Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?
What’s the go, in the battling ideas who is ahead, string or multiverse?
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
There would be many calculations in string theory, e=mc2 is a calculation so its probably true.
Whats the go with universes? Its bubbles, bubbles all the way down and bubbles all the way up.
Tau.Neutrino said:
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
There would be many calculations in string theory, e=mc2 is a calculation so its probably true.
Whats the go with universes? Its bubbles, bubbles all the way down and bubbles all the way up.
Supposedly the physics and mathematics are checked
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
Not sure what you mean by “pops out”, but string theory is compatible with special relativity and the rest of Einstein’s physics.
String theory and multiverse concepts are not necessarily in competition. M-theory (which unifies all the superstring theories) is itself a multiverse theory.
Cymek said:
Tau.Neutrino said:
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
There would be many calculations in string theory, e=mc2 is a calculation so its probably true.
Whats the go with universes? Its bubbles, bubbles all the way down and bubbles all the way up.
Supposedly the physics and mathematics are checked
Yes, verified by peers, other colleagues in the field.
Bubblecar said:
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
Not sure what you mean by “pops out”, but string theory is compatible with special relativity and the rest of Einstein’s physics.
String theory and multiverse concepts are not necessarily in competition. M-theory (which unifies all the superstring theories) is itself a multiverse theory.
Quantum mechanics fits in somewhere as well.
Tau.Neutrino said:
Bubblecar said:
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
Not sure what you mean by “pops out”, but string theory is compatible with special relativity and the rest of Einstein’s physics.
String theory and multiverse concepts are not necessarily in competition. M-theory (which unifies all the superstring theories) is itself a multiverse theory.
Quantum mechanics fits in somewhere as well.
A place for everything, and everything in its two places at the same time.
Pops out was Sheldons words as if it was an unintended result of other calculations. He said something like, “that can’t be a coincidence”.
I think dark matter and dark energy have to be worked out before any unified theory can be figured out properly.
The vast number of possible universes that can be described by string theory ensures that it is a multiverse theory, which has been regarded as one of its drawbacks. Wikipedia takes up the story:
Many critics of string theory have expressed concerns about the large number of possible universes described by string theory. In his book Not Even Wrong, Peter Woit, a lecturer in the mathematics department at Columbia University, has argued that the large number of different physical scenarios renders string theory vacuous as a framework for constructing models of particle physics. According to Woit,
The possible existence of, say, 10 to-power-of 500 consistent different vacuum states for superstring theory probably destroys the hope of using the theory to predict anything. If one picks among this large set just those states whose properties agree with present experimental observations, it is likely there still will be such a large number of these that one can get just about whatever value one wants for the results of any new observation.
https://en.wikipedia.org/wiki/String_theory#Criticism
AwesomeO said:
Pops out was Sheldons words as if it was an unintended result of other calculations. He said something like, “that can’t be a coincidence”.
He means that the equations of string theory produce those other equations when requested.
Tau.Neutrino said:
I think dark matter and dark energy have to be worked out before any unified theory can be figured out properly.
What effects does dark energy and dark matter have on string theory?
Tau.Neutrino said:
Tau.Neutrino said:
I think dark matter and dark energy have to be worked out before any unified theory can be figured out properly.What effects does dark energy and dark matter have on string theory?
And other theories?
Bubblecar said:
AwesomeO said:
Pops out was Sheldons words as if it was an unintended result of other calculations. He said something like, “that can’t be a coincidence”.
He means that the equations of string theory produce those other equations when requested.
or more broadly, it can be shown that mass-energy equivalence also holds for string theory, which is why it’s considered supersymmetric. Only problem is that while we can demonstrate that the mathematics ‘works’, we can’t verify this result via experiment.
For what it is worth, our resident (OK, he hasn’t been seen in a while) physicist, Cusp, thought that string theory was hooey.
Tau.Neutrino said:
Tau.Neutrino said:
I think dark matter and dark energy have to be worked out before any unified theory can be figured out properly.What effects does dark energy and dark matter have on string theory?
it’s another supersymmetric property of string theory. There are a series of particles that are predicted by string theory (noting that these particles have never been observed) that would make great candidates for dark matter/energy.
sibeen said:
For what it is worth, our resident (OK, he hasn’t been seen in a while) physicist, Cusp, thought that string theory was hooey.
in fairness… his critique was that it was naught but hanv waving and coffee table musings… which to an experimental scientist (like an astrologer) isn’t very helpful.
Tau.Neutrino said:
Tau.Neutrino said:
I think dark matter and dark energy have to be worked out before any unified theory can be figured out properly.What effects does dark energy and dark matter have on string theory?
String theory relies on the concept of supersymmetry to account for dark matter (and everything else for that matter).
Supersymmetry theories are out of favour these days, due to various experimental results including the work of the Large Hadron Collider.
sibeen said:
For what it is worth, our resident (OK, he hasn’t been seen in a while) physicist, Cusp, thought that string theory was hooey.
But he does work at the extreme opposite end of the size scale in his work, so maybe he’s not that much into the details of string theory anyway.
diddly-squat said:
sibeen said:
For what it is worth, our resident (OK, he hasn’t been seen in a while) physicist, Cusp, thought that string theory was hooey.
in fairness… his critique was that it was naught but hanv waving and coffee table musings… which to an experimental scientist (like an astrologer) isn’t very helpful.
:)
The Rev Dodgson said:
sibeen said:
For what it is worth, our resident (OK, he hasn’t been seen in a while) physicist, Cusp, thought that string theory was hooey.
But he does work at the extreme opposite end of the size scale in his work, so maybe he’s not that much into the details of string theory anyway.
I’m no fizzyist, but I thought the whole thing about string theory was that it provided a vehicle for a TOE – which has kind of wide reaching implications
Stephen Hawking’s final paper grapples with the nature of a multiverse
IN HIS final paper published after his death, Professor Stephen Hawking grappled with one the most fascinating ideas in cosmology and theoretical physics — proposing a new reality for our universe, and perhaps others like it.
The paper, titled ‘A Smooth Exit from Eternal Inflation?’ explores the notion of alternative universes — an idea known as the multiverse — and what we might be able to do to prove their existence and nature.
The latest paper uses a mix of string theory and complex maths problems that resemble hieroglyphics to arrive at his theory on the multiverse.
more…
Eh. String theory was developed in a world where the details of general relativity were already known. It didn’t “pop” out. It’s an overdetermined model.
from the above Stephen Hawking link
SO WHAT IS A MULTIVERSE?
Scientists believe our universe sprang into existence with the Big Bang, followed by an unimaginably rapid expansion known as inflation. Within our observable universe, inflation ended long ago.
But some ideas of inflation say it never stops, persisting in other regions of the cosmos forever. This eternal inflation produces a “multiverse,” a collection of pocket universes of which our own universe is just one.
Theoretical physicist Dr Brian Greene describes the idea of a multiverse like a “cosmic bubble bath” where each bubble represents a separate universe. Earth is just a planet, inside a galaxy, inside a single bubble floating in that bathtub.
These universes could have different features, different properties, different kinds of particles, different structures.
more…
dv said:
Eh. String theory was developed in a world where the details of general relativity were already known. It didn’t “pop” out. It’s an overdetermined model.
There are particles that pop in and out of existence maybe he meant those?
AwesomeO said:
Last night on TBBT Sheldon says that in 11 dimensional string theory calculations, e=mc2 pops out. Is that true?What’s the go, in the battling ideas who is ahead, string or multiverse?
My understanding is that e=mc^2 doesn’t “pop out” but the graviton does. So gravity can be thought of as a prediction of string theory.
In the battling ideas – unfortunately, who is ahead right now is the standard model + dark matter. Extensions beyond the standard model have just about all been crushed. Which reminds me, what has the Large Hadron Collider being doing lately? It woke up after its midwinter nap on the 12th April and started collecting real data on the 28th April. https://home.cern/about/updates/2018/04/2018-data-taking-run-lhc-has-begun
As for quantum multiverse. Hardly matters. Wake me up when someone has experimentally managed to dismiss any of the 18 or more “interpretations” of quantum mechanics.
Another confirmation of standard model.
Predicted mass of W boson from standard model.
80362+-8 Mev.
Observed mass of W boson from Atlas detector at the LHC.
80370+-19 Mev.
The W boson is the particle that runs the weak force.
mollwollfumble said:
Another confirmation of standard model.Predicted mass of W boson from standard model.
80362+-8 Mev.Observed mass of W boson from Atlas detector at the LHC.
80370+-19 Mev.The W boson is the particle that runs the weak force.
All this stuff is designed to tie you up in knots.
PermeateFree said:
mollwollfumble said:
Another confirmation of standard model.Predicted mass of W boson from standard model.
80362+-8 Mev.Observed mass of W boson from Atlas detector at the LHC.
80370+-19 Mev.The W boson is the particle that runs the weak force.
All this stuff is designed to tie you up in knots.
That’s topology not cosmology.
;-)
ChrispenEvan said:
PermeateFree said:
mollwollfumble said:
Another confirmation of standard model.Predicted mass of W boson from standard model.
80362+-8 Mev.Observed mass of W boson from Atlas detector at the LHC.
80370+-19 Mev.The W boson is the particle that runs the weak force.
All this stuff is designed to tie you up in knots.
That’s topology not cosmology.
;-)
How long is your piece of string.
;)
PermeateFree said:
ChrispenEvan said:
PermeateFree said:All this stuff is designed to tie you up in knots.
That’s topology not cosmology.
;-)
How long is your piece of string.
;)
His preference is to cut short.
roughbarked said:
PermeateFree said:
ChrispenEvan said:That’s topology not cosmology.
;-)
How long is your piece of string.
;)
His preference is to cut short.
Always have a long piece of string.
Very handy to have around.
Tau.Neutrino said:
roughbarked said:
PermeateFree said:How long is your piece of string.
;)
His preference is to cut short.
Always have a long piece of string.
Very handy to have around.
Off topic, but “how long is a piece of string?” is a major worry to me right now. Hey, just solved that problem, I don’t have to use the shortest string and all the others will be long enough. That leaves the questions of “how tight a diameter is it safe to bend a string?” and “How many mm do I need under the eye of the tuning peg for coiling of the string?”
mollwollfumble said:
Tau.Neutrino said:
roughbarked said:His preference is to cut short.
Always have a long piece of string.
Very handy to have around.
Off topic, but “how long is a piece of string?” is a major worry to me right now. Hey, just solved that problem, I don’t have to use the shortest string and all the others will be long enough. That leaves the questions of “how tight a diameter is it safe to bend a string?” and “How many mm do I need under the eye of the tuning peg for coiling of the string?”
> “how tight a diameter is it safe to bend a string?”
Probably no problem with steel cello strings but avoid nylon and gut ones. Just beware.
> “How many mm do I need under the eye of the tuning peg for coiling of the string?”
Enough for three turns. That’s up to 4 mm. That’s a lot.
Aha. “Most standard guitar tuners, whether sealed-gear or open-gear, are intended to be used on a headstock that is about 9/16” (0.5625 inches/14.3mm) thick. Ukulele tuners are made to work on thinner headstocks, usually in the range of ⅜” (0.375 inches/9.53mm) or 7/16” (0.4375 inches/11.1mm).”
My tuning pegs have two sets of holes for two different headstock thicknesses. I had planned to use 11.5 mm but that only left about 1.5 mm clearance for string coiling, not enough. 9.5 mm leaves 3.5 mm clearance, close enough to the 4 mm found above. I also have enough wood for the 14.3 mm option if I want a stronger headstock to better resist 50 kg of compression without long term warping.