current Amazon rank: 1106), but here are the results from my incomplete survey of local book stores regarding How to Teach Physics to Your Dog:
Barnes & Noble: "Out of Stock" in all local stores. Has never been in stock, really.
Borders in Crossgates Mall: "Likely in store" according to the book finder computer, but if they actually put any out, either they sold them, or they're well hidden.
The Book House of Stuyvesant Plaza: Two copies prominently displayed in the top row of the "new arrivals" case, between David Byrne's book about bicycling and John…
drorzel | December 22, 2009I'm typing this from the local Barnes and Noble, waiting for the dealership next door to finish changing my oil and inspecting my car. Sadly, they don't have How to Teach Physics to Your Dog on the shelves in their (rather small) science section. Grump, grump, grump.
The disappointment at not immediately finding it on the shelves is tempered a bit by seeing it featured in The Big Idea at Scalzi's blog:
Want a Big Idea that's about a really big idea? Well, this week's book is about quantum physics, and it doesn't get much bigger than that (well, given the scale quantum physics works on, it…
drorzel | December 22, 2009Today is the official publication date for How to Teach Physics to your Dog!
I've got another reason or two why dogs should love quantum physics that I'll probably post later, but if the ones posted so far haven't sold you on the book, how about a really nice review from Cory Doctorow at Boing Boing:
Chad Orzel's How to Teach Physics to Your Dog is an absolutely delightful book on many axes: first, its subject matter, quantum physics, is arguably the most mind-bending scientific subject we have; second, the device of the book -- a quantum physicist, Orzel, explains quantum physics to Emmy,…
drorzel | December 21, 2009How to Teach Physics to Your Dog goes on sale in fine bookstores everywhere tomorrow. But maybe the four previous posts explaining why dogs should care about quantum physics haven't yet convinced you to go buy a copy. So here's another reason, one appropriate to this solstice season, when dogs in the Northern Hemisphere will start to enjoy longer days again: Sunlight.
You like sunlight, right? Of course you do, unless you're a vampire. And what dog doesn't like a sunny day? Well, you have quantum physics to thank for sunlight, because as hot as the Sun is, it's not nearly hot enough to burn…