3 ms·

Your proposed test would not be conclusive because magnetic fields are a thing which can be pushed against.

stale2002 8y ago
Who cares? That would still be an extremely useful invention. I was thinking about this more from a practical perspective. And what matters is "does it work", and much less so "how does it work". I guess if it based on magnetic fields, then it wouldn't be useful for long range space travel but it would still be extremely useful for planet scale space travel!
- stouset 8y ago
  Even from a practical perspective, how it works is infinitely, infinitely more important, because learning this is the only way we can make dramatic improvements in our ability to use it.
- sigstoat 8y ago
  > That would still be an extremely useful invention. already invented, already in use, not as great as you'd hope. https://en.wikipedia.org/wiki/Magnetorquer https://en.wikipedia.org/wiki/Magnetorquer > I guess if it based on magnetic fields, then it wouldn't be useful for long range space travel but it would still be extremely useful for planet scale space travel! turns out it isn't that effective. which can be determined with a sophomore-level understanding of physics and magnetic fields.
- Retra 8y ago
  We can already propel things in a magnetic field. If that's all the EM drive is doing, then who cares?
  - stale2002 8y ago
    We would care because the claimed forces of the EM drive are quite high (for space at least).
    - Retra 8y ago
      Explain, please? That doesn't make sense to me. What's so special about 'space' that makes you think the forces would increase there relative to here?
      - aetherspawn 8y ago
        Because space is big and there’s no friction. Your 0-60 time is not as relevant as here on earth. 0-60 in 1 hour is actually not so bad in space! That’s 10,000mph per week.
        Retra 8y ago
        There's no friction, but there's gravity almost everywhere you've got a magnetic field. And gravity accelerates things pretty hard.
      - stale2002 8y ago
        No, I am saying that there are observable effects of the EM drive, right now (which, might be due to experiment error). And these observable effects are large when you compare them to OTHER forms of space travel. IE, if you can have a propellant less method of travel in space, of the amount that the EM drive supposedly does, this is a BIG DEAL. The effect doesn't increase in space. Instead, the "small" effect when compared to earth methods of transportation, are extremely useful in space.
- db48x 8y ago
  Satellites already use Earth's magnetic field for stabilization and manoeuvring, but we do it using devices which are orders of magnitude simpler and cheaper than the "EMDrive". They also generate more thrust. On the other hand, because they work by the known and proven laws of physics, rather than hand-waving, we already know that they'll only work in orbit of a planet with a magnetic field, and not deep space (or if you prefer, we can calculate just how useless they'll be in deep space, because there is an ambient magnetic field out there, even if it is tiny).

stale2002 8y ago

Who cares? That would still be an extremely useful invention. I was thinking about this more from a practical perspective. And what matters is "does it work", and much less so "how does it work". I guess if it based on magnetic fields, then it wouldn't be useful for long range space travel but it would still be extremely useful for planet scale space travel!

stouset 8y ago
Even from a practical perspective, how it works is infinitely, infinitely more important, because learning this is the only way we can make dramatic improvements in our ability to use it.
sigstoat 8y ago
> That would still be an extremely useful invention. already invented, already in use, not as great as you'd hope. https://en.wikipedia.org/wiki/Magnetorquer https://en.wikipedia.org/wiki/Magnetorquer > I guess if it based on magnetic fields, then it wouldn't be useful for long range space travel but it would still be extremely useful for planet scale space travel! turns out it isn't that effective. which can be determined with a sophomore-level understanding of physics and magnetic fields.
Retra 8y ago
We can already propel things in a magnetic field. If that's all the EM drive is doing, then who cares?
- stale2002 8y ago
  We would care because the claimed forces of the EM drive are quite high (for space at least).
  - Retra 8y ago
    Explain, please? That doesn't make sense to me. What's so special about 'space' that makes you think the forces would increase there relative to here?
    - aetherspawn 8y ago
      Because space is big and there’s no friction. Your 0-60 time is not as relevant as here on earth. 0-60 in 1 hour is actually not so bad in space! That’s 10,000mph per week.
      - Retra 8y ago
        There's no friction, but there's gravity almost everywhere you've got a magnetic field. And gravity accelerates things pretty hard.
    - stale2002 8y ago
      No, I am saying that there are observable effects of the EM drive, right now (which, might be due to experiment error). And these observable effects are large when you compare them to OTHER forms of space travel. IE, if you can have a propellant less method of travel in space, of the amount that the EM drive supposedly does, this is a BIG DEAL. The effect doesn't increase in space. Instead, the "small" effect when compared to earth methods of transportation, are extremely useful in space.
db48x 8y ago
Satellites already use Earth's magnetic field for stabilization and manoeuvring, but we do it using devices which are orders of magnitude simpler and cheaper than the "EMDrive". They also generate more thrust. On the other hand, because they work by the known and proven laws of physics, rather than hand-waving, we already know that they'll only work in orbit of a planet with a magnetic field, and not deep space (or if you prefer, we can calculate just how useless they'll be in deep space, because there is an ambient magnetic field out there, even if it is tiny).