gravity

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Yesterday, I uploaded a post from my old site about slowing down time to make videos look like they were on the moon. If you haven’t read that, the short story is that it doesn’t look right when speed Apollo videos up so that the acceleration is -9.8 m/s2. What started that whole thing was…

Note: This is a repost from my old site. Time to move it over. First, what is different about motion on the moon and on Earth? Since the moon has a smaller mass in spite of its smaller size*, the moon has a smaller gravitational field. The gravitational field on the surface of the moon…

July 4th can be fun. One activity my family enjoys is playing in the lake at my parents house. Along with this comes the jumping off the dock. Great fun, and great physics. Here is a short clip. Work Energy Example from Rhett Allain on Vimeo. Notice that I violated my own rules for making…

Was the moonwalk fake? No, not the Apollo landings. I am talking about Michael Jackson’s moonwalk. You got to admit, he had a big impact on a lot of stuff and this is my way to give him respect – physics. I am sure you know about the moonwalk. Maybe you can even do the…

Maybe this isn’t the best video to analyze, but it sure is funny. I am not sure why it is so funny – maybe you should just watch it first. Sledgehammer Funby Stressmaker I don’t really know why these guys are putting explosive on sledge hammers. Sure it looks fun, but I think I would…

Jennifer over at Cocktail Party Physics has a nice post about her trip to Disneyland. The one ride that would be fun to play with (in terms of physics) would be the tower of terror. Think of the cool things you could do with a video camera during that ride. It would be like a…

Dear Ruff Ruffman, My kids really like your show. However, there is a problem. You promote it like it is science, but the content keeps having mistakes in it. Previously, I pointed out your mistake about in infrared thermometer (if can’t remember, you said the thermometer measures the temperature with a laser. In fact, the…

Air equals gravity in movies (again)

The 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…

Buzz Out Loud and Black Holes

Buzz Out Loud is one of my favorite tech podcasts. Unfortunately, I am a little behind in the episodes. However, in the episode 900 there was an email from a listener regarding LHC and black holes. The emailer claims that a massive black hole would mess up Earth’s orbit. This is not quite true. I…

WALL-E Gravity and Air

I 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…