6 ms·

Maybe I'm missing something but hitting a gas just above absolute zero with lasers from every direction doesn't sound as something that could be miniaturised.

gridspy 2y ago
Most technology has a limit like this (for instance CPU transistor size in the past). However once this is a proven technology, money will be invested in solving these issues.
porphyra 2y ago
Theoretically you might be able to do it with some VCSELs, not sure though...
nine_k 2y ago
Maybe not down to a pea size, but possibly down to an orange size. Lasers are tiny, and "every direction" does not involve many of them, it involves some fiber optics, I suppose. The bulk of the device would be thermal insulation, and a volume for liquid helium + some piping to let it evaporate, and to replenish it.
- deleted 2y ago
  [deleted]
- horstbort 2y ago
  You don't need any helium or nitrogen here, cooling happens only by laser cooling and evaporative cooling from magnetic or optical traps. The atoms are perfectly insulated in an ultra high vacuum. Electronics still take the bulk of the volume here, as does the laser system. While the lasers themselves are tiny indeed, the light needs to be manipulated before reaching the atoms. And yes, it involves quite a lot of fiber optics :-).
greenavocado 2y ago
[flagged]
- ziddoap 2y ago
  You don't need to copy/paste the exact same comment three times in one topic. We read it the first time.
  - greenavocado 2y ago
    Fixed
- Waterluvian 2y ago
  The “nuke Moscow” case doesn’t require GPS. You’ll get plenty sufficient precision from inertial systems.
  - roywiggins 2y ago
    Precision is, counterintuitively, still a big deal in the logic of nuclear weapons strategy. Nuking Moscow is easy, nuking hardened targets can be a lot harder. > Before the invention of this new fuzing mechanism, even the most accurate ballistic missile warheads might not detonate close enough to targets hardened against nuclear attack to destroy them. But the new super-fuze is designed to destroy fixed targets by detonating above and around a target in a much more effective way. Warheads that would otherwise overfly a target and land too far away will now, because of the new fuzing system, detonate above the target... > As a consequence, the US submarine force today is much more capable than it was previously against hardened targets such as Russian ICBM silos. A decade ago, only about 20 percent of US submarine warheads had hard-target kill capability; today they all do. https://thebulletin.org/2017/03/how-us-nuclear-force-modernization-is-undermining-strategic-stability-the-burst-height-compensating-super-fuze/amp/ https://thebulletin.org/2017/03/how-us-nuclear-force-moderni...
    - Dylan16807 2y ago
      But importantly, making sure a nuke can still hit Moscow despite geolocation countermeasures has lots of worrying consequences for normal people that are in normal cities. If nukes are hitting random countryside then a lot less people die. But when it's the difference between hitting a hardened target or being off by 200 meters, that doesn't really affect normal people.
BurningFrog 2y ago
For many purposes, "every direction" is only three directions in our 3D space.
tonyarkles 2y ago
It's pretty amazing what's slowly but surely becoming possible. This company, for example, has successfully made chip-scale "fiber" ring gyros with incredible performance that would have been very large heavy units 5-10 years ago: https://www.anellophotonics.com/products/x3 https://www.anellophotonics.com/products/x3

gridspy 2y ago

Most technology has a limit like this (for instance CPU transistor size in the past). However once this is a proven technology, money will be invested in solving these issues.

porphyra 2y ago

Theoretically you might be able to do it with some VCSELs, not sure though...

nine_k 2y ago

Maybe not down to a pea size, but possibly down to an orange size. Lasers are tiny, and "every direction" does not involve many of them, it involves some fiber optics, I suppose. The bulk of the device would be thermal insulation, and a volume for liquid helium + some piping to let it evaporate, and to replenish it.

deleted 2y ago
[deleted]
horstbort 2y ago
You don't need any helium or nitrogen here, cooling happens only by laser cooling and evaporative cooling from magnetic or optical traps. The atoms are perfectly insulated in an ultra high vacuum. Electronics still take the bulk of the volume here, as does the laser system. While the lasers themselves are tiny indeed, the light needs to be manipulated before reaching the atoms. And yes, it involves quite a lot of fiber optics :-).

greenavocado 2y ago

[flagged]

ziddoap 2y ago
You don't need to copy/paste the exact same comment three times in one topic. We read it the first time.
- greenavocado 2y ago
  Fixed
Waterluvian 2y ago
The “nuke Moscow” case doesn’t require GPS. You’ll get plenty sufficient precision from inertial systems.
- roywiggins 2y ago
  Precision is, counterintuitively, still a big deal in the logic of nuclear weapons strategy. Nuking Moscow is easy, nuking hardened targets can be a lot harder. > Before the invention of this new fuzing mechanism, even the most accurate ballistic missile warheads might not detonate close enough to targets hardened against nuclear attack to destroy them. But the new super-fuze is designed to destroy fixed targets by detonating above and around a target in a much more effective way. Warheads that would otherwise overfly a target and land too far away will now, because of the new fuzing system, detonate above the target... > As a consequence, the US submarine force today is much more capable than it was previously against hardened targets such as Russian ICBM silos. A decade ago, only about 20 percent of US submarine warheads had hard-target kill capability; today they all do. https://thebulletin.org/2017/03/how-us-nuclear-force-modernization-is-undermining-strategic-stability-the-burst-height-compensating-super-fuze/amp/ https://thebulletin.org/2017/03/how-us-nuclear-force-moderni...
  - Dylan16807 2y ago
    But importantly, making sure a nuke can still hit Moscow despite geolocation countermeasures has lots of worrying consequences for normal people that are in normal cities. If nukes are hitting random countryside then a lot less people die. But when it's the difference between hitting a hardened target or being off by 200 meters, that doesn't really affect normal people.

BurningFrog 2y ago

For many purposes, "every direction" is only three directions in our 3D space.

tonyarkles 2y ago

It's pretty amazing what's slowly but surely becoming possible. This company, for example, has successfully made chip-scale "fiber" ring gyros with incredible performance that would have been very large heavy units 5-10 years ago: https://www.anellophotonics.com/products/x3 https://www.anellophotonics.com/products/x3