Can We Travel To That Exciting New Exoplanet?

An anonymous reader writes "The news last week that exoplanet Gliese 581g may be in the 'Goldilocks zone' and could therefore hold liquid water and alien life got everyone all excited, with good reason. A potentially habitable planet — and only 20 light years away! But to put things in perspective, here are a couple of estimates on what it would take to travel to Gliese 581g. One scientist puts the travel time at 180,000 years based on current space flight technology, while another explains that it could be quite quick if we build a matter-antimatter drive, and can figure out how to bring along 530 times as much mass in fuel as is contained in the ship and cargo itself."

Comments

Re:Nuclear pulse propulsion

[Mr. Slippery]

A vegan diet reduces the need to support non-human animal mass, but adds a requirement to be able to synthesize some vitamins and proteins.

No, it doesn't. Protein needs are easily met on a vegan diet; the only vitamin that can really be troublesome is B12, which is made by bacteria and so doesn't need to be synthesized.

Re:Our world

[FrangoAssado]

You're forgetting that the volume is proportional to the cube of the radius, while gravity is proportional to the inverse square of the radius. So, while gravity doesn't increase linearly with mass, it's not constant either:

4x mass -> 4x volume -> 4^(1/3)x radius -> 4/4^(2/3)x gravity

So, gravity would be increased about 1.6 times. You should apologize to him if he weighs 380 pounds, not 500. :)