estimation

Dot Physics

Category archives for estimation

Pi: how many digits do you need?

The most basic explanation of Pi is that it is the ratio of the circumference to the diameter for a circle. That seems simple enough, but it turns out that Pi is an irrational number – so you can’t just write it down. Oh, I know that you are an uber-geek and you could recite…

There was a Buzz Out Loud episode in the not-to-distant past where the discussion of youtube came up. I can’t remember the exact details, but the main point was that it would be impossible for google (the owners of youtube) to review all of the videos that were submitted. And here is my calculation. How…

Power source for a lightsaber

This one has been on my mind for quite some time. What kind of power source would you need to run a lightsaber? I was actually worried recently about this post when I saw the Discovery Channel show “Sci Fi Science“. In that particular episode Michio Kaku talks about how you would actually build a…

The speed of exploding Galacticus

This is really random, but quick. I was channel surfing and saw the end of the movie: Fantastic 4 – Rise of the Silver Surfer. SPOILER: At the end someone really big explodes in space. There, that wasn’t too much of a spoiler, was it? (unless you read the title) I know I am a…

R2 flying at a constant speed

Since my previous post on R2-D2 flying was so popular, I thought I would follow it up. I was going to add these two points in the comments, but a separate post seems to make more sense. Point 1 – R2 flies at a constant speed Well, he obviously doesn’t always have to fly at…

Flying R2-D2, you are doing it wrong

You know I can’t help but like Star Wars. Even with the new stuff, I watch it. Recently, I was watching the Clone Wars cartoon and noticed something odd about the way R2-D2 flies. I know what you are saying….”the odd thing is that he flies at all. Why didn’t he fly in episodes 4-6?”…

Battery to power a house for a week

I saw this post about Panasonic’s home battery. The claim is that this will lead a battery that can power a house for a week. I wonder if I can estimate how big this battery would be. First – to estimate the energy a house consumes. My first approximation is that you could probably run…

RP 4: More on the movie Up! (or Upper)

So, analysis of the movie Up is pretty popular in the blogosphere. Figure I might as well surf the popularity wave. So, I have a couple more questions. The most important thing to estimate is the mass of the house. I am going to completely ignore the buoyancy of the house. I figure this will…

Underwater explosion analysis

I 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…

This was on my ‘to do’ list, but Tom at Swans on Tea beat me to it. Basically, this grocery store has these plates that when depressed produce electrical energy. Tom does a good job pointing out that this is not free energy (the original article says this also). Clearly, the energy comes from the…