
Solution: ‘Is It Turtles All the Way Down?’ - theafh
https://www.quantamagazine.org/puzzle-solution-is-it-turtles-all-the-way-down-20200327/
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scythe
> As Torbjörn commented, Smolin is considered a fringe figure in the field and
> has not had the compelling successes required for his theory of the
> evolution of the universe to become mainstream.

Fringe is an exaggeration. Smolin is certainly a dissident in theories of
quantum gravity. I would imagine most physicists, including myself, are not
impressed by his convictions about various aspects of reality. But at the same
time, I think most physicists share his view that string theory is not likely
to be fruitful anytime soon. Historically, quantum mechanics, which unites the
physics of light and matter, was discovered only after many mathematical
developments in both fields that led to the two analogous theories of the
principle of least time and the principle of least action. By contrast, the
exegesis of quantum mechanics and general relativity has only just begun.
Smolin has gained notoriety by appealing to this sense of doubt. "Fringe"
however is a term more commonly applied to arguments and theories widely
believed to be without merit. That would be an unfair characterization here.

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DyslexicAtheist
sorry for going on a tangent ...

is there such a thing as populism in physics?

I have read couple of Brian Greene, and Stephen Hawking's books (also read
some to my kids "the key to the universe" which he wrote as children book
together with his daughter iirc) and I/we loved them. It made me wonder if the
gift of writing good prose (and in Hawking's case his disability and
popularization of mechanic speech especially) has contributed more to his
success than his actual scientific research.

Somewhere I read that people in his field weren't happy with his contribution.
They didn't say it as bluntly as myself but it sure sounded a lot like it.

Is there such a thing as populism in physics - and if yes is it more
pronounced than in other fields?

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amelius
I'm intrigued by commenter Roger's (attempted) answer of the question of
whether there is something rather than nothing.

[https://www.quantamagazine.org/puzzle-with-infinite-
regress-...](https://www.quantamagazine.org/puzzle-with-infinite-regress-is-
it-turtles-all-the-way-down-20200206/#comment-4787981708)

If I understand this correctly, then "nothing" is in itself something, and you
can create more structure by grouping the original "nothing" with itself, and
you can similarly combine the groupings, so the entire universe is essentially
built from sets with "nothing" as the leaves.

But this still leaves open a lot of questions, such as who is controlling this
grouping, or do simply all possible groupings exist? Is grouping what makes
time progress? And if so, can we estimate/determine how many groupings the
current universe is from the leaves? And where does consciousness enter the
picture?

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adwn
> _I 'm intrigued by commenter Roger's (attempted) answer of the question of
> whether there is something rather than nothing._

Really? It's just playing semantic games with the definition of "nothing" and
"something". It doesn't explain anything: neither why there is something
instead of nothing, nor why that something is the way it is.

Thinking about Roger's comment some more, I believe the error he makes is that
he treats "nothing" like the empty set {}, which can be used to form non-empty
sets {{}}, {{}, {}}, {{{}}} ("something"), when really the term "nothing"
denotes a concept closer to the non-existence of the empty set and the
construction of sets from other sets.

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lioeters
From my quick reading, it sounds like he's proposing that there is no such
thing as "nothing", that what we call "nothing" is in fact like an empty set.
There's still something there.

I kind of see what he means - in his view, it _is_ turtles all the way down,
and the bottom turtle, what seems to us empty, is made of the same
being/existence.

~~~
stanfordkid
It takes 1-bit to store the state “nothing” vs “something” — so it’s a
question of information content — whether or not it is perceivable information
is what we traditionally use to delineate existence vs. non existence.

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huffmsa
> _The chicken is the closest living relative to theropod dinosaurs._

Which makes the "T-rex was actually a chubby little chonk" feel more
plausible.

[https://twitter.com/quilpatay/status/911342546386907136?s=20](https://twitter.com/quilpatay/status/911342546386907136?s=20)

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DavidVoid
_sine qua non_ : something absolutely indispensable or essential.

First time I've heard that phrase I think.

