mspringer | January 2, 2009The Constant Fire: Beyond the Science vs. Religion DebateAdam Frank
Adam Frank is an astrophysicist and a man on a mission. It's a brave mission, one which cuts strongly against the grain of the science vs. religion zeitgeist. It's probably a mission which won't succeed.
Beyond the Science vs. Religion Debate is the book's subtitle, and in fact if you ignore the first word you'll be expecting a very different book. Frank feels that all of the sound and fury behind the debate either misses the point or accomplishes nothing. It is not about the debate, and if you're looking for that kind of…
mspringer | January 1, 2009Real-life physics can be a pain.
New Year's Eve I went with an old high school friend of mine to meet some people and shoot fireworks. This concluded at a little before one in the morning, and after that we left. We wanted to catch up on what had been happening some more and so we drove around town for a few minutes before heading to our respective homes. Unfortunately we hit an unfamiliar gravel road (this is kind of a rural area) and in the process of turning around we got stuck in the mud. Well, I say "we". Both of us were stuck by virtue of being in the same vehicle, but he was…
mspringer | December 31, 2008When I was a kid my younger sister used to play basketball in a city league and my family would go watch. The game clock would reach the final seconds of each period and the kids in the stands would count down. 3! 2! 1! Zero!
The clocks were such that with less than one minute remaining, the clock would display tenths of a second. This resulted in a problem that bothered me but probably no one else ever. So as soon as (say) the 5 popped up the kids would shout "5!" when in fact there were 5.9 - or really six seconds left. This lead to the inevitable embarrassing moment when everyone…
mspringer | December 30, 2008Apropos of the calorie/Calorie discussion yesterday, here's something interesting to think about with regard to the energy used in exercise.
The formula for gravitational potential energy is m*g*h, where m is mass, g is the acceleration due to gravity, and h is the height. Of course this is if the changes in h are small enough so that g can be taken as truly constant. So any change in height is going to require energy if you're going up, and will release energy if you're going down. This is why you hit the gas driving up a hill and hit the brake going down a hill. Actually since we're…
mspringer | December 29, 2008Over this past semester I've discovered something unfortunate. If a person doesn't get much exercise, snacks when bored, and shops when hungry, that person will tend to gain weight. That person is of course me, and so I'm going to try to do something about it. It's by no means a new year's resolution, I've been aware of the problem for several months now. And fortunately we're early in the game yet. My BMI is roughly 25.5, which is just a hair into the "overweight" range. Some of you might be in the same boat, so we might be able to do some thinking about how to best put ourselves where…
mspringer | December 28, 2008Here's this week's Sunday Function. In the universe of functions it's an utterly typical suburban middle class citizen, with a pleasant but quite ordinary job in a downtown cubicle farm for Physics Incorporated.
His name is
.
In a little more detail, you'll notice that this function is the product of two elementary functions. There's x squared, and there's e raised to the negative x power. As x increases, obviously x squared increases quite quickly. By the time you get to x = 500, x squared is equal to 250,000. But on the other hand, e^-x is shrinking as x increases. It happens to be…
mspringer | December 27, 2008Great! So did I!
Now the sky is a big place, and telescopes don't often come with an astronomer to explain how to use them. I'm not an astronomer either, but I've been an amateur stargazer on and off for years and I might be able to give you some good advice.
First, the telescope itself. There's basically two kinds, assuming your budget was under a couple grand. There's the refractor (which has a lens on the front) and the reflector (which has a mirror at the end). If you have a cheap refractor, trade it in and get a reflector. Essentially the only parameter of interest at the amateur…
mspringer | December 25, 2008On this, my first 25th of December here on ScienceBlogs, I'd like to wish you and all your family and loved ones a happy, merry, and joyful Christmas. In honor of the occasion, my favorite Christmas song:
O Holy Night
O holy night! The stars are brightly shining,
It is the night of our dear Saviour's birth.
Long lay the world in sin and error pining,
'Til He appear'd and the soul felt its worth.
A thrill of hope the weary world rejoices,
For yonder breaks a new and glorious morn.
Fall on your knees! O, hear the angels' voices!
O night divine, O night when Christ was born;
O night…
mspringer | December 16, 2008Greatest Physicists #1 - Isaac Newton
The first and greatest physicist in my estimation is Isaac Newton, born in 1643. Lots of commenters absolutely correctly picked out Newton for the top spot, and had I picked anyone else (with the just barely plausible alternatives of Einstein or Galileo (and see his honorable mention for details)) I'd have been justifiably thought to be nuts.
Before Newton, there was no physics. There was science, but a systematic mathematical description of the laws of nature did not exist. Indeed it could not exist, mathematics itself had not yet developed to the…
mspringer | December 15, 2008#2 - Albert Einstein
Einstein. When a person's name and photograph are both literal synonyms for genius, it's a pretty good sign they're among the greatest of the greats. But even if Einstein had not become the popular legend which lives on to this day, he'd still tower above the science of physics.
In one year - his annus mirabilis of 1905 - he wrote four papers, any of which would have cemented his reputation in the canon of the great physicists.
The first was an analysis of Brownian motion. If you drop a pollen grain into a glass of water and look very closely with a microscope, you'll…
mspringer | December 14, 2008The Exponential Function. I think this is the first time we've done it here. It won't be the last. You could write a book about it, and someone probably has. Here's the usual picture:
This graph isn't as pretty as the usual, because I'm at home with my old copy of Mathematica 5 instead of the new version that's much better at drawing smooth and professionally-colored graphs. Nonetheless, the essential details are made clear. The exponential function drops off to zero very rapidly as you go left, and increases rapidly as you go right.
You can define the exponential function in any of…
mspringer | December 13, 2008I dislike the remake of The Day The Earth Stood Still, and I haven't even seen it. Not for the usual reasons - for instance, I think Keanu Reeves is a good actor when used in the right roles, and "space alien" is certainly one of those roles. I dislike the premise. Some alien species comes down and declares that it likes the other earth species more than it likes the smart monkeys. Therefore it demands that the smart monkeys stop their tool use or it will kill them all.
I suppose it would be too simple for the aliens just to drop the blueprints for some of their own snazzy tools so that…
mspringer | December 12, 2008From the inimitable xkcd, a comic about relativity in sex:
This rather clever piece of humor is referring to the relativity of simultaneity. According to relativity, time and space are different for observers in different reference frames. Events which are simultaneous in one frame are not necessarily going to be simultaneous in a different frame moving with respect to the first frame. This isn't just a failure to correct for light travel time either, it's a genuine geometric effect of spacetime.
So if one person is, er, moving at near the speed of light the effect can be quite pronounced…
mspringer | December 11, 2008So Tony Soprano pitches ties a concrete block to Salvatore Bonpensiero and pitches him into the ocean, where he will inform the police no more. Being a big guy, Bonpensiero has a fairly low density compared to your average human being - say, 0.96 grams per cubic centimeter. That's less than water and so he'd have floated were it not for the weight. Assuming Bonpensiero has a mass of 140 kilograms, how much concrete would Tony need to sink him?
Hey, don't look at me. I just grade the finals. The professor writes them.
Anyway, after grading this question a couple hundred times I figured it…
mspringer | December 10, 2008A mysterious gap in posting? Must be finals time! As of now I'm done. We'll see how they went. One of them went well for sure, the other sort of depends. My own students are having their own exams as well, and I've got my fingers crossed for them.
One of the things that's going to be on the exam (or at least it in a chapter they covered) is the speeds of molecules in a gas. Like people milling around in a crowd, as the molecules fly around and bump into each other they'll be exchanging energy and moving at different speeds. Some molecules will have just been hit in just the right way…
mspringer | December 7, 2008This rather striking image is the imaginary part of the Airy function. Rather than a lot of words today, I'd like to just present this mathematical function as art.
I've always disagreed with Whitman in his assessment of science, but it is nonetheless a good thing to occasionally look up in silence at the stars - or function plots.
WHEN I heard the learn'd astronomer;
When the proofs, the figures, were ranged in columns before me;
When I was shown the charts and the diagrams, to add, divide, and measure them;
When I, sitting, heard the astronomer, where he lectured with much applause in the…
mspringer | December 6, 2008Yesterday I posed a famous trick question, and we had the shortcut answer, the long "standard" answer, and a particularly elegant solution by commenter meichenl. Turns out he has his own blog called Arcsecond, and it's really fantastic. He focuses mostly on examining interesting mathematical situations. Check it out!
Some physics news: the perils of the LHC continue. As you have probably heard, the LHC experienced a severe breakdown during some of the early test runs. Aside from the break itself putting the collider out of commission, the particular system that broke was discovered to…
mspringer | December 5, 2008Challenge question! It's either very easy or somewhat difficult depending on how clever you are at approaching it. No fair answering if you've already seen the problem before, though if no one's managed it in a few hours I'd say it's fair game to post the solution if you already know it.
Two trains are 100 miles apart on the same track, headed on a collision course towards each other. Both are traveling 50 miles per hour. A very speedy bird takes off from the first train and flies at 75 miles per hour toward the second train. The bird then immediately turns around and flies back to the…
mspringer | December 4, 2008Seed's editorial policy is unusually generous in the latitude we ScienceBloggers get. Let's hope it's generous enough for this!
Linked via Instapundit, I saw this interesting article about theft of and damage to speed cameras. As an strong supporter of civil liberties, this warms my heart. If a flesh-and-blood police officer catches me speeding, fair enough. But ubiquitous surveillance of every move, invading privacy in order to fill city treasuries... I'm not such a fan.
And make no mistake, it is to fill treasuries. Public safety is a convenient fig leaf. Studies have shown that in…
mspringer | December 3, 2008Before the physics, I want to point out one of the most interesting ScienceBlogs posts I've seen in a long time: Not Exactly Rocket Science discussing the body-swapping illusion. You should read it.
Now, here's a quiz I gave my Physics 201 students. Easy as usual, but I'm a sucker for these order-of-magnitude problems where you get an intuitive feel for what a right answer "feels like". It's taken from one of the homework problems in their textbook:
What is the length of the side of a cube containing a number of molecules equal to the number of people in the world (~6 billion) assuming a…