On 10/23/2020 3:52 PM, Jason Resch wrote:
On Fri, Oct 23, 2020 at 4:54 PM 'Brent Meeker' via Everything List
<[email protected]
<mailto:[email protected]>> wrote:
On 10/23/2020 8:15 AM, Jason Resch wrote:
On Tue, Oct 20, 2020 at 4:37 PM 'Brent Meeker' via Everything
List <[email protected]
<mailto:[email protected]>> wrote:
On 10/20/2020 1:20 PM, Jason Resch wrote:
On Tue, Oct 20, 2020 at 1:23 PM 'Brent Meeker' via
Everything List <[email protected]
<mailto:[email protected]>> wrote:
On 10/20/2020 5:39 AM, Bruno Marchal wrote:
On 15 Oct 2020, at 20:56, 'Brent Meeker' via
Everything List <[email protected]
<mailto:[email protected]>> wrote:
You should have read Vic Stenger's "The Fallacy of
Fine Tuning". Vic points out how many examples of
fine tuning are mis-conceived...including Hoyle's
prediction of an excited state of carbon. Vic also
points out the fallacy of just considering one
parameter when the parameter space is high dimensional.
But my general criticism of fine-tuning is two-fold.
First, the concept is not well defined. There is no
apriori probability distribution over possible
values. If the possible values are infinite, then any
realized value is improbable.
I don’t think so. That is why Kolmogorov defines a
measure space by forbidding infinite intersection of
events. In the finite case the space of events is the
complete boolean structure coming from the subset of
the set of the possible results. In the infinite
domain, the measure space os defined by a strict
subset. I miss perhaps something, but the axiomatic of
Kolmogorov has been invented to solve that “infinite
number of value” problem.
That's a non-answer. I was just using infinite (as
physicists do) to mean bigger than anything we're
thinking of. Kolmogorov just shaped his definition to
make the mathematics simpler. There's nothing in
Jason's analyses that defines the variables as finite.
Jason just helps jimself to an intuition that a value
between 7.5 and 7.7 is "fine-tuned". He didn't first
justify the finite interval.
I admit as much in the article. For most parameters, we
don't understand the range or probability distribution for
the constants.
Then how can you assert there is fine tuning. Is a value of
20_+_1 qualify? Does it matter whether the possible range
was (0,100) or (19,21)?
However, see my explanation for the cosmological constant, a
value for which the theory can account for the expected
range and probability distribution.
That's right, there is a theory that tells us something about
a range and probability distribution. But it's far from an
accepted theory, and might well be wrong.
It comes out of QFT, perhaps our most strongly tested theory in
science, at least one that offers the most accurate verified
prediction in physics.
That "comes out of" is very misleading, since it's applying QFT to
general relativity which is not even a quantum theory.
But the quantum fields (vacuum) are known to gravitate.
"Known" how? You can write down a calculation...which give infinity as
an answer. Having arrived at an obviously wrong answer, you can
introduce a cutoff that you guess at based on some dimensional analysis
and get an answer that's wrong by 120 orders of magnitude, instead of
infinitely. And you then say this shows we know something like this
must be right???
The first application of QFT to the problem gave the wrong answer
by 120 orders of magnitude.
Wrong is the wrong word here. The answer was unexpectedly small by
that many orders of magnitude, but it is still within the range of
possibility.
Which is exactly what's wrong with the idea of "fine-tuning". The
"range of possibility" is just pulled out of thin air. Suppose life
were possible for 1e-60 ev/m3 to 1e-20 ev/m3. Would that be
"fine-tuning" because (1-e-20 - 1e-60)<<1 or because 30 orders of
magnitude is small compared to infinity.
I don't know what prediction you're referring to, there have been
several. Can you cite the paper?
The prediction that the vacuum state contains energy, and that this
energy under QFT is the sum of each of the field energies, some of
which may be positive or negative, and when they are summed, they come
out to be 120 orders of magnitude smaller than the Planck energy
(which is the expected energy level of each field). I don't know of a
reference to the paper, but I've read it was first calculated by
Feynman and Wheeler. I also found this derivation:
https://i.imgur.com/m0QhWOv.png
This paper <https://arxiv.org/pdf/1906.00986.pdf> gives three
citations [6-8] to accompany this statement, which might also be
useful to you:
"Nature contains two relative mass scales: the vacuum energy
density V ∼ (10−30MPl) 4 and the weak scale v 2 ∼ (10−17MPl) 2
where v is the Higgs vacuum expectation value. Their smallness
with respect to the Planck scale MPl = 1.2 1019 GeV is not
understood and is considered as ‘unnatural’ in relativistic
quantum field theory, because it seems to require precise
cancellations among much larger contributions. If these
cancellations happen for no fundamental reason, they are
‘unlikely’, in the sense that summing random order one numbers
gives 10^−120 with a ‘probability’ of about 10^−120."
But who says the random number are order 1.
It's all just fantasizing.
Brent
"No natural theoretical alternatives are known (for example,
supergravity does not select V = 0 as a special point [1]), and
anthropic selection of the cosmological constant seems possible in
theories with some tens of scalars such that their potential has
more than 10^120 different vacua, which get ‘populated’ forming a
‘multiverse’ through eternal inflation. String theory could
realise this scenario [6–8]."
[6] R. Bousso, J. Polchinski, “Quantization of four form fluxes and
dynamical neutralization of the cosmological constant”, JHEP 0006
(2000) 006 [arXiv:hep-th/0004134].
[7] L. Susskind, “The Anthropic landscape of string theory”
[arXiv:hep-th/0302219].
[8] S. Kachru, R. Kallosh, A.D. Linde, S.P. Trivedi, “De Sitter vacua
in string theory”, Phys. Rev. D68 (2003) 046005 [arXiv:hep-th/0301240].
Jason
Brent
It might well be wrong, but that would be more surprising to me
than the idea of an anthropic selection process operating in a
multiverse.
Jason
--
You received this message because you are subscribed to the
Google Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected]
<mailto:[email protected]>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/CA%2BBCJUiJ5c3kakLGC73zuRGX-6gafk0W7NGhuJJn9VOQEtzriA%40mail.gmail.com
<https://groups.google.com/d/msgid/everything-list/CA%2BBCJUiJ5c3kakLGC73zuRGX-6gafk0W7NGhuJJn9VOQEtzriA%40mail.gmail.com?utm_medium=email&utm_source=footer>.
--
You received this message because you are subscribed to the Google
Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to [email protected]
<mailto:[email protected]>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/a3039f54-142f-9558-984d-cfa5f65d56a0%40verizon.net
<https://groups.google.com/d/msgid/everything-list/a3039f54-142f-9558-984d-cfa5f65d56a0%40verizon.net?utm_medium=email&utm_source=footer>.
--
You received this message because you are subscribed to the Google
Groups "Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to [email protected]
<mailto:[email protected]>.
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/CA%2BBCJUh3auOJ8fLVaLUFF2dsyHZSHPd%3DXjDQRwLQFuTvJjiH4A%40mail.gmail.com
<https://groups.google.com/d/msgid/everything-list/CA%2BBCJUh3auOJ8fLVaLUFF2dsyHZSHPd%3DXjDQRwLQFuTvJjiH4A%40mail.gmail.com?utm_medium=email&utm_source=footer>.
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/everything-list/4770fd6e-3c2b-94aa-ee9d-af56ff6a0ae6%40verizon.net.
