rallain | September 29, 2009I was shocked. After installing Mac OS 10.6 (Snow Leopard) Tracker Video Analysis didn't work. This is one of my favorite programs for blogging.
It appears that the problem is with 32 bit Java vs. 64 bit. I don't really understand why one doesn't work, but Tracker doesn't work with 64 bit Java and that is now the default for 10.6 You can fix it. Go to Java Preferences.app (under applications/utilities) and drag 32-bit above 64 bit. It should look like this:
I had also installed QuickTime 7 (along with the newer QuickTime X) in the hopes that would fix the problem. I don't think you…
rallain | September 28, 2009I think we are entering a new era. An era where it is quite simple to find and get great videos. Oh, just saw a great tackle on the TV? In the old days, you would have to get that video off the TV yourself. Not anymore. Welcome to the interwebs. Also, the quality is awesome compared to 10 years ago. Here is the video. Yes, I know this is from several weeks ago - I am slow. Also, thanks to the person that put this on youtube - I edited your clip to remove the music and just look at the one collision. You did a good job though.
In terms of video analysis, this isn't too bad of a video…
rallain | September 23, 2009You know I like the Mythbusters, right? Well, I have been meaning to look at the shooting bullets in the air myth for quite some time. Now is that time. If you didn't catch that particular episode, the MythBusters wanted to see how dangerous it was to shoot a bullet straight up in the air.
I am not going to shoot any guns, or even drop bullets - that is for the MythBusters. What I will do instead is make a numerical calculation of the motion of a bullet shot into the air. Here is what Adam said about the bullets:
A .30-06 cartridge will go 10,000 feet high and take 58 seconds to come…
rallain | September 21, 2009Thanks to all who participated in the Dot Physics Census. Let me share some of the things that I learned:
The survey was flawed. How dumb was I? Almost everyone would fit into more than one of those categories. Oh well.
Google Docs makes pretty good surveys. I made a form in google docs and embedded it in my webpage. The only thing that I didn't do (but I do know one way to do it) was to have live results. PollDaddy does this, but the free account is limited to 100 responses. I am too cheap for that.
I was surprised by the large percent of college students. College students, I…
rallain | September 17, 2009This is Tom's fault (Swans on Tea). He suspects that most of the physics blogs are read by physics bloggers.
I have kind of been avoiding this, but I guess I need to know who my readers are. Actually, there are two groups of readers - regular readers and googlers. So, who are you?
Loading...If you are a blogger, maybe you could list your blog in the comments. I will post the results after some time (or live if I figure that out).
Responses so far
I don't know how to make this live, so I will just update it every once and a while.
Here is a list of what was submitted as "other" (at this…
rallain | September 17, 2009Yes, this can be very complicated. But what should a middle-school student understand about light? You see stuff in textbooks that is either wrong or just a bunch of disconnected factoids (I like the word factoid). So, what do I think is important about light (not at the Maxwell's equations level)
What is a wave
If you want to talk about light, you need to talk about waves. So what is a wave? I like to start with an example. Suppose you are in a sports stadium - maybe a football game. Some inspired fan decides to start a wave. If you look at the individual people, the wave might be…
rallain | September 16, 2009The administration are people too. I just want to start off saying that. However, in this case, I just don't get it. The more I think about it, the less I get it.
Here is the plan our administration came up with. Faculty will report class absences for every Tuesday and Wednesday course. Absence reports are due online by Friday. I guess the goal here is to try to monitor the health of the student population and see if we have a flu outbreak or something. Here are the first problems I thought of:
Won't there be some type of attendance noise anyway? Maybe attendance goes up and down…
rallain | September 15, 2009As I said before, I went a SPIN-UP workshop (you can find tons of info and the SPIN-UP report here). The basic idea of the SPIN-UP program is to first look at schools that are successful in their production of undergraduate physics majors. And with an understanding of what makes them successful, help other institutions become successful. Maybe you couldn't make it to the meeting, so here are some highlights. Oh. I believe that this highlights have very general applications. Although this is aimed at undergraduate physics, it seems it would apply to many other majors and maybe even to…
rallain | September 14, 2009I really shouldn't do this. I might be helping someone to set up something dangerous. But, I am going to anyway. Here is a question posted on some forum. (actually, it is from math help forum)
"I'm anticipating a good winter this year, one with lots of snow. My yard is sloped quite a bit and it would be the ideal place for a huge snowboard jump, only problem is I need to calculate how fast I will be traveling when I hit the jump, how high and what angle the jump should be, and the distance and angle of the landing ramp to optimize my range."
So, what am I going to do? I am going to give…
rallain | September 9, 2009This weekend I am off to a SPIN-UP (Strategic Programs for Innovations in Undergraduate Physics) meeting. The basic idea is for physics departments to meet and discuss how they can be better. Note: if you don't have a good acronym, you don't get any funding. In preparation for this meeting, I was thinking - what is the one thing I think could make a difference.
Maybe the most important thing is to create a community of learners. The department should be a place where students can be students. It would be awesome if this included space (in whatever form possible) for studying, learning,…
rallain | September 9, 2009I love this question:
Why is it warmer in the summer than in the winter (for the Northern hemisphere)?
Go ahead and ask your friends. I suppose they will give one of the following likely answers:
The tilt of the Earth
The tilt of the Earth makes us closer to the Sun
We are closer to the Sun
Really, that should be at least 85% of the answers. To really answer the question, think of the following key points:
When it is warm in the Northern Hemisphere, it is cold in the Southern Hemisphere
The Earth's orbit around the Sun is very close to being circular
The seasons depend on the time of…
rallain | September 8, 2009Here is a quick story. A faculty member came to me last week disappointed about the introductory physics students' lack of understanding with regard to electric potential. Let me call the faculty Beta, because I think that would be a cool name. Beta was disturbed that the students didn't get potential and it was covered last semester in the first part of the course.
Beta also said, "and electric potential is so simple". My reply was to show Beta my favorite 3-d puzzle. I think it is called a snake cube. Basically, it is a set of 27 wooden cubes attached together in some fashion that…
rallain | September 4, 2009I love this story. It is a story of how ideas changed about the nature of the atom. These are the notes (and diagrams) I use when I teach the atomic nature of matter to non-science majors. The best thing about this story is that it is a great example of science. Science (or scientists) build a model. If new evidence comes along, the model gets changed. There are several other websites that describe all of this stuff, I will list a couple at the end of this post.
Typical textbook model of an atom
Look in an intro, non-science majors textbook and you will probably see a picture like this…
rallain | September 2, 2009Students are starting to get the flu around here - and that means that it is time to debate. Clearly there are going to be some absences in the coming month. The question is: what to do about it? There are two camps of thought here:
Camp 1: Excuses are bad
This camp of faculty is worried. They are worried that the administration is going to issue a statement something like this:
"These are difficult times. Every is somehow affected by the flu. To encourage...blah..blah...blah... please allow students to make up any missed work without any doctor's note."
So the faculty in camp 1 say "…
rallain | August 31, 2009Maybe this is a little old (in internet age), but it is a great example. Here is the Loop-the-loop stunt from the show Fifth Gear.
I like this. First, it is a bold stunt. But also, there is some good physics here. Though, most importantly, the Fifth Gear producers were kind enough to include a shot that was very compatible with video analysis.
I went to the official site of this stunt - http://looptheloop.dunlop.eu. From here I found some useful info:
Loop is 40 feet tall
The car is a Toyota Aygo
Some physics-y guy calculated that the car must go 36 mph to do the loop (I think that is…
rallain | August 28, 2009I found this in the most recent issue of The Physics Teacher (September 2009). Surprisingly, there were several good articles in this issue. One article discusses a doable version of the Millikan Oil drop experiment. Maybe you are not a (or were not) a physics major, so you might not be familiar with how cool, but tedious and squinty the oil drop experiment can be.
In the Millikan Oil drop experiment, small electrically charged drops of oil are placed in a constant electric field. It turns out that a small enough number of electrons are on each drop so that the quantization of charge can…
rallain | August 26, 2009I re-watched Harry Potter and the Order of the Phoenix last night and my wife and I noticed something about teaching. Of course I mentioned that this would make a good blog post (and she may still post it on her blog, but I can't help myself). If you have not read the book or seen the movie, I don't think I will give away any serious spoilers - but who hasn't at least seen the movie? If you were going to see it (or read it) you would have done so by now - right?
The Order of the Phoenix shows at least three different examples of teachers and teachings in the movie. Here they are:
Dolores…
rallain | August 23, 2009I saw this video on digg or reddit. I can't remember which.
I was in awe. Then I started thinking. I wonder how fast that water was moving up right after the explosion. Too bad the video doesn't have a scale. Well, it kind of does - there is that ship. I am terrible at ship identification though. Maybe I can use my favorite scaling trick - assume the stuff is on the surface of the Earth. This means that free falling objects would have an acceleration of -9.8 m/s2. Let me try this on the water as it falls. Oh, trust me. I know it is not really free falling, but it is in this big…
rallain | August 22, 2009I found this link on twitter from New Scientist.
'iTunes university' better than the real thing
This pretty much sums it up:
"Students have been handed another excuse to skip class from an unusual quarter. New psychological research suggests that university students who download a podcast lecture achieve substantially higher exam results than those who attend the lecture in person."
The article also mentions a research study by McKinney that gave half of a class of 64 podcast lectures instead of a traditional lecture. Looking at the details, it doesn't seem like too convincing of a study.…
rallain | August 21, 2009Forgive me if I don't know the official parkour term for this move. This is where you have two walls that are close to each other and you vertically climb them. Here is a shot of Mark Witmer (from Ninja Warrior) doing the wall climb.
Doesn't look too hard, does it? Well, I think it depends on how far apart the two walls are. This is actually one parkour move that my kids like to do (Hey kids! Don't do that! Let me get my camera though because this will be perfect for my blog)
I am going to start with this second kind of wall climb. Simply because it is easier due to symmetry. So,…