Four Earth-sized planets detected orbiting the nearest sun-like star • Hacker News Board

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#301

Post by Retra » Sat, Aug 12, 2017, 8:54 PM UTC

ExactoKnight wrote: post #298

Retra wrote: post #236

Earlier quoted context omitted.

If we discovered actual humans on a near-exact clone of earth, we'd still be about 50,000 years from something relevant here on Earth. Outer space is staggeringly expansive. Staggeringly . Like "your space probe is sad joke" expansive. We could develop our own alien life right on Earth within that timeframe.

You're thinking about this wrong. As long as we can send probes and/or communicate within compressed timeframes than physical transportation of humans doesn't matter. E.g. Breakthrough Starshot can get us to many exoplanets within 20-30 years: https://en.wikipedia.org/wiki/Breakthrough_Starshot

"Many" exoplanets? How many planets does Alpha Centauri have?

It is ~4 ly away. If you're willing to go ~10 ly, you get 6 more stars to look at. And it gets far worse from there.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#302

Post by dredmorbius » Sun, Aug 13, 2017, 7:49 AM UTC

ExactoKnight wrote: post #299

dredmorbius wrote: post #271

Earlier quoted context omitted.

The James Webb Space Telescope is an example of a segmented-mirror optical scope. The deployment video (simulation) is fascinating to watch: https://m.youtube.com/watch?v=v6ihVeEoUdo It has a 6.4m (21ft 4in) primary mirror. Which, from a pragmatics standpoint, answers your question. Though I suspect mission plans could be drafted for a larger scope yet. https://en.m.wikipedia.org/wiki/James_Webb_Space_Telescope

Fascinating video, but honestly the only thought that kept going through my head is: they've overcomplicated this. Despite it's impressive number of steps, this does not look like good engineering. Instead, it looks like a design by committee, with engineers going drunk on complex parts coming together rather than dumbing down the unfurling of this telescope down to its most basic possible mechanism, with the fewest…

I strongly suspect they aren't.

You're looking at a high-precision instrument, that's being fit inside a distinctly finite space and mass budget, that will have to operate for years (possibly decades), and which is beyond reach of any conceivable service mission for a very long time.

Movement, thermal control (the Webb operates in the low end of the visible spectrum, through the infrared, so its temperature itself is critical), alignment, and drift, all matter.

And every piece of equipment has to be tested and trialed to the maximum extent possible.

Yes, it's a bit Rube-Goldbergish, but then, so is the specification.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#303

Post by dTal » Sun, Aug 13, 2017, 2:56 PM UTC

Retra wrote: post #300

ExactoKnight wrote: post #260

Earlier quoted context omitted.

Not at all. I don't care about traveling there, I want to know about what other life exists. Once we find a good target, the Breakthrough Starshot program is one example of a promising project that could get us results within our lifetime.

Breakthrough Starshot will get you to a negligible number of stars. Fewer than ten, probably. You think one in ten stars has life?

That wouldn't necessarily be a surprising figure. I might even be tempted to assign a similar probability to finding life elsewhere in the Solar System.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#304

Post by Pigo » Mon, Aug 14, 2017, 1:05 PM UTC

ceejayoz wrote: post #87

Pigo wrote: post #43

Earlier quoted context omitted.

I'm left wondering these same kind of issues every time there's a Mars habitation post. Having a third the gravity, microscopic dust, and a complete lack of nature (or Internet) seems to be trivial to some people.

> Having a third the gravity Sounds fun! > microscopic dust Found on earth! I change my HVAC filters regularly. > and a complete lack of nature There's plenty of nature on Mars. Not much life, but we'll bring that with us. I'd suspect early colonists will have more plant life in their quarters and living areas than your average NYC resident. > or Internet I'd fully expect a solution along the lines of Netflix's edge…

You think existing in a third the gravity, most likely for the rest of your life, wouldn't effect your body in untold ways?

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#305

Post by ExactoKnight » Thu, Aug 17, 2017, 9:25 PM UTC

Retra wrote: post #301

ExactoKnight wrote: post #298

Earlier quoted context omitted.

You're thinking about this wrong. As long as we can send probes and/or communicate within compressed timeframes than physical transportation of humans doesn't matter. E.g. Breakthrough Starshot can get us to many exoplanets within 20-30 years: https://en.wikipedia.org/wiki/Breakthrough_Starshot

"Many" exoplanets? How many planets does Alpha Centauri have? It is ~4 ly away. If you're willing to go ~10 ly, you get 6 more stars to look at. And it gets far worse from there.

It's now estimated there are more Earth-sized planets than gas giants on most stars, and that every star has at least 1 planet, likely more.

So that's 7 or more planets. That's many.