Hacker News Reader

Comment by kbenson | Hacker News Reader

The future where human spaceflight to other worlds is common, and not relegated to a few specific optimal times because it is so costly?

Basically, the future where the distance is a calculation on the cost of the trip like prevailing wind direction and speed is for airlines. We may never get there, but it's a nice thought.

View on HN

Except in general, cost in space flight scales with delta-v, which is roughly proportional to the distance between the relative orbits, not the average point distance between planets (barring any clever transfer maneuvers).

Unless torch drives are taken into consideration, like a NSWR thruster or black hole engine.

http://www.projectrho.com/public_html/rocket/torchships.php

Sci-Fi for now, though.

I love the idea, either as a fusion drive or annihilation drive, but the world had better be damned peaceful before we start making that kind of thing. As Larry Niven explored several times, such a drive is also a weapon of mass destruction on a potentially global scale. It’s the ultimate dual use tech, because it’s effectiveness as a drive is directly proportional to its effectiveness as a weapon. Whether in the form of “The Kzinti Lesson” or a smalle scale like what’s found in The Ethics of Madness we’re talking about something serious. The only difference between peaceful use and militaristic use is just where and how you aim the exhaust.

Thst without worrying about someone turning a ship into an R-Bomb!

> Thst without worrying about someone turning a ship into an R-Bomb!

And thus Burnside's Advice - "Friends don't let friends use reactionless drives in their universes."

Semi-related, but Project Rho is awesome. http://www.projectrho.com/public_html/rocket/reactionlessdri...

Also, regarding The Kzinti Lesson ("A reaction drive's efficiency as a weapon is in direct proportion to its efficiency as a drive.") I have to feel like you could drop 'reaction' and maintain accuracy... Given that reactionless drives are planet killers.

Agreed on Project Rho, it mixes entertainment and intellectual stimulation to the point I occasionally find myself giggling. Good point about reactionless drives too!

We already live in a world where if e.g. North Korea wanted to destroy the huge swaths of our entire species, they probably could. See things such as salted nukes, like a cobalt bomb. [1]. I think there's an even more general lesson there as well. We first utilized nuclear weapons in 1942. Up until that time major developed powers going to war with each other was a relatively normal part of existence. And given that reality, it would not have been unreasonable to predict nuclear weapons resulting in the end of the world. As Einstein witted, "I don't know what world war 3 will be fought with, but world war 4 will be fought with sticks and stones."

But after the realization of nuclear weapons, unrestrained war between developed nations simply ended. And we've entered in what is likely the safest and most peaceful 80 years of human existence ever. I realize how absurd that sounds, but statistically it is almost certainly true. It's hard to even imagine the death toll of previous wars. In World War 2, some 3% of the world's population was killed. Today that would be 231 million people. For some scale imagine a 9/11 type event happening, every single day, for 211 years. If you have kids when you're 30 then your great great great great great grandchildren would be experiencing a daily 9/11 event each and every day of their life. Now take all that death and suffering, and compress it into 6 years. Really puts our modern losses into context.

The point of this is that weapons (or equivalent) capable of immense harm don't necessarily have the impact you might expect. Similarly, get rid of all nukes in the world today while guaranteeing they could not be easily recreated - and you'd likely set in motion a series of actions that would lead to the violent deaths of what could be billions. I find unforeseen consequences endlessly fascinating. Bring on the planet busters. Hope there's nothing we're not foreseeing!

[1] - https://en.wikipedia.org/wiki/Cobalt_bomb

The thing is, there's the time when nobody has nukes, the time when multiple people have nukes and keep each other in check, and the time where one party has nukes. We've got plenty of experience with no nukes and multiple groups with nukes, but had a very short period where one side had nukes. How confident are we that they wouldn't be used much if that period lasted much longer, and the US was less blindsided by the Russian development of nuclear weapons?

I worry less about a future with lots of planet-killer grade weapons than I do about the period where one group has access to them and the others do not. There are any number of ways to justify violence to yourself when you don't have to worry much about the response. For example, preemptively striking before the other side get the same capability because that might lead to another MAD situation which is arguably worse for the species overall...

well when everybody is dead that would be the end of wars

Could you please stop posting unsubstantive comments to Hacker News?

The point I am making is that war has and will always be part of human societies and therefore all technological progress will be applied to warfare. There's no point to complaining about potential use of new tech in war the same way that there's no point in complaining about the laws of physics.

I just thought I didn't need to spell it out.

That's more likely to be a function of: what proportion of the time is the planet within X distance of the earth, though.

Reply on news.ycombinator.com