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At Multiverse Impasse, a New Theory of Scale

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Re: At Multiverse Impasse, a New Theory of Scale

#131

Post by Strilanc »

trhway wrote: post #130
Strilanc wrote: post #90

Earlier quoted context omitted.

I'm not sure why you're grouping entanglement in with the multiverse. One of those is a theoretical idea for reducing the Solomonoff complexity of the universe with no clear experimental implications. The other is an integral component of how we predicted and explain experimentally confirmed phenomena like violations of Bell's inequalities, the Elitzur-Vaidman bomb tester, quantum cryptography, and quantum teleportat…

because both violate Occam's razor (and both stem from very specific treatment of superposition). Like in the above mentioned "imaging by entanglement", a closer look at the experiment always reveals explanations for the observed effect without necessity to involve the "magic" of entanglement.

How do you explain Bell inequality violations without involving entanglement?

If we get quantum computers working at a non-trivial scale, would you consider that to be strong evidence for entanglement?

Re: At Multiverse Impasse, a New Theory of Scale

#132

Post by sampo »

lutusp wrote: post #91
sampo wrote: post #39

Earlier quoted context omitted.

That was my point. Natsu was worrying about the ability of a technological civilization to function near the heat death of the universe. Which is much further than 5-6 billion years away. A more "immediate" problem is the death of our own Sun. Of course, what you say is even more immediate.

> Natsu was worrying about the ability of a technological civilization to function near the heat death of the universe. Unless by "heat death" he meant a cold death, current thinking has it that the universe will gradually cool off, and ultimately freeze, because of the endless expansion provided by Dark Energy. The fact that the universe is expanding exponentially, i.e. with a positive second derivative, was the fir…

"Heat death does not imply any particular absolute temperature; it only requires that temperature differences or other processes may no longer be exploited to perform work."

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

Re: At Multiverse Impasse, a New Theory of Scale

#133

Post by halfcat »

goblin89 wrote: post #33
collyw wrote: post #24

Earlier quoted context omitted.

Yes. Open minded comments like this, questioning the limits of science get down voted here on HN.

I didn't downvote, but if you ask me I'd say others did it mainly because grandparent brought philosophy into scientific discussion. (And with reasoning or phrasing issues at that: “we can't do something even if we can”, for example, contradicts itself.)

Ironic that science is a subset of philosophy.

Re: At Multiverse Impasse, a New Theory of Scale

#134

Post by evanb »

nilaykumar wrote: post #106
evanb wrote: post #83

Earlier quoted context omitted.

Do you have any rumors or specific knowledge (even if it's not something you'll share) regarding SUSY? They found missing energy? A new plethora of resonances? Higgsinos or sfermions? Something more exotic?

By the end of the last run, the people I talked to at CERN were fairly certain that there's no SUSY in the current dataset and that SUSY will likely not be found during the upcoming run. But perhaps the people I talked to are simply of a different persuasion.

Hi Nilay!

-- Evan from TQHN.

Re: At Multiverse Impasse, a New Theory of Scale

#135

Post by goblin89 »

halfcat wrote: post #133
goblin89 wrote: post #33

Earlier quoted context omitted.

I didn't downvote, but if you ask me I'd say others did it mainly because grandparent brought philosophy into scientific discussion. (And with reasoning or phrasing issues at that: “we can't do something even if we can”, for example, contradicts itself.)

Ironic that science is a subset of philosophy.

That's precisely why, IMHO, if you aren't prepared to make a complete well-thought-through argument, then you should think twice before venturing into a philosophical discussion.

On the other hand, due to the nature of HN, one has to choose between either spending a few days researching the comment and posting it with a very slim chance of being read or answered, or blurting out something not very polished.

In this case it's the latter. (How you define “objective”? “reality”? A rough example of how could the answer to the question “what reality is” roughly look like? Any links to existing research—people certainly attempted to ask a question of this nature before?) The resulting discussion may be worth it, though.

Re: At Multiverse Impasse, a New Theory of Scale

#136

Post by eli_gottlieb »

mkaziz wrote: post #85
smokel wrote: post #72

Earlier quoted context omitted.

Your statement that we will never get to the bottom may be true, but the reasoning is flawed. Gödel's incompleteness theorems are about mathematical theories, not about physical theories. It may well be that for physical understanding a very limited arithmetic is sufficient. Also, there may be statements that are unprovable, but these might turn out to be irrelevant to sufficiently understanding the universe. Also, a…

Do you not have to start off with a set of axioms though? Assumptions that will never be proven?

Scientific reasoning is inductive, not deductive. When doing inductive reasoning you are allowed to update your belief in your axioms based on the empirical evidence you see.

In fact, the theorem showing how to do so (Bayes' Theorem) is so utterly elementary we teach it in the first probability course everyone takes.

Re: At Multiverse Impasse, a New Theory of Scale

#137

Post by eli_gottlieb »

trhway wrote: post #130
Strilanc wrote: post #90

Earlier quoted context omitted.

I'm not sure why you're grouping entanglement in with the multiverse. One of those is a theoretical idea for reducing the Solomonoff complexity of the universe with no clear experimental implications. The other is an integral component of how we predicted and explain experimentally confirmed phenomena like violations of Bell's inequalities, the Elitzur-Vaidman bomb tester, quantum cryptography, and quantum teleportat…

because both violate Occam's razor (and both stem from very specific treatment of superposition). Like in the above mentioned "imaging by entanglement", a closer look at the experiment always reveals explanations for the observed effect without necessity to involve the "magic" of entanglement.

Entanglement isn't magic: it's just correlation. Behind every pair of entangled particles you find a single original causal event that created them and entangled them. Entanglement just seems like magic because the actual reality is a joint distribution over particle states that already obeys the appropriate physics, but you're thinking of it as two separate distributions whose results are "forced" by "magic" to conform to the appropriate correlation after the "sampling".

There's no magic: you're just sampling a joint distribution in the first place.

Re: At Multiverse Impasse, a New Theory of Scale

#138

Post by auxbuss »

jrussino wrote: post #111
MisterMashable wrote: post #74

There's a very subtle undertone of negativity in this article about physics. Before I get into, William Bardeen is not in the same league as 'Surfer Dude and his E8 Theory of Everything' which throws basic facts about representation theory out the window, coming up with 'todalay boogus' arguments which amazes auntie, mommie and magazine editors but a real physicist would instantly dismiss. Bardeen is the real deal. H…

Are there any particular resources that you recommend for a high-level overview of this kind of stuff? I'm an engineer with a solid grasp of classical mechanics and strong math background, but very little exposure to modern physics (basically, anything discovered after 1905) and I would like to be able to read about and appreciate this type of work. Where to start? Apologies for taking the conversation off on a tange…

The short course, 'From the Big Bang to Dark Energy'[0], is an excellent introduction.

[0] https://www.coursera.org/course/bigbang

Re: At Multiverse Impasse, a New Theory of Scale

#139

Post by trhway »

eli_gottlieb wrote: post #137
trhway wrote: post #130

Earlier quoted context omitted.

because both violate Occam's razor (and both stem from very specific treatment of superposition). Like in the above mentioned "imaging by entanglement", a closer look at the experiment always reveals explanations for the observed effect without necessity to involve the "magic" of entanglement.

Entanglement isn't magic: it's just correlation. Behind every pair of entangled particles you find a single original causal event that created them and entangled them. Entanglement just seems like magic because the actual reality is a joint distribution over particle states that already obeys the appropriate physics, but you're thinking of it as two separate distributions whose results are "forced" by "magic" to conf…

>Behind every pair of entangled particles you find a single original causal event .... the actual reality is a joint distribution over particle states that already obeys the appropriate physics

that is exactly my views too. QM people call it "hidden variable" theory.

>two separate distributions whose results are "forced" by "magic" to conform to the appropriate correlation after the "sampling"

and that is Copenhagen interpretation superposition wave function collapse based theory of entanglement.

>you're just sampling a joint distribution in the first place.

if somebody shows that Bell violations can happen here too the Nobel prize will be his/her. I though think that Bell violations can't happen at all. That would be another Nobel prize i guess :)

Re: At Multiverse Impasse, a New Theory of Scale

#140

Post by trhway »

Strilanc wrote: post #131
trhway wrote: post #130

Earlier quoted context omitted.

because both violate Occam's razor (and both stem from very specific treatment of superposition). Like in the above mentioned "imaging by entanglement", a closer look at the experiment always reveals explanations for the observed effect without necessity to involve the "magic" of entanglement.

How do you explain Bell inequality violations without involving entanglement? If we get quantum computers working at a non-trivial scale, would you consider that to be strong evidence for entanglement?

>How do you explain Bell inequality violations without involving entanglement?

i still can't in details :) I so far have worked my way only until double-slit experiments - no superposition there :) For Bell violations i bet we have the same mis-interpretation of statistical aggregate description as individual realization (this "mis-interpreation" is the Copenghagen's superposition) as in double-slits. In case of Bell violations experiments it seems to be the same as "disjoint sampling loophole" http://en.wikipedia.org/wiki/Loopholes_in_Bell_test_experime...

>If we get quantum computers working at a non-trivial scale, would you consider that to be strong evidence for entanglement?

it would be strong evidence for superposition and thus for entanglement. Want these computers like anybody else, yet don't really see them happening :(

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