attack
rallain | February 15, 2009Someone complained about a teacher using this question and the answer was disputed. After some time, the teacher claimed that the answer was that lightning is static electricity because she looked it up on the internet. So, I decided to look also, here is what I found searching for "what kind of electricity is lightning?" in google:
Electricity Facts - Dialogue for Kids (Idaho Public Television)
A couple of complaints about this site:
First, I am not fond of the term "Science Facts". What is a science fact? Something that is proven true? This really is not how science works.
Second, I am not…
rallain | February 13, 2009The local Society of Physics Students invited me to watch the movie Sunshine and then participate in a post movie discussion. There was one thing in the movie that really got me. Of course the movie made many of the common space mistakes. But this one didn't seem necessary. Let me outline this part of the movie (I guess I should say spoiler alert - although this isn't central to the main plot). Here are three frames of a comic I drew to reproduce the scene.
After watching Sunshine, the astronauts try to go from one ship to another without space suits (well, one of them had a suit).…
rallain | February 3, 2009People say I am picky. Ok, sometimes I am. But somebody has to stand up for what is right and just. Maybe I am that person.
Please stop using the word force if you don't know what it is.
There. I said it. You can attack me now.
It wasn't just one thing that got me fired up. It was two things. First, I read this article on physics and football (Physics of 'The Hit' from the NY Times). If it was just this article, I would have let it go and moved on. But no. One of my kids just happened to be watching MythBusters (We all love MythBusters) and there was a discussion that used the term…
rallain | January 5, 2009I finally saw the movie WALL-E. Good flick, I liked it. There was, however, one part I must comment on. You know I can't help myself. I feel like the shark Bruce in Finding Nemo. I try not to attack, but there is a tiny drop of blood in the water. Here is the scene that I want to talk about:
I guess I should give a spoiler alert. Although, I will not talk about the plot of the movie.
In this scene, WALL-E is hitching a ride on this space craft. The space craft is entering a hanger deck of a space station. While the hanger door is still open, WALL-E is clearly hanging on so that he…
rallain | December 19, 2008I am sure I have mentioned the Discovery show Time Warp before. The basic idea of the show is to find how many cool things they can look at with an ultra slow motion video camera (btw - this is on my christmas list).
So, I have seen this Samurai guy on the show twice. Yes, he has a big sword. Yes, he could utterly destroy me if he wished. However, I can not handle him talking about physics. Mr. Samurai guy, please stop using the words "kinetic energy" until you know what they mean (I said please). Here is my first problem. Samurai guy is showing how to chop people down. He plans to…
rallain | November 20, 2008Georgia Tech is playing Miami (not the real Miami, the other one Miami Florida). Right after a commercial, the camera shows this sign from a student (or just person) at the game:
(Sorry if the image isn't that great.) I had to pause the game and take a closer look at this sign. I am not sure I get it. In case you can't see, the sign shows two players and the trajectory of a ball (clearly labeled x and y axes). The equations are:
. Here is my analysis:
Here is the important data I have gathered from the Internets.
The truck (a Ford F-150) stops a plane C-123 Provider
The curb weight of the F-150 is around 5,000 lbs - depending on options and stuff.
The empty weight of…
rallain | November 6, 2008I just watched two episodes of the discovery show [Time Warp](http://dsc.discovery.com/tv/time-warp/time-warp.html). Really an interesting show. There are many videos that I could see some analysis project for (too bad I am like 20 projects behind schedule - I think of things faster than I can do them). There is one problem though. It seems like all of the people on the show like to use physics terms, but they use them incorrectly. This DRIVES ME NUTS. You can't have "energy going this way". Energy is a scalar, not a vector. You can't have "force flowing through this". You can't "put…
rallain | November 5, 2008[Here is a LiveScience article on cars that run "mostly" on air](http://www.livescience.com/technology/081103-air-car.html). I also hear students talking about this - how the world will change when cars run on air. This is misleading. These cars do not really run on air. It is not like you put them outside and BOOM - instant energy.
A better way to say this is that these cars run on energy STORED in compressed air. How do you store energy in compressed air? You need a compressor that typically runs on electricity. Where does that energy come from? Probably coal or natural gas.
It…
rallain | October 23, 2008I am sorry to point this out, but I can't help it. My kids watch this show "Fetch with Ruff Ruffman". It's mostly an ok kids show. However, there was a problem. In one episode, some kids were in the desert and measuring temperature with (they said it several times and it was even a quiz question at the end) - a LASER. Here is the device they used:
This is an infrared thermometer with a LASER aiming system. The laser is only there to help you aim. The temperature is determined by measuring the infrared…
rallain | October 21, 2008I know I should just let go, but this is what makes me, me. I understand that there are terms in physics (like for instance 'pressure') that are used in all sorts of ways in common language. The problem is when someone tries to explain something scientifically and misuses a word. Pressure means something. It is the average force per area due to collisions of a gas or liquid on a surface. Really, you can see a good animation of this, I have a link and explanation when [I talked about MythBuster's Lead Balloon](http://scienceblogs.com/dotphysics/2008/09/mythbusters-how-small-could-…).
So,…
rallain | October 13, 2008There is this show "Weapon Masters" - I think it comes on the discovery channel. It is not a bad show. The basic idea is that they have this history guy talk about the historical aspect of some type of weapon and this other guy tries to make an improved version. Last night the goal was to recreate the original flame thrower mounted on a boat.
They found a boat and they needed to test it's sea worthiness. The builder guy (sorry, I don't know his name) estimated that they would have 1000 lbs of equipment in the boat. To simulate this weight, they put 4 guys and two barrels of water in…
rallain | September 8, 2008My kids like books. Especially when they are going to bed. I let my daughter pick a book and she picked "Clam-I-am. All About the BEACH" by Trish Rabe. It is nice, it rhymes. The pictures are pretty. Then I get to this page:
So, the ocean is blue because of the sky? How do you get green oceans? How about brown (I live in Louisiana, trust me - the gulf of Mexico can be brown)? What about when you are underwater, everything looks blue. The best answer to why the ocean is blue is that that is what color does…