Magnets!

[Cipher]

Originally Posted by Have At You

The red shift part of your question arises from a common confusion about what causes it. Popular conception is that it is a Doppler effect, that the stars are moving away and therefore the light appears to have a longer wavelength, like a passing siren gets lower in tone as it recedes.

In fact, there is no Doppler effect to light waves, because they are the ultimate relative phenomenon. That's a big part of relativity.

Which means that no matter how fast or slow the universe expands, light travels from point A to point B at the same relative rate.

Actually that is incorrect. There is a doppler effect with light (and all types of electromagnetic radiation), but it doesn't disagree with relativity in any way. It is actually because of relativity that this would occur. There is also a few different reasons that a change in frequency or wavelength can be observed in the electromagnetic spectrum; relative motion of bodies (doppler effect), strong gravitational fields (gravitational redshift), and the expansion of the universe itself (cosmological redshift). It is even possible for all three effects to be taking place at the same time (relative motion between bodies, photons coming from far enough away that cosmological redshift is visible, and the photons travelling past a strong gravitational field such as that produced by a super-massive black hole).

[J.Harris]

Originally Posted by Soldier

if you break a magnet in half, you don't end up with a North end and a South end. You end up with two smaller magnets, each with a North and South end. What's up with that?

I think someone may have mention this on here earlier.

Inside a magnet are lots of little magnets, all pointing north. This is what makes it mangnetic
S>>>>>>>>>>N

If you break it in two you have two magnets each made up off little magnets still pointing North.
S>>>>N S>>>>>N

[scrapinpeg]

Originally Posted by Cipher

Actually that is incorrect. There is a doppler effect with light (and all types of electromagnetic radiation), but it doesn't disagree with relativity in any way. It is actually because of relativity that this would occur. There is also a few different reasons that a change in frequency or wavelength can be observed in the electromagnetic spectrum; relative motion of bodies (doppler effect), strong gravitational fields (gravitational redshift), and the expansion of the universe itself (cosmological redshift). It is even possible for all three effects to be taking place at the same time (relative motion between bodies, photons coming from far enough away that cosmological redshift is visible, and the photons travelling past a strong gravitational field such as that produced by a super-massive black hole).

Cosmological redshift is more important for objects beyond our local group of galaxies. Doppler redshift is more important for local objects. Gravitational redshift is just cool -- photons losing energy by passing through gravity fields.
Something to do with the universe being a bedwetter, I am led to understand. Makes as much sense as anything else.

I still don't understand where the energy is coming from in magnetism. Say I put a strong magnet at the top of a small ramp. I put a steel marble at the bottom of the ramp. The steel ball rolls up the ramp and sticks to the magnet. This took energy to overcome gravity and friction. What created the energy?

[Cipher]

Originally Posted by scrapinpeg

Something to do with the universe being a bedwetter, I am led to understand. Makes as much sense as anything else.

Hehe... yeah, the old rubber sheet analogy.

Originally Posted by scrapinpeg

I still don't understand where the energy is coming from in magnetism. Say I put a strong magnet at the top of a small ramp. I put a steel marble at the bottom of the ramp. The steel ball rolls up the ramp and sticks to the magnet. This took energy to overcome gravity and friction. What created the energy?

The energy comes from the potential energy stored in the field. That potential energy is put there, in the case of ferromagnetism, by the electrons orbitting the nuclei of the atoms and their "spin" property. It's much easier to demonstrate with an electric current (electrons) moving through a coil. In that case you can even measure the power spike that occurs when you collapse the field and the potential energy is flooded back into the system.

[Soldier]

Originally Posted by mrbiggs

Actually, those are magnets hovering over the magnetic coffee, which is being developed by the air force.

(By the way, you draw the friction as pulling the magnet up. Yet I'd say that it's just making the magnet stay where it is. In other words, if the gravity were removed, the magnet wouldn't travel up. What am I missing?) ('Cuz I know I'm missing something.)

As others have mentioned, yes, friction is a reaction force. There's actually another reaction force that I didn't bother to draw on there, which is the force of the refrigerator on the magnet.

[Soldier]

Originally Posted by J.Harris

I think someone may have mention this on here earlier.

Inside a magnet are lots of little magnets, all pointing north. This is what makes it mangnetic
S>>>>>>>>>>N

If you break it in two you have two magnets each made up off little magnets still pointing North.
S>>>>N S>>>>>N

That's...exactly what I said. The issue, again, is that it is not a relative matter.

S>>>>>>>>>>N
becoming
S>>>>N S>>>>N
implies that when you break one of the smaller magnetic areas in two, the first N is north only relative to the other end, but in fact still south relative to the other half; this is not true.

[Cipher]

Originally Posted by Soldier

That's...exactly what I said. The issue, again, is that it is not a relative matter.

S>>>>>>>>>>N
becoming
S>>>>N S>>>>N
implies that when you break one of the smaller magnetic areas in two, the first N is north only relative to the other end, but in fact still south relative to the other half; this is not true.

An interesting thing regarding this is that some modern physics theories, including string theory, indicate that magnetic monopoles "should" exist. I think one of the latest theories predicts that only a single monopole exists in the universe though. It would be very interesting to see what kind of properties that thing has if it is discovered.

[Soldier]

Only one? How the heck does that work?

And how would we find it, anyway? Just be walking along someday, exploring a new planet, trip over something, and be like, "What the - hey, check out what I found!"

Or maybe some other race has already found it, and they've got it in a museum someplace...

[Cipher]

Not sure... center of the universe maybe??? I'm not as up on my cosmology as I should be.

[ThatReallyHurt]

Originally Posted by Soldier

Or maybe some other race has already found it, and they've got it in a museum someplace...

Hmm... monopole magnets would have made building the pyramids an awful lot easier, methinks...

[mrbiggs]

Originally Posted by Cipher

An interesting thing regarding this is that some modern physics theories, including string theory, indicate that magnetic monopoles "should" exist. I think one of the latest theories predicts that only a single monopole exists in the universe though. It would be very interesting to see what kind of properties that thing has if it is discovered.

Wouldn't it be like gravity, except with the electromagnetic force?

By the way, here's something I've been thinking. If you make a spherical magnet, where are the poles?

[Soldier]

I think it would split itself N/S along some arbitrary circumference.

[mrbiggs]

Originally Posted by Soldier

I think it would split itself N/S along some arbitrary circumference.

but how would it choose the circumference?

[Soldier]

One half would become N, the other S. If you split a sphere in half, you've got a circumference by default.

[ThatReallyHurt]

Originally Posted by mrbiggs

but how would it choose the circumference?

Inside the magnet, the N/S lines go straight through from one pole to the other. If you cut away a spherical shape, you'll end up with a sphere where half is N and the other half is S. Don't think of it as a spherical magnet - think of it as a bar magnet where parts have been chipped off so it looks like a sphere...

[Cipher]

The poles wouldn't be arbitrary, it would depend on the orientation of the atoms of the substance, or in the case of a created permanent magnet, it would depend entirely on the field that it was exposed to.

[Westley]

I have a better question that all you quantum geniuses probably can't answer. WHY ARE ALL WOMEN INSANE!?!?!?!?!?!?

[Epee_Pox]

Originally Posted by Westley

I have a better question that all you quantum geniuses probably can't answer. WHY ARE ALL WOMEN INSANE!?!?!?!?!?!?

Example, please. They're insane for different reasons, so it depends on what particular insanity you've experienced.

[Epee_Pox]

Originally Posted by Epee_Pox

Wow, there must be physics in the air today. I woke up with a profound feeling of "aha!" this morning, about the nature of photons. (Probably the result of strange dreams brought on by a midnight snack of oreos and scotch.)

My "aha!" was that photons could be considered, not so much things in and of themselves, but rather points of intersection between three fields at right angles to each other -- the X & Y of the electromagnetic field, and the Z axis being gravity.

This would explain how photons appear to behave as massless pointlike particles, while really behaving as waves that somehow are able to interfere with themselves.

Probably wrong, but it's good enough for Monday morning.

Wow, see what oreos and scotch can do? Oddly enough, there's some new papers out there that sound vaguely like this, only with actual evidence and serious thinking having gone into it first. I'm content to let others do the hard work, so long as I get credit for thinking of it first.