Hacker News Reader

Comment by chenning | Hacker News Reader

A very quick search suggests that earth will become uninhabitable somewhere between 500 million and 2 billion years from now. If we shot a probe to this life-friendly alien planet with some sort of primordial soup, even traveling at the speed of light it would take 4 billion earth years to get there. Do I have that right? Basically we'll never even come close to being around when it finally arrives, if it ever arrives. Has anyone ever thought about doing this? We've shot gold records out into space for aliens with turn-tables. Why haven't we tried this?

View on HN

It would not take 4 billion years at the speed of light, it would take 111 years. That's what light-years are, the distance travelled by light in a year.

Strictly speaking, if you actually traveled at the speed of light, the trip would be instantaneous from the reference frame of the craft making the trip. It would still take 111 years from our frame of reference on Earth.

Also assuming no acceleration or deceleration time in this made up impossible scenario. In the more likely scenario where we can get to a fraction of the speed of light using current technology we do have to account for both factors in both time and space probe weight.

Yes, but we can't actually travel there with our current technology, and while you're speculating about future technology, you can pick the number of 9's to tack on to your cruise speed pretty much arbitrarily. So from the probe's perspective, it takes somewhere between a fraction of a second and many billions of years to arrive.

Ah, right. Basically I vote for firing a primordial soup probe to this sucker.

There are people working on the basic technology [0]. It's going to be quite a while before we visit nearby stars though. Even launching a probe that has a reasonable chance of successfully visiting (and communicating back to us!) this star system is probably not going to happen in the lifetime of anyone currently living.

[0] https://en.wikipedia.org/wiki/Breakthrough_Starshot

If the goal is to seed life, why not send something already alive instead? Though I don't think we know what to send that would be a living colony still by the time it arrived, even if we knew how to send it exactly. And it'd probably just die when it arrived unless we get a much better idea of what's there already.

An artificial intelligence would likely be the best bet actually, but there's a bunch of challenges there we don't actually know how to solve either. Maybe in a few decades there will be fewer unknowns at least.

That does raise a huge number of ethical issues.

Do we have the right to interfere on a planet which may already have life?

Survival of the fittest. We launch our virus first... assuming they didn't already launch theirs, in which case it's mutual destruction.

Ignoring the moral problems ...

Nitpicking: Virus are a bad choice. Most are highly specific and reuse a lot of the machinery of the cell they attack. It's much better to send a mix of bacteria and archaea (ask an specialist to get a good combination of strands that like to live in different conditions (hot/cold, oxygen/no-oxygen, ...)). Put them inside a shell to protect them from radiation and a good shell for landing/crashing (ask another specialist for this part too), perhaps like a multiheaded interplanetary missile with many a copy of your minizoo.

Probably anything you send has enough bacterias to have a chance, unless it's super clean an sterilized. They try not to send bacterias to Mars, but I think bacterias will win. They only need a single error to get a free trip.

I remember a joke that someone said that Eukaryotes is the method that Prokaryotes use to travel from planet to planet.

> Survival of the fittest.

Right, which is why the only rational approach to life is to literally try your best to kill everyone that isn't you.

It seems like it would be much easier to terraform the real estate around us than try to opt for something 100 light years away.

Mars has a leaky atmosphere - sure it's a real fixer upper. But we have a better chance of fixing it, or even correcting the orbit of our planet so that in 500 million years it's still livable.

Or sending a HUGE human civilization spaceship somewhere.. maybe it will outlast the earth?

In a lot of ways, living on spaceships/space stations/other artificial constructions is likely a better path forward than looking to colonize new planets in general. O'Neill cylinders are quite practical, and with advances in technology that seem likely to occur, even larger projects like Bishop rings should be doable. They can be linked together to form constellations, and have enough free floating resources within the solar system to be able to build enough of them to support populations in the trillions.

It probably sounds less than ideal to you and me, vs. living on a planet, but it probably wouldn't be so bad to someone born in that sort of environment and is used to it.

With that in mind, I don't know if it makes sense to try and find human habitable planets, vs. just places with lots of raw material we can use. Unless there's alien life we want to go meet up with, at any rate.

>> It probably sounds less than ideal to you and me, vs. living on a planet, but it probably wouldn't be so bad to someone born in that sort of environment and is used to it.

Yeah, and also at some point, it won't matter what's ideal or not.. it'll be about survival.

O'Neill cylinders are so practical that most of this stuff we have no idea how to practically accomplish.

Edit: The sizes involved for launch would present no less than a hundred trillion budget at the moment.

I mean practical in that there's no exotic science required. Everything required we have ideas on how to accomplish now, and the big issues are making it cost effective.

And as for the 100 trillion budget, if you're launching from the earth, sure. Geologists are pretty sure the moon has plenty of materials useful for building stuff. We've already built mass drivers, and the physics for building one that could launch raw materials from the moon are perfectly sound.

Yes, we need to figure out mining materials and building stuff in space. But we're going to have to figure that out anyway if we want to survive as a species in the long term, and there's plenty of advantages in starting to figure that out now, especially since we're staring down the barrel of a gun vis-a-vis climate change.

Or creating our own planet at an appropriate orbit somewhere.

Even easier is to stop digging stuff up and burning it. But we can't even do that.

Christ, why even go to Mars? Even in the worst cases the damage we do to Earth will still leave it significantly more hospitable than Mars.

>A very quick search suggests that earth will become inhabitable somewhere between 500 million and 2 billion years from now.

I'm 99% sure that Earth is inhabitable right now... perhaps you meant "uninhabitable"?

Is it though??? (edited, thanks)

> traveling at the speed of light it would take 4 billion earth years to get there

Genuinely wondering how you got that number. I'm reading 111 light years in the article, wouldn't that simply be 111 years of travel time, at the speed of light? Am I missing something?

The threat in 500 mln years is that all CO2 will be used in shells of see creatures. But considering how good we are at freeing more carbon this issue should be easy to fix.

Your assumptions may be wrong especially considering how far in the future we're talking.

That's what wormholes are for...

Reply on news.ycombinator.com