Why we are unlikely to ever leave the solar system. • Hacker News Board

Re: Why we are unlikely to ever leave the solar system.

#131

Post by ericb » Fri, Jun 10, 2011, 2:53 PM UTC

adrianN wrote: post #87

bad_user wrote: post #78

Earlier quoted context omitted.

Yeah, but give it another 200 years and those magic wands may be possible. I'm not holding my breath as neither me nor my children or grandchildren are leaving this planet, but look at the progress in technology we've made since the industrial revolution happened.

Indeed. Two hundred years ago it seemed impossible to cross the Atlantik in less than a week, now we can send people to the Moon and back in that time.

How unlikely would the iPhone in my pocket have seemed 80 years ago?

Magic wands? 1-computing, 2-wireless data transmission, 3-display (television), 4-rechargeable batteries, 5-touch interface, 6-price drops.

Re: Why we are unlikely to ever leave the solar system.

#132

Post by nkassis » Fri, Jun 10, 2011, 3:01 PM UTC

adrianN wrote: post #86

nkassis wrote: post #29

Earlier quoted context omitted.

Yeah I don't think it's impossible to build a bomb that big, as far as I understand it, no one felt like building bigger bombs than tsar bomba because it becomes useless, if I'm not mistaken after 400 megaton or so, most of the energy will just be sent to space. From the Tsar Bomba article on wikipedia: "Since 50 Mt is 2.1×1017 joules, the average power produced during the entire fission-fusion process, lasting aroun…

You wouldn't build one huge bomb, but instead use lots and lots of tiny bombs in an Orion-type spacecraft. That way you get a better utilisation of your energy.

Doesn't that make it even easier? But then again I think 400 megaton isn't enough. Last time I calculated it ( I probably made a ton of mistakes ;p) it was in the the 10s of thousands or something like that.

Accelerating the space shuttle to 0.10c : (2,030 t * (0.10c)(0.10*c))/210 PJ = 8700 (wolfram alpha)

2,030 mass of space shuttle in metric tons 210PJ the energy from tsar bomba.

But then you have to add in the weight of the bombs too. since they are each 27,000kg and then you have to sum it up to get to something that can approach 0.10c (and I don't remmember how I had figured that one out)

And what says once you get to the other planet you can't fill the tank with nuclear materials over there for the return trip?

Re: Why we are unlikely to ever leave the solar system.

#133

Post by DennisP » Fri, Jun 10, 2011, 3:02 PM UTC

"Ever" is a pretty strong word, and I think he's going to look pretty silly in a century or so. For example, here's an estimate of travel costs with boron fusion rockets: http://nextbigfuture.com/2007/11/fusion-propulsion-if-bussar...

If either Bussard's polywell fusion or focus fusion turn out to work, that'll be achievable within a couple decades. As Moore's Law continues and we get better at simulating plasma, it's not that unlikely that some form of fusion will work out.

There are a lot of possibilities for non-rocket launch, including various space-elevator-like schemes, laser launch, and mass drivers. Even without fusion, thorium fission could provide plenty of power.

It'd be pretty expensive and slow to travel to another star with fusion...but eventually, with large solar panels in close orbit around the sun, we'll have an awful lot of energy to play with, and just maybe we'll figure out efficient laser or microwave power transmission sometime in the next thousand years.

On the other hand, maybe we'll just colonize the Oort Cloud and gradually migrate to other stars over the next million years or so without really trying.

(And, not that I'm holding my breath for this one, but if Woodward's right about the Mach effect we'll get to other stars pretty quickly.)

As for the reasons...the resources of the solar system are millions of times what's available on Earth. Once launch is cheap it'll be a no-brainer to start mining the asteroids.

Re: Why we are unlikely to ever leave the solar system.

#134

Post by DennisP » Fri, Jun 10, 2011, 3:04 PM UTC

syncopated wrote: post #12

"That's the same as the yield of the entire US Minuteman III ICBM force." So you're saying there's a chance!

The fact that we've already built equipment capable of delivering that much energy in a short time makes me think, holy crap, there really is.

Re: Why we are unlikely to ever leave the solar system.

#135

Post by ceejayoz » Fri, Jun 10, 2011, 3:26 PM UTC

JanezStupar wrote: post #94

zeteo wrote: post #10

Earlier quoted context omitted.

>Just think about computer chips. On any long voyage they'd break down so you need to be able to make new ones. Chips are small and light enough that you can bring along a thousand times more chips than you need, at negligible additional cost. PCBs are a bit more trouble, but those are much easier to produce and recycle.

They would still age. Were talking thousands of years here. In space, with all the radiation. In interstellar space.

So you store them in the middle of your water tank. A hundred feet of water will block that radiation quite nicely.

Re: Why we are unlikely to ever leave the solar system.

#136

Post by Kilimanjaro » Fri, Jun 10, 2011, 4:05 PM UTC

Phoenicians circa 1000bc:

"We won't make it to america unless we build ships as large as a stadium and can put a thousand slaves with oars in them. But then, where are we going to put all the food to feed them? Well, we let them die and throw them in the ocean, only the stronger will deserve to be called the first american settlers"

We don't know yet what the future may teach us.

Re: Why we are unlikely to ever leave the solar system.

#137

Post by maratd » Fri, Jun 10, 2011, 4:07 PM UTC

DennisP wrote: post #133

"Ever" is a pretty strong word, and I think he's going to look pretty silly in a century or so. For example, here's an estimate of travel costs with boron fusion rockets: http://nextbigfuture.com/2007/11/fusion-propulsion-if-bussar... If either Bussard's polywell fusion or focus fusion turn out to work, that'll be achievable within a couple decades. As Moore's Law continues and we get better at simulating plasma, it'…

This is exactly right. It is not possible to predict technological advancement. 250 years ago, the idea of traveling between London and New York within a few hours would have seemed ludicrous ... and yet, that technology is easily available to most people today. We may never leave the solar system, but then again, we just might.

Re: Why we are unlikely to ever leave the solar system.

#138

Post by chadgeidel » Fri, Jun 10, 2011, 4:10 PM UTC

forgottenpaswrd wrote: post #108

Oh, the ego, what a marvelous thing! Believing that what we currently know is applicable to humans in the future, that our current limits are immutable. We know all the laws of physics, right? We know if the universe is finite or infinite(because we had traveled there and seen the limits), we know what creates gravity and exactly how electromagnetic attraction really works... the same way the people Socrates asked 25…

My answer to him was, "John, when people thought the earth was flat, they were wrong. When people thought the earth was spherical, they were wrong. But if you think that thinking the earth is spherical is just as wrong as thinking the earth is flat, then your view is wronger than both of them put together."

http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm

Re: Why we are unlikely to ever leave the solar system.

#139

Post by justin_vanw » Fri, Jun 10, 2011, 4:34 PM UTC

Because we'll fall off the side! Oh, that's why we can't circumnavigate.

Some other things man will never do: http://www.rense.com/general81/dw.htm

Re: Why we are unlikely to ever leave the solar system.

#140

Post by Apocryphon » Fri, Jun 10, 2011, 4:45 PM UTC

I will take the man at his challenge, become a multi-trillionaire, and start building a domed city in the Gobi and a floating base in the North Atlantic.