[ExI] Simulating the brain
John Clark
johnkclark at gmail.com
Wed Jul 19 23:34:03 UTC 2017
On Wed, Jul 19, 2017 at 9:05 AM, Stuart LaForge <avant at sollegro.com> wrote:
>
>> >
>> There are only 3 possibilities:
>> >
>> >
>> 1) Nothing exists outside the cosmological horizon.
>
>
> >
> Gakk. "Nothing" is a loaded term in modern cosmology. Define it please?
Infinite unbounded homogeneity
.
>
>> >
>> 2) A Finite amount of stuff exists outside the cosmological horizon.
>
>
> >
> Again is flat space-time or quantum vacuum "stuff" in your opinion?
Yes and there are 2 possibilities, you can only stuff a finite number of Planck
volume cubes (a Planck length cubed) into the universe or there is room for
a infinite number of such cubes. It's got to be one or the other but I
don't see how I can ever know which possibility is true.
>
>> >
>> 3) A infinite amount of stuff exists outside the cosmological horizon.
>
>
> >
> An infinite amount of flat spacetime could exist outside the cosmological
> horizon but that would be incredulously unlikely. I mean come on: a finite
> island of matter embedded in infinite space-time and we happen to be in
> the exact center of it?
If
spacetime
is infinite it has no center, if
spacetime
is finite and flat and bounded then it does.
>
> Instead, I think it much more likely that a countably infinite amount of
> matter and an uncountably infinite amount of space-time exist outside of
> the cosmological horizon.
That would be my hunch too but I think it's useful to sometimes put theory
asides and remind ourselves what our largest telescopes actually observe;
they observe a boundary and they observe that we are the same distance from
that boundary regardless of what direction the telescope is pointed.
> >
> Much of reality, finite or not, lies outside your lightcone.
There might be a infinite number of stars that are more distant from me
than 13.8 billion light years, or there might be none at all, given the
fact that the universe is not only expanding it is accelerating there is no
way I can ever know.
> >
>> >
>> The human mind is not infinitely powerful so in dealing with the
>>
>> staggering complexity of the world
>> a
>> pproximations are needed. The idea that
>>
>> the planets moved in perfect circles around the sun worked pretty well but
>>
>> Kepler showed that a more complex
>> m
>> athematical curve, the ellipse, worked
>>
>> better. And then Einstein showed that even a ellipse wasn't quite right,
>> but to understand how and why Einstein said the planets move high school
>>
>> geometry is not enough, you need 4 dimensional Tensor calculus and
>>
>> hyperbolic spacetime. And even Einstein wasn't quite right because he
>> didn't take quantum mechanics into account. So when a child asks you how
>>
>> planets move it's best to just say "in a circle".
>
>
>
> But if the Lorentz transformation is correct that implies that for every
>
> elliptical orbit there exists at least one inertial reference frame in
>
> which the orbit *is* circular.
Lorentz transform
s only apply for things
at constant velocity relative to each other
, but p
lanets in orbit around the sun are undergoing constant acceleration and
thus are not in a
inertial reference frame
.
When things accelerate Special Relativity isn't good enough, you've got
to go to General Relativity.
> >>
>> without a brain made of atoms that obey the laws of physics "you"
>>
>> can't have probability amplitudes
>>
>> , in fact you can't even have you.
>
>
> >
> But if the laws of physics are only useful fictions
>
> created by the mind
with no physical reality than how do the physically real atoms of my brain
> know them well enough to obey them?
>
The laws of physics are
certainly
not
useful fictions, but something human beings
have
call
ed
"
probability amplitudes
" for the last few decades might be. Or maybe not.
John K Clark
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20170719/1d63593c/attachment.html>
More information about the extropy-chat
mailing list