Necessity of building a starship

An interesting article written by Ian Crawford, a Professor of Planetary Science and Astrobiology, Birkbeck, University of London, contemplating of possibilities of building a starship and why we should start thinking about it right now.
http://singularityhub.com/2016/01/2...nd-why-we-should-start-thinking-about-it-now/

Mirror link (if the one above doesn't work)

Would this century see manned spacecraft? Or at least the first attempts to build it?

 

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Might depend on the point from where something is a called a spacecraft. We sent men to moon already, and several countries have plans to repeat this, or take the next step, to mars, right away.

Given the fact that 50 or 60 year old technology was enough to reach the moon, and that we saw tremendous advancements in this frame of time, I think it is quite likely that we'll see this.

The only question these days seems to be the money.

 

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It is my impression that money is not going to be an issue. We are publically funding private space vehicles and ventures today. There are very likely undisclosed connections behind those private ventures and corporate/elite with the plans to escape Earth before the planet beomes uninhabitable.

 

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I hope you are right.

I have read about plans to harvest space bodies which are rich in valuable metals, but that's been unmanned spacecrafts. But yes, if there is enough incentive, the money usually comes together.

PS: I hope it won't end in this dystopian future where the poor are left on a depleted and polluted earth without a future, and the rich are off to better planets :/

 

Just having a spaceship wouldn't be good enough. You need somewhere to go that would be able to sustain humans. To think about going to Mars would be very difficult for humans. -250 at night, no atmosphere , no oxygen, little water, solar winds hitting it, cosmic radiation bombarding it and nothing to use there to build a home that is radiation proof. So if you think that going to live on Mars is getting away from this planets problems you'd be hard pressed to find anyone that would enjoy living like that there.

 

and go where?

 

I'm not saying they are the brightest bulbs, lol. But if you have the money to spend, and don't want to be left behind, you have to start the planning somewhere ...

 

The least habitable location on Earth is still far FAR more habitable than the most habitable location anywhere else in the solar system.

If you want to escape a toxic Earth, the best place to go is still Earth. Just build your secret base under water, or under the Antarctic ice sheet or somewhere.

 

Some scenarios include an asteroid collision, nuclear war, out of control virus; but it is a long term issue that can't be solved with a spaceship; as you point out, they would need someplace to go.

 

In my opinion, this idea is pretty silly and it is disappointing to see a real scientist involved in it. In particular:

First off, that's a little disingenuous. They skipped the order of magnitude in between, and in fact at the moment there is only one known exoplanet that fits that criteria (for a round-trip anyway) and it happens to be orbiting our second closest neighbor, Alpha Centuari. A round trip at 10% of the speed of light would take just under a century. There's only one other reachable one-way in under a century. Overall, there are only eight stars total that are reachable in under a century, one-way.

And if we achieve this goal, what have we won? It would be a one-way trip for humans (indeed, a generation trip, with the first generation being dead before reaching the destination) and even for probes, the people who sent them would be dead before we received information back. It's tough to see a ton of value in that. The "why" section of the article ignores this issue completely.

 

They will need to send exploratory robotic spacecraft to these far away places and send back information about what is actually there before sending humans.

 

The only real alternative for instellar travel is the relativistic rocket. The generation trip doesn't make any sense. Either way the technical issues needed to be resolved are huge. The relativistic rocket could make the AC round trip in less than ten earth years proper time. My reasoning for the first trip is to prove it can be done for when we need it. I'd say the likelihood would be nil for having proved it before we need it.

 

Or build a machine that can produce a "worm hole" to go through to other worlds without the need of a spacecraft but only the machine that makes the wormhole.

 

The machine that makes the wormhole is negative energy. Same for the super luminal warp. It keeps the walls of the warp spacetime from collapsing. That's why I prefer the idea of the relativistic rocket with a sublight warp which only needs massive amounts of energy rather than massive amounts of negative energy. Only. LOL Both are a stretch in reality. If we can't make some kind of relativistic journey interstellar space flight is a myth in my opinion.

 

Since there is no evidence that such a thing exists/is possible, I won't be holding my breath.

 

A wormhole or Einstein-Rosen Bridge is a hypothetical topological feature that would fundamentally be a shortcut connecting two separate points in spacetime.

https://www.google.com/url?sa=t&rct...dqV0wyFSkBDsQOYINmaHCw&bvm=bv.113034660,d.eWE

 

The metric says it's possible or we would have never heard of a wormhole. It's possible but any reality includes violating all the minimum energy requirements associated with metric components. Metric solutions, to the EFE, that predict violation of minimum energy conditions are allowed. Will they be more than a curiosity is the question.

 

I was talking about the negative energy required to make one.

 

If, big if, worm holes do exist in nature, they just form and where they lead doesn't matter.
If we have to form a worm hole, how do we aim it? Sending probes to pop-out the other end and make observations could show we are light years off our chosen target.
Or, remembering those SciFi stories where the baddies somehow form a worm hole in the centre of a star and direct the other end onto their enemies, we in our first attempts to form a worm hole may accidentally open the other end on a supernova.

 

The following link has several Kip Thorne thought experiments about using a wormhole. Wormhole for time travel.
http://www.space.com/28000-physicist-kip-thorne-wildest-theories.html
Last year I read a paper where the author does an analysis for a microscopic wormhole. The analysis questions whether Casimir physics could open the mouth and support the interior walls long enough for a photon to pass through. The conclusion was the wall energy is negative up to the point where the wall spacetime becomes flat but the photon makes it through before collapse. Something like that. This would be a theoretical prediction based on the analysis. Love that kind of stuff. Wonder how big a Casimir machine would have to be to hold open a super luminal warp spacetime geometry? Here's the paper.
http://arxiv.org/abs/1405.1283