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U.S. military shoots down suspected Chinese surveillance balloon

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Re: U.S. military shoots down suspected Chinese surveillance balloon

#801
post #773

Earlier quoted context omitted.

Why not? Add a fin to a baloon and you can steer it. And once the baloon can hold direction in the wind with the help of the fin, you can add sail to actually get some propulsion in direction other than wind.

The balloon moves with the wind. You cannot steer it because from the point of view of the balloon it is not moving . There is no keel on a balloon. Without a keel, one is only going downwind.

I think you should be able to on a wind current boundary

Re: U.S. military shoots down suspected Chinese surveillance balloon

#802
post #711

Earlier quoted context omitted.

They can use strong encryption, but can they protect their private keys?

Asymmetric encryption. The private key does not have to be stored in the balloon at all (only the public key that can encrypt but NOT decrypt), it can stay safely in a PLA datacenter in China.

Right, the question is how safe are those datacenters.

Re: U.S. military shoots down suspected Chinese surveillance balloon

#803
post #496

Earlier quoted context omitted.

Hmm, do we even need trig? Naively I would imagine that simple proportions would hold — e.g. same visible size @ twice the distance = object is twice as big

4x as big, since we see in two dimensions — you can judge length & height (but not depth). So if it appears the same size but twice as far away, the the length and height are each 2x. So that would make it the size of ~4 airplanes

Not super relevant but I find this to be true when spotting a 747/757/767 vs say a 737

Re: U.S. military shoots down suspected Chinese surveillance balloon

#804
post #437

Earlier quoted context omitted.

[flagged]

Must be nice being so privileged to talk down the very thing that maintains global trade channels (diplomacy) and keeps most of the world in check. Most of the world is backwater nations who oppress the shit out of their population making whatever faults you find in the US seem trivial. And yes the world isn’t fair and entropy exists. EU is basically a forced alliance after thousand years of constant fighting that le…

Hmmm… I wonder why the country with the biggest military (and their Allies) is the only place rich enough not to be a backwater? I implore you to think how you might answer that question if you were born in such a backwater.

Especially if it was a backwater where the US had recently used that military to significantly influence the government, such as Iran, 1953 Guatemala, 1954, Congo, 1960, Laos, 1960, Iraq, 1963, Brazil, 1964, British Guiana, 1964, Bolivia, 1964, Dominican Republic, 1965, Indonesia, 1965, Ghana, 1966, Greece, 1967, Cambodia, 1970, Bolivia, 1971, Chile, 1973, Australia, 1975, Portugal, 1976, Argentina, 1976, Jamaica, 1980, Turkey, 1980, Chad, 1982, Fiji, 1987, Nicaragua, 1987, Afghanistan, 1989, Panama, 1989, Bulgaria, 1990, Albania, 1991, Yugoslavia, 2000, Ecuador, 2000, Afghanistan, 2001, Venezuela, 2002, Iraq, 2003, Haiti, 2004, or Libya, 2011. Oo or Israel earlier this week.

That said yeah definitely should’ve shot down that ballon over the Aleutians

Re: U.S. military shoots down suspected Chinese surveillance balloon

#805
post #498

Earlier quoted context omitted.

The idea people would still function while the entire east and west coast burns is the same fantasy at massive scale as people who walk around with guns thinking they are going to somehow defeat someone who has planned and already actively shooting at them. I believe great many ICBMs would definitely make it to major cities and that is the end of the world. We've already seen how people handle a pandemic, imagine act…

I don’t believe that deploying the entire nuclear arsenal of the world would wipe humanity off the face of earth. Would it suck and render some places uninhabitable? Yes. Would it affect fresh water and air quality? You bet. But people will find a way like a worm and some will survive. I am in Bay Area so I probably won’t, but others will. What about places in Africa and South East Asia? Probably will be “fine”. Besi…

You should read “A Canticle for Lebowitz” :)

Re: U.S. military shoots down suspected Chinese surveillance balloon

#806
post #102

I am so tired of China being used to stoke American jingoism, of politicians making a contest of who is really 'tough on China' and, most horrifyingly, of seeing other USians online practically salivate as they fantasize about a war with China. It's some cold war boogieman horseshit. And it's depressing to watch here on Hacker News, too, any comments that question the beating of those war drums go dead. Yesterday I h…

Based on how many replies are directly attacking you or repeating propagandic lines, the jingoism mind virus is already here and the infection is deep. I salute you for the courage to speak out against the overwhelming pro-conflict campaign, but I am afraid we are past the point to reverse course.

Re: U.S. military shoots down suspected Chinese surveillance balloon

#807
post #773

Earlier quoted context omitted.

Why not? Add a fin to a baloon and you can steer it. And once the baloon can hold direction in the wind with the help of the fin, you can add sail to actually get some propulsion in direction other than wind.

The balloon moves with the wind. You cannot steer it because from the point of view of the balloon it is not moving . There is no keel on a balloon. Without a keel, one is only going downwind.

> from the point of view of the balloon it is not moving.

Mind == blown*

*Sincere, but pun intended

Re: U.S. military shoots down suspected Chinese surveillance balloon

#808
post #773

Earlier quoted context omitted.

Why not? Add a fin to a baloon and you can steer it. And once the baloon can hold direction in the wind with the help of the fin, you can add sail to actually get some propulsion in direction other than wind.

The balloon moves with the wind. You cannot steer it because from the point of view of the balloon it is not moving . There is no keel on a balloon. Without a keel, one is only going downwind.

Wind is still flowing over the balloon and able to generate a steering force.

Re: U.S. military shoots down suspected Chinese surveillance balloon

#809
post #305

Earlier quoted context omitted.

Technically the ballon isn't moving itself in anyway at all, it instead is depending on the wind. As the atmospheric pressure lowers the maximum speed of the wind can increase greatly. For example the speed of the jet stream commonly exceeds 275 miles per hour. It looks like the strongest jet winds were closer to canada, had the jet been in the US it could have made it across the country in a day.

Imagine the earth is also spinning under the balloon?

It doesn’t matter for the same reason that the earth doesn’t go flying out from under you if you jump into the air. Yes, it’s spinning, but so is everything else, so it nets to 0

Re: U.S. military shoots down suspected Chinese surveillance balloon

#810
post #502

Earlier quoted context omitted.

maybe but... it seems clear enough they did not do this given that it seems to have been piloted through a very nice high-value course across the US

Weather balloons aren’t piloted. I don’t think it had any control planes at all, beyond just floating along atmospheric currents. At best they can control elevation? Ok, googling a bit: > Is it possible to steer or otherwise control a typical high-altitude balloon? It can be controlled, but let me be careful about what I mean by that. Balloons go with the wind. And so the only control that a balloon has is: in some b…

IIRC google loon did exactly this and was able to basically go wherever they wanted.
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