Recent content by user299792458

Isn't a spherically symmetric transverse wave inconsistent with the "hairy ball" theorem that has been mentioned here?

I've never heard of that theorem (just looked it up in Wikipedia), but that's basically what I was thinking, that you can't have a truly spherically symmetric EM wave. It seems that even the magnitude of the electric field vectors can't be completely spherically symmetric? So I guess it varies...

What does the electric field of a "spherical wave" look like? You often hear about spherical light waves. For example, something like a light bulb is said to emit waves which are more or less spherical. Let's assume this light bulb is perfectrly round and emits in all directions (as opposed to...

It is often stated that ANY accelerating charge radiates, so this includes uniformly accelerating charges. But the radiation reaction force is proportional to the THIRD derivative of x, so it vanishes when acceleration is constant. What's the deal here? Here's a graph which supposedly shows...

:biggrin: I'm just saying, I'm not very impressed with this cheap trick. There are many impressive tricks various animals can do, but I don't think this is one of them.

Twiggy the Water Skiing Squirrel - OH REALLY? Ok, you've probably seen this, the squirrel which, supposedly, water skis. But to me, it looks like the damn thing is simply riding in a boat (made to look like a pair of water skis) which is being pulled by another boat. I find it annoying that...

Um, and how many parking lots have STAIRS? Parking spots for the "disabled" are merely closer to the entrance than the other ones, but it's not like if you park somewhere else you have to go down an extra flight of stairs. And I think if you add spikes to that thing it would be better for...

I don't disagree with you about the possibility that prosthetics do provide an advantage for maintaining speed (although certainly not for accelerating, to accelerate quickly with prosthetics, they would need a built in power source). However, you do have to consider that all other double...

I'm sure (or hope, anyway) people know that the ankle is operated by the calf muscle. Here are some links, you can find more by googling "Oscar Pistorius": http://sport.independent.co.uk/olympics/article2377707.ece http://www.wired.com/wired/archive/15.03/blade.html...

Biological legs vs Cheetah prosthetic legs - which is better for running? EDIT: I misspelled "which" in the subject line, how embarrassing. You may have heard of Oscar Pistorius, a double below-knee amputee from South Africa who recently won the silver medal in the 400m at the South African...

It would've been better if she had been concerned about moving conveyor belts though...

The last time I checked, most students were getting more like $6/hour, not $24.

But check this out: Can you imagine getting paid $24 an hour for pushing paper around with a broom (which is what she did, according to another article)? Well, that's sweet, guess she had a loving father. Why wasn't she making pancakes for him though?

LOL! As I read her story, I noticed that she mentioned her parents, her friends, her co-workers, but she never ever mentioned how her boyfriend reacted to the accident! At first, I thought maybe she had a girlfriend instead of a boyfriend, but then I read another article about her, which said...

Yeah... I find her statements to be pretty shocking actually. I just can't wrap my mind around the fact that a (presumably non-retarded) 21-year-old would say such things. I remember when I was 12 I already knew very well that I had to look out for myself, I didn't even trust close relatives to...