Jenny Phillips, Warwick England

I realize that these are 3 quite different environments with regard to atmosphere and gravity, and therefore should involve 3 different answers.

For example I am wondering, in the following thought experiment: If you have a single atom resting in a vacum and it is hit by a photon, causing it to heat, what is the reason for the resulting motion of the atom? i.e. what intrinsic changes occour in a single atom when heat is applied.

During an A-Level physics lesson we were shown a cross-section of a super-conductive wire that consisted of copper wire strands and several super-conductive fibres. If a super-conducting material has no resistance what-so-ever, then surely an infinite current can be passed through it (V=IR) and so what is the need for more than one super-conductive fibre?

I'm reading a sci-fi novel about an encounter with people from another universe, with different laws of physics giving rise to differen matter. would such matter even be able to exist in this universe? if it could, would we be able to see them? smell them? could they breathe our air and eat our food?

i have this Physics question from my teacher that says:

'Dogs are pulling a sled on the snow. If the dogs have stopped pulling draw the force diagram'

Well apparently the question only had three forces - gravity (pulling down), reaction forces (arrow going up), and friction (pulling the opposite directiong of the sled).

Well we also learnt that forces come in pairs so can someone please explain how this is possible. And if it is not can you please give the correct answer as I also put the force inertia which is currently wrong...

When physicists first split the atom by firing a proton at it, how did they a/ get a proton in the first place, and b/ know they were firing a proton, since they had not yet split the atom?

Whilst studying Mechanics (M1), you often use "light and inextensible" to describe string. So my friend posed a hypothetical question that if you had some string that was 1million light years long with me on one end and him on the other. If he pulled one end how long would it take for the my end to move. I thought it would be instantaneous but my teacher thought different.