If fusion is a 'clean' source of energy, why is there so much radiation in space?
Chris - The answer is that in space thereís nothing to stop the radiation and so thereís a million mile an hour maelstrom of cosmic radiation which is streaming off our own sun. If we didnít have the magnetic field of the Earth to deflect it away then it would be basting us in radiation. It would also be plucking away our water and our gases on our planet and weíd end up like Mars ultimately did. It isnít a safe and nice hospitable place in space. Itís not just because of the use of fusion.