Tuesday, November 30, 2010

Internal FTL May Be Possible

I ran into an article about making wormholes which pointed out that there is nothing in principle wrong with them. More importantly, the mathematicians' distaste for topology changes which I had unthinkingly assimilated is bullshit. There is no justification whatsoever in physics for wormholes not to exist. Mathematicians might not like them but fuck em.

Then again, maybe I hadn't assimilated mathematicians' distaste of topology changes too much. My main objection to wormholes has always been the unthinking unquestioned claim that a wormholes' insides have no geometry. That travel inside a wormhole is instantaneous because there is no distance between the wormhole mouths. When you start taking geometry seriously and dismissing topology, such a claim becomes bloody fucking stupid.

But just because faster-than-light travel through wormholes doesn't look even remotely likely, it doesn't mean it's impossible. And what's interesting about wormholes is that in order to create a wormhole between two points light years apart, you need to transport the wormhole mouth at sublight speeds. Unless you've got a warp drive of course since a wormhole mouth is just a bunch of warped spacetime and not matter.

That's where things get interesting because it means wormholes can't be used by a civilization to expand faster than light, only to travel faster than light internally inside the civilization's boundaries. And that makes wormholes really, really interesting because they don't violate the Fermi Paradox.

The Fermi Paradox is bad enough when confined to sub-light speeds. It's bad enough that it proves conclusively and without a doubt that aliens do not exist. If a civilization could expand at FTL speeds, that would mean aliens don't exist in the entire universe. Something which is not even remotely credible. Hence the Fermi Paradox proves that FTL cannot be a feasible method of civilization expansion.

But, wormholes don't offer any way for a civilization to expand faster than the speed of light, only to stay unified as a civilization as it expands. And that makes them rather interesting. Because they're feasible. Maybe. Whether they're possible at all is an independent question. As I already said, I don't think they are, but it would be fun to discover otherwise.

7 comments:

Stephen R. Diamond said...

I read the essay you referred to proving the nonexistence of intelligent alien life in the galaxy. I'm surprised that in the 40 comments, none raised what seem the most obvious objections.

First, why on earth would you assume that any civilization could possibly last anywhere approaching 100,000 years? Optimistic forecast! I tend to see technological civilizations as flashing in and out of existence. Unsupported assertion—but no more so than the opposite. [But maybe not completely unsupported. The likelihood of extinction seems to increase here over time.]

Second, you assume that if such civilization exist, they would devour resources, requiring expansion. But you don't know what forms of energy extraction—even what forms of energy—might be invented or discovered in the very-distant future.

Richard Kulisz said...

> First, why on earth would you assume that any civilization could possibly last anywhere approaching 100,000 years?

I don't assume anything. I know it's possible for a fact. If a dumb species like pine trees can survive for millions of years on a single planet then so can civilization.

Pine trees exist only on a single planet, their only mechanism of self-preservation is self-replication, and they are subject to regular GLOBAL catastrophes.

In contrast, technological civilization can escape the confines of its planet of origin, reach to the asteroids and beyond. It can avert and undo planetary catastrophes such as super-earthquakes, supervolcanoes and super-asteroidal impacts. And once out in the galaxy, it's vulnerable to precious little.

So you see, there is nothing "optimistic" about any of this. I am being entirely REALISTIC. Civilization is far more adaptable and powerful than a biological species of plant! YOUR assertion is not merely unsupported but flies contrary to the facts as we both know them.

> The likelihood of extinction seems to increase here over time.

That's not how probability works. The likelihood of an Extinction Level Event is constant over any length of time. And the probability of SELF-extinction is likely negated by our increasing capacity for survival.

> But you don't know what forms of energy extraction—even what forms of energy—might be invented or discovered in the very-distant future.

Yes I do because the laws of physics are constant. And some of the things the laws of physics say, and I have pointed this out in comments to that post or its follow-ups in the series, is this:

1) any unit of computation takes non-zero energy, depending on temperature

2) information storage takes non-zero energy, depending on temperature

3) the background temperature of the cosmic microwave background puts a lower bound on the temperature

4) which puts a lower bound on the minimum amount of energy it takes to do computation and information storage

5) the law of gravitation put an UPPER bound in how much energy can be put into a volume of space without its collapsing into a black hole

6) the amount of information and computation you can have in a finite volume of space is finite.

There's a fantastic essay out there by Freeman Dyson that posits trying to extract infinite amounts of computation out of an infinite classical universe. Too bad our universe isn't classical but quantum mechanical and so his scheme would never work.

We'd all like an infinite source of energy, computation and negentropy. To the best of our knowledge, the laws of physics do not permit ANY of that. And isn't it best to reason based on the laws of physics as we actually know them instead of engaging in wishful thinking?

Richard Kulisz said...

http://morningcoffeephysics.wordpress.com/2009/01/14/eternal-life-dyson-vs-krauss/

Stephen R. Diamond said...

> don't assume anything. I know it's possible for a fact. If a dumb species like pine trees can survive for millions of years on a single planet then so can civilization.

Totally lame argument, and I think you know it—I would have expected greater intellectual honesty.

>That's not how probability works. The likelihood of an Extinction Level Event is constant over any length of time. And the probability of SELF-extinction is likely negated by our increasing capacity for survival.

Very uncharitable, thinking I have a concept of probability as cumulative. But as a general principle, taking what you say literally, it is not true that "The likelihood of an Extinction Level Event is constant over any length of time." And you actually know that, too; you know it because you go on to consider the tradeoff between adaptations and risks.

>Yes I do because the laws of physics are constant.

Irrelevant. What's relevant is that our _understanding_ of the laws of physics is *not* constant.

But the second argument, I'll admit, is indecisive. Not so with the first.

Richard Kulisz said...

I would say that I expected greater intellect from you ... but I didn't.

Even as I wrote it, I doubted most people would comprehend complex systems abstractions like 'species' and 'civilization' enough to realize that comparing them strictly in terms of survivability against natural threats provides a sound basis for comparison between them.

Basically, the reason you think it's a lame argument (as opposed to a trivial counter-example to a stupid argument on your part) is because you're not that smart. In fact, I seriously doubt you can state the difference between a tree species and humanity (or civilization) in a rigorously correct and succinct manner. Because if you could, you would have realized it's irrelevant to the problem at hand.

In rot13: pbafpvbhfarff

> Very uncharitable

On the contrary. I am always, always overwhelmingly charitable. If people do not think so it is because I know so much that there is literally no doubt in my mind for them to benefit from. I suspect this is why people routinely object to my mis-assigning them belief Y when their actual belief X is worse than Y.

> literally, it is not true that "The likelihood of an Extinction Level Event is constant over any length of time." And you actually know that, too; you know it because you go on to consider the tradeoff between adaptations and risks.

I don't consider humans capable of producing a genuine extinction level event. The only possibility I know of (raining down asteroids using an unopposed manned nuclear starship) has been effectively invalidated by the Nuclear Test Ban Treaty.

I also don't seriously consider possible artificial ELEs because they are ALL highly speculative. The notion that you can assign probabilities to such highly speculative events is completely fucking wacko. Which leaves only natural events to consider.

Of the natural events, asteroids are random and constant over sub-billion year timescales. As are earthquakes and tidal waves. Which leaves only super-volcanoes. And those are constant over sub-million year timescales.

As a matter of terminology, by an Extinction Level Event I obviously don't mean something that ACTUALLY causes the extinction of humanity, but only something that WOULD cause its extinction if untreated. That's what the word "level" in ELE is for.

Failure to understand ANY of 1) you can't assign probabilities to speculative events, 2) supervolcanoes occur on hundred million year timescales, which makes their risk constant on 100,000 year timescales, 3) the technical term ELE is not synonymous to 'actual human extinction'. ANY of those misunderstandings are worse than failure to understand statistics.

#1 because it would mean you don't understand the concept of 'uncertainty' in the simplest sense of "we don't know".
#2 because it would mean you don't understand the concept of 'vanishing fraction'.
#3 because it would mean you don't understand how human language works.

So enlighten me, just exactly what did you fuck up? Or shall we go with 'non-cumulative statistics' after all?

Richard Kulisz said...

> Irrelevant. What's relevant is that our _understanding_ of the laws of physics is *not* constant.

We can either act on our knowledge or we can refuse to act. Our knowledge is finite, our ignorance is literally beyond infinite. We are finite beings. Your implicit proposition that we finite beings ought to act based on infinite ignorance ... isn't even coherent.

Yes it COULD be the case that our planet is a simple simulation inside of an alien child's computer in a universe with 67 large dimensions. Until we prove this is the case, the mere possibility amounts to nothing, says nothing and means nothing. Math is beyond infinite, and in that math are infinities of possibilities that say nothing about our physical universe.

Simple math thwarts you. Infinite ignorance, finite beings, end of story.

Richard Kulisz said...

And even if you woke up tomorrow with an infinite amount of memories thus proving that everything we think we know about our universe is false, your ignorance will always ALWAYS be bigger than that.