It's around 100 light years away from Earth for anyone interested.
So the distance would be like a weekend getaway when it comes to space travel.
An extrasolar world covered in water?
111–120 of 150 posts
Re: An extrasolar world covered in water?
#112Earlier quoted context omitted.
Since it's heavier than Earth, what about the rocket equation? Colonizing it may mean the inhabitants could never leave it.
It'd just be 13 km/s to low orbit (or 19 km/s to escape), which isn't really that much for small payloads -- New Horizons had a total of 17 km/s delta-v. You don't even need to look at space elevators or fission or fusion launch systems, all of which are probably viable on first principles.
That orbit or escape velocity really is that much. The rocket equation is exponential, such that even a small change in the required speed means a large change in requirements. The difference between Earth's escape velocity of 11 km/s and this planet's of 19 is actually quite huge. Imagine you build an 11 km/s rocket as you would on Earth... to get it off this other planet, first you have to accelerate that rocket and all its fuel to 8 km/s.
The rocket equation is Δv = Ve ln (m0 / m1), where Ve is exhaust velocity, m0 is payload mass, m1 is mass including fuel. To get 19/11 as much Δv, you need a fuel/mass ratio of e^(19/11) = 5.6 times greater.
Re: An extrasolar world covered in water?
#113Re: An extrasolar world covered in water?
#114Earlier quoted context omitted.
The seeds of humanity won't be humanity at all, but the AI.
It seems that there's a very pessimistic trend with regards to estimating the feasibility of engineering human biology for inhabiting outer space. Everyone just wants to let AI do it. I think this is because the progress of biotech has been so glacial. This is largely due to regulation. China will probably change the rules around at some point to allow for more flexibility here, with lots of moral outrage and handwri…
Well, I think that's really just an implementation detail. The point is that we will engineer our successor beings, whether than engineering is computery or mad sciencey or both.
Re: An extrasolar world covered in water?
#115Url changed from https://www.freethink.com/space/ocean-planet, which points to this.
Re: An extrasolar world covered in water?
#116This is both exciting and somewhat disappointing. It sounds like the water is so deep that it's probably solid ice (due to the intense pressure) before you get to a rocky core. Life on earth needs nutrients extracted from the rocks. If life formed on this planet, any non-buoyant corpse would sink to the bottom and disappear forever. That is to say, it would almost certainly die out very quickly from lack of nutrition.
Re: An extrasolar world covered in water?
#117Earlier quoted context omitted.
Is this really how time dilation works?
Yip, although there's also length contraction in play. The universe just starts contorting itself to ensure nothing ever exceeds the speed of light. What the GP post is referring to is called a 'relativistic rocket'. You can find plenty of calculators for them, like here [1]. It leads to really mind-bending scenarios. For instance a single human could easily travel a billion light years within their lifetime, requiri…
Yea, the calculators really help show how wild it is. I could outlive Earth's sun by simply accelerating away at 1.25G for ~35 years (ship time), not to mention how stacked I'd be from the workout of merely existing at 1.25G for half my life. The very concept of simultaneity is completely whack at such distances, times, and speeds.
Re: An extrasolar world covered in water?
#118Earlier quoted context omitted.
Since it's heavier than Earth, what about the rocket equation? Colonizing it may mean the inhabitants could never leave it.
There are non-rocket ways to space, like a catapult or maglev accelerator. Or ways to assist the rocket outside the rocket equation, like a spaceplane launch platform. Or even Project Orion nuclear explosion propulsion. (Which is subject to the rocket equation, but with nuclear rather than chemical fuel for a much higher multiplier of energy per mass.)
I'm skeptical a catapult could ever work in an atmosphere as thick as Earth's. The drag would be incredible.
Re: An extrasolar world covered in water?
#119Earlier quoted context omitted.
I think the AI will find little reason to take us with them to the stars.
I don't understand people who say things like this. If we invented AGI tomorrow, how would it achieve domination over us humans? It is like Voltaire, Rousseau, Locke, Milton, Hobbes, Rawls never even existed and we don't have any sort of coherent understanding of political philosophy and how power is gained and enacted at the consent of the governed. I also find that discussions of interstellar travel tend to conveni…
> If we invented AGI tomorrow, how would it achieve domination over us humans?
Completely depends on if super-intelligence is possible from that AGI model, and if so, how fast the ramp up will be to super-intelligence.
The problem for insects is not that humans "dominate" them (in fact most insects have total "freedom"); the problem is that humans do not take the concerns of insects into account for any of their decision making.
Re: An extrasolar world covered in water?
#120Getting flashbacks to the sci-fi short story "Grenville's Planet". First contact may not go very well.