Never ask a deep physics question on a Yahoo Answers forum. I'll give you a hint: there aren't any experts (seemingly of anything) who bother using Yahoo.

For anything.

During my furious and ultimately pointless study session last night, I realized something interesting. Let me begin with the obvious. Matter has potential energy and kinetic energy. Kinetic energy is easy: it's the energy an object gets from being in motion. When I throw a ball, I add kinetic energy to it. M(V^2)/2.

Potential energy is a little trickier. It's the amount of energy an object MIGHT have. It's situational; if I have a have a ball on a table, I could say it has 0 potential, or some number x, or some huge number X, depending on if I use the table, the ground, or the center of the planet as my reference point. If I "drop" it onto the table, it won't gain energy because it's already there. If I drop it from table height to the ground, it'll have x joules of kinetic energy when it hits. If I drop it to the center of the earth, it'll have...a lot more kinetic energy when it hits.

Potential is based purely on position and acting forces. Kinetic is based purely on mass and velocity. Energy flows between one and the other. If I hold my ball over the ground, it has x potential and 0 kinetic. After I drop it, right before it hits the ground, it has exactly 0 potential and x kinetic energy. Pretty cool.

So we're studying electrodynamics. It's time dependent electronic and magnetic fields, and how they get mixed up. A single charged particle creates an electric field, sort of like gravity (except gravity always attracts, but electric fields can repel). If the charge is moving, it creates a magnetic field, which is pretty complicated. I'm skipping a lot of stuff, but basically when you put the two together you can get crazy things. If I drive a current through a loop, it creates a magnetic field. Let's say that field goes through a different loop that isn't connected at all to the first loop. If my current changes, the magnetic field changes, and that changing field drives a current through the second loop.

That's pretty cool, but it's not my point. Another effect is that if there's a current, the field lines from the first loop are actually affecting it as well. If I try to change the current, the changing field lines make a new current that counters the change I've made. It's called self-inductance, and it's sort of like inertia, the property of mass that makes it want to stay the same speed. The current wants to stay the same. In fact, if I call the inductance L and the current I, then the energy I have to expend to create the current is L(I^2)/2.

Wait.

Inductance acts just like inertia, and the energy stored in a magnetic field looks and acts the same as kinetic energy.

As for stationary charges, the energy I have to expend to make a configuration of charges (for example, holding together two charges that don't want to be close) is related to their position...and the force that they exert on each other.

Do you see what I'm getting at? Kinetic and Potential energy of matter correspond to electric and magnetic energy, respectively.

That's about as far as I've taken the parallel. Not very exciting. :D Have a good day guys.

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I'm going to bed now.

I'm more than mildly surprised that nobody felt the urge to respond to the post before...

Today was awesome because I had been missing Katezor on the weekends and now I won't have to until the next homework splurge (tomorrow).

Good night to everybody!

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Listening to music as much as I do, I'm starting to get the urge to post the lyrics everywhere. On second thought, I already do that. The heck?

I used to not listen to music. EVER. And the music I did like, I only liked because I didn't listen to it. Hahaha. I definitely remember there were some Disney endorsed songs on there. And "Who Let The Dogs Out?" Oh, geeze.

Thankfully, my "aunt" Donna gave me a Sansa E200 as a Christmas gift, and I've been perfecting my musical taste since then.

And what a long way I've come. Phew.

Hey, I could have written about that for my life changing event. And it would have been much less emotional. Crud.

EDIT:

wiseguysupreme4: Dodododo
Romanticocabrita: :3
Romanticocabrita: Hi.
wiseguysupreme4: Rollin' deep in momentum.
wiseguysupreme4: ...oops.
wiseguysupreme4: Hai.

See what I mean?

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It's the summer. I'm allowed to use passive voice and make tense shifts. Although, it would probably be a good idea for me to stay in the habit...blah.

Did I say how Ian's game disk has a bajillion scratches, but AJ's only had 5 or 6 light ones? And did I go on to say that I thought it was weird that Ian's disk would be the one that had the most data still intact?

Because I do think that's weird. AJ's disk wouldn't even start, and Ian's only had problems in certain areas of the game.

Well. Not weird, because it's a possibility, but worth commenting on. Anyway.

I went to the local music store with AJ's disk because I heard they had a machine that would buff the scratches out of it. The guy looks at me and says, "Dude, I'm just going to say that I don't think any of these scratches are deep enough to be causing the problem." For a while that worried me, because if the scratches on the bottom weren't problematic, then the problem was coming from scratches on the top. And you can't fix them. But I told him to clean it anyway, and it's fine now, so it's all good.

-phew-

Ian didn't fix his disk because he thought it would drain him on cash. (It was only 3 bucks for the first disk, 2 for the rest.) Instead he cleaned it himself.

With Windex.

And now it works fine, apparently. Even with all those scratches.

-facepalm-



This is the first song I ever heard by Family Force 5. I don't listen to them anymore much, but they still hold a certain charm for me. Especially this song.

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