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Two potentially life-friendly planets found orbiting a nearby star

nationalgeographic.com

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Re: Two potentially life-friendly planets found orbiting a nearby star

#111

Post by airstrike »

gambiting wrote: post #85
ekianjo wrote: post #80

Earlier quoted context omitted.

Just going to Mars will significantly increase your risk of cancer, unless we find smart ways to repair our genetic material as we go.

Well, for the journey itself the problem has a simple solution - more shielding. Then of course we have to answer the question of how can we get ships into orbit when they are full of shielding, but that's not insurmountable. The bigger issue is actually living on mars - as romantic as that idea is, human habitation on the surface is really dumb, the radiation level is not insignificant, so anything long term would e…

> And if we are going to build an underground colony....then why not start with one here on Earth?

Because if an asteroid hits Earth or if the world superpowers decide to go full nuclear, the underground colony in Mars will survive (unless superpowers decide to nuke that from here as well...)

Re: Two potentially life-friendly planets found orbiting a nearby star

#112

Post by techdragon »

DCKing wrote: post #84
lmm wrote: post #30

Earlier quoted context omitted.

> I know it's nearby on galactic scales but it's practically about 450,000 Earth years away with current technology :-) If we had the political will, the Orion design could get people there in, what, 200 years, and that's with '70s technology.

The Orion program had this potential on paper. Nuclear bomb propulsion is a complicated thing, but we don't understand if it's a feasible propulsion method in practice, like, at all . Political will in this case brings us more understanding of the feasibility of this propulsion method, but it's way too big of a stretch that political will alone would get us to the nearest starts in 200 years.

Actually we do know it would work. The fundamental physics are sound.

A pusher plate can in fact transfer net positive momentum from a series of explosive shockwaves detonated aft of the pusher plate in the desired direction of travel. There’s plenty of video footage from the Hot Rod tests showing it working. https://youtu.be/Q8Sv5y6iHUM

The hot rod test article was actually donated to the national air and space museum unfortunately it is not currently on display. https://airandspace.si.edu/collection-objects/propulsion-tes...

And for the realities of scaling up from conventional explosives to nuclear detonations you can read a little more here http://www.spacedaily.com/news/nuclearspace-03h.html and http://www.projectrho.com/public_html/rocket/realdesigns2.ph... (scroll down till you get tot project Orion and they have a pretty good summary) And the Project Rho information has links to lots of the technical details and material as well if you want to learn a lot more.

Re: Two potentially life-friendly planets found orbiting a nearby star

#113

Post by [deleted] »

brianbreslin wrote: post #103
gutnor wrote: post #53

Earlier quoted context omitted.

> If we had the political will It takes more than that. We need political maturity and stability. There is no way we can send people today on a 200 years journey and be sure they will both make it and be able to create a somewhat stable society on the other side. Also, that would be a earth level effort, another thing that is seriously irrealistic right now. The very best we can achieve right now is the ISS and that'…

Would a vessel from 50 years from now beat the original crew there? If we assume we are advancing speed-wise by X% each year, the poor folks sent and likely put into cryo-stasis would get lapped by people who left 10 years or 25 years after them.

[deleted]

Re: Two potentially life-friendly planets found orbiting a nearby star

#114

Post by option »

ekianjo wrote: post #76
option wrote: post #51

Earlier quoted context omitted.

yes, we should explore (and eventually exploit) all forms of propulsion and decide between them based on physics, not politics

That Orion project was a failure though. No tangible results to exploit.

my point is that because of fear of nuclear no further research was done. It is now super hard to even get enough material for a rector/battery such as the one on Curiosity

Re: Two potentially life-friendly planets found orbiting a nearby star

#115

Post by corodra »

onemoresoop wrote: post #108
corodra wrote: post #100

Earlier quoted context omitted.

This is also assuming A) Human engineering can create something that can last 200+ years of space travel. We don't even build houses anymore that can feasibly last 100 years. 2) People don't go mad and kill each other or do a mutiny III) Any number of stray objects from asteroids to rogue planets that just slams into the ship and causes major malfunctions d) Food and life support sustainability I mean... there are SO…

Of course we’re far from it, if ever possible. I was just being playful on the whole premise of “colonizing” another earthlike planet

Oh, I'm not bashing you at all. You're absolutely correct. You bring up extremely important things to realize when discussing space travel. Especially long term missions. Political will being the reason why these missions haven't happened, as someone else mentioned, is total crap. It's just an easy excuse to not think of ACTUAL consequences and live in a scifi fantasy.

Re: Two potentially life-friendly planets found orbiting a nearby star

#116

Post by fastball »

sulam wrote: post #73
krisroadruck wrote: post #49

Earlier quoted context omitted.

Check out the Dyson Dilemma for a well-reasoned theory as to why it is a high probability that there is no space-faring intelligent life anywhere in our galaxy or even perhaps our super-cluster. https://www.youtube.com/watch?v=QfuK8la0y6s

There are holes wide enough to fit a solar system through that argument. Reductio ad absurdum. Here, I'll construct an argument in a similar form. People don't like mosquitos, for various reasons including that they transfer deadly diseases. Therefore the presence of mosquitos says there's a high probability that the planet isn't actually inhabited by us, because we would have killed them by now. After all, we have t…

To be honest, I've never really understood how a Dyson sphere would be superior to many nuclear fusion reactors that you can move around / turn off and on / build more of / etc

Re: Two potentially life-friendly planets found orbiting a nearby star

#117

Post by wongarsu »

consp wrote: post #15
wongarsu wrote: post #12

Earlier quoted context omitted.

Atmospheres are useful, but are they a requirement for calling a planet life-friendly? Life on earth first developed in liquid oceans, not in the atmosphere.

Wouldn't an ocean vaporise somewhat automatically to create an atmosphere of there wasn't one already?

Only if it's exposed to vacuum (or an atmosphere). It might be enclosed by ice or other (preferably but not nessesarily transparent) material.

Even if the ocean is exposed, we now have the time it takes for 1. the planet to become tidally locked due to tidal forces, 2. the atmosphere to be stripped away, 3. the ocean to evaporate. That might be plenty of time for higher lifeforms to develop.

Re: Two potentially life-friendly planets found orbiting a nearby star

#118

Post by XorNot »

radmuzom wrote: post #97
sebazzz wrote: post #75

Earlier quoted context omitted.

Let's just say a part of Mass Effect is real and there are actually many civilizations right now. What are the chances that we could even know they exist with the current technology?

We need to discover the mass relays first. Or the Asari needs to find us.

De-icing Charon seems like an appropriate peace-time use of the world's nuclear arsenal :)

Re: Two potentially life-friendly planets found orbiting a nearby star

#120

Post by SEJeff »

gambiting wrote: post #85
ekianjo wrote: post #80

Earlier quoted context omitted.

Just going to Mars will significantly increase your risk of cancer, unless we find smart ways to repair our genetic material as we go.

Well, for the journey itself the problem has a simple solution - more shielding. Then of course we have to answer the question of how can we get ships into orbit when they are full of shielding, but that's not insurmountable. The bigger issue is actually living on mars - as romantic as that idea is, human habitation on the surface is really dumb, the radiation level is not insignificant, so anything long term would e…

The good thing is that Mars is chock full of dormant lava tubes[1]. That provides a solution to the problem you propose assuming we figure out how to seal them and make them habitable for human life. It is an exceptionally difficult, but tractable problem. FTL travel however, is not tractable at all with our current tech and (lack of) understanding of physics.

[1] https://en.wikipedia.org/wiki/Martian_lava_tube

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