We assume that life possibly came to Earth through the landing of a relatively large body of mass from somewhere else in the cosmos.  Could the inverse happen?  Could a large volcano (or any other natural means such as storm pressures or atmospheric disruptions), have sufficient energy and force to eject material from our planet (no matter how small a fragment, but sufficient to contain and protect bacteria) to send life onto somewhere else (no matter how improbable)?  Could Earth be a staging post in life's spread further across the universe?

If a camera was placed 1 light year away from Earth with a high enough definition, could it be used to spy on events that took place on Earth one year ago? And, if so, could this technique be used to record our past by sending an array of such cameras to the appropriate distance in order to capture momentous events in Earth's history?

Jon King, Swindon, Wiltshire, UK

If you were to fly in a rocket to the end of the universe, there should be something there to stop you getting out of the universe so what would it be and what would it feel like?  for the sake of this question just assume we could reach the point where the universe is expanding.

If you sink an object and then let go then it accelerates upwards. What if I sank something a very long way (say a mile or so)?

I've read in New Scientist about the potential of using supercavitation to travel very fast through water.

So what’s to stop me attaching a lightweight projectile onto a big rock with a piece of string which will detach at a certain depth, dropping it off a boat and firing something into space?

According to Einstein's famous equation E = MC2, or Energy = Mass times the speed of light times the speed of light. This tells us that anything that has mass, such as matter, is comprised entirely of energy. Any physical object with mass is therefore simply a lump of energy existing in some stable form.

As I understand it, all forms of energy, including chemical energy, kinetic energy and potential energy are covered by Einstein's equation, meaning that fundamentally all forms of energy are the same basic 'stuff' (for want of a better word). My question is, therefore, what exactly is energy? I want to get to a fundamental understanding of energy, because it seems that such an understanding would help to explain much of reality.

I'm not asking for explanations about work done etc, I'm asking at the fundamental level what is energy?

An electron is both a particle and a wave, and we cannot define exactly where a subatomic particle/wave is because it is spread out across time and space - we can only define it through probabilities. Wouldn't there need to be infinite precision and no uncertainty in nature for nature to be deterministic? Considering that infinite precision and certainty don't appear to exist - because experiments show randomness and uncertainty exists at the heart of nature, then would it be correct to assume that both atomic and subatomic particles/waves do not always interact with one another with infinite precision and if so then is it correct to conclude that nature cannot be deterministic - i.e. by having exact knowledge of the starting conditions of the universe and infinite computing power it would still be impossible to calculate exactly how the universe would evolve?

Are all the stars we can see within the milky way?  and if so are there any stars that are in the spaces between galaxies?

I was thinking about this when star trek was on, as they always have millions of stars in the background of space shots.  Does this mean that instead of exploring the whole universe they were actually only looking around in one galaxy?

If a space craft uses a laser to push it along in space could it at one point hit the speed of light?

I herd that are people that are trying to build a space elevator, but is there a tether strong enough to take the strain of a space station on the other end of the tether ? 

My limited understanding of science tells me that

a year is the period taken for the earth to orbit the sun, but

seasons are dictated by the tilt of the earth.

Why should there be a link between these?