Sending a swarm of unguided relativistic projectiles across the universe seems profoundly rude.
Ten thousand years from then, some alien on some planet somewhere might have a very bad day.
A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
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Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#12Sending a swarm of unguided relativistic projectiles across the universe seems profoundly rude.
It would be nice if they could use solar wind to decelerate as they approached. I know there's not enough energy there to insert them into an orbit, but they might get time for a few more pictures?
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#13Moreover, to keep the beam tightly focused on one probe at a time would require an adaptive optics system that compensated for atmospheric turbulence — something astronomers know how to do over a span of 10 meters, the size of a big telescope mirror now, but not over a mile.
Would it be easier just to put the lasers on the moon?
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#14I thought very strange things start to happen at even 10% the speed of light (mass increase, etc.) so 20% sounds impossibly ambitious? Also the fastest physical object we've ever observed is only 1000 miles per second. A far cry from even 10% of c Then there is that pesky problem of deceleration.
They're not going to put them into orbit, just a fly-by. Then they'll continue until they hit something some time in the future. In a million years some unlucky alien might get hit by an iPhone.
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#15Sending a swarm of unguided relativistic projectiles across the universe seems profoundly rude.
Maybe it's the backstory for Seveneves.
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#16How significant are the relativistic effects at 0.2c (the probe speed they are aiming for)?
To the probes, wouldn't the 20-year flight 'feel' like 16?
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#17Moreover, to keep the beam tightly focused on one probe at a time would require an adaptive optics system that compensated for atmospheric turbulence — something astronomers know how to do over a span of 10 meters, the size of a big telescope mirror now, but not over a mile. Would it be easier just to put the lasers on the moon?
It might be easier to fire the lasers from the moon, but getting the lasers to the moon would be a huge pain.
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#18So, how is a tiny smartphone-sized probe supposed to transmit data back to Earth from 4.37ly away?
Thinking out loud: You need an ingenious design that allows the laser sail to double as a directional antenna. And you pick a frequency which is not radiated by many other objects in space so it's easier to pick up the dim signal. And then you build a ginormous radio telescope bigger than any ever built before. Luckily you have a decade or two to build the telescope after the probes are launched.
Re: A Visionary Project Aims for Alpha Centauri, a Star 4.37 Light-Years Away
#19Sending a swarm of unguided relativistic projectiles across the universe seems profoundly rude.
> a swarm of unguided relativistic projectiles
In a sense, this is essentially what the universe is.