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Earth-like planet spotted orbiting Sun’s closest star

nature.com

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Re: Earth-like planet spotted orbiting Sun’s closest star

#71

Post by adflux »

cletus wrote: post #68

Other commenters (rightly) pointed out this is a stretch to the term "habitable". What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes. So planets seem to be really common. If they wer…

I will start off by saying I have very little knowledge of physics or astronomy, but reading comments like these feels like I'm watching a 13th century British sailor confidently state what's on the other side of the Atlantic ocean...

Do we really know enough to be able to say if a planet is habitable? Or could there be other forms of life that we don't know of yet... We have only recently put a man on the moon, and now we're saying we would be able to detect dyson spheres...?

Re: Earth-like planet spotted orbiting Sun’s closest star

#72

Post by IHLayman »

withinboredom wrote: post #34
Udo wrote: post #21

Earlier quoted context omitted.

I find it enjoyable to think about the technologies that might just be in the cards further into the future. If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g…

IIRC, the limit with humans on-board is like .3c due to the red/blue shifting of the background radiation of the universe. At about .3c, it turns into microwaves/radar/x-rays and such, becoming quite bad for humans. There’s so much background radiation, there may be no way to adequately shield from it and/or travel may be limited only in the direction of less background radiation. Maybe someone has a link to more inf…

Here’s a link to a Gizmodo article talking about the study… unfortunately I can’t get the original study to load: https://gizmodo.com/this-is-what-it-would-really-look-like-t...

Re: Earth-like planet spotted orbiting Sun’s closest star

#73

Post by virgildotcodes »

grishka wrote: post #63
rbanffy wrote: post #53

Earlier quoted context omitted.

> If various forms of rapidly ejecting matter out of a nozzle really are the only physically viable option for spaceflight, it would be an extremely disappointing universe. Indeed. If that's the case, the universe is an infinitely big and infinitely boring place. OTOH, our future uploaded selves may be able to slow down their clock rates and make the trip so much shorter. And you don't need to leave your dear ones on…

Frankly, I believe that any form of mind upload or consciousness transfer is a much harder problem than both rejuvenation and interstellar spaceflight. Looking at current aging research, there's a good possibility we'll see rejuvenation in the next decade or two and it'll profoundly change our society. In 20 years, everyone will be looking 25 years old and pointing at frail people with wrinkly faces and laughing, sam…

Any chance you could link to some stuff that's making you so optimistic about rejuvenation on that timeline?

Re: Earth-like planet spotted orbiting Sun’s closest star

#74

Post by Loughla »

adflux wrote: post #71
cletus wrote: post #68

Other commenters (rightly) pointed out this is a stretch to the term "habitable". What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes. So planets seem to be really common. If they wer…

I will start off by saying I have very little knowledge of physics or astronomy, but reading comments like these feels like I'm watching a 13th century British sailor confidently state what's on the other side of the Atlantic ocean... Do we really know enough to be able to say if a planet is habitable? Or could there be other forms of life that we don't know of yet... We have only recently put a man on the moon, and…

And it's also assuming that any life is like us, with no other technology or way to cycle/recycle heat other than to radiate it into space.

I mean, I know the proof of life is us, but the human-centered view of the universe does reek of prior historical "knowledge" that the earth was the center of the universe. I understand searching for life like us, as that is what we can extrapolate from current data. But to use that to infer that we're it, it's just too much for me.

Re: Earth-like planet spotted orbiting Sun’s closest star

#75

Post by koheripbal »

cletus wrote: post #68

Other commenters (rightly) pointed out this is a stretch to the term "habitable". What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes. So planets seem to be really common. If they wer…

There is a major logical flaw in your argument.

Space travel is only considered to be impractical for humans, or similarly large organic entities within their limited lifespan.

The time constraint and the mass constraint may not be particularly relevant to intelligence that no longer has organic form.

An artificial lifeform may not have a defined life span and thus taking 100,000 years to travel the stars may be acceptable.

Additionally, they may only need to make the trip once to establish the receiving antenna, in order to transmit their "progeny" around the galaxy.

Tldr; We are like ants thinking that we need to figure out how to make really long tunnels to cross the Atlantic, instead of focusing on the limitations of our physical bodies.

Re: Earth-like planet spotted orbiting Sun’s closest star

#76

Post by wizzwizz4 »

adflux wrote: post #71
cletus wrote: post #68

Other commenters (rightly) pointed out this is a stretch to the term "habitable". What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes. So planets seem to be really common. If they wer…

I will start off by saying I have very little knowledge of physics or astronomy, but reading comments like these feels like I'm watching a 13th century British sailor confidently state what's on the other side of the Atlantic ocean... Do we really know enough to be able to say if a planet is habitable? Or could there be other forms of life that we don't know of yet... We have only recently put a man on the moon, and…

> We have only recently put a man on the moon, and now we're saying we would be able to detect dyson spheres...?

A moth doesn't even have electricity, but it can detect a lampshade. A Dyson sphere is basically a stellar lampshade; we can detect it if the laws of thermodynamics hold, and we're pretty sure they do. (A Dyson swarm is similar, though a bit harder to detect.)

Re: Earth-like planet spotted orbiting Sun’s closest star

#77

Post by ffhhj »

withinboredom wrote: post #34
Udo wrote: post #21

Earlier quoted context omitted.

I find it enjoyable to think about the technologies that might just be in the cards further into the future. If we ever figure out light-weight fusion drives, we could build light hugger space ships that accelerate to a decent fraction of the speed of light. At 1g acceleration it takes about one year to get to 0.9c, which would make the Proxima system accessible with a travel time of about 6 years. Or 8 years at 0.5g…

IIRC, the limit with humans on-board is like .3c due to the red/blue shifting of the background radiation of the universe. At about .3c, it turns into microwaves/radar/x-rays and such, becoming quite bad for humans. There’s so much background radiation, there may be no way to adequately shield from it and/or travel may be limited only in the direction of less background radiation. Maybe someone has a link to more inf…

Right, also the hull must resist the impact against hidrogen atoms at near the speed of light, which would apply tremendous forces. Dust will be like exploding nukes.

Re: Earth-like planet spotted orbiting Sun’s closest star

#78

Post by anders_p »

rbanffy wrote: post #47
5350-uiop-1130 wrote: post #35

Earlier quoted context omitted.

>something like 18 000 years this is why we don't see any signs of life out there. there really isn't any point in trying to venture beyond your home. universe is just too big even at the speed of light when you start venturing beyond your local group.

> even at the speed of light If you get really close to the speed of light (which is not really practical from a materials engineering standpoint) your time of transit is significantly shorter. Once these (extremely hard) engineering problems are solved, a trip to the next star can be a week-long affair from your point of view, but your friends back on Earth won't see you for about a decade.

You'd have to get very close to the speed of light, before you'd see any really significant relativistic effects.

That just isn't practically doable with any technology within humanity's reach, probably for centuries. If it ever will be at all.

The amount of energy needed to propel anything at that speed is enormous.

Re: Earth-like planet spotted orbiting Sun’s closest star

#79

Post by grishka »

virgildotcodes wrote: post #73
grishka wrote: post #63

Earlier quoted context omitted.

Frankly, I believe that any form of mind upload or consciousness transfer is a much harder problem than both rejuvenation and interstellar spaceflight. Looking at current aging research, there's a good possibility we'll see rejuvenation in the next decade or two and it'll profoundly change our society. In 20 years, everyone will be looking 25 years old and pointing at frail people with wrinkly faces and laughing, sam…

Any chance you could link to some stuff that's making you so optimistic about rejuvenation on that timeline?

https://old.reddit.com/r/longevity has a lot of links to various articles and papers, and I also collect relevant videos and talks into a playlist: https://www.youtube.com/playlist?list=PLLvA7pB41pDk27XOjqbXi...

Re: Earth-like planet spotted orbiting Sun’s closest star

#80

Post by bgroat »

koheripbal wrote: post #75
cletus wrote: post #68

Other commenters (rightly) pointed out this is a stretch to the term "habitable". What's becoming clear though is the only thing stopping us from lots of Earth-mass planets is the abilities of our detectors to detect ever-smaller gravitational wobbles and ever-smaller transits. Bear in mind we only tend to find planets around stars where we're on their ecliptic planes. So planets seem to be really common. If they wer…

There is a major logical flaw in your argument. Space travel is only considered to be impractical for humans , or similarly large organic entities within their limited lifespan. The time constraint and the mass constraint may not be particularly relevant to intelligence that no longer has organic form. An artificial lifeform may not have a defined life span and thus taking 100,000 years to travel the stars may be acc…

I'm reminded of the wonderful book "Blindsight" which features vampire astronauts because they can put themselves into states of suspended animation
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