5 ms·

The fastest spacecraft ever built would take 4000 years to travel one light year.

kowdermeister 9y ago
In 4000 years we can build way way more faster ships and catch up to those poor guys launched a centuries earlier just because they thought they are fast enough :) On the serious side, we only need antimatter and the drive problem is kind of solved (yes, I might be the one in the good enough ship :)).
- jcadam 9y ago
  Good, the folks on the faster ship can arrive ahead of us 'poor guys' on the first ship and get stuck with all of the hard work of establishing the colony and performing any necessary terraforming before we arrive.
  - kowdermeister 9y ago
    It would still suck to arrive at a supposed to be human free planet just to realize they have a 2000 years of history :) On the other hand, they would probably have beer.
    - pc86 9y ago
      If they don't, I'm going back home.
- delecti 9y ago
  I don't see us doubling-up on the initial missions unless it becomes really trivial to catch up. Even if technology gets a 4000 year trip down to 500, even or 100, we'd probably just let the poor 4000 year schmucks go on their way. If it got down under a year maybe, but predicting what might happen if we invent FTL is a job for people who are deliberately making things up.
- peckrob 9y ago
  What you're describing is called the Wait Calculation [0]. 0. https://en.m.wikipedia.org/wiki/Wait_Calculation https://en.m.wikipedia.org/wiki/Wait_Calculation
lmm 9y ago
If we wanted it badly enough, we could get to tau Ceti with current technology. The Orion designs are sound, and could carry a population capable of sustaining itself for the 100-odd years it would take to get there.
- gnarbarian 9y ago
  https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... Project Orion is awesome and I am a big supporter. Unfortunately people won't stand for the thousand some odd nuclear bombs it would take to get the interplanetary version out of the atmosphere. Because it is so massive, building it in space also poses a problem unless we capture a iron meteorite and bring it back or mine/build it on the moon. Both of which we should really do because it would be by far the fastest ship we can build right now.
  - dmix 9y ago
    Is there a significant difference between a nuclear explosion in space compared to on earth? Would it be less powerful or offer greater thrust?
    - sqeaky 9y ago
      A nuclear explosion in space wouldn't push against the air and would expand spherically unless somehow contained. Because it doesn't use conventional chemistry the presence or absence of chemicals, like ambient oxygen wouldn't change the output (like it might for a fuel air bomb) but their their properties might change it. Air will provide some resistance and fluoresce at high enough temperatures. I am curious how big this effect would be though. Debris leaving a nuclear explosion in space would only stop when it hit something and that I think is the biggest flaw with the Orion motor. If the motor and fuel can be designed so only particles are emitted and somehow ensure that no bullet size fragments are ejected then it seems likely it could be made safe in a practical sense.
      - dmix 9y ago
kyberias 9y ago
But isn't it merely about fuel? I mean, in space you can just accelerate to most any speed significantly under light-speed just by running the engines. Right?
- peatmoss 9y ago
  Believe so, but the major limiting factor is the amount of mass that you can carry to eject out the back of your ship. The Expanse series is predicated on the development of a reactionless drive that converts energy directly into thrust without expenditure of mass. If such a technology existed, you could get going pretty fast just motoring along at a constant 1-g acceleration, and have "gravity" too.

In 4000 years we can build way way more faster ships and catch up to those poor guys launched a centuries earlier just because they thought they are fast enough :) On the serious side, we only need antimatter and the drive problem is kind of solved (yes, I might be the one in the good enough ship :)).

jcadam 9y ago
Good, the folks on the faster ship can arrive ahead of us 'poor guys' on the first ship and get stuck with all of the hard work of establishing the colony and performing any necessary terraforming before we arrive.
- kowdermeister 9y ago
  It would still suck to arrive at a supposed to be human free planet just to realize they have a 2000 years of history :) On the other hand, they would probably have beer.
  - pc86 9y ago
    If they don't, I'm going back home.
delecti 9y ago
I don't see us doubling-up on the initial missions unless it becomes really trivial to catch up. Even if technology gets a 4000 year trip down to 500, even or 100, we'd probably just let the poor 4000 year schmucks go on their way. If it got down under a year maybe, but predicting what might happen if we invent FTL is a job for people who are deliberately making things up.
peckrob 9y ago
What you're describing is called the Wait Calculation [0]. 0. https://en.m.wikipedia.org/wiki/Wait_Calculation https://en.m.wikipedia.org/wiki/Wait_Calculation

lmm 9y ago

If we wanted it badly enough, we could get to tau Ceti with current technology. The Orion designs are sound, and could carry a population capable of sustaining itself for the 100-odd years it would take to get there.

gnarbarian 9y ago
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls... Project Orion is awesome and I am a big supporter. Unfortunately people won't stand for the thousand some odd nuclear bombs it would take to get the interplanetary version out of the atmosphere. Because it is so massive, building it in space also poses a problem unless we capture a iron meteorite and bring it back or mine/build it on the moon. Both of which we should really do because it would be by far the fastest ship we can build right now.
- dmix 9y ago
  Is there a significant difference between a nuclear explosion in space compared to on earth? Would it be less powerful or offer greater thrust?
  - sqeaky 9y ago
    A nuclear explosion in space wouldn't push against the air and would expand spherically unless somehow contained. Because it doesn't use conventional chemistry the presence or absence of chemicals, like ambient oxygen wouldn't change the output (like it might for a fuel air bomb) but their their properties might change it. Air will provide some resistance and fluoresce at high enough temperatures. I am curious how big this effect would be though. Debris leaving a nuclear explosion in space would only stop when it hit something and that I think is the biggest flaw with the Orion motor. If the motor and fuel can be designed so only particles are emitted and somehow ensure that no bullet size fragments are ejected then it seems likely it could be made safe in a practical sense.
    - dmix 9y ago

kyberias 9y ago

But isn't it merely about fuel? I mean, in space you can just accelerate to most any speed significantly under light-speed just by running the engines. Right?

peatmoss 9y ago
Believe so, but the major limiting factor is the amount of mass that you can carry to eject out the back of your ship. The Expanse series is predicated on the development of a reactionless drive that converts energy directly into thrust without expenditure of mass. If such a technology existed, you could get going pretty fast just motoring along at a constant 1-g acceleration, and have "gravity" too.