- Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ] [ by messages with attachments ]

From: Hal Finney <hal.domain.name.hidden>

Date: Fri, 9 Jan 2004 15:03:18 -0800

John Collins writes:

*> I described a special case of this in a posting on this list a while
*

*> ago, suggesting that we're almost certainly not in a simulated, 'second
*

*> order' universe: Basically, for every arrangement of matter you could append
*

*> to our universe that would look like some creature controlling/observing us,
*

*> there would be many more arrangements that looked like no living creature.
*

That's an interesting point, but I'm not sure it's correct.

You might want to consider Nick Bostrom's "Simulation Argument" at

www.simulation-argument.com as an alternative.

I think the problem with your argument is that you are assuming that all

physical arrangements of matter appended to the universe are equally

likely. And in that case, you are right that some random arrangement

would be far more likely than one which looks like an observer who has

set up a computer to simulate our universe.

However, I prefer a model in which what we consider equally likely is

not patterns of matter, but the laws of physics and initial conditions

which generate a given universe. In this model, universes with simple

laws are far more likely than universes with complex ones.

It seems plausible that our own laws of physics are not particularly

complex. If string theory or loop quantum gravity or some other merging

of QM and GR can work, we may well find that our entire universe is

isomorphic to a few lines of mathematical equations. Similarly there are

provocative hints that the initial state of the universe was extremely

simple and had low complexity.

These prospects lend support to my view, even though the universe

contains objects of immense complexity. It's not the complexity of

the universe that counts, it's the complexity of the equations that

generate the universe. Consider a universe just like ours but where a

given person is replaced by a random pattern of matter. Based on matter

complexity, such a universe may seem more likely, since the structure

of a human being is incredibly complex. But based on generative-law

complexity, such a universe is much less likely, since it has a "hole"

where the laws of physics did not apply, where what should have been a

human being was artificially replaced by a random pattern.

Therefore I'd suggest that when you consider the possibility that our

universe is embedded in a larger structure, you can't just look at

the matter complexity of that structure. Rather, you should look at

the physical-law complexity. And it seems plausible to me that the

physical laws of the outer universe don't necessarily have to be much

more complex than our own. In fact, it may be that we are capable of

simulating our own universe (we don't know the laws of physics well enough

to answer that question, IMO).

Nick Bostrom proposes in effect that the outer universe could be the

mathematically identical to the inner one. He also suggests that there

could be many simulations running, so that the number of observers in

the simulated universes is far greater than the number in the outer

universe.

Based on this reasoning, the likelihood of our being in a second-order

simulated universe is very considerable and can't be ruled out.

Hal Finney

Received on Fri Jan 09 2004 - 18:04:58 PST

Date: Fri, 9 Jan 2004 15:03:18 -0800

John Collins writes:

That's an interesting point, but I'm not sure it's correct.

You might want to consider Nick Bostrom's "Simulation Argument" at

www.simulation-argument.com as an alternative.

I think the problem with your argument is that you are assuming that all

physical arrangements of matter appended to the universe are equally

likely. And in that case, you are right that some random arrangement

would be far more likely than one which looks like an observer who has

set up a computer to simulate our universe.

However, I prefer a model in which what we consider equally likely is

not patterns of matter, but the laws of physics and initial conditions

which generate a given universe. In this model, universes with simple

laws are far more likely than universes with complex ones.

It seems plausible that our own laws of physics are not particularly

complex. If string theory or loop quantum gravity or some other merging

of QM and GR can work, we may well find that our entire universe is

isomorphic to a few lines of mathematical equations. Similarly there are

provocative hints that the initial state of the universe was extremely

simple and had low complexity.

These prospects lend support to my view, even though the universe

contains objects of immense complexity. It's not the complexity of

the universe that counts, it's the complexity of the equations that

generate the universe. Consider a universe just like ours but where a

given person is replaced by a random pattern of matter. Based on matter

complexity, such a universe may seem more likely, since the structure

of a human being is incredibly complex. But based on generative-law

complexity, such a universe is much less likely, since it has a "hole"

where the laws of physics did not apply, where what should have been a

human being was artificially replaced by a random pattern.

Therefore I'd suggest that when you consider the possibility that our

universe is embedded in a larger structure, you can't just look at

the matter complexity of that structure. Rather, you should look at

the physical-law complexity. And it seems plausible to me that the

physical laws of the outer universe don't necessarily have to be much

more complex than our own. In fact, it may be that we are capable of

simulating our own universe (we don't know the laws of physics well enough

to answer that question, IMO).

Nick Bostrom proposes in effect that the outer universe could be the

mathematically identical to the inner one. He also suggests that there

could be many simulations running, so that the number of observers in

the simulated universes is far greater than the number in the outer

universe.

Based on this reasoning, the likelihood of our being in a second-order

simulated universe is very considerable and can't be ruled out.

Hal Finney

Received on Fri Jan 09 2004 - 18:04:58 PST

*
This archive was generated by hypermail 2.3.0
: Fri Feb 16 2018 - 13:20:09 PST
*