[devx]

Yeah, unreachable without FTL travel.

[deletes]

It would take about 15.6 years [0] to reach the star on a ship capable of a constant 1G acceleration.

Here is the explanation and equations: http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.h...

[0]: https://news.ycombinator.com/item?id=6637131

[gnaritas]

15.6 years for the passenger, thousands of years from our perspective.

[alex-g]

So after a few subjective years, you will be overtaken by newer and faster ships, and when you arrive, there will be a flourishing civilization already there to greet you.

[fernly]

And the people in the faster ships will be your grandchildren, yup. Plot of Heinlein's "Time for the Stars", pretty much.

[bpicolo]

I read this when I was younger and had no idea what it was called until now. I've tried to remember it a bunch. Thanks!

[alex-g]

I was thinking of "Far Centaurus" by A. E. van Vogt, but I'll look up the Heinlein as well now.

[Groxx]

Meh. People were willing to go half-way across the world to try living somewhere new, probably never to return. Announce the trip, and you'll have to weed out volunteers pretty viciously.

[evoloution]

Does this take the needed deceleration in account? If we are to land there anyway :P

[deletes]

Yes, but the real problem is fuel( even with antimatter ). And radiation.

[pdonis]

I agree that the real problem is fuel, but 10 years isn't quite long enough if you are going to accelerate halfway and decelerate halfway to arrive at low speed. For a 2,500 light year trip composed of two 1,250 light year legs, the time experienced by the ship will be (in units where c and a are both approximately 1):

2 * T(1250 lyr) = 2 * (c/a) arccosh (ad/c^2 + 1) = 2 * arccosh(1250 + 1) = 2 * 7.8 = 15.6 yr.

[ck2]

It is dubious we will ever travel faster than 10% the speed of light.

But a probe might be able to.

[wikiburner]

Not dubious - speculative:

https://news.ycombinator.com/item?id=4534359

https://news.ycombinator.com/item?id=6238297

Although, I certainly wouldn't bet against it long term.

[maaku]

If you did, you'd really be betting on your ability to collect / pay up the debt.

[vectorjohn]

What does that even mean? Of course it is reachable without FTL travel. Besides time dilation which could make it a subjectively short trip, there is also cryogenics and other life extension techniques that could get us there.

If you accept any ship could get there, you might as well consider that space travel isn't the only technology that will advance.

[ars]

> there is also cryogenics and other life extension techniques that could get us there.

You are aware those don't actually exist?

People assume they will exist, but we have nothing to base that assumption on except "it would be cool".

[vectorjohn]

Besides the fact I think it's clear they will exist (assuming we don't destroy ourselves somehow), I already addressed that. We're already talking about things that don't currently exist. I can talk about a ship to Mars which doesn't currently exist. But both a Mars trip and cryogenics seem pretty reasonable to me.

[ars]

> it's clear they will exist

???? Based on what exactly?

> But both a Mars trip and cryogenics seem pretty reasonable to me.

You think those are similar? We could do a Mars trip today with enough money. Every bit of money in the entire world would still not get you cryogenics - it requires a new idea that doesn't exist right now.

[robryan]

That is arguable, we have the freezing people but going. Sure it is being done in a very destructive way to the human body, it is a bet though that at some point in the distant future technology will get good enough that the current freezing method could be reversed.

[Dylan16807]

There are animals that are naturally capable of freezing and thawing. We don't have to invent the process, we only need to adapt it. I bet it would be cheaper than a Mars trip.

[kondro]

We can't even freeze and thaw a steak and have it taste the same… let alone any living mammals.