rallain | August 1, 2010Chasing Mummies is kind of like a cross between the reality showness of Deadliest Catch and History's Mysteries. I like these kind of shows. My kids like these shows. It's win-win.
The basic idea of this show is to follow this dude, Zahi Hawass- he is like in charge of all the Egyptian museums. Here is a youtube clip that gives a pretty good overview.
However, I do have a beef - well maybe it is just a small quibble. At the beginning of one show, Zahi is all pumped up about some new discovery. They found some tombs near the great pyramids that seem to be the tombs of workers that did…
rallain | July 30, 2010The Lord of the Rings trilogy came on TV again recently. My wife and I can't help but to watch this even though we have it on DVD. Anyway, I was thinking about the part where Gondor sends a signal to Rohan asking them for military aid. Since this was before the invention of email, they had to do it with a signal fire. Hopefully this clip won't be a spoiler for you, but this is from the movie. Actually, all of the clips available have embedding disabled. So this is just a picture of that clip. If you want to see it, go to the youtube version.
One other spoiler: Sauron is really Frodo's…
rallain | July 26, 2010Here is part of a picture some of my friends posted from a recent high school reunion.
It may be hard to tell, but this is part of a picture of 7 females all wearing black. I just wanted to show you that they were indeed wearing black without giving away anymore details. If you are one of these people and you want your whole picture included, I will be happy to make that change and include your face.
Anyway, my first comment was: "Wow, everyone is wearing black. Was this a planned event or was black part of the dress code?" The response was that it was just pure chance that all the women…
rallain | July 24, 2010WOMWorld/Noika has invited me to travel to Salzburg Austria and visit with the Felix and the Red Bull Stratos team. I am pumped up.
Why? Why oh why you might ask. Well, I guess it is for several reasons.
First, I have several posts about the physics of the Red Bull Stratos jump. (quickly, the stratos jump has Felix Baumgartner jumping out of a balloon at 120,000 feet).
Nokia and WOMWorld get some exposure because I will blog about my experiences.
You, the readers, get to read about it.
Really, it is win-win-win. And trust me, I will find some good stuff to blog about.
rallain | July 23, 2010Check this out - NY Times: No Motors, but Mistrust at Tour de France.
So, the short story is that some people claim that Cancellara is cheating by putting a hidden electric motor in his bike. Now they are going to do random hidden-motor checks.
I have analyzed this motor-in-a-bike already:
Energy in a hidden battery: The short answer is that you could get about 500 watts for about 1.5 hours with a hidden battery that weighs 1.6 kg. Doable, yes. Advisable? Probably not. Also, you would probably hear the motor being used.
Do bikers cheat? In this post I look at some clips of Cancellara…
rallain | July 21, 2010Frank Noschese is a physics teacher and a blogger (and frequent commenter on Dot Physics). And I nominate Frank as the new librarian of videos that can be analyzed for realness or fakeness. Or, as Frank calls them Win-Fail Physics. Note that I sort of changed his theme a little - sorry Frank.
Win-Fail physics videos are all over the place. You know I like these things. They are videos that look cool and people question if they are real or fake. Sometimes it is easy to tell, sometimes it takes a little analysis, and sometimes it is very difficult to tell (and I get it wrong).
So, here is…
rallain | July 20, 2010I don't hate math, that is just the title of the post - notice that I put it in quotes.
As you may know, I teach this physics course for elementary education majors (using Physics and Everyday Thinking - which is awesome). The curriculum has very little math in it. That is not necessarily a good thing, but it helps the students understand science and the nature of science without bringing in this mental block they have for math. One of the activities has them look at the energy efficiency of different devices. At the end of the activity, they are asked:
A fluorescent bulb is 25% efficient…
rallain | July 19, 2010(alternate title: how to make pretty graphs in vpython)
I am happy. Finally, I can use the visual module in python (vPython.org) and plotting with Matplotlib. Maybe this isn't such a big deal for many of you, but for me, it never worked until now.
In the past, I blogged about plotting in vpython vs. matplotlib. My conclusion was that it was easier in vpython, but prettier in matplotlib. So, why not just use matplotlib? There are a couple of things that make vypthon very attractive.
Vectors. Vpython has a built in vector class (or function - I don't know what I am talking about). There…
rallain | July 16, 2010I have been thinking about grades lately and I am pretty sure they are dumb. The main problem is that it seems that many many many people (politicians, parents, students, administrators, some other faculty, and zombies) think that the grade is the THE THING to worry about. Really, it is just a pale representation of the real thing.
This brings me to the allegory of the cave. I know you remember this when you read Plato's The Republic, right? Here is a picture that explains the whole thing:
I don't know where this image came from, it was on a boat load of other websites, none looked like…
rallain | July 15, 2010Just a quick note. Some of the images on posts before Jan 2010 might not be loading. I am working on this, but it might take some time. If there is some old post that you need or link to, let me know and I will fix those first.
rallain | July 13, 2010Here is a commercial for some Mercedes car. The first part is quite boring, but check out the stunt at around 2:00 minutes into the video.
I haven't bothered to check if this is officially fake or not. Instead, I will do what I do - see if this is even feasible.
The common question people ask when they see something like this is: "how does the car defy gravity?" Well, it doesn't. Why doesn't it fall? In a sense it does. This is essentially the same as spinning a bucket of water over your head. Maybe a diagram of the car at the top of the tunnel will help.
I tried to make the car stand…
rallain | July 13, 2010The other day I found myself faced with six equations that needed to be solved algebraically. Just so you know, I am a big fan of paper for most of these cases - but this was out of control. I was making silly mistakes and causing all sorts of problems. What to do? My first though was to use some symbolic plugins for python. I tried sympy and it is nice. However, it was not giving correct solutions for solving 3 equations - I don't know if this is a bug or what.
Maxima
I think I found Maxima through Wikipedia's Computer algebra system page. It's free and free and runs on Mac OS X and…
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…
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…
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…
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…
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…
rallain | June 27, 2010Sometimes I get asked to do some demos for kids. I like this, it is fun. This week, I was asked to do just such a demo. Kind of as a historical record, I am going to document what I did.
The audience
It is always important to think about who you are talking to. Is this a group of high school physics students? High school teachers? Middle school teachers? Kids? It could be anything. In this case, I was meeting with a group of kids from ages 8 to 12 as part of a science camp.
The Objective
Is there a reason for the demo show? In this case, there was no stated objective. That means I can…
rallain | June 25, 2010The oil spill is still in the news (sadly). One thing that keeps coming up is the speed that the oil bubbles rise to the surface. This is important in different oil-capture methods. The common statement is that smaller bubbles of oil can take quite a long time to reach the surface and larger bubbles can take about 2 days.
This is one of those cases where things do not scale quite the same. Suppose there is a spherical oil bubble rising at a constant speed. Here is a force diagram for such a bubble:
If this drop is going at a constant speed, then all these forces have to add up to the…