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Comment by equalarrow | Hacker News Reader

WOW, that is amazing. I'm always blown away by stuff like this, where you can actually get a sense of how small we all are and how distant even the closest neighbor stars are.

I just close my eyes for a minute and think (or try to), what would it be like for those people that are finally able to reach, say, Vega (I know it's not the closest). Sure, this is not a big deal in sci-fi, but for reality, it's pretty mind blowing. This is 100% why I seriously want to live for a few hundred years: to have an opportunity to see the first time we actually go to the nearest star.

In the meantime, I guess this will have to suffice.

I also love this image that is not interactive like this, but still mind blowing: http://en.wikipedia.org/wiki/File:Earths_Location_in_the_Uni...

View on HN

Working link:http://en.wikipedia.org/wiki/File:Earth%27s_Location_in_the_...

Pannable version, that file was too big for me & I remembered this tool from another HN post:

http://hugepic.io/7c2aaf4a6

>WOW, that is amazing. I'm always blown away by stuff like this, where you can actually get a sense of how small we all are and how distant even the closest neighbor stars are.

Same.

If you don't already own a pair, I'd recommend getting a basic pair of binoculars and doing some backyard astronomy. You'd be amazed how much more you can see with even a basic 10x50 pair, even in thoroughly light-polluted skies.

Also SpaceRip [1] collects hundreds of interesting, easily digestible and pretty timely videos.

1: http://www.youtube.com/user/SpaceRip

> I'd recommend getting a basic pair of binoculars and doing some backyard astronomy

If you've got the spare cash, get image stabilized ones. I could clearly see the moons around Jupiter with my Canon 12x36 IS binos the other night despite my hand tremors. The real party trick is handing them to a friend and telling them to look at the moon. Blows them away every time - to most people it's just a yellowish glowing thing in the sky, rather than a scarred rocky globe.

Yes, this is great

Be sure to check out the middle "star" in Orion's sword.

Obligatory buzz-kill, Charles Stross on why we're unlikely to leave the solar system: http://news.ycombinator.com/item?id=2639456

He's wrong.

For starters, there's this assertion: "The far-fetched version is to use back holes as power sources [1] as this is, as far as I've read anyway, the only remotely viable method of providing propulsion without reaction mass to speak of and reaction mass is the death of any form of interstellar propulsion."

Not true. We can definitely build something with today's technology that allows for propulsion without reaction mass: light-sails pushed by lasers[1]. I can address some of his other points but it's not necessary. If you crunch the numbers, it should be doable to travel to another star in about 150 years.

[1] See Humble's canonical text on space propulsion design: http://www.amazon.com/Propulsion-Analysis-Design-Ronald-Humb...

So you're suggesting two almost completely undeveloped technologies (light sails and extremely high-powered lasers in space) and telling us that interstellar propulsion is a solved problem? That's a tad optimistic :)

Btw, if you'd read 'Accelerando' you'd know that Charlie is fully aware of the possibilities offered by laser powered light sails.

Stross and cletus both say we will never leave the solar system and travel to another star. Never!

I'm trying to show that notion is dead wrong. I didn't say it was a solved problem, if you mean in the sense of the engineering is basically done and we're launching something tomorrow. But certainly it is very reasonable to think that within with 150 years we will have both the technological and economic advancement to do a mission to another star. We know how we'd do it, and it uses real physics and engineering, materials, etc. that already exist.

The main reason Stross is wrong though, is he says we'd need free energy to do it. He's right that the limiting factor is the cost of energy, but he's overlooking what you get for 150 years of economic growth. World GDP has grown at an average annual rate of 3.5% over the last 100 years. World GDP is currently at about $80 trillion. If it grows at 3.5% for another 150 years, it will be $14,000 trillion. You can buy a lot of energy with that. And a lot of spaceships.

  World GDP has grown at an average annual rate of 3.5% over the last 100 years.

That's not actually very relevant. According to DeLong[1], the rate of growth has been anything but constant over the last 100 years, nor has it always been positive. You may well expect the industrial revolution to carry us forward for another 150 years, but I'm not sure if I do.

[1] http://img641.imageshack.us/img641/1946/gwp.png

edit: corrected the 2000-2011 segment for inflation with CPI data (not int$).

50 years ago it was very reasonable to think that we'd have worked out how to make a fusion reactor too.

Just because something uses real physics and engineering materials that already exist, doesn't mean that it's actually possible in the real world & getting to the stars requires that we solve three or four very hard problems.

Impossible? Of course not. Much, much harder than the 'whee, we're all going to space!' crowd likes to think? I'm afraid so.

NB. GDP is not a good proxy for available energy for hopefully obvious reasons: Just because you have a high GDP doesn't mean that you have a lot of energy available, it may mean that you use the energy you have very effectively.

>50 years ago it was very reasonable to think that we'd have worked out how to make a fusion reactor too.

Most of the reason we haven't is economic; modern fission reactor designs are far more efficient than even the most optimistic estimates of 50 years ago.

Most of the reason we haven't is because it turns out to be really, really hard to contain a high energy plasma long enough to get useful levels of fusion out of it. We still haven't effectively solved the 'how do we efficiently extract the generated energy' problem either.

Perhaps these problems will be solved in the future, but so far we've spent billions and billions of $ with (relatively) little to show for it in terms of output.

How powerful do the lasers need to be? How are you going to power it for 150 years?

The mission would leave in 150 years. It would last for 20-30 years one way.

The laser (a bank of lasers, more likely) would need to consume energy at a rate approximately equal to the world's entire current electricity production, basically continuously for the duration of the mission.

That seems absurd of course. But again, you can't underestimate compounded interest applied to GDP growth (see above comment). In 150 years time, the cost to do the mission could easily be the same percentage of US GDP as the Apollo mission was in the 1960's.

Of course if the assumption of continuous future economic growth doesn't hold up, this isn't going to happen. But in that case the world will have much bigger problems... this will be something of a non-issue.

You're in "magic wand" territory, and in agreement with Stross' arguments.

Same here, but I doubt we'll ever be able to do that without some serious genetic enhacements to the point where we might not be recognizable as humans, or an even better solution, transferring our minds to machines, and then being able to live thousands of years or more and make it more possible for us to travel there.

But it seems a lot more likely that we'll just send some strong AI robots to send us back the data until then.

EDIT: I suggest checking out Space Engine. It seems to cover more than one galaxy and being able to change the viewing/moving speed feels like being in a Star Trek starship. Going through space like that feels a bit unsettling:

http://en.spaceengine.org

You could also take a look at http://htwins.net/scale2/. It's also a very nice demonstration of the scale of the universe from the smallest to the largest objects.

yeah makes us feel small.

Life on Earth has existed for about 26% of the age of the Universe. Feel any bigger?

(3.6 billion years / 13.75 billion years)

Indeed that was a bit of an epiphany for me recently whe I read a site that listed major astronomical and terrestrian events in parralel. Despite knowing many of the numbers, somehow my gut feeling had always been that since Earth is so tiny in size compared to the universe at large, the same must be true about timescales.

Hmmm... but what about intelligent life? Or technologically sophisticated (relatively speaking) intelligent life. Still feeling small here.

Then if you imagine how long the Internet has existed compared to the universe, all of this hullabaloo on HN becomes even funnier .

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