Physics
grrlscientist | June 14, 2010tags: The Science Behind Gliding Paper Airplanes, physics, teaching, flight, pressure, paper airplanes, streaming video
Do you need a fun, hands-on experiment for your physics classroom? This video shows how a group of high school students, led by a terrific teacher, made origami paper airplanes from phone book pages that glide on a wave of air and what they learned from this experience. Magnificent.
rallain | June 14, 2010Suppose there was an imaginary university. (is that statement redundant?) Let me call this TIU (The Imaginary University). Also, suppose TIU offers summer courses. Further, suppose there is an instructor teaching 2 sections of lab during the summer. Here is a communication that instructor might have received.
Dear Person Teaching a Summer Course:
It appears you are teaching 2 sections of lab. One lab only has 13 students enrolled in it. We have determined that it is not financially appropriate for us to give you a full course pay for this partially full lab. We are going to pay you 13/…
rallain | June 14, 2010Pre Reqs: Electric Field, Work-Energy, Potential Energy
If you are already familiar with the topics listed in the pre-reqs above, this will be uber-simple.
Potential energy - short version
The work-energy principle basically says:
In this most basic form, the energy is just kinetic energy (if you are not going near the speed of light). BUT...if you have a force that is conservative (meaning the work done does not depend on the path you take), then you can make it a potential energy and move it to the other side.
Warning: you can not have a force and have that force do both work AND be a…
drorzel | June 14, 2010At last weekend's Hidden Dimensions event, Brian Greene had a graphic of a Calabi-Yau object (it wasn't this one, but it's the same idea). He put this up several times, but never actually explained what the hell it was supposed to show. It just looked kind of cool.
Last week's Through the Wormhole program segment on Garrett Lisi kept showing an animation of some sort of graphical representation of the E8 group, shifting between some collection of circles and that giant mandala-looking thing they use to illustrate every story about the guy. Again, there was no explanation of what the hell this…
drorzel | June 14, 2010There was a nice story in the Schenectady Gazette about How to Teach Physics to Your Dog. I'd love to link to it, but the Gazette paywalls everything, so all you really get is the story title, unless you subscribe. And if you subscribe to the Gazette, you don't really need me to tell you there was a story in it about my book. So you'll just have to take my word that ther's a story, and a nice short review.
The reason for this late attention is that I'll be signing books at the Open Door bookstore in Schenectady this Saturday, the 19th. In fact, they did up a nice little flyer for the signing…
drorzel | June 13, 2010A grey and dreary day here in Schenectady for the 216th Commencement at Union College. This is probably healthier for the graduates than the years when it's sunny and hot and people pass out in their seats, but it isn't the most pleasant send-off. Then again, my own college graduation was a grey and dismal day, and that's worked out all right.
This year's class of Physics majors was small, but stellar. We only had four majors, but every one of them graduated with both departmental honors (for doing thesis research) and Latin honors ([superlative] cum laude), and those honors were well…
rallain | June 11, 2010Back to the discussion about hiding an electric motor in a pro racing cycle. Before, I looked at a video of Fabian Cancellara to see how his speed and acceleration compare to other bikers. The claim on the internet is that he pulls away so fast that he must have a motor hidden in his bike.
Just to be completely clear, I don't think he is cheating. Then why bother? If you ask that then this must be the first time you reading this blog. I welcome you. No, but really, this is what scientists do. How hard would it be to cheat?
From my analysis, it seems that a person could ride like he…
esiegel | June 10, 2010"A good heart is the Sun and the Moon; or, rather, the Sun and not the Moon, for it shines bright and never changes." -William Shakespeare
Did I ever tell you how lucky you are?
Lucky, indeed, to have the Sun for a star?
Our Sun -- the ultimate source of all the light, heat, energy, and life on our world -- is remarkable in how constant it is. In fact, we didn't even know just how constant it was until we launched the SOHO satellite, shown below.
SOHO has just released their results from more than 12 years of observing the Sun from space, and found that the size of the Sun has been constant…
rallain | June 10, 2010In the last episode of MythBusters, they wanted to see if a tornado could make some glass cut off a person's head. The first attempt was just to take some glass and through it at a simulated human neck. Clearly, this wasn't quite the same as a tornado.
So, here was their plan. If they want to simulate glass moving at 300 mph, they could get a bigger piece of glass and put it on a truck moving at 80 mph. The result would give a piece of glass with the same kinetic energy as a smaller piece moving at 300 mph. Their calculations look to be correct. However, the question is: would this make…
drorzel | June 10, 2010The Science Channel debuted a new show last night, Through the Wormhole with Morgan Freeman, with the premier apparently designed by committee to piss off as many Internet types as possible. The overall theme was "Is there a creator?" and it featured physicist-turned-Anglican-priest John Polkinghorne talking about fine-tuning but no atheist rebuttal. It spent a good ten minutes on Garrett Lisi and his E8 theory, making it sound a whole lot more complete than it is. And it got this aggressively stupid review in the Times:
Oh, let's face it: it was hard to concentrate on the first half of the…
drorzel | June 10, 2010One of the questions asked of Neil deGrasse Tyson at the WSF thing last week was "When did you change from a mild-mannered astrophysicist to a rock-star scientist?" (or something close to that phrasing). In his answer, he said that after his first tv interview was edited down to a three-second shot of him wiggling his hips, he made a deliberate effort to practice giving sound bites-- answering questions in 3-4 sentences with a good "hook" for the tv people to work with.
I thought of this when I stumbled across the following YouTube clips, which were shot by TV Ontario when I was at the…
rallain | June 9, 2010Here is another question from Ask a ScienceBlogger. Reader Uday Panta asks:
How does water evaporate in the seas? Doesn't water evaporate at 100 C?
There were some very good responses in the comments where the question was, but I am going to answer it with some more details.
Small Particle Model
This is where we need to start - the small particle model of liquids and gases. This model treats the liquid as being made up of a lot of particles (well, obviously). If there is a gas (or liquid) at a certain temperature, then there are particles moving around at different speeds. Often it is…
drorzel | June 9, 2010I'm back in Niskayuna, dealing with mountains of end-of-term paperwork. Which means you get a poll to pass the time:
The best end-of-term evaluation method is:survey software
This poll is brought to you by the number π, the letter q, and the two take-home exams I'm waiting for before I can finish my grading.
rallain | June 8, 2010Well, maybe that isn't the best title. You see, there is this video going around saying that it is possible that a professional bike racer was cheating by putting a hidden motor in his bike. I am not really going to talk about the cheating aspect (my gut feeling says that it would be too easy to catch, so he is not cheating).
Actually, there was an interesting analysis by Ron at CozyBeeHive. Quite a thorough job. He even used Tracker Video Analysis. However, he didn't use some of the nicer features of Tracker, so I figured I would do this analysis also. Plus, you know I love bikes.…
pontiff | June 7, 2010Rob sends me information about an interesting new position at the Perimeter Institute (more info here):
The Perimeter Institute for Theoretical Physics (PI) is looking for a Scientific IT specialist -- a creative individual with experience in both scientific research and information technology (IT). This is a new, hybrid, research/IT position within the Institute, dedicated to helping PI's scientific staff make effective use of IT resources. It has two clear missions. First, to directly assist researchers in using known, available IT tools to do their research. Second, to uncover or…
drorzel | June 7, 2010In my write-up about the Hidden Dimensions panel, I mentioned in passing that:
I also would've liked to see an experimental physicist up there, to provide a little more grounding about what the actual problems are, and how you might hope to look for something. But then, I always think there should be more experimental physicists involved in everything.
I'm going to be traveling today, so I thought I would throw up a filler post offering a list of things that would be improved by the inclusion of an experimental physicist. Then I realized that that would be kind of difficult, as everything is…
rallain | June 7, 2010As part of the Ask a ScienceBlogger series, reader Jim Swanson asks:
When I open the dishwasher after washing and the contents are still hot, why do the glass and ceramic items dry off more quickly than the plastic items?
This is a great question. Great because it is something most everyone can relate to and great because there is some good science. Really, this shows the difference between temperature and thermal energy. I think the common idea is that temperature is a measure of the energy something has - but this isn't quite true.
Ok, let me first start with a sample case. Suppose you…
rallain | June 6, 2010So, I hear you are starting your second semester of physics. One of the cool things about physics is that the second semester still uses stuff from the first semester. Maybe you forgot some of that stuff, so here are the bare essentials you will need to get by (this is assuming you are in the algebra-based second semester of physics)
Vectors
Really, just about the entire semester course is about the electric and magnetic field. Both of these are easiest to represent as vectors. So, you pretty much need to know how to deal with vectors. Here are some reviews:
How do you represent vectors…
drorzel | June 6, 2010You might not know this, because I've been so shy about mentioning it here, but I'll be signing How to Teach Physics to Your Dog at 1:30 pm today as part of the Authors Alley program at the World Science Festival Street Fair. It's true.
It looks (at least in the tiny patch of sky I can see out our hotel window) like a beautiful day here in Manhattan, so if you're in the area, it would be a great day to come by an outdoor science festival. And given the stuff they were setting up last night, and the atmosphere at the events we've attended so far, it should be plenty festive, even if you're a…
drorzel | June 5, 2010Since I was going to be down here anyway to sign books at the World Science Festival Street Fair, Kate and I decided to catch one of the Saturday events at the Festival. It was hard to choose, but we opted for the program on Hidden Dimensions: Exploring Hyperspace (Live coverage was here, but the video is off), because it was a physics-based topic, and because I wrote a guest-blog post on the topic for them.
(No, we didn't go to the controversial "Science and Faith" panel, opting instead to have a very nice Caribbean dinner at Negril Village, just around the corner. I'll take excellent…