Re: A quote from Hawking
Resources on a planet can for the most part never actually be used up. It is one of these layman views on the world and how it works that is simplified until it is plain wrong. There are a few exceptions. We could theoretically use up radioactive materials and some fusion materials like heavy hydrogen. Also we can in theory, but that will take a stupid amount of effort, take in use all of some of the elements present on the planet. For instance we could mine out all the gold and take it in use, but unless we start shooting it out into space or radiate it with particles to turn it into lead we will never use it up. Gold will forever be gold.
Chemical compounds such as oil and coal can be taken out of the ground and spent. Then we have to lower our consumption to whatever rate it is replenished, which is quite small, or we have to make it ourself. But since what we really get out of fossil fuel is energy and not the chemicals themselves*, we can get that from somewhere else. If there is one thing we do not lack, it is energy. At this particular point in time though we do have a somewhat limited supply of energy we are able to use. We are also quite bad at making use of the energy we do spend. However let us assume that if we were able to build ships that could send our entire species through space then we are also able to make decent solar panels.
Then we have such things as food and other resources we harvest. But that is just it, we harvest them which implies that there is a replenishing supply. We can screw up the supply by over harvesting, but it is a hell of a lot easier to regulate the outtake than to go to another planetary system, adapt an existing flora (in lack of a better word) or terraform to suit your needs.
Expansion and colonization is of course valid reasons to go out there, but using up the resources are just stupid. Resources are used not spent in a close systems such as these. Whatever Hawkins are thinking of I don't know and I haven't bothered to read up on it, but I have some much faith in the man that it is either something he just said as some thinking aloud, he just wanted to seed a discussion and spark an interest in the population or his argument is more complicated than that.
*The chemicals are quite easy to make if we have energy.
Biting the hand that feeds IT
