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Comment Re:One time pad (Score 2) 128

OTPs are great. On the other hand, you have to use each pad only once. Ever. So to encrypt 1GB of data, you need 1GB of cryptographically random pad. Which you can never use again. And must be a secret with regards to the rest of the world. And must be present on both the sending and receiving end of the communication.

If I knew how to get 1GB of unique data (be in OTP pad or the real data) from the sender to the receiver in secrecy I wouldn't need encryption in the first place.

Submission + - Ask Slashdot: Can some of us get together and rebuild this community? 21

wbr1 writes: It seems abundantly clear now that Dice and the SlashBeta designers do not care one whit about the community here. They do not care about rolling in crapware into sourceforge installers. In short, the only thing that talks to them is money and stupid ideas.

Granted, it takes cash to run sites like these, but they were fine before. The question is, do some of you here want to band together, get whatever is available of slashcode and rebuild this community somewhere else? We can try to make it as it once was, a haven of geeky knowledge and frosty piss, delivered free of charge in a clean community moderated format.

Comment Re:How fast was that galaxy moving? (Score 1) 196

And what really makes my head spin: If this galaxy is moving away from us at the speed of light, and has been doing so for almost the entire age of the universe, doesn't that mean that it (and all observable universe) started out from "our" position, even though the big bang should NOT be considered to extend from a central position?

Yes, in that the universe was a point at the beginning, therefore 'our position' was at the center of it, as was the position of everything else in the universe. It might be more accurate to say that instead of this galaxy moving away from us, the space between our galaxies is expanding. All of space is expanding, with gravity keeping structures at the galaxy/local group level close enough together that they do not expand themselves.

By the time our universe is 20 billion years old, that galaxy will be 19.4 billion light years away. The above math would then result in the galaxy moving away at a speed greater than the speed of light. I guess we'll see time moving backwards?

Nope, actually we won't see anything at all, as the light emitted by this galaxy will never be able to reach us. The light from this galaxy will redshift to a greater degree until no more information reaches us.

Comment Re:The hand of Godel? (Score 1) 465

Turing Completeness is based upon the ability to simulate a Turing Machine (if/else and random access to infinite memory). Obviously there is no such thing as infinite memory, but that is a nitpick that we don't pay attention to when talking about Turing completeness.

That we can create a physical system that is Turing Complete (a computer) in our physical universe strongly suggests that our universe is Turing Complete.

The initial question was about whether the universe was Turing Equivalent. A TE system must be TC, with the additional restriction that it has no more capability than a TM. According to Wikipedia, all known Turing Complete structures are Turing Equivalent.

However, as there is much about the universe we don't know, it is possible that there are some functions of it that are not simulate-able on a TM, and thus while the universe is TC, it is not TE.

So the universe is probably Turing Complete.
All currently known Turing Complete systems are Turing Equivalent.
This may suggest that the universe is Turing Equivalent, but answering that question is for smarter people than I.

The obvious consequence of the universe being Turing Equivalent is that as the universe can simulate/sustain a physical computer, so can a physical computer of whatever complexity simulate a universe. The simulated universe must be less complex than the one which is simulating it, as a universe has only a particular amount of information in it (so far as we can tell - size of the visible universe and all that), and only some subset of that state/information is available for simulating universe-b, each simulated universe is inherently limited by the amount of information in the universe 'higher' in the chain that is used to simulate it.

If all information in universe-a was being used to simulate universe-b either:
1) Overhead from the simulation would cause the limitation effect.
2) There is no overhead, universe-a perfectly simulates universe-b with no overhead. In this case, they are equivalent and the same.

Comment Re:System (Score 1) 225

They were using a Ruger .22, suppressed to be easy on the ears (no need for hearing protection). Assuming that subsonic ammunition would cycle the firearm, and keep everything quieter, you can pick up 500 rounds of .22 subsonic for less than $40. If they didn't want to use subsonic, it's less than $20 for 525 rounds. Fairly inexpensive on the whole, since the system doesn't care what you hit the target surface with.

In 1750 Issac Newton became discouraged when he fell up a flight of stairs.