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Cosmologically Unique IDs

jasonfantl.com

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Re: Cosmologically Unique IDs

#121

Post by Dylan16807 »

kmoser wrote: post #108
Dylan16807 wrote: post #106

Earlier quoted context omitted.

> This doesn't take into account that you will inevitably want to assign unique IDs to various groups of atoms (e.g. this microchip, that car, etc.). Sure it does. Those are not going to add up to a single extra bit.

Even every possible permutation of every single subatomic element in the universe? Even if we just consider atoms, at 10^80 atoms in the entire universe, there are (10^80)! possible permutations, which is many, many, many orders of magnitude larger. And this isn't even counting sets that include multiples of the same item; once you get into that territory, there really is no upper bound.

No, not every permutation. An atom gets to be in one larger object (recursively).

Definitely no multiples. What would that even mean, also you would need unbounded space for multiples of just two atoms.

Re: Cosmologically Unique IDs

#122

Post by throwaway290 »

Towaway69 wrote: post #114
disconcision wrote: post #83

Earlier quoted context omitted.

not obvious to me this makes things better as opposed to worse? sure, the time bound helps but in the runup to a crunch won't we get vastly more devices in causal range at an asymptotically increasing rate?

Who’s there doing the counting? I would assume the temperatures at those extremes won’t support life in its known forms. Perhaps some Adamesque (as in douglas adams) creature whose sole purpose is to collect all unique UUIDs and give them names.

Runup to the crunch is a looong time lots of which is probably very habitable. in 5 billion years life can arise from scratch become conscious and exterminate itself

Re: Cosmologically Unique IDs

#124

Post by brainwad »

QuiCasseRien wrote: post #56

I really love everything related to Cosmology but I always struggle with two contrary concepts that lead to paradox (for me) : - Infinity : from school, we learn our universe is infinite. - We often do calculation with upper limit like this one : 10^240. This is a big number butttttt it's not infinite you know. 10^240+1, 10^240+2... So : 1. if it's infinite, why doing upper limit calculation ? 2. if it's limited, wha…

People say the universe is "infinite" because spacetime's curvature is, as far as we can tell, flat, and so it should continue in all directions without ever wrapping back on itself (unlike, say, the Earth, which has spherical curvature).

But practically it's finite because we are only in causal contact with things up to 13.7b ly from us, and given space appears to be expanding at an accelerating rate, we probably will never get into causal contact with (almost all of) the part of the infinite universe outside of our light cone, even though things ought to exist over the "horizon". So only a tiny infinitesimal sliver of the infinite universe is knowable by us.

Re: Cosmologically Unique IDs

#125

Post by imglorp »

k_roy wrote: post #70
lisper wrote: post #7

This analysis is not quite fair. It takes into account locality (i.e. the speed of light) when designing UUID schemes but not when computing the odds of a collision. Collisions only matter if the colliding UUIDs actually come into causal contact with each other after being generated. So just as you have to take locality into account when designing UUID trees, you also have to take it into account when computing the o…

Reminds me of a time many years ago when I received a whole case of Intel NICs all with the same MAC address. It was an interesting couple of days before we figured it out.

How does that happen? Was it an OEM bulk kind of deal where you were expected to write a new MAC for each NIC when deploying them?

Re: Cosmologically Unique IDs

#126

Post by missingdays »

jl6 wrote: post #116
lisper wrote: post #7

This analysis is not quite fair. It takes into account locality (i.e. the speed of light) when designing UUID schemes but not when computing the odds of a collision. Collisions only matter if the colliding UUIDs actually come into causal contact with each other after being generated. So just as you have to take locality into account when designing UUID trees, you also have to take it into account when computing the o…

Ah but if we are considering near-infinitesimal probabilities, we should metagame and consider the very low probability that our understanding of cosmology is flawed and light cones aren’t actually a limiting factor on causal contact.

Sorry, your laptop was produced before FTL was invented, so its MAC address is only recognized in the Milky Way sector.

Re: Cosmologically Unique IDs

#128

Post by exfalso »

lisper wrote: post #7

This analysis is not quite fair. It takes into account locality (i.e. the speed of light) when designing UUID schemes but not when computing the odds of a collision. Collisions only matter if the colliding UUIDs actually come into causal contact with each other after being generated. So just as you have to take locality into account when designing UUID trees, you also have to take it into account when computing the o…

There's a fun hypothesis I've read about somewhere, goes something like this:

As the universe expands the gap between galaxies widens until they start "disappearing" as no information can travel anymore between them. Therefore, if we assume that intelligent lifeforms exist out there, it is likely that these will slowly converge to the place in the universe with the highest mass density for survival. IIRC we even know approximately where this is.

This means a sort of "grand meeting of alien advanced cultures" before the heat death. Which in turn also means that previously uncollided UUIDs may start to collide.

Those damned Vogons thrashing all our stats with their gazillion documents. Why do they have a UUID for each xml tag??

Re: Cosmologically Unique IDs

#129

Post by program_whiz »

Is it possible to construct an ID using some kind of centralized observable phenomena? Due to how time and distance distinguish things, would they always be unique? Like only one person will ever simultaneously observe stars in certain positions and intensities, color, etc. Similar to how I've heard some companies use lava lamps or other noisy processes to generate entropy.

I guess I'm wondering if there is a way to construct a universal coordinate frame for the whole universe? If so, then its possible to trivially assign local time + x + y + z + salt to make unique ids.

Re: Cosmologically Unique IDs

#130

Post by notepad0x90 »

Use a deck of cards for representation. 52 digits where 'K♠' for king-of-spades would be one character in Unicode. it isn't just cosmological unique, it's easier to read, harder to edit manually, and easier for our pattern recognition to keep track of.

And best feature: anyone can generate a random id of such representation by getting a deck of cards and shuffling it properly. Playing cards are ubiquitous. I can see a camera "reading" the decks after they've been splayed on a table after a shuffle. This might even make a better random number seeds.

You're not sure if there is any demand for this sort of stuff? Look at dicekeys:

https://dicekeys.com/

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