4 ms·

One thing I've always wondered is what fraction of c is actually realistically achievable with current technologies? (Maybe with scenarios for manned/unmanned s

One thing I've always wondered is what fraction of c is actually realistically achievable with current technologies? (Maybe with scenarios for manned/unmanned spacecraft.) Like are we at 0.1% or 0.01% or more orders of magnitude off?

Scarblac 1y ago
According to the first Google hit, https://scitechdaily.com/nasas-parker-solar-probe-the-fastest-spacecraft-ever-just-skimmed-the-sun-at-430000-mph/ https://scitechdaily.com/nasas-parker-solar-probe-the-fastes... , the fastest we've made so far went 430k mph (falling towards the sun), or about 0.064% of c. Good guess.
anon_cow1111 1y ago
We have a number! Around 0.1c maximum and unsurprisingly it involves using nuclear bombs to push yourself. https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
btilly 1y ago
If you enjoy such questions, I highly recommend https://www.amazon.com/Indistinguishable-Magic-Robert-L-Forward/dp/0671876864 https://www.amazon.com/Indistinguishable-Magic-Robert-L-Forw.... The best speed for interstellar travel with technologies that current theory says should be within our reach can be achieved with a vehicle with a light sail pushed by a giant laser, that is powered by solar power. There is even a way to brake it when it reaches the target star. I forget what the predicted velocity was though. This technology is basically the same as one that the Moties developed in the story, The Mote in God's Eye.
- DiggyJohnson 1y ago
  Slow down by pulling on the fishing line tied to the back of it, carefully.
  - btilly 1y ago
    It slows down by releasing a large light sail in front of it, designed to reflect light back to a much smaller light sail behind it. The laser then pushes the large sail away, and as the sail goes it pushes the smaller sail (and ship) back. This leaves the ship at moderate speed relative to the new star, and a large sail traveling very, very quickly beyond it. We do not yet have this technology. But we can show that it is plausible.

Scarblac 1y ago

According to the first Google hit, https://scitechdaily.com/nasas-parker-solar-probe-the-fastest-spacecraft-ever-just-skimmed-the-sun-at-430000-mph/ https://scitechdaily.com/nasas-parker-solar-probe-the-fastes... , the fastest we've made so far went 430k mph (falling towards the sun), or about 0.064% of c. Good guess.

anon_cow1111 1y ago

We have a number! Around 0.1c maximum and unsurprisingly it involves using nuclear bombs to push yourself. https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...

btilly 1y ago

If you enjoy such questions, I highly recommend https://www.amazon.com/Indistinguishable-Magic-Robert-L-Forward/dp/0671876864 https://www.amazon.com/Indistinguishable-Magic-Robert-L-Forw.... The best speed for interstellar travel with technologies that current theory says should be within our reach can be achieved with a vehicle with a light sail pushed by a giant laser, that is powered by solar power. There is even a way to brake it when it reaches the target star. I forget what the predicted velocity was though. This technology is basically the same as one that the Moties developed in the story, The Mote in God's Eye.

DiggyJohnson 1y ago
Slow down by pulling on the fishing line tied to the back of it, carefully.
- btilly 1y ago
  It slows down by releasing a large light sail in front of it, designed to reflect light back to a much smaller light sail behind it. The laser then pushes the large sail away, and as the sail goes it pushes the smaller sail (and ship) back. This leaves the ship at moderate speed relative to the new star, and a large sail traveling very, very quickly beyond it. We do not yet have this technology. But we can show that it is plausible.