Rhett Allain
rallain
Posts by this author
May 20, 2010
And there's parliament. Ok - sorry, I had to make a "Tom (Swans on Tea)" title for this one. Tom, forgive me.
Here are two great circular motion videos. First, this one is from Dale Basler. He made himself a fine little floater-type accelerometer. Better than just make it, he made a video of…
May 20, 2010
Grades are all over the place, but what are they? Well, I guess there are a few questions. What is a grade? What is the grade supposed to be? Why do we give grades?
I think the grade is supposed to be a measure of a students' understanding of the material. Probably everyone would agree with…
May 19, 2010
A new video from the Red Bull Stratos Jump guys came out. Here it is:
This reminds me of an unanswered question about the Stratos jump that I didn't address on my last post on this topic. Commenter Long Drop asked about how much Felix would heat up as he falls from 120,000 feet. This is a great…
May 17, 2010
Grades are in. So, let me just say a couple of trends that I saw on the physical science final exam.
Gravity on the moon
I asked the question: "why is the gravitational force on an astronaut less on the moon than on Earth?"
The simplest answer is that the gravitational field on the moon is smaller…
May 17, 2010
And lo and behold. Another semester has ended. I was going to post about somethings from my physical science course (for non-science) majors. Then I noticed that both Ethan at Starts With a Bang! and Farady's Cage posted about their semester reflections. I vote that the academic blogging…
May 17, 2010
Galactic Binder (a Star Wars fan site) invited me to write an article for them. Obviously, I said "yes". But what to write about? I decided to write a different version of my flying R2-D2 post. What is different? In my original post, I go into a lot of details. Essentially, that post is like…
May 16, 2010
I am excited. This Wednesday, the MythBusters are doing the giant water slide jump. Maybe you are new to the internet and you haven't seen this video. Here it is:
And since it is as old as the hills, of course I have already analyzed it - actually twice. First, the video is fake - but it is an…
May 15, 2010
I was going to just leave the oil spill in the gulf topic alone. Not because it isn't important, obviously it is. Rather, I wasn't going to do anything because I didn't really have anything to add to the topic. After a couple of readers requested it, I think I do have something to add. How…
May 13, 2010
Yes, green laser pointers are cool. Especially when you use them to make stuff fluoresce. Ok, what about a blue laser pointer? They are getting surprisingly cheap (Amazon has a 10 mW for pretty cheap). Still not cheap enough for me. But, you know what? Some of the physics majors here at…
May 13, 2010
Yes, I am going to talk about the MythBusters latest duct tape episode. A couple of pre-post points:
They call it "duct" tape. I call it duck tape. It doesn't work very well with ducts. Also, it is good for water proofing stuff - you know like a duck. For the rest of this post, I am calling it…
May 12, 2010
ScienceBlogs.com is running "Ask a Science Blogger". The basic idea is that you, the reader, get a chance to ask questions to us, the bloggers. You can either post a comment in the link above or send an email to .
I would like to go ahead and answer one of the questions already posted. nemski…
May 10, 2010
This is a question that comes up every now in then. But I would like to ask a few similar questions with my first order approximation answers. I would love to hear some other ideas on these questions.
Do people need a functional understanding of math to function in this world?
I say no. Maybe…
May 8, 2010
I have one more comment about the previous MythBusters episode where they compared two cars crashing into each other at 50 mph vs. one car crashing into a wall at 100 mph. At the end of the episode, Jamie reflected on the experiment. He said something like (regarding how he incorrectly thought…
May 6, 2010
I already mentioned the MythBusters' crashing two cars episode where they correctly doubled the speed of a pendulum type object. Overall, this was a very visual (although expensive) demo. There was one part that left a sour taste in my mouth - the final explanation from the narrator. First, they…
May 6, 2010
In the last episode of MythBusters, Adam and Jamie wanted to test something that Jamie had said earlier:
"Two cars crashing head on at 50 mph is the same as one car crashing into a wall at 100 mph"
Jamie was wrong, but that is not what I am going to talk about. Instead, I am going to talk about…
May 5, 2010
I was going to make this as a video tutorial, but it just didn't work out right. So, here it is in blog post form.
How do you deal with a video that zoom and pans at the same time? You could keep on adjusting the coordinate axis AND adjust the scale for each frame - but sometimes that is not…
May 4, 2010
Really, I have many jobs. But in this case, I am talking about my two jobs inside my one job as learning facilitator. I like to call myself a learning facilitator rather than a teacher or a professor because I can't make people learn (that would be teacher). Professor would imply that I am…
May 4, 2010
So you have seen these color filters (or gels as they are also called). When you look through a red filter, everything looks red. What do they do to the light? I am not going to tell you the answer. However, I will show you some examples so that you can figure out the answer yourself.
In this…
May 4, 2010
It is my duty as a blogger to mention lasers in this time of international laser celebration. This May is the 50th anniversary of the first lasers. Everyone knows a laser that they love, right? We all use them. So, instead of talking about lasers, I am going to post some great links to other…
May 3, 2010
This video seems like it is getting popular, but maybe that is because it is so awesome.
Maybe it is just me, but I find this video very visually satisfying. I love the way they compare the different runners.
Anyway, there is some physics here. Commenter Ben sent me the link to this video (thanks…
April 28, 2010
Normally, it isn't really news when a show doesn't do anything wrong. I am making an exception for ESPN's Sport Science. Here is part 2 of Sport Science trying to reproduce Kobe Bryant's "jumping over a car" stunt.
And here is part 1 (although part 2 is the only interesting part). See. I can get…
April 28, 2010
You see in my experimental determination of the location of the accelerometer in an iPod, I used two different iPhone apps. Let me briefly mention some of the free iPhone apps that give you acceleration data.
AccelGraph: This is one of the apps I actually used. What do I like about it? Well, it…
April 27, 2010
There are several free iPhone-iPod Touch apps that let you look at the acceleration of the device using the built in accelerometer. I was planning on reviewing some of these free apps, but I didn't. When I started playing around with them, it was clear that I needed some way to make a constant…
April 26, 2010
I meant to mention this earlier since it happened a little while ago. There is this "mini-conference" with three schools: Southeastern Louisiana University, Southern Mississippi University, and the University of South Alabama. The purpose is to give students (and some faculty) a chance to present…
April 24, 2010
Check this out.
So, the guy jumps from 150 feet into some cardboard boxes. Why are the boxes important? You want something that can stop you in the largest distance to make your acceleration the smallest. Here is my Dangerous Jumping Calculator. Basically, you put in how high you will jump from…
April 22, 2010
I would just like to take this post and use it to promote some relatively new blogs that I like. Speaking of blogs, I think I have classified blog posts into 3 different kinds.
Link aggregators. Chad at Uncertain Principles does this with his Links posts. These kind of blog posts are the glue of…
April 22, 2010
I wasn't paying attention. Earth Day is today. If I would have thought of this before, I could have done something awesome. Instead, here are some reposts related to the Earth and energy. They have been sitting for a while in my post-compost, so they are nice and smelly.
Most of these deal with…
April 21, 2010
I want to give ESPN's Sport Science another chance. The segment on Tim Tebow didn't really have any errors. I thought, cool - what about this one on Jason Pierre-Paul? Here is the clip. Oh wait, embedding is disabled. Ok - if you want to watch go here (the image is a link)
The goal of this…
April 19, 2010
You probably already know how I feel about the "media" and their physics explanations (see attacks). Let me summarize the problem. There are a whole bunch of cool shows on tv that deal with sciency stuff - that is good. These shows then try to teach some science along with their demos and…
April 16, 2010
If you have been on the internet, you surely have seen this website showing the sizes of different starships. Way cool. Here is a small sample - but it doesn't do the site justice. You really need to go browse around.
Of course, I can't let something like this just go. One of the things I…