5 ms·
Solar sails only absorb enough energy for tiny crafts in space, a frictionless environment. You overestimate photon flux momentum from the sun.
by goldenkey 5y ago
Solar sails only absorb enough energy for tiny crafts in space, a frictionless environment. You overestimate photon flux momentum from the sun.
- Akronymus 5y agoSolar sails indeed only absorb a tiny amount of energy, BUT per given area. They can theoretically made to be extremely large without much weight relative to the size. Which in turn allows you to accelerate even quite large payloads in a reasonable amount of time.
- goldenkey 5y agoThe mirrors are extremely heavy and solar sails are exclusively used above our atmosphere, in space, where more flux from the sun is received. The flux even at earth orbit is a measly 47e-7 Newtons per square meter. That's 0.00016905632 pounds per square inch. You still stand by what you just stated? It's not feasible to do below clouds, in an environment with constant friction, air or water resistance. The only reason you can do it in space is because that tiny slow acceleration can accumulate over a long period of time. This precludes frictional losses that would normally be incurred within atmospheres.
- Akronymus 5y agoIt seems I misunderstood the thread. I somehow thought we were talking about sails in space rather than in atmo.
- goldenkey 5y agoSo what were you originally referring to? Solar wind in space? I'm honestly confused now.
- Akronymus 5y agoI was actually. I rhought the parent I originally replied to was saying that solar sails aren't useful for large payloads in space.
- andrewflnr 5y agoThey overreached a tiny bit in reaction, but they were responding to someone who seemed to be proposing solar sails inside the atmosphere.
- goldenkey 5y agoI didn't overreach at all. Nearly all the creatures of HN just try to save face after they make invalid statements. This involves acting confused, changing the subject, or a barely clever combination of both. The desire to be correct and win what barely even counts as a debate is a contagion deeply plaguing these creatures.