5 ms·

how about we just figure out how to get as close as possible to 1C?

Xophmeister 8y ago
We already know how to get arbitrarily close to 1C: just keep adding energy to the system to produce enough thrust to overcome the additional mass of said energy's source and the relative mass increase from getting closer to 1C. It's just not practical and the laws of physics forbid it from ever being practical.
- jlebrech 8y ago
  but if we keep trying there should be a spacefaring equivalent of Moores law? what if instead of formula 1 we had races in orbit? this would push the boat out.
  - 3rdAccount 8y ago
    No. Moore's law is about making things smaller for speedups. We can't shrink Relativistic Physics like that to lower the energy required to reach 1c (infinite). Of course, it is possible that there is a better standard model of physics which does a better job of explaining things and which does say we can do so. Another space race or space F1 would definitely make our engineering better and more reliable, but at massive cost and we still won't get FTL.
  - avian 8y ago
    I doubt any metric in Formula 1 doubles every 2 years. To get something like Moore’s law you need a breakthrough that opens up possibilities for many orders of magnitude in improvements. Baring new physics there’s just nothing like that available for rocketry.
  - logfromblammo 8y ago
    Nearly all racing formats have banned certain technologies. For instance, swimming banned LZR Racer swimsuits as "technology doping". Formula 1 has banned a variety of technologies, some just for increasing risk to spectators. America's Cup banned pedal power and cyborgs. Most human-powered races ban performance enhancing drugs. I could easily see space racing banning negative mass.
russdill 8y ago
Without a preferential reference frame, that's a nonsensical question. You can define your velocity to be arbitrarily close to C just be defining in relation to which inertial reference frame.
- russdill 8y ago
  The more important question is with an Alcubierre drive, how do you decide which direction it was traveling. Since it is traveling faster than C, you can pick a reference frame where it goes frame A to B, one where it disappears from A and arrives at B instantly, and one where it goes from B to A.
  - raattgift 8y ago
    Which of those gives you observables like a very nearly isotropic 2.725 K (and slowly cooling) blackbody spectrum, for example ? The universe gives virtually everything in it some observables it seems silly to ignore: https://en.wikipedia.org/wiki/Scale_factor_(cosmology) https://en.wikipedia.org/wiki/Scale_factor_(cosmology) just because the vast majority of observers aren't strictly Eulerian and thus there are lots of little details, like a dipole anisotropy in the CMB, or small deviations from a perfect blackbody spectrum. For A and B separated by non-cosmological distances, there are plenty of other local clocks available; around here one might use the orbital period of the Hulse-Taylor binary, for instance. Of course the Alcubierre metric doesn't use the scale factor, since it is an everywhere-flat spacetime (i.e., not expanding) except in the compact region of the warp bubble's walls, and the metric does not admit a varying scale factor, and it is a vacuum solution so there are no CMB photons, binary pulsars, or any other matter -- not even a spaceship. Making the Alcubierre metric even slightly more realistic exposes problems [1] which don't vanish when you make a reasonable (or any) choice of frame of reference. - -- [1] Lobo & Visser (2004) https://doi.org/10.1088/0264-9381/21/24/011 https://doi.org/10.1088/0264-9381/21/24/011 https://arxiv.org/abs/gr-qc/0406083 https://arxiv.org/abs/gr-qc/0406083 (note that the problems do not depend on superluminality)
    - russdill 8y ago

We already know how to get arbitrarily close to 1C: just keep adding energy to the system to produce enough thrust to overcome the additional mass of said energy's source and the relative mass increase from getting closer to 1C. It's just not practical and the laws of physics forbid it from ever being practical.

jlebrech 8y ago
but if we keep trying there should be a spacefaring equivalent of Moores law? what if instead of formula 1 we had races in orbit? this would push the boat out.
- 3rdAccount 8y ago
  No. Moore's law is about making things smaller for speedups. We can't shrink Relativistic Physics like that to lower the energy required to reach 1c (infinite). Of course, it is possible that there is a better standard model of physics which does a better job of explaining things and which does say we can do so. Another space race or space F1 would definitely make our engineering better and more reliable, but at massive cost and we still won't get FTL.
- avian 8y ago
  I doubt any metric in Formula 1 doubles every 2 years. To get something like Moore’s law you need a breakthrough that opens up possibilities for many orders of magnitude in improvements. Baring new physics there’s just nothing like that available for rocketry.
- logfromblammo 8y ago
  Nearly all racing formats have banned certain technologies. For instance, swimming banned LZR Racer swimsuits as "technology doping". Formula 1 has banned a variety of technologies, some just for increasing risk to spectators. America's Cup banned pedal power and cyborgs. Most human-powered races ban performance enhancing drugs. I could easily see space racing banning negative mass.

russdill 8y ago

Without a preferential reference frame, that's a nonsensical question. You can define your velocity to be arbitrarily close to C just be defining in relation to which inertial reference frame.

russdill 8y ago
The more important question is with an Alcubierre drive, how do you decide which direction it was traveling. Since it is traveling faster than C, you can pick a reference frame where it goes frame A to B, one where it disappears from A and arrives at B instantly, and one where it goes from B to A.
- raattgift 8y ago
  Which of those gives you observables like a very nearly isotropic 2.725 K (and slowly cooling) blackbody spectrum, for example ? The universe gives virtually everything in it some observables it seems silly to ignore: https://en.wikipedia.org/wiki/Scale_factor_(cosmology) https://en.wikipedia.org/wiki/Scale_factor_(cosmology) just because the vast majority of observers aren't strictly Eulerian and thus there are lots of little details, like a dipole anisotropy in the CMB, or small deviations from a perfect blackbody spectrum. For A and B separated by non-cosmological distances, there are plenty of other local clocks available; around here one might use the orbital period of the Hulse-Taylor binary, for instance. Of course the Alcubierre metric doesn't use the scale factor, since it is an everywhere-flat spacetime (i.e., not expanding) except in the compact region of the warp bubble's walls, and the metric does not admit a varying scale factor, and it is a vacuum solution so there are no CMB photons, binary pulsars, or any other matter -- not even a spaceship. Making the Alcubierre metric even slightly more realistic exposes problems [1] which don't vanish when you make a reasonable (or any) choice of frame of reference. - -- [1] Lobo & Visser (2004) https://doi.org/10.1088/0264-9381/21/24/011 https://doi.org/10.1088/0264-9381/21/24/011 https://arxiv.org/abs/gr-qc/0406083 https://arxiv.org/abs/gr-qc/0406083 (note that the problems do not depend on superluminality)
  - russdill 8y ago