4 ms·

Mirror shields in the Culture series use the 'field' magic that so much of the Culture's science relies on. Presumably a reflector field is both insanely reflec

Mirror shields in the Culture series use the 'field' magic that so much of the Culture's science relies on. Presumably a reflector field is both insanely reflective (99.999% or better, like dielectric mirrors) and resilient to the air the field's being projected in heating up massively from the small energy fraction which is absorbed. Your typical "glass with metal on it" mirror will fare very poorly against a high power laser. They're only ~90% reflective, and 10% of a high power beam is more than enough to turn your mirror into a 0% reflective smoldering black lump. Even if you build a mirror with very high reflecting factor in the wavelength of your enemy's weapon, all it takes is a smudge of dust or oil on the surface and the thing is toast.

mirimir 9y ago
True. But on the other hand, there are mirrors in the laser itself that don't end up as toast. And in some circumstances, I can imagine throwaway mirrors that would reflect back substantial power before destruction. More or less a variant on chaff.
- Pamar 9y ago
  If memory serves Traveller (game) mentioned aereosols (like smoke grenades) to counter lasers.
  - usrusr 9y ago
    "Sandcasters". And in some incarnations of the game the clouds they produced would even be actively manoeuvred through space by some absurdly improbable application of magnetic force, to make defense an active skill (vs mindlessly pumping "more energy to shields")
    - Pamar 9y ago
      Sandcasters were used for space combat. I am away from my library so I cannot check but I seem to remember smoke/aereosols to be used for ground combat to reduce laser effectiveness.
- michaelt 9y ago
  there are mirrors in the laser itself that don't end up as toast. Someone showed an industrial laser cutter to me once. He told me that: 1. The internal mirrors were about 5cm diameter, and water cooled. 2. The laser is only brought fully into focus at the final lens, just before the cutting point. So the beam at the mirror might have a 2cm diameter, before being focused down to a 0.5mm diameter at the cutting point. Point 2 was also a key part of the safety system; the safety barriers could actually be quite thin, as the laser would be out of focus at that distance no matter how far wrong the optics went :)

mirimir 9y ago

True. But on the other hand, there are mirrors in the laser itself that don't end up as toast. And in some circumstances, I can imagine throwaway mirrors that would reflect back substantial power before destruction. More or less a variant on chaff.

Pamar 9y ago
If memory serves Traveller (game) mentioned aereosols (like smoke grenades) to counter lasers.
- usrusr 9y ago
  "Sandcasters". And in some incarnations of the game the clouds they produced would even be actively manoeuvred through space by some absurdly improbable application of magnetic force, to make defense an active skill (vs mindlessly pumping "more energy to shields")
  - Pamar 9y ago
    Sandcasters were used for space combat. I am away from my library so I cannot check but I seem to remember smoke/aereosols to be used for ground combat to reduce laser effectiveness.
michaelt 9y ago
there are mirrors in the laser itself that don't end up as toast. Someone showed an industrial laser cutter to me once. He told me that: 1. The internal mirrors were about 5cm diameter, and water cooled. 2. The laser is only brought fully into focus at the final lens, just before the cutting point. So the beam at the mirror might have a 2cm diameter, before being focused down to a 0.5mm diameter at the cutting point. Point 2 was also a key part of the safety system; the safety barriers could actually be quite thin, as the laser would be out of focus at that distance no matter how far wrong the optics went :)