Only 1,050,000,000,000,000 kilometers away...
Water found on a potentially life-friendly alien planet
201–210 of 410 posts
Re: Water found on a potentially life-friendly alien planet
#202Earlier quoted context omitted.
currently we have no known materials that would actually be strong enough to support their own weight at the length of a space elevator on earth. double the gravity and the length will also at least double (possibly quadruple? not sure on the math here) so it may also be impossible to build a space elevator on one of these planets, at least without the use of active suspension (possible? theoretically.)
Currently we have no known materials that would actually survive a 111 light year trip to another solar system, so that fact that we can't actually build the space elevator when we get there seems irrelevant. They're both roughly the same order of magnitude of impossible with our current technology.
Sure we do. Chuck a rock in the right direction, it'll still be a rock 111 light years later.
Re: Water found on a potentially life-friendly alien planet
#203Some caveats per Marina Koren https://twitter.com/marinakoren/status/1171873631808438273 1. This planet probably doesn’t have a solid surface 2. Being in the “habitable zone” doesn’t mean a planet is habitable 3. The detection is of water molecules, chances are the water only exists as vapour in the atmosphere of this small gas giant. 4. If you ask 10 astronomers about this you will get 11 opinions
I am amused by the idea of a "small giant".
Neptune is ‘only’ 57 times the volume of Earth, whereas Jupiter is 1321 times the volume of Earth. The size range of ice/gas giants is bigger than the gap between Earth and the smallest ice giants.
Re: Water found on a potentially life-friendly alien planet
#204I got into the Wait Calculation[1] a few weeks back and made a Jupyter notebook out of it.
At our current max speed (692,000 km/hr, stated max speed of Parker Space Probe), it would take about 173,000 years to get to that planet.
We could instead choose to Wait and grow our tech. By picking a constant annual growth rate and then doing some calculus to find the minimum, we can calculate the shortest possible time it will take for us to arrive there.
One common recommendation for annual energy growth rate is 1.4%, and then taking the square root to get velocity growth rate since velocity has a square root relationship with energy.
By plugging that in, we can minimize our time by growing for 1020 years, and then traveling for 144 years, for a total time-from-now at 1164 years.
Another paper[2] estimated an annual velocity growth rate of 4.72%, quite a bit faster. Plugging that in, it says we should wait 195 years for a travel time of about 21 years, or 216 years overall. This is of course incorrect since it assumes being able to travel FTL. So if you instead look at how long it would take to get to light speed travel at that rate, you're looking about about 159 years, or arriving at the planet at a time-from-now of about 270 years.
Of course, if you're seeking to minimize time-from-now from the perspective of a traveler, maybe you'd take off sooner. Kind of a tradeoff - less time to wait for the traveler, more time to wait for the home planet. I haven't figured out that part of the math yet.
[1] https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1m... [2] https://arxiv.org/abs/1705.01481
Re: Water found on a potentially life-friendly alien planet
#205Earlier quoted context omitted.
I believe the last 2 points because I don't believe that credible military personnel with long and distinguished careers, would tarnish their reputations terribly for no apparent gain, especially near the end of their lives. Check out Philip J Corso or Robert Salas, but there are , many, many others who have blown the whistle including Walter Haut the public affairs officer during the Roswell crash (and recovery). ht…
I don't know, certain end of life seems to be the perfect opportunity to publish all that fantastic evidence that would mark the most important distinguishable moment for humanity as a whole so far.
Just because they were there doesn't mean they the have evidence
Re: Water found on a potentially life-friendly alien planet
#206There are lots of people in the comments here talking about how long it would take to send a probe, or how many generations a generation ship would have, but it seems clear to me that that's not how humans are going to go to other solar systems. Once we solve mind uploading (assuming that it's possible), we can send a blob of grey goo on a solar sail at a very high acceleration to another solar system. It can shed ha…
If we can simulate wetware perfectly, we would also be able to solve any health condition.
This is all presumptive of the preferences of individual humans. It may be that the giant extrasolar Earth-type planets could be dismantled and rebuilt into smaller Earths located at various Lagrange points.
Re: Water found on a potentially life-friendly alien planet
#207Earlier quoted context omitted.
Theoretically, you can. At 0.99c 111 light years take about 15 years of ship time to travel.
And how much time will it take a person to reach that speed at human-safe acceleration? And how much energy would it take?
It will take longer that people here have calculated. As you approach c the energy required to accelerate quickly rises. To reach c you need infinite energy.
Maintaining 1g of acceleration for a useful amount of time would require an extraordinary amount of propellant.
All of those estimates are tongue-in-cheek and are accurate if your energy expenditure is actually unlimited.
Re: Water found on a potentially life-friendly alien planet
#208Someone please correct me, because with a planet that is at 111 light years away aren't we technically looking back in time?
Any type of observation was only a period Of time and any type of life used to be there, but may not be there presently?
Re: Water found on a potentially life-friendly alien planet
#209Earlier quoted context omitted.
I wonder if we could work around the stronger gravity by using a spaceship as the anchor for a space elevator or skyhook? Both of those technologies are pretty far off, but so is getting humans to another star system.
As gravity increases the tensile strength necessary for the elevator increases. We haven't even figured out how to mass produce materials that would suffice for an elevator on earth yet.
I mean, we're already talking about getting humans to another star 111 lightyears away; I'd assume by the time we're ready to do that we'll have figured out how to mass-produced nanotubes or something.
Re: Water found on a potentially life-friendly alien planet
#210I got into the Wait Calculation[1] a few weeks back and made a Jupyter notebook out of it. At our current max speed (692,000 km/hr, stated max speed of Parker Space Probe), it would take about 173,000 years to get to that planet. We could instead choose to Wait and grow our tech. By picking a constant annual growth rate and then doing some calculus to find the minimum, we can calculate the shortest possible time it w…
> taking the square root to get velocity growth rate
This is your mistake. It's an approximation that works well only at low speeds.