5 ms·
>accelerating it via radiation pressure to 0.2𝑐 within a few minutes [7]. That probe must be made in unobtainium to handle that acceleration. For 0.2c in 5 mi
by mpsprd 3y ago
>accelerating it via radiation pressure to 0.2𝑐 within a few minutes [7].
That probe must be made in unobtainium to handle that acceleration. For 0.2c in 5 minutes it's 20394G!
- MichaelZuo 3y agoProbably a typo, otherwise the writers are very confused?
- thechao 3y agoWell below the G forces experienced by smart artillery. Solid state is pretty solid.
- MichaelZuo 3y agoNot for sustained minutes, a few miliseconds.
- zardo 3y agoThat's probably worse as the jerk must also be very high
- K0balt 3y agoAbsolutely. 20kg pushing evenly on a flat piece of glass an inch in diameter is no big deal. People are forgetting that small things are really, really tough. People have a bias against high forces because they’re made of meat.
- FredPret 3y agoI'm not going to do the calculation right now, but I wonder what G-force would be needed to deform a steel shell, for example. How much worse would it be if sustained over a long period?
- K0balt 3y agoIt’s 20kg of force evenly distributed on a little chunk of glass. It would be fine.
- K0balt 3y agoNope. 1 gram spacecraft, 20kg of thrust. Glass is tough. A 1 gram flat chip of glass with about 6cm2 of area (the proposed “spaceship” design) would withstand even more than steel by nearly a factor of two. People are freaking out about 20,000g, but you could push a flat disk of glass like that at about 60,000,000g before it failed. Good Glass has a compressive strength of about 1000 megapascals.
- _8j50 3y agoMaybe 0.2%c? Either way, no gravity in outer space so isn't it like 0G?
- BenjiWiebe 3y agoNope, G forces don't need gravity. If you are in a "0G" environment but accelerating at 9.8 m/s², that's indistinguishable from being "at rest" in a 1G environment.
- K0balt 3y agoTBF 20,000g is totally doable. The spacecraft weigh 1 gram each, so that would be 20kg of thrust pressure. Assuming he spacecraft are nominally 2d in construction (a silicon wafer) and the pressure is evenly distributed, I see no reason why you couldn’t expect them to withstand 20k g acceleration. 20kg isn’t a lot to stack on essentially a chunk of solid glass if evenly applied.