'Wobbly spacetime' is latest stab at unifying physics Since the early 20th century, physicists have struggled to marry theories governing the very big with those for the very small. Despite the staggering achievements in modern science, the conflict between Einstein's general theory of relativity and quantum mechanics has become a stumbling block in developing a consistent, …
That's already explained by quantum fluctuations. Gravity doesn't really come into it at that early point. If Oppenheim's hypothesis turns out to be true (well, a better theory than nothing until something else pops up, as is the way of things) it might offer a more exact description but not a new explanation.
Quantum fluctuations are too small to explain the large scale structures we see, so extreme inflation in the very early universe was postulated to explain it - but some even larger structures have since been found which would require even more extreme inflation - but fluctuations larger than predicted by quantum theory would also explain it.
The "quantum imperialists" have always tried too hard IMO to subsume GR, for no good reason AFAICS ;)
When all is said and done, both theories are merely mathematical models, not "reality", and there is no reason to assume that a model covering all ranges of validity should even exist.
“ merely mathematical models, not "reality"”
Proof that reality and mathematics are different things is not yet shown. Other than the “how do we know that we aren’t living in a simulation” rants, we also were wrong about “the Earth is special”, “electrical activity in the body is special”, “humans are not animals” and “the soul is special”
We are probably wrong about “reality is special and totally not mathematics”….
I suppose "in trouble" is sufficiently vague that you can argue either side, but yes. Incomplete is a problem if you wanted completeness, but it's not the sort of problem that inconsistency is.
And you can get the same result in other ways than Gödel, of course. You can reach it through doxastic logic, for example. You can hypothesize it through the Church-Turing Hypothesis, though that's on a much softer foundation than Gödel's proof or its equivalents. And while Algorithmic Information Theory was inspired by Gödel, I believe its incompleteness results could have been arrived at independently. (At least that's true of Chaitin's version of AIT, according to Chaitin's own account. I don't know what sort of debt Kolmogorov's version owes to Gödel.)
"Reality" is a philosophical concept, not a scientific one. All we have are observations and measurements. We can often use mathematics to make sense of them, in certain circumstances, but it is naive to assume that nature cares about our differential equations, boundary conditions, and orders of complexity.
What precisely leads you to say we are "probably wrong"? That is an pretty outrageous claim, that warrants an explanation.
It’s not outrageous (certainly no more than appealing to a deity). If the Universe is an outcome of mathematics existing, then a lot of philosophical questions get answered.
“Why are we here?” become “why does mathematics exist?” becomes “mathematics cannot not exist”
“Is there a creator?” Becomes “does mathematics need a creator” becomes “no mathematics exists only as logic and is independent of a creator”
Eh - I don’t spend too much time proof-reading my ramblings on random forums. I probably would use more careful working if “Post Anonymously” wasn’t ticked!
I like the idea of a Max Tegman Mathematical Universe, personally. It’s the closest I have heard to a sensible explanation….
Mathematics is a language that we use to describe the universe. It is incomplete, which is why we can't describe things like the interior of a black hole. "Infinity" is merely the contemporary equivalent of "here be dragons".
Don't mistake the map for the terrain.
Mathematics _can_ describe the inside apart from the "singularity". Science (i.e. observations) cannot penetrate the horizon. Anything that we think happens _inside_ the horizon can never be proved, whether you say it is mathematics, "reality", or angels dancing on the head of a pin.
It seems the Planck length, black holes, and the confines of the Universe are all an event horizon, and I hypothesise they are all the same one.
And in the style of Fermat’s Last Theorem I hereby state that I have proved it mathematically, but omitted to show my workings!
All my homies exist as logical implications of formal systems.
The thing that makes Tegmark IV appealing for me is that I've always thought: "no matter what actually exists or doesn't exist, the fact that the laws of physics if computed will contain myself is immutable and inescapable." So if that's true, and it's hard to see how it couldn't be, why would existence need anything else?
"But mere mathematics doesn't give you the passage of time, or consciousness, or the phenomenal feeling of selfhood." "Yeah, I calculated the laws of physics and turns out that's what you said in that mathematical formalism as well."
Try explaining Recursion errors to your 90 year old Granny who has never used a computer? Or perhaps the intricacies of Superheat Phases in a non-ideal Rankine cycle? Or quite frankly String Theory or any of the other competing Unification Theories?
There are some topics that require a minimum level of expertise to be able to communicate effectively. And let's face it, the entire realm of Theoretical Physics is by now almost entirely pure mathematics.
I'm sure with time, Oppenheim would be able to come up with a suitable abstraction, but quite frankly does it help anyone outside the Theoretical Physics community? Leave it at, "It's complicated, but we have ideas for experiments that could prove or disprove it...". If enough people in the community of theoretical physicists start taking it seriously, then those tests will happen, and we'll quickly see if it joins the thousands of other disproven Unification Theories or if it joins the not-yet-disproven pile...
I was listening to an old "In Our Time" on Einstein the other day, and one of the Profs opined that Einsteins tendency to use analogies, and the press lapping up things like E=MC^2 from his special theory of relativity set hugely unrealistic expectations for future physicists (and also Einstein himself, with his general theory of relativity a few years later). Physics from that point on became increasingly mathematical and harder to understand for the layperson.
> and the press lapping up things like E=MC^2 from his special theory of relativity
I find that highly unlikely as E=mc^2 isn't from his Special Theory of Relativity, it's from his Mass-Energy Equivalence paper (english title "Does the Inertia of a Body Depend Upon Its Energy Content?").
It sounds as if he's saying it's monotonic but not rectilinear. Even a non-mathematician like me can grok that. Doing it 4 dimensions - maybe a bit trickier.
And if you want a physical representation, think of an old surveyor's tape (it's probably an old surveyor who owns it). It's a bit stretched in places - the tape, not the surveyor (well, maybe the surveyor as well). As you trace along the tape the numbers get bigger all the time (monotonic) but sometimes the next number is further away and sometimes it's closer (not rectilinear).
Now you can roll it up but keep it safe - I may need it later to explain the difference between accuracy and precision.
If it's very mathematical, then the real challenge is to point to something tangible as a prediction. This is why we refer to General Relativity on its own, and not as General Relativity Theory. There are a number of predictions of GR that have been successfully tested. String Theory on the other hand, is only ever referred to as theory. Good on them for having a crack. Maths is important but it's not so important to frame the question as it is to explain the answer.
> This is why we refer to General Relativity on its own, and not as General Relativity Theory.
Err, no, it is correctly The Theory of General Relativity, calling it General Relativity or GR are both shorthands.
I think you are doing the classic 'casual english' thing and using 'theory' to mean (as Merriam-Websters's '2b' definition - which is the 4th definition for theory)
2 b:: an ideal or hypothetical set of facts, principles, or circumstances —often used in the phrase in theoryrather than the precise scientific use of the word theory as per Merriam-Webster's 1a (i.e. first) definition:
1 a: a plausible or scientifically acceptable general principle or body of principles offered to explain phenomenaString Theory is correctly labelled a hypothesis, not an actual accepted Scientific Theory, whereas General Relativity is a generally accepted Scientific Theory.
String Theory plays with semantics by including the word 'theory' as part of the title of the hypothesis, therefore it is "the hypothesis that is titled String Theory", and if it is ever elevated to the status of Scientific Theory (doubtful ... see fo example this youtube video from a working physicist ) then it would be "the theory that is titled String Theory, or The Theory of String Theory."
Experiments can prove wrong theories are wrong. They can also fail to prove theories wrong even if they are through lack of precision or range - you need a fairly long experiment performed with reasonable accuracy just to prove the Earth is not flat.
Betting against a theory being proved correct is always safe. No matter how closely experimental results match theory just claim that more precision or a longer/shorter scale would have proved the theory false.
A friend of mine works in string theory. Thirty years ago he said they were near predicting the charge-mass ratio for electrons. As far as I know, that still hasn't happened. String theory has been a spectacular dud,
But then, so has much of modern physics, which is now reduced to inventing "dark matter" and "dark energy" is a desperate attempt to change the universe to fit their theories, a la epicycles. Perhaps we'll just have to accept that human brains are not good enough to understand what's going on, in much the way that no dog will ever understand how microprocessors work.
> As far as I know, that still hasn't happened. String theory has been a spectacular dud,
As a general note, String Theory is not popular among the physics community as a whole. It is only popular in the tiny subset that support it (basically the ones who work on it and write books on it and get paid to present talks about it, Brian Greene, Michio Kaku, et al.) and the media and, through the media, the public.
acollierastro (a random physicist) did an interesting youtube video, string theory lied to us and now science communication is hard.
I believe that there's already much experimental evidence for such a theory :
1) Take a person and put them in a 90 minute meeting discussing which database access framework a new application should use. Time will be observed to have stretched out to what felt like a week amongst all observers.
2) Take the same person and send them on a week's holiday to some sunny island where good food and wine are abundant and cheap. Time will be observed to pass so quickly that it's time to go home again before they know it.
This is ample proof that we live in a giant cosmic jelly.
A college professor's salary at the time was about $4000 on average, but since Kistiakowsky had been at Harvard he'd likely have earned more there. He also headed the Explosives Research Lab before joining the Manhattan Project, so the government was probably paying him more than Harvard. A monthly pay of about $500-$600 seems likely.
As a colleague of mine used to say, all scientists know that in due course everything they have discovered will be proved wrong. Perhaps fundamentally, perhaps only at the tenth decimal place, but eventually wrong. Which is why scientists are generally much more humble than religious types, or social scientists, neither of which groups admit that being proved wrong is even a possibility.
We have shown that if spacetime doesn't have a quantum nature, then there must be random fluctuations in the curvature of spacetime
El Reg first published the discovery of non-random fluctuations in space time in 2016 - "Boffins' gravitational wave detection hat trick blows open astronomy"- news that is still reverberating today. These were non-random fluctuations because they were pronounced enough and correlated with enough other observed data to attribute them with high certainty to colliding black holes.
What if such gravitation waves didn't die but continued to reverberate, mixing it up with waves from other gravitational events, leaving space time riddled with mutually interfering ripples of all sizes whose origins are impossible to attribute to any particular event? You might as well call them random.
People expecting unity on something as yet untested really don't understand the scientific method. Any theory can be proposed; the question is whether it matches the data (known and later) better than other theories. And even then it's only a provisional best-guess since some other data or idea may either refine it or replace it later.
As far as I can tell even philosophy admits of this process. Individual philosophers may not, but that's _their_ current theory, which may not survive.
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