Can we really get to Alpha Centauri? The Breakthrough Starshot initiative

[brooklynite]

https://phys.org/news/2020-05-interstellar-probes-starshot.html

[Jeebo]

1. Carl Sagan talked on "Cosmos" about...

...several different kinds of starships to visit relatively nearby star systems.

Also, one of the best science fiction novels I've ever read was about some extraterrestrials who visited Earth 15 or 20 thousand years ago. Crash landed on Earth, lost a lot of their technology, the rest of it kind of dissipated away in the decades that followed, while they dealt with being stranded on our world and mingling with, and being enslaved by, humans. They came from the Alpha Centauri system, as I recall. It's been 20-plus years since I read that novel. It's "Encounter With Tiber" by Buzz Aldrin and John Barnes. Yes, THAT Buzz Aldrin, the one who stepped onto the moon with Neil Armstrong 51 years and one day ago.

-- Ron

[triron]

3. I believe thaere is ample evidence that we have been (and are being) visited by

advanced extraterrestrial intelligence (may not be biological).

[edhopper]

4. No

there really isn't any.

As Sagan said, "Extraordinary claims..."

[triron]

2. Certainly seems technically feasible. I wonder if before it gets there, another

more advanced starship (from earth) would get there sooner? It is theoretically possible to
exceed the speed of light by creating a capsule of spacetime that moves through the ambient
spacetime (Or possibly utilizing hypothetical 'wormholes' in spacetime). We just don't know how to do that now.

[lagomorph777]

6. Much as I would like this to work, the problems are pretty obvious.

How do you accelerate any material object to 0.2c in an instant without blasting it to a puff of atoms?

Assuming you do that, why wouldn't it become said puff of atoms the first time it hits a dust particle? And then, all of the nearby (or trailing) Starshots would encounter that puff and go poof too.

Once they get there, what is the energy source to transmit a signal 24 trillion miles back to Earth? How does a 1m antenna focus that energy so it has some shred of hope to ever reach Earth? A tight beam requires a very large aperture. And by the way, how do you aim that pencil-thin beam?

Edited to correct "0.2g" to "0.2c"

[Disaffected]

8. Yeah,

so far the very considerable problem of transmitting the signal back to earth has received pretty much only hand waving. There's a lot of other issues too, if one wishes to google for it.

[blitzen]

5. "Mad is the Captain of Alpha Centauri..."

[Disaffected]

7. Don't hold your breath,

he only hit on some of the formidable technological hurdles that will need to be overcome.

For example, producing lasers of the required power and controllability that will fire continuously for the required length of time (nothing even close to that exists now).

And the unobtainium needed for the sails (extremely high reflectivity is required to avoid burning up, something like 5 or 6 nines worth IIRC and, extremely light (as he mentioned) but physically strong enough to withstand the v high accelerative forces).

Maybe it'll happen but I expect the project will eventually die.

[hatrack]

9. Depends - how much of a hurry are you in?