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Comment Where it all went wrong: (Score 1) 300

"changing perceptions" through marketing? that sounds like an arms race with the other side. Long time ago we thought the right way to change perceptions was through good education and development of critical thinking skills.

Where did it all go wrong :)

It all went wrong when each sides of the discussion concluded that scientific papers supporting the other side were marketing fake-news, trying to gaslight them into supporting a scam to let the opposing side acquire money and/or power, rather than actual science.

Warmists think evidence against any aspect of their side's story is akin to smoking research sponsored by tobacco companies. Skeptics think any evidence for a global warming story has been corrupted, ala early drug war research on psychedelic drugs, to feed government power grabs and attempts to put rent-seeking taxes on commerce (e.g. Gore's carbon-credit exchange).

Now neither side believes academic papers on the subject. We'll just have to wait and see what the climate does.

Following this paper's prescription, of course, would just put the nail in the coffin on any remaining hope of convincing the population to pay attention to the sort of propaganda it prescribes. (Assuming the very existence of the paper hasn't already done that.)

Comment Re:Read the paper. (Score 1) 113

Flight time is about 20 years. (Proxima is about 4 light years away and the swarm is averaging about 1/5th lightspeed.) I suspect even some of us boomers can hang in here that long - even if life-extension treatments don't become available.

Oops. Maybe not. They're talking about 75 years before getting around to a launch.

Comment Read the paper. (Score 1) 113

I'll be surprised if the project stays funded, since even without delays everyone funding it will die before there's any payoff.

Flight time is about 20 years. (Proxima is about 4 light years away and the swarm is averaging about 1/5th lightspeed.) I suspect even some of us boomers can hang in here that long - even if life-extension treatments don't become available.

Also, I wonder what it will cost to fund the laser for half a century.

The launch and acceleration of the whole swarm is over in about a year. Individual elements are up to speed in much less than that.

(You HAVE to do it fast: Once they're moving they're out of range darned quick, so you have to get them to cruising speed before you can't hit them any more. Fortunately the little motes are really sturdy so you can give them a BIG big push.)

Read The Paper.

Comment Oh, yes... (Score 1) 113

You cannot aim sufficient energy over distances like that
[description of betavoltaic battery run off "interstellar wind" of high-speed travel]

Oh, yes...

You CAN aim the propulsion energy well enough for long enough to get them up to 20%ish of lightspeed. After that the energy is stored in their momentum relative to that of the interstellar gas. You don't have to keep powering them from home and there's far more than you need to power them for the rest of the mission.

Comment Re:No (Score 1) 113

(I happen to know one of the people involved.)

You cannot aim sufficient energy over distances like that

They were originally intended to be powered by betavoltaic batteries (solar cell sandwich with a charged particle emitter for the peanut butter - like the "radioactive diamond" batteries but with Strontium 90 for the radiation source). But another dude computed what local interstellar hydrogen looked like when treated as a proton/electron beam at 20% of light speed and concluded no other radiation source would be necessary - by a long shot. Just launch with the supercaps charged and you're up to power-generation speed long before they're discharged. You only harvest a fraction of that energy - the "solar cells" are far to thin to stop many of the protons but they make lots of electron-hole pairs on the way through - and you use heavy atoms (much charge per atom) in their semiconductor structure to maximize that. That gives you plenty of power to run the computer, sensors, and attitude control. Also the transmitters to phone home, with several watts total over the surviving portion of the swarm.

and you can't slow these gram-weight "robots" down with this propulsion system.

Sure you can. That not-quite-relativistic hydrogen wind through the radiation battery gives you enough friction, when combined with attitude adjustments, to bring the swarm into proper formation and all traveling at the same speed by the time it reaches the target. (You launch it over a considerable period, with the later ones faster than the earlier ones so they all arrive at the same time.) It's slowed a bit by encounter time, but not by very much. So it has to look fast as it flies by.

Comment If worked that way, war photogs die at first snap (Score 1) 109

Timestamp doesn't match if the signing is done by remote server, which at least some of these services have been doing.

A camera that has to be connected to the internet and a remote timeserver/signature generator to record and sign a picture? JUST what I DON'T want to press "take picture" on in a war zone.

Can't you just imagine an automatic "hear the camara talk to the net, identify its location, and hand that to the weapons aiming system" device, and how deploying that would affect war reporting?

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