Physics
rallain | July 11, 2010My car had a flat tire. When you get a flat tire, you might as well make something useful of it - right? As I was jacking the car up, I had a great idea. Use this for one of my "Spoof Science" videos. The only problem is that this takes a ton of work to put together a short video. So, I am just going to talk about what I could have done.
Here is a quick clip of my 4 year old lifting the car.
So, he lifted the car - it maybe be difficult to tell, but he did. HE LIFTED THE CAR! Ok, I know, he only lifted part of the car. If I were to use this in a real Spoof Science video, I would have…
esiegel | July 9, 2010"I admitted, that the world had existed millions of years. I am astonished at the ignorance of the masses on these subjects. Hugh Miller has it right when he says that 'the battle of evidences must now be fought on the field of the natural sciences.'"
-James A. Garfield, future U.S. President, in 1859
You will find all sorts of ideas out there on how old the Earth, the Galaxy, and the Universe are. Some contend that it's only a few thousand years old, while others contend that it's infinitely old.
You and I are free to believe whatever we want, of course. But before you decide what you…
drorzel | July 9, 2010The big physics story at the moment is probably the new measurement of the size of the proton, which is reported in this Nature paper (which does not seem to be on the arxiv, alas). This is kind of a hybrid of nuclear and atomic physics, as it's a spectroscopic measurement of a quasi-atom involving an exotic particle produced in an accelerator. In a technical sense, it's a really impressive piece of work, and as a bonus, the result is surprising.
This is worth a little explanation, in the usual Q&A format.
So, what did they do to measure the size of a proton? Can you get rulers that small…
drorzel | July 9, 2010Thoreau offers without qualification some complaints about a paper in a glamour journal, ending with:
All of this might have been excusable if the big flashy Glamour Journal paper had been followed up with more detailed papers in other places (a common practice in some fields). However, when I searched to see what the authors have done since and whether they've cited that paper, the only places I found them citing their own paper was in papers only marginally related to the work published in the glitzy place. So there was no follow-up, just something that was trendy enough to get into a…
rallain | July 9, 2010In regards to the recent PepsiCo blog situation (you know the one I mean), I wasn't going to say much. First, because Chad did a good job at expressing my views (without me even telling him ). Second, I am just happy to be at ScienceBlogs - I had been kicked off two servers and had to hitch a ride on a friend's server (thanks Bill) before arriving here.
Some other bloggers, were a little more put out. Now I understand why. I came to this understanding by doing a thought experiment. What if it wasn't PepsiCo that paid for a sponsored blog? What if instead it was ESPN's Sport Science? I…
rallain | July 8, 2010In my last zombie post, I looked at a human moving in a circle to avoid a zombie (if they are stuck in a room). What if I build a zombie evading robot that always moves perpendicular to the path of the zombie? Would this work?
This shouldn't be too difficult to model. I can use my existing model for the zombie (where there is a force towards the human and a drag force). For the right-turning-robot, I will also have a drag force and a "driving" force. How do I find the direction of the driving force for the robot? Here is a diagram.
This Fdrive force will really be the frictional force…
drorzel | July 8, 2010Kevin Drum has done a couple of education-related posts recently, first noting a story claiming that college kids study less than they used to, and following that up with an anecdotal report on kids these days, from an email correspondent who teaches physics. Kevin's emailer writes of his recent experiences with two different groups of students:
Since the early 1990's, I have pre and post tested all of my introductory mechanics classes using a research based diagnostic instrument, the Force and Motion Conceptual Evaluation. This instrument is based on research by Ron Thornton at Tufts that…
drorzel | July 7, 2010Over in yesterday's communications skills post commenter Paul raises a question about priorities:
I wonder to what extent good writers, public speakers and communicators are being promoted in science in place of good thinkers - people who can challenge prevailing dogma, invent promising novel approaches to old problems, and who have the intuition needed for deducing correct theories from just a few observations.
I think of this as the "Weinstein Perelman Theory" because Eric Weinstein on Twitter has been pushing something similar with respect to Grisha Perelman turning down major math…
rallain | July 6, 2010It is that part of the semester where the Right Hand Rule (RHR) comes out. Really, the best part is the students taking the tests. They make all these funny motions with their hands. That makes tests more entertaining (for me) than they usually are.
What is the RHR?
Suppose I have two numbers. Maybe these two numbers are the length and width of a piece of paper. Now suppose I need to multiply length times width to get the area (A = L x W). Simple - right? But that is multiplication for scalar variables. How do you multiply vectors?
There are two common operations you can do with…
drorzel | July 6, 2010As I am still getting lengthy comments at the Chris Mooney post accusing me of making unreasonable demands on scientists, I thought I should spell out as explicitly as possible what skills I think scientists ought to have. This probably won't solve the problem, but it'll give me something to point to the next time I get asked.
So, what communications skills should scientists have? The answer depends on what kind of science you're going to do, and what you want to do with it.
First and foremost, though: If you want to be a successful scientist, you need good communications skills. Full stop.…
drorzel | July 2, 2010Summer is here, which means vacations for lots of people, which means "beach reading"-- trying to read a book or two while kicking back somewhere. The ideal beach read is something that isn't so heavy as to bring you down or demand too much attention, but is also serious enough that it's not embarrassing to be seen in public reading it.
Clearly, the best choice for beach reading this summer is How to Teach Physics to Your Dog-- it's got real, solid physics, but also a talking dog. What more could you want?
What if you've already read How to Teach Physics to Your Dog, though? Are there other…
ksnyder | July 2, 2010If you're American, chances are you'll be looking up this weekend for a spectacle of physics. But you also can look down from above -- way, way above -- to see the homes of some of the greatest physics experiments on Earth.
Brookhaven's Relativistic Heavy Ion Collider (RHIC) is probably one of the most visible particle accelerators from space.
Check out this satellite shot from 1982, when construction was underway for RHIC's predecessor, ISABELLE:
And this more recent aerial shot, taken in May:
RHIC is the first machine in the world capable of colliding heavy ions, which are atoms that…
esiegel | July 1, 2010"Prediction is very difficult, especially if it's about the future." -Neils Bohr
As many of you know, the Big Bang is one of the most powerful scientific theories we have.
It's also one of the most unsettling. The idea that our entire Universe -- filled with practically a trillion galaxies -- is only three times as old as our Sun and was once compressed into the size of your thumb is pretty unsettling.
As an astute commenter noted earlier this week,
I'm asking what persuasive predictions BB has to its credit. Most usually the best I see is new observations favoring one BB variant over…
rallain | July 1, 2010Title: Chased by zombies
When I heard word about the ScienceBlogs Zombie Day, I knew I wanted to participate with a post - but I had no idea what to do. My first thought was to somehow talk about living off the electric grid in the case of a zombipocolypse - you know, like how big of a solar panel would you need?
But you know what? Physics is difficult - but modeling is easy. How about I model something? How about a model for the motion of a zombie horde? This will be great.
Zombie motion model
What do I want in my model? What are the constraints? What real-life situations can I use to…
grrlscientist | June 30, 2010tags: How Can You Filter Out The Vuvuzela?, World Cup 2010, physics, technology, football, soccer, sports, television, Sixty Symbols, University of Nottingham, streaming video
A University of Nottingham video explains the physics that underlies the technology being developed to filter out that annoying drone from 30,000 blasting vuvuzelas in the background of all World Cup football matches. It's interesting to note that this is the same sort of software technology that ornithologists use to record (and "clean up" background noise inadvertently captured by) birdsong recordings.
rallain | June 30, 2010This is so awesome - an arduino controlled fan cart.
If you are not familiar with the arduino, basically it is just a very simple and cheap programmable chip. I have been meaning to play around with one of these, but really I am afraid. Afraid I will like it just a little too much.
In this fan cart (made by Eric Ayars - who was at NC State when I was there), the arduino tells the fan when to turn on and off by sensing magnets on the track. Who cares? I care. This allows you to do some cool demos and activities with non-constant forces.
Some other things I can think of:
You could make…
drorzel | June 29, 2010I gave a short introduction to how to give a presentation today to the students who will be presenting their research in our twice-weekly Summer Student Seminar Series. This included examples of a data slide that is bad in the ways that students' first attempts at data slides tend to be bad, and the same graph re-done in a more appropriate manner. As long as I'm doing format conversions of this anyway, I figure it might be amusing to post them here. So, here's the bad graph, with the bullet points highlighting the mistakes:
And here's the good version:
(The seminar series features three…
drorzel | June 29, 2010A couple of significant news items from the world of particle physics:
There was a conference on neutrino physics recently, and the big news from there is that two experiments measure something funny with neutrino oscillations, namely that the oscillations seem to proceed at different rates for neutrinos and antineutrinos. This is a really surprising sort of asymmetry, and would be awfully hard to explain. These are, however, preliminary results that are being released now because there was a conference on neutrino physics, not because the people doing the experiments have rock-solid proof…
esiegel | June 28, 2010The task is not so much to see what no one yet has seen, but to think what no body yet has thought about that which everyone sees. -Arthur Schopenhauer
Most of you who've been reading Starts With A Bang for a while have seen this picture come up many, many times.
Why do I keep putting it up, and why is it so important?
Let's go back to the 1960s for a little bit. Back then, there were two major rival theories about the origin of the Universe: the Big Bang theory and the Steady-State model of the Universe. The Big Bang contended that the Universe was hotter and denser in the past, and thus of…
elerner | June 28, 2010Team USA's World Cup dreams may have been dashed by Ghana over the weekend, but there's nary a bad word to be said by the performance of its goalkeeper, Tim Howard, who again proved he's capable of hanging with his peers from the global soccer powerhouses. But besides his spectacular saves, the one thing World Cup coverage has brought to our attention is that Howard has Tourette's Syndrome, a disorder of the nervous system that causes involuntary movements and would seem to disqualify one from an occupation where precise muscle control is paramount. But as our neurobloggers David Dobbs and…