21–30 of 103 posts
An ultra sensitive motion sensor. Intriguing. Could one derive the Earth's rotation? The motion of the solar system? By watching vibrations could it be a microphone?
For the first two questions I wouldn't think so because it detects acceleration. But I also only have a high school level of physics knowledge so maybe I'm wrong.
Earlier quoted context omitted.
No because velocity only makes sense as relative to something else. There’s no ‘fixed points’ in the universe This device will track acceleration rather than velocity
Points on the Earth's surface are experiencing an acceleration- after all, after 12 hours their velocity has changed direction by ~180 degrees. You can detect Earth's rotation with a sufficiently large pendulum[0] or a good gyroscope. Something with enough inertia will tend to refuse to rotate with the planet, which lets you compare the two and infer the absolute rotational speed of the planet. https://en.wikipedia.o…
The main application would obviously be missiles and autonomous military drones. If you can use GPS - you should. It's crazy cheap and it doesn't accumulate errors over time. But in a war GPS can be jammed. This can't.
https://en.wikipedia.org/wiki/AGM-158_JASSM
> Guidance system: GPS, INS, IIR
Earlier quoted context omitted.
This will absolutely go in missiles to handle GPS jamming and submarines where satellite signals are unavailable, yes. It'll be nice if they can get it small enough for a phone, though.
> This will absolutely go in missiles to handle GPS jamming Depending on when the tech is available, preventing GPS jamming of drones is probably much more urgent in Ukraine.
HIMARS, on the other hand, will enjoy the improvements.
Earlier quoted context omitted.
No because velocity only makes sense as relative to something else. There’s no ‘fixed points’ in the universe This device will track acceleration rather than velocity
Points on the Earth's surface are experiencing an acceleration- after all, after 12 hours their velocity has changed direction by ~180 degrees. You can detect Earth's rotation with a sufficiently large pendulum[0] or a good gyroscope. Something with enough inertia will tend to refuse to rotate with the planet, which lets you compare the two and infer the absolute rotational speed of the planet. https://en.wikipedia.o…
Is that... assful?
Earlier quoted context omitted.
More specifically, nuclear arms, where the budget is "there is no budget." Just the inertial guidance system of a 90's-era ICBM cost over six figures per missile. The ability to precisely place a missile without any external navigation (except for stars.) Once it gets cheap enough, it'll probably go into cruise missiles; it could eliminate or reduce the need for terrain contour matching, which requires radar transmis…
Nuclear arms doesn't need as much accuracy as other weapons though: when using a cruise missile or a glide bomb with a few hundreds of kilograms of explosives, you need metric precision to get the military effect, when the payload is a 100kt bomb, then 100m is accurate enough. Unlike other bombs it must absolutely be 100% resilient to any kind of spoofing though, for obvious reasons, hence GNSS is a nonstarter for th…
Not accurate enough for counterforce. When a missile silo lid can withstand 600 atmospheres of overpressure, "close enough" isn't good enough.
The main application would obviously be missiles and autonomous military drones. If you can use GPS - you should. It's crazy cheap and it doesn't accumulate errors over time. But in a war GPS can be jammed. This can't.
Lot's of Western weapons already combine INS and GPS. I suppose this could be a better alternative to INS. https://en.wikipedia.org/wiki/AGM-158_JASSM > Guidance system: GPS, INS, IIR
By the time the small diameter bombs had been married to a rocket the Russians had effective and pervasive gps jamming and accuracy plummeted.
The older more expensive systems with ins like atacms maintained accuracy.
We’ve had other discussions of these sort of quantum compass ideas, see https://news.ycombinator.com/item?id=40692333 for example. I can never quite wrap my head around it or figure out if they are all the same idea, or what, and what exactly the idea is. In particular, the article soften describe something that “could replace GPS.” But then they start taking about compasses, and things that sound a lot like IMUs. In…
Gravity map matching is an approach that can provide absolute references, the general problem there is that gravity maps are not good enough.
Earlier quoted context omitted.
More specifically, nuclear arms, where the budget is "there is no budget." Just the inertial guidance system of a 90's-era ICBM cost over six figures per missile. The ability to precisely place a missile without any external navigation (except for stars.) Once it gets cheap enough, it'll probably go into cruise missiles; it could eliminate or reduce the need for terrain contour matching, which requires radar transmis…
Nuclear arms doesn't need as much accuracy as other weapons though: when using a cruise missile or a glide bomb with a few hundreds of kilograms of explosives, you need metric precision to get the military effect, when the payload is a 100kt bomb, then 100m is accurate enough. Unlike other bombs it must absolutely be 100% resilient to any kind of spoofing though, for obvious reasons, hence GNSS is a nonstarter for th…
I'm not sure what point you're trying to make here?
Accuracy is incredibly important because you don't put a nuke somewhere to kill people; you put it there to destroy infrastructure. More specifically nuclear missile silos, and bomb shelters (well, the people inside them.)
Reducing the CEP means you can use a smaller nuclear yield to get the job done, which is preferable for a number of reasons, including politics, but also allowing for more targets in a strike.
The very latest US ICBMs are suspected of having sub-100m CEP. CEP for ICBMs is "bad" enough that it is typical for planners to figure three warheads per target, but accuracy is rumored to be getting good enough where that is no longer necessary.
ICBM warheads are small. Space in drones and fighter jets is at a premium.
This is military.