4 ms·

If poodles are at a zero, we are at a zero too. We can "theoretically" dump massive quantities of cash into building a giant craft but we are nowhere close to m

by pekk 14y ago

If poodles are at a zero, we are at a zero too. We can "theoretically" dump massive quantities of cash into building a giant craft but we are nowhere close to making a craft or society that will sustain itself for ~100,000 years until it gets to another star. We cannot even guarantee that we can sustain ourselves with all the earth's resources without wiping out our own society for 100 years.

davedx 14y ago
Where do you get the 100,000 years number to get to another star?
- pekk 14y ago
  Where do you get any number? It's a back of the envelope, order-of-magnitude thing. We don't have anything close to faster-than-light spacecraft and there's no reason to think we will in the near future, except for pure religious hope.
  - coldtea 14y ago
    >Where do you get any number? By studying the actual quantities involved? >It's a back of the envelope, order-of-magnitude thing. No, that's not how you get "any number". Just some of them, the more sloppy ones. The nearest star is like 5 light years away. With 1/10 of the speed of light that's like 50 years. Wanna make it 1/100 and 500 years? In any case much less than the 100,000 years estimation. >We don't have anything close to faster-than-light spacecraft and there's no reason to think we will in the near future, except for pure religious hope. First, we don't need "faster than light" to make it to there to less than 100,000 years. Second, we actually DO have some ideas about that, too: http://www.space.com/17628-warp-drive-possible-interstellar-spaceflight.html http://www.space.com/17628-warp-drive-possible-interstellar-...
  - jacobparker 14y ago
    > It's a back of the envelope, order-of-magnitude thing. You... need to work on that. There are plenty of stars within 14 light years. https://www.google.ca/search?client=ubuntu&hs=HNq&channel=cs&q=%28%2814+light+years%29+%2F+%28100000++years%29%29+%2F+speed+of+light&oq=%28%2814+light+years%29+%2F+%28100000++years%29%29+%2F+speed+of+light&gs_l=serp.3...2254.7658.0.7809.23.23.0.0.0.0.212.2144.12j10j1.23.0...0.0...1c.1.11.serp.A_x0eX9ctDA https://www.google.ca/search?client=ubuntu&hs=HNq&ch... If you took 100,000 years that would be a speed of 0.00014c. That is pretty pessimistic - we have put objects into space that are travelling away from earth faster than that already! (Yada yada accleration :).) At 0.1c you can go 14 lightyears in 140 years. There are stars closer than this. http://en.wikipedia.org/wiki/List_of_nearest_stars#Map_of_nearby_stars http://en.wikipedia.org/wiki/List_of_nearest_stars#Map_of_ne...
    - acqq 14y ago
      > If you took 100,000 years that would be a speed of 0.00014c. That is pretty pessimistic - we have put objects into space that are travelling away from earth faster than that already! Citation needed. http://en.wikipedia.org/wiki/Voyager_1 http://en.wikipedia.org/wiki/Voyager_1 travels now at 17 km/s which is cca 6e-5 of c, twice slower than your 1.4e-4. However the bigger the object, the inertia is bigger too, so it is harder to speed up the bigger things, especially anything that would sustain life long enough for more generations. Then don't forget, as much as you speed up something, you have to speed it down too and you need the same amount of energy for that.
      - jacobparker 14y ago
        http://en.wikipedia.org/wiki/Helios_(spacecraft) http://en.wikipedia.org/wiki/Helios_(spacecraft) 70 km/s. I personally wouldn't want to take that specific trip, but regardless :) Inertia is a much smaller problem than subjecting humans to acceleration :) You can't afford to accelerate fast anyway. Thankfully spacecraft speed up and slow down quadratically with respect to acceleration. To get to a speed of 0.00014c if you were accelerating at 9.8m/s^2 ("Earth gravity") you would need to wait... https://www.google.ca/search?client=ubuntu&hs=2dC&channel=cs&q=%280.00014+*+speed+of+light%29+%2F+%289.8m%2Fs%5E2%29&oq=%280.00014+*+speed+of+light%29+%2F+%289.8m%2Fs%5E2%29&gs_l=serp.3...62176.68334.0.68491.22.21.1.0.0.3.122.1601.18j3.21.0...0.0...1c.1.11.serp.zU9YJuGGHp0 https://www.google.ca/search?client=ubuntu&hs=2dC&ch... 1 hour and 15 minutes to reach top speed. (The same to slow down (ignoring relativistic effects.)) This is a drop in the bucket vs. 100,000 years, or a human lifetime :)

by pekk 14y ago

davedx 14y ago

Where do you get the 100,000 years number to get to another star?

pekk 14y ago
Where do you get any number? It's a back of the envelope, order-of-magnitude thing. We don't have anything close to faster-than-light spacecraft and there's no reason to think we will in the near future, except for pure religious hope.
- coldtea 14y ago
  >Where do you get any number? By studying the actual quantities involved? >It's a back of the envelope, order-of-magnitude thing. No, that's not how you get "any number". Just some of them, the more sloppy ones. The nearest star is like 5 light years away. With 1/10 of the speed of light that's like 50 years. Wanna make it 1/100 and 500 years? In any case much less than the 100,000 years estimation. >We don't have anything close to faster-than-light spacecraft and there's no reason to think we will in the near future, except for pure religious hope. First, we don't need "faster than light" to make it to there to less than 100,000 years. Second, we actually DO have some ideas about that, too: http://www.space.com/17628-warp-drive-possible-interstellar-spaceflight.html http://www.space.com/17628-warp-drive-possible-interstellar-...
- jacobparker 14y ago
  > It's a back of the envelope, order-of-magnitude thing. You... need to work on that. There are plenty of stars within 14 light years. https://www.google.ca/search?client=ubuntu&hs=HNq&channel=cs&q=%28%2814+light+years%29+%2F+%28100000++years%29%29+%2F+speed+of+light&oq=%28%2814+light+years%29+%2F+%28100000++years%29%29+%2F+speed+of+light&gs_l=serp.3...2254.7658.0.7809.23.23.0.0.0.0.212.2144.12j10j1.23.0...0.0...1c.1.11.serp.A_x0eX9ctDA https://www.google.ca/search?client=ubuntu&hs=HNq&ch... If you took 100,000 years that would be a speed of 0.00014c. That is pretty pessimistic - we have put objects into space that are travelling away from earth faster than that already! (Yada yada accleration :).) At 0.1c you can go 14 lightyears in 140 years. There are stars closer than this. http://en.wikipedia.org/wiki/List_of_nearest_stars#Map_of_nearby_stars http://en.wikipedia.org/wiki/List_of_nearest_stars#Map_of_ne...
  - acqq 14y ago
    > If you took 100,000 years that would be a speed of 0.00014c. That is pretty pessimistic - we have put objects into space that are travelling away from earth faster than that already! Citation needed. http://en.wikipedia.org/wiki/Voyager_1 http://en.wikipedia.org/wiki/Voyager_1 travels now at 17 km/s which is cca 6e-5 of c, twice slower than your 1.4e-4. However the bigger the object, the inertia is bigger too, so it is harder to speed up the bigger things, especially anything that would sustain life long enough for more generations. Then don't forget, as much as you speed up something, you have to speed it down too and you need the same amount of energy for that.
    - jacobparker 14y ago
      http://en.wikipedia.org/wiki/Helios_(spacecraft) http://en.wikipedia.org/wiki/Helios_(spacecraft) 70 km/s. I personally wouldn't want to take that specific trip, but regardless :) Inertia is a much smaller problem than subjecting humans to acceleration :) You can't afford to accelerate fast anyway. Thankfully spacecraft speed up and slow down quadratically with respect to acceleration. To get to a speed of 0.00014c if you were accelerating at 9.8m/s^2 ("Earth gravity") you would need to wait... https://www.google.ca/search?client=ubuntu&hs=2dC&channel=cs&q=%280.00014+*+speed+of+light%29+%2F+%289.8m%2Fs%5E2%29&oq=%280.00014+*+speed+of+light%29+%2F+%289.8m%2Fs%5E2%29&gs_l=serp.3...62176.68334.0.68491.22.21.1.0.0.3.122.1601.18j3.21.0...0.0...1c.1.11.serp.zU9YJuGGHp0 https://www.google.ca/search?client=ubuntu&hs=2dC&ch... 1 hour and 15 minutes to reach top speed. (The same to slow down (ignoring relativistic effects.)) This is a drop in the bucket vs. 100,000 years, or a human lifetime :)