3 ms·

Dumb Question: Could this tech somehow be harnessed for space propulsion?

tim333 8y ago
I doubt that particular magnet but there is a YC startup working on a magnets -> fusion -> space drive thing https://news.ycombinator.com/item?id=8178450 https://news.ycombinator.com/item?id=8178450 https://www.nextbigfuture.com/2013/11/john-slough-personally-explains-his.html https://www.nextbigfuture.com/2013/11/john-slough-personally...
kadoban 8y ago
For a magnet to be used as propulsion, you'd need something for it to pull or push against. Finding a likely target seems impossible. The way magnetism drops off with distance means it would only be useful when you were already there (or just starting out). Also the magnetic field in this case is only lasting a tiny fraction of a second, which would be an issue for propulsion.
- EthanHeilman 8y ago
  From the impractical ideas dept: Could make a magnet strong enough that it would pull apart virtual particles, i.e. Vacuum polarization [0], and based on some asymmetry in the magnetic field created the particles would pull/push you forward? [0]: https://en.wikipedia.org/wiki/Vacuum_polarization https://en.wikipedia.org/wiki/Vacuum_polarization
- mathnmusic 8y ago
  I guess what OP meant is interaction with earth's magnetic field to get out of its gravitational pull.
macromaniac 8y ago
If can get to 4 billion tesla I /think/ that's enough to generate electrons from the vacuum of space (see:schwinger magnetic induction) and you could do something akin to magnetohydrodynamics ( see: https://youtu.be/LS3GQk9ETRU https://youtu.be/LS3GQk9ETRU ) which would use the magnetic field to accelerate the electrons away from the ship, I could be incorrect here though
twic 8y ago
In a manner of speaking. There is an idea called a "magnetic sail": https://www.centauri-dreams.org/2014/08/28/thinking-about-magnetic-sails/ https://www.centauri-dreams.org/2014/08/28/thinking-about-ma... https://en.wikipedia.org/wiki/Magnetic_sail https://en.wikipedia.org/wiki/Magnetic_sail http://casa.colorado.edu/~danforth/science/magsail/magsail.html http://casa.colorado.edu/~danforth/science/magsail/magsail.h... My understanding is that it's more useful as a "magnetic parachute", as it lets you brake without using reaction mass, just electrical power. That could let make an interstellar journey with less mass, as you only need reaction mass to accelerate on departure, and not to decelerate on arrival.

I doubt that particular magnet but there is a YC startup working on a magnets -> fusion -> space drive thing https://news.ycombinator.com/item?id=8178450 https://news.ycombinator.com/item?id=8178450 https://www.nextbigfuture.com/2013/11/john-slough-personally-explains-his.html https://www.nextbigfuture.com/2013/11/john-slough-personally...

kadoban 8y ago

For a magnet to be used as propulsion, you'd need something for it to pull or push against. Finding a likely target seems impossible. The way magnetism drops off with distance means it would only be useful when you were already there (or just starting out). Also the magnetic field in this case is only lasting a tiny fraction of a second, which would be an issue for propulsion.

EthanHeilman 8y ago
From the impractical ideas dept: Could make a magnet strong enough that it would pull apart virtual particles, i.e. Vacuum polarization [0], and based on some asymmetry in the magnetic field created the particles would pull/push you forward? [0]: https://en.wikipedia.org/wiki/Vacuum_polarization https://en.wikipedia.org/wiki/Vacuum_polarization
mathnmusic 8y ago
I guess what OP meant is interaction with earth's magnetic field to get out of its gravitational pull.

macromaniac 8y ago

If can get to 4 billion tesla I /think/ that's enough to generate electrons from the vacuum of space (see:schwinger magnetic induction) and you could do something akin to magnetohydrodynamics ( see: https://youtu.be/LS3GQk9ETRU https://youtu.be/LS3GQk9ETRU ) which would use the magnetic field to accelerate the electrons away from the ship, I could be incorrect here though

twic 8y ago

In a manner of speaking. There is an idea called a "magnetic sail": https://www.centauri-dreams.org/2014/08/28/thinking-about-magnetic-sails/ https://www.centauri-dreams.org/2014/08/28/thinking-about-ma... https://en.wikipedia.org/wiki/Magnetic_sail https://en.wikipedia.org/wiki/Magnetic_sail http://casa.colorado.edu/~danforth/science/magsail/magsail.html http://casa.colorado.edu/~danforth/science/magsail/magsail.h... My understanding is that it's more useful as a "magnetic parachute", as it lets you brake without using reaction mass, just electrical power. That could let make an interstellar journey with less mass, as you only need reaction mass to accelerate on departure, and not to decelerate on arrival.