SoylentNews is people
SoylentNews
from the unterminated-strings-cause-inflation dept.
Submitted via IRC for SoyCow1984
Our universe: An expanding bubble in an extra dimension
According to string theory, all matter consists of tiny, vibrating "stringlike" entities. The theory also requires there to be more spatial dimensions than the three that are already part of everyday knowledge. For 15 years, there have been models in string theory that have been thought to give rise to dark energy. However, these have come in for increasingly harsh criticism, and several researchers are now asserting that none of the models proposed to date are workable.
In their article, the scientists propose a new model with dark energy and our Universe riding on an expanding bubble in an extra dimension. The whole Universe is accommodated on the edge of this expanding bubble. All existing matter in the Universe corresponds to the ends of strings that extend out into the extra dimension. The researchers also show that expanding bubbles of this kind can come into existence within the framework of string theory. It is conceivable that there are more bubbles than ours, corresponding to other universes.
Journal Reference:
Souvik Banerjee, Ulf Danielsson, Giuseppe Dibitetto, Suvendu Giri, Marjorie Schillo. Emergent de Sitter Cosmology from Decaying Anti–de Sitter Space. Physical Review Letters, 2018; 121 (26) DOI: 10.1103/PhysRevLett.121.261301
(Score: 3, Insightful) by Anonymous Coward on Sunday December 30 2018, @05:16PM (9 children)
I realize that these stories are abstracts of information given by scientists who are dumbing it down for reporters, who are in turn dumbing it down even more when they write it. So judging the actual state of the field from this is simply not appropriate, really. But not being a cosmologist, or physicist, or whatever, this stuff is all I've got to work with.
Having said that... am I the only one who's starting to think all this tinkering with this theory or that theory is sounding more like a desperate science fiction author trying to tweak a story to get it past a deranged editor who keeps changing what he wants? With perhaps the author being a bit stoned? "Like, man, what if the whole universe, was, like, just the edge of a huge bubble, man?"
Is it overly cynical to wonder if string theory is trying to explain the universe, or is trying to keep the grant money coming in?
(Score: 5, Interesting) by Anonymous Coward on Sunday December 30 2018, @06:51PM (1 child)
here's a specialists' view on it: http://backreaction.blogspot.com/ [blogspot.com]
this is a blog where a physicist tries to explain why current theories of high energy physics are mostly junk, but the community refuses to do anything else. most of the entries deal with this problem.
string theory is a beautiful mathematical abstraction that has so far not given one verifiable result.
well, they did predict the cosmological constant. and they failed miserably. after which they made their theory even more abstract, so now it can predict any value of the cosmological constant you want it to, in many different ways --- so many that you can't actually use it for anything.
unfortunately, these "physicists" have tenured positions, and they're sticking to their idiotic nonsense, keeping out the people with alternative ideas.
the entire community of theoretical high energy physics is basically trapped in a cycle where if you don't work on the popular stuff you don't get a permanent position, even though the popular stuff doesn't predict anything that can be verified by experiment. and if you do get a permanent position by working on the popular stuff, you want to continue working on it (either because you believe it's the right thing to do because you're an idiot, or because it's easy).
(Score: 0) by Anonymous Coward on Sunday December 30 2018, @11:05PM
Thank you for that link, it is most enlightening.
(Score: 0) by Anonymous Coward on Sunday December 30 2018, @07:07PM
"wonder if string theory is trying to explain the universe, or is trying to keep the grant money coming in?"
You are asking
Number1) is it fake? No, look at the paper, it is filled with formulas that can be proven/disproven by other scientists
Number2) is it Valuable?
Just because it does not produce immediately tangible benefits does not make it worthless. An analogy: think of all those annoying people who question the value of exploring space; solve the problems on earth first they say. The same responses to them apply here.
(Score: 2) by seeprime on Sunday December 30 2018, @09:42PM (2 children)
What better job than one where you theorize a reality that can never be proven? Possibly a TV weatherman, who is rarely correct more than 48 hours out.
(Score: 2) by TheGratefulNet on Monday December 31 2018, @12:13AM (1 child)
"tonite, its going to be dark. real dark.
followed, tomorrow, by random scattering of light."
"It is now safe to switch off your computer."
(Score: 3, Touché) by coolgopher on Monday December 31 2018, @02:24AM
Cue full moon in a clear sky followed by a dark and stormy day.
(Score: 5, Insightful) by ledow on Sunday December 30 2018, @11:41PM (1 child)
What you know as physics is actually just maths.
Quantum physics is utter horseshit from a real-world viewpoint. Nobody would have ever come up with that nonsense and been respected.
But what we did was generate the maths that we already had. Took it a step further. Solved equations that we couldn't previously solve. And for nearly 100 years people like Einstein were laughed at as it was all just nonsense on paper that had no visible real-world analogue. Until we found out that, actually, the stuff that dropped out of the equations was out there, in the world, visible, testable, verifiable.
Things like relativity, quantum physics, and anything sub-quantum are the same. They are there because they are a consequence of the mathematics. Now, they may just be deadends and nonsense, literally mathematical facts that are "correct" but which are damn useless without context, 11-dimensions, or the missing pieces, or even a decent interpretation of the numbers that we KNOW are right.
String theory is no different. GR/Quantum physics were nearly 100 years old before anyone could actually see any use or proof in them. String theory could be no different, or it could be a nonsense deadend. Nobody knows.
Fact is, the entirety of high-end physics is mathematics. Because you have to PREDICT and then OBSERVE, not OBSERVE and then make up nonsense that might explain. The latter is where we are at. We're measuring dark matter and other things, and stabbing at physical explanations for them. But until we can derive equations that naturally leave space for dark matter, and then predict a way for us to observe it, and THEN we can observe it by following what those equations tell us should happen? We're just plucking at straws.
We've been plucking at straws for at least 20, maybe more, years in these areas. We don't have the magic equations that explain everything, or even some that could predict something unusual that we don't expect to see but could actually later observe. We have an handful of really-open-answers that aren't much cop until we can use them. And no practical and feasible experiments that would reveal if they are useful or even vaguely correct.
It'll come someday. But at the moment, we lack the mathematical link, not just the interpretation of that mathematical link that might help us understand something new.
Most of these equations are so difficult-to-solve and open-ended that even with a field of supercomputers and a plethora of mathematicians working on them for decades, we get no closer to anything substantial and definitive, and the only answers we've ever got ever since quantum-physics/GR are basically so difficult to solve that they can only give extremely vague and wide-ranging answers dependent on so many unknown variables that we just can't ever know, that we haven't progressed in a long time.
All we can do is come up with a million theories, and then next time we discover something unusual eliminate all the models that no longer fit. It's like a huge game of Guess Who - all we know is that the guy is male, so we can knock down the female theories, but other than that there are still dozens of viable candidates and until we can ask the next question and get a distinguishing answer, we can only add more characters to the board.
(Score: -1, Flamebait) by Anonymous Coward on Monday December 31 2018, @12:17AM
Wow, you are an idiot.
(Score: 2) by bradley13 on Monday December 31 2018, @08:23AM
"am I the only one who's starting to think all this tinkering with this theory or that theory is sounding more like a desperate science fiction author trying to tweak a story"
I would be a bit more charitable. It seems to me that physicists are just missing some essential insight. The universe exists, and we can understand a lot of the interactions that we see, but the why of it eludes us. Quarks exist, but why do they exist? Why is there an electromagnetic force? Why is there gravity? Even if string theory were to prove out, it's only one more turtle in the stack, because why are there strings?
Maybe these are questions beyond our capabilities. Being inside the universe and subject to its laws, are we even capable of imagining what underlies it?
Personally, intuitively, (IANAP = not a physicist) I am happiest with the "we are a simulation" explanation. It would intuitively explain so much. For example, quantum mechanics is just revealing the finest level of resolution available. Of course, this still begs the question: what are the rules of the simulation? Can we derive them? Understand them? Manipulate them from the inside? Evil laugh Can we become malware?
Everyone is somebody else's weirdo.