I've been told that temperature can be explained by how fast molecules are moving around, the higher the temperature the faster they move and the more kinetic energy they have.  This is however confusing as different molecules will move around at different paces and will exist as different states at the same temperature i.e. at room temperature oxygen will be a gas whereas molecules in a chair will be solid.

 Therefore how do you define temperature?

Scientists said that the Big Bang was caused by the conversion of energy into mass, according to Einstein's E=mc2 formula. But where does this energy come from? And what actually triggered the Big Bang?

If one drops a frozen turkey from a table, it hits the floor. If one instead drops it from space, it burns up in the atmosphere. Thus, there should be one altitude in between from which you can drop it for it to be done when it comes down.

I realize that it's probably going to go black on the outside and still stay frozen on the inside. How can you deal with this? I will accept leaving it for some time after the fall to allow the heat to distribute properly, I will also accept some or a lot of the outside to burn up if the centre is cooked, burned turkey can be removed but I've heard bad things about uncooked bird.

How does this change with the stuffing? Will it help a lot to thaw it?

Weather across the UK and Western Europe appear to be strongly affected by the position of the jet stream and its involvement in moving storms across the Atlantic.

From what i've read the temperature contrasts between the subtropical and polar air mass along with the corriolis force create a strong wind high up in the atmosphere.  What I want to know is why the jet stream migrates northwards and southwards with the seasons and meanders around a bit?

 I can understand why the jet stream might be slower during the summer as the temperature contrasts between the air massess are lower, but i still dont understand the physics of why it moves.

How do people think the jet stream will respond to climate change?

The inflation model is apparently needed to explain why the universe is homogeneous at large scales as there would be not be enough time for photons to travel between points if inflation had been constant.

Feynman's QED series says that there are small probability amplitudes for photons travelling faster than the usual speed of light.

In the early universe where space was small in each dimension, wouldn't the Uncertainty Principle have caused photons' velocity to fluctuate wildly and be above the general speed of light much more often than normal, thereby allowing signals to move from one part of the early universe to another very quickly and removing the need for an exponential inflation theory? Please can someone inform me what is wrong with this logic =)

Take a simple wooden spinning top, manually set it spinning say in a clockwise direction (viewed from above).

As the top slows it becomes more wobbly.  Eventually to the point where one edge of the top touches the surface it's spinning on.  Then as if by magic (to me at any rate) it comes to halt spinning in the opposite direction (completely on it's outer edge).

How can all of this rotation energy suddenly change direction?

Thanks.

Mal

Royston, Herts.

I've worked out mine because I'm applying to Uni, and I've shoved it into my personal statement. I want to make sure I have a reasonable (approximate) answer, so if you fancy working out an approximation of your angular momentum, it would be really useful. 

It's also quite a fun experiment. Don't get too dizzy. 

Say, a diamond. Tetrahedral giant structure with each carbon atom bonded to four other carbon atoms. What happens at the surface of the diamond where the last atom is? Does it just end with one layer of atoms with incomplete octets?