Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Alphabet spins out Taara – Internet over lasers

x.company

Post reply on HN
Print view View original

111–120 of 285 posts

Re: Alphabet spins out Taara – Internet over lasers

#111

Post by aerostable_slug »

umvi wrote: post #80
jauntywundrkind wrote: post #41

I'm low key afraid that this stuff is gonna get popular for .mil usage. Line of sight free space optics can be immune to many many forms of jamming. Its usage dots the sci books I've read over the years, but almost always for scary reasons. Here's the Navy today announcing work on AirBorne System for Optical Relay and Broadcast (ABSORB), a (for now) low-cost prototype one-to-many (I maybe mis-inferring what multi-acc…

> Line of sight free space optics can be immune to many many forms of jamming The most powerful weapons on earth already are immune to jamming. ICBMs use celestial navigation (pictures of the stars) to course-correct, which is a form of navigation you cannot jam.

To risk being pedantic, US SLBMs (Tridents) indeed use stellar updates for their inertial guidance system.

Our ICBMs have no update mechanism at all. Once they're out of the silo, they're completely on their own.

Re: Alphabet spins out Taara – Internet over lasers

#112

Post by echoangle »

cogman10 wrote: post #104
echoangle wrote: post #96

Earlier quoted context omitted.

This form of navigation is probably only accurate enough for nuclear weapons, you’re not going to get meter-Range CEPs with that. You probably have to select a city you want to hit.

While you probably can't target a cigarette butt on the street, you could definitely hit a building. Especially if the ICBM is paired with image recognition (which it has already for star nav) and/or backup positioning mechanisms like cell tower locations or well-known broadcasting tower locations (think television stations).

An ICBM is coming in at hypersonic speeds in the terminal phase, you’re not going to guide it anywhere using cell tower signals. The guidance is done much earlier.

And I would doubt image recognition for ground features would make it that accurate, too. Before reentry, you’re very high and fast and reentry isn’t that predictable to get you accurate enough to hit a house. And during reentry, you’re not going to see anything though plasma. And after reentry, you probably don’t have enough time and control authority to still guide into a specific house.

ICBM guidance is very different from cruise missiles.

Re: Alphabet spins out Taara – Internet over lasers

#113

Post by aerostable_slug »

echoangle wrote: post #96
umvi wrote: post #80

Earlier quoted context omitted.

> Line of sight free space optics can be immune to many many forms of jamming The most powerful weapons on earth already are immune to jamming. ICBMs use celestial navigation (pictures of the stars) to course-correct, which is a form of navigation you cannot jam.

This form of navigation is probably only accurate enough for nuclear weapons, you’re not going to get meter-Range CEPs with that. You probably have to select a city you want to hit.

This is a very good read on the state of the art when it comes to submarine-launched missile accuracy, which are presently inertially guided with a stellar update during flight.

https://thebulletin.org/2017/03/how-us-nuclear-force-moderni...

Re: Alphabet spins out Taara – Internet over lasers

#114

Post by tryauuum »

umvi wrote: post #80
jauntywundrkind wrote: post #41

I'm low key afraid that this stuff is gonna get popular for .mil usage. Line of sight free space optics can be immune to many many forms of jamming. Its usage dots the sci books I've read over the years, but almost always for scary reasons. Here's the Navy today announcing work on AirBorne System for Optical Relay and Broadcast (ABSORB), a (for now) low-cost prototype one-to-many (I maybe mis-inferring what multi-acc…

> Line of sight free space optics can be immune to many many forms of jamming The most powerful weapons on earth already are immune to jamming. ICBMs use celestial navigation (pictures of the stars) to course-correct, which is a form of navigation you cannot jam.

that is so romantic. Rockets looking at the stars one last time before obliterating $cityname

Re: Alphabet spins out Taara – Internet over lasers

#117

Post by echoangle »

aerostable_slug wrote: post #113
echoangle wrote: post #96

Earlier quoted context omitted.

This form of navigation is probably only accurate enough for nuclear weapons, you’re not going to get meter-Range CEPs with that. You probably have to select a city you want to hit.

This is a very good read on the state of the art when it comes to submarine-launched missile accuracy, which are presently inertially guided with a stellar update during flight. https://thebulletin.org/2017/03/how-us-nuclear-force-moderni...

Thanks for the link, very interesting. So CEP is estimated to be around 100m. Better than I thought but I wouldn’t call it hitting a specific house yet.

Re: Alphabet spins out Taara – Internet over lasers

#119

Post by krisoft »

jauntywundrkind wrote: post #41

I'm low key afraid that this stuff is gonna get popular for .mil usage. Line of sight free space optics can be immune to many many forms of jamming. Its usage dots the sci books I've read over the years, but almost always for scary reasons. Here's the Navy today announcing work on AirBorne System for Optical Relay and Broadcast (ABSORB), a (for now) low-cost prototype one-to-many (I maybe mis-inferring what multi-acc…

> Line of sight free space optics can be immune to many many forms of jamming.

I’m a bit of two minds about this. Obviously jamming resistant high bandwidth communication enables some scarry possibilities.

But the lack of it is what drives and will drive militaries around the world to put more and more autonomy into weapons. It doesn’t matter what kind of treaties we write on paper to prohibit technologies. During a war if your drones/loitering munition are less effective than those of your enemies because your control signals are jammed you will give in and make your weapons find their target without that control signal. That leads to an arm race of ever more sophisticated autonomous weapons. That is scarry for many reasons, and probably a worse outcome for all of us.

On the other hand if communication is possible that puts a leash on this dynamic and ensurers that a human mind can remain in the loop. So… maybe being better at jamming resistant communication is actually better for humankind?

Re: Alphabet spins out Taara – Internet over lasers

#120

Post by walrus01 »

ecshafer wrote: post #55
seanp2k2 wrote: post #38

When I came to Silicon Valley in the early 2010s and realized that all of the king's horses and all of the king's men could not defeat the scourge that is the US ISP oligopoly even in their own backyards, I knew it was pointless to ever hope for real FTTH in Bay Area markets in the next couple of decades. Wireless solutions have orders of magnitude less bandwidth than fiber, and you can run lots of fiber in a bundle,…

In Silicon Valley, in a neighborhood of $2.5M homes, and thus household incomes on average of probably $600k+. It should be possible to get a fiber rollout, they aren't that expensive. Make a neighborhood ISP, or try and get a municipal ISP.

People want their nice neighborhood of 2.5 m homes where 100% of utilities are underground and aesthetically pleasing. While people in ordinary neighborhoods in Japan with 100% aerial fiber on utility poles have far superior fiber based last mile ISP service.
Post reply on HN