145 points by wwarner a day ago
So this is something I was thinking about recently. Given that quantum harmonic oscillation indicates that quanta are actually defined as harmonics of a fundamental frequency, what if dark matter is simply all energy at a frequency that isn’t a harmonic? Likewise, what if dark energy is simply the quantum harmonic oscillator that is our universe undergoing damping? That is to say, it’s not so much that space is expanding as it is that the frequency of our universe is diminishing: lower frequency = higher wavelength, which appears to us like space is growing. The graph of an oscillator undergoing damping looks an awful lot like models of dark energy expansion of the universe.
If this were the case, we could think of black holes as nodes on this wave.
No. The solution to the problem you are proposing is well known and is part of any (advanced?) QM course, and it doesn't involve dark matter or dark energy.
In an harmonic oscillator (an ideal perfect spring with an ideal punctual mass) the energies are (2n+1)ħ/2*ω. They are all multiples of the minimal value for this oscillator. Note that it is a different set of values for each oscillator.
Each of these energies is associated with a wavefunction with a well defined energy. Combining all these wavefunctions you can represent any wavefunction. (The technical term is "orthonormal base", or simply "base".) This is easy to prove. More details in https://en.wikipedia.org/wiki/Quantum_harmonic_oscillator
So if you try to put the oscillator in a state that is not a wavefunction with a well defined energy, the state can be represented as a linear combination of the wavefunction with a well defined energy, and it will evolve following the laws of QM. It will not get transformed to dark energy or dark matter or get lost by damping.
If you later make measure the energy of the harmonic oscillator, the arbitrary wavefunction will colapse to a wavefunction with a well defined energy, and the probabilities are easy to calculate knowing how the initial state was decomposed in wavefunction with a well defined energy. If you measure the position or speed, the calculation is similar but there are a few more technical details.
In a more realistic system like an Hydrogen atoms, the energies are not multiples of a minimal value, the energies are like -E0/n^2. The corresponding wavefunctions are a base anyway, so any initial state can be decomposed in wavefunction with a well defined energy (that sometimes are calles "orbitals", but sometimes more general states are called "orbitals"). So there is no a fundamental frequency, there is no a minimal energy that is the divisor of all the energies, there is no dark energy.
In atoms with more electrons the calculations are more complicated, there is no nice formula for the energies, but is anyway possible to decompose any initial state without using dark energy.
Interesting question, but also interesting answer. Thanks for the detailed response!
Some comments, since this post is generating some discussion:
1. If you squint, the inflation model is something in this spirit. The "inflaton" field corresponds to the harmonic oscillator like variable that ismovingunder a potential, and causing space to expand.
2. The quantization of frequencies for a harmonic oscillator (or a particle in a box) comes from spatial bounds on it's profile -- through some potential function. The quanta are separated by inverse of the region size (like aliasing effects a la Fourier). If we're imagining a field spread all throughout space then the "harmonics" are very closely spaced enough to be considered a continuous spectrum, sort of.
3. All that was just quantum mechanics. A more appropriate framework to have this conversation is quantum field theory (and not just in flat spacetime, but curved spacetime). In that context, quanta refer to number of inflaton particles at a specific frequency, and that goes in a direction different from what we're interested in. So that was just a paranthetical aside.
4. As far as we can tell from observations space hasn't been globally oscillating. So it's more like an overdamped oscillator (with a lot of "friction") than an underdamped one -- see "slow roll inflation". (For examples of where space was locally affected by underdamped oscillations, see baryonic acoustic oscillations).
Beyond just a few technical nuggets, what I hope to have conveyed is that the way to research these things is to take every word/facet seriously and try to operationalize it in an appropriate framework (which is very hard) and verify whether it matches our experience of reality.
I think you've hit the nail in the head. I recently had a similar thought that the 'expansion' of the cosmos may simply be "the same distances divided into more chunks". I.e. initially, at the big bang, the analogy was 1/1, i.e. the whole universe was of distance '1' divided by '1', and as the universe 'expanded', it didn't really expand, it was actually the divident being incremented, which created more chunks in the universe. It is as if we have a computer display of 1x1 meter, and we gradually increase the resolution; the actual size of the display wouldn't change, but its resolution would.
Of course your explanation is much more scientific than mine, which is just a hunch.
Such 'resolution' increase of the universe would explain nicely its expansion.
I wonder if the creation of wormwholes that would allow travelling to distant systems in human lifetimes would simply be the opposite effect of damping of this frequence of our universe. By reversing the damping, the "resolution" of the universe may decrease and then moving from one place to the other would require a lot less time.
Also, could gravity be a change of this frequency by mass?
The quantum states only have discrete frequencies because they are bound states contained within a trap. If you consider H = p^2/2m, a free particle, the frequencies are continuous. The universe isn't a trap.
It would be cool to see exactly what sort of model would produce behavior like this. I'm a theoretical physicist, and at first glance I have absolutely no idea how one could write down a model that had "energy at a frequency that isn't a harmonic": it doesn't really fit with anything that I know about quantum systems or quantum field theory, which pretty solidly force us into discrete energy spectra for the types of systems that you're talking about. But I'd love to see a mathematically consistent model that does what you're talking about: it sounds fresh and different, if it turns out to be possible at all. If you come up with some math to share, please do! (Hmm... in the back of my mind, there was some interest years ago in "unparticle" models that might maybe possibly be related, or maybe I'm just completely fuzzy on what that idea was about.)
I am not a physicist or a mathematician, but wouldn't a virtual particle be more or less what I'm talking about? They exist for a limited time because they are producing interference with our universe's 'wave' but they don't stick around because they are not at a harmonic frequency. Likewise they cannot have a precisely defined energy or momentum because they break our frame of reference by not being at a harmonic frequency.
The s orbital electrons around an atom is the fundamental, the p and other orbitals are harmonics. I think you’ve stretched your analogy too far.
Couldn’t the s orbital itself be a harmonic of an even lower fundamental?
I think if that were true, we’d see other orbitals that are harmonics of the lower fundamental, but not a harmonic of the s orbital... which we I don’t think we see in practice? (If we did, we wouldn’t consider the s orbital to be fundamental.)
This is very interesting.
So, if we interpret all matter to be different expressions of a fundamental frequency, it means us, the observers are also made up of the same, and to observe you would be basically sampling reality. Even if you consider measurement instruments to be an observer, they also sample other things that are made up of the same.
Then maybe there's a fundamental limit to what we can sample, hence observe. And that could explain why we only observe harmonics of the s orbital.
In this case, the lower fundamental would be something that permeates space (zero-point energy?), so the orbitals that are harmonics of the lower fundamental but not an atom's s orbital would be on other atoms entirely.
No, because the energy of the electron is known and is always quantized.
When you say this what do you mean?
Here are some statements of my own, typed quickly on a phone before I head to work:
-Electrons do not in general have quantized energy; only bound electrons have a discrete energy spectrum
-Electrons do not necessarily have a single energy; although energy eigenstates form a basis that can describe all states, very often the electron won't be in a pure eigenstate
-Single electron models are simplifications; in general, atoms will have multielectron states that are very difficult to write down or reason about; it's deep and non-obvious why single electron models do so well at describing behavior of multielectron wavefunctions
By the way you seem really smart and I love the enthusiasm, I don’t want to seem like a downer.. if you haven’t already taken some classes in physics, you should
What about rotation of the universe?
Does this change the whole heat death/big freeze question about the End of the Universe?
Wow! What about posting this on /r/asksciencediscussion or Physics.SE and get some review? I would be interested in reading discussions about this
>what if dark energy is simply the quantum harmonic oscillator
Is there anything at all in the whole of physics that isn't, at some point, shoehorned in the "mass on a spring" framework </sarcasm>
The reason everything gets "shoehorned" into "mass on a spring" is that this is the first term in the Taylor expansion.
No matter how ugly an expression you have for force as a function of distance, if you do the Taylor expansion you inevitably get a constant force term (often zero) and a "mass on a spring" term.
As usual, phys.org makes claims that go way beyond what the actual paper justifies. The actual paper is here:
The phys.org article says "Two University of Hawaii at Manoa researchers have identified and corrected a subtle error that was made when applying Einstein's equations to model the growth of the universe". A more accurate phrasing would be that the researchers have proposed a modified model. Whether their proposal is valid remains to be seen as other researchers in the field check their work.
I've always felt that phys.org is a reliable, less-sensationalized source for interesting science articles. Is it common for them to "make claims that go way beyond what the paper justifies"?
> Is it common for them to "make claims that go way beyond what the paper justifies"?
I've seen it enough times that it doesn't surprise me.
This is actually a pretty well known, but not generally accepted alternative theory of dark energy called backreaction https://en.wikipedia.org/wiki/Back-reaction#Cosmology
> In 1998, two independent teams of astronomers discovered that the expansion of the Universe is accelerating, consistent with the presence of a uniform contribution of Dark Energy. It was not recognized, however, that GEODEs could contribute in this way. With the corrected formalism, Croker and Weiner showed that if a fraction of the oldest stars collapsed into GEODEs, instead of black holes, their averaged contribution today would naturally produce the required uniform Dark Energy.
Hmmm, if this is true, then it means it's possible (in principle) to engineer the expansion rate of the universe by either preventing or causing the collapse of stars in a certain way. See the concept of Star Lifting: https://en.wikipedia.org/wiki/Star_lifting
Where did the dark energy come from? Before collapse these are just normal big stars, we cannot detect dark energy from them, but after explosion they suddenly become GEODE teemed with dark energy? I am a bit confused.
Dark energy is simply a theory with a classical hidden constant, which solves all the measurements and theories, but does most likely not exist.
Until a better theory explains more (like the Mond or a better gravity theory), it will stay with us for a while.
I'm reminded about Mach's principle . Its interesting to see a connection between local structure and then something more global.
Interesting to see a causal connection from local scopes to universal. I've been thinking about the converse. A fair number of theories of black holes, like the event horizon firewall, depend on interaction with cosmic background radiation. If fundamental properties of black holes are tied to the circumstances of the formation of the universe they live in, and those properties end up, and those properties are also tied to quantum gravity, that would mean there's an interesting connection between the three story of the universe's formation and it's fundamental laws. I realize I'm pretty deep into crackpot territory, even with all the if's, but it's at least a fun idea.
Does dark energy or dark matter box-in our way of thinking?
Have we actually proved scientifically there's a force or physical matter acting on something and it's not just being obscured from our vantage point?
Isn't dark energy/matter only visible at huge scales? Is there any pictures of dark energy or matter in any localized system? We didn't even know the correct color of Pluto until we got close, how could we know if something isn't actually there, or spacetime just twists and contorts for the sake of it without outside interaction/gravity acting on it?
Isn't there also a chance we're in a literal simulation of Plato's cave allegory until we see stuff up close? Not in the sense he meant it, but in the sense we're using assumptions/tools that involve inference. Wouldn't this risk assigning character/classifications to things that don't turn out to be true in the end?
-- In the case of dark matter, the answer is yes. Dark matter has been indirectly observed from the gravitational lensing of the dark matter shrouds surrounding galaxies - notably in situations where the shrouds of two colliding galaxies separate from the galaxies themselves. It's a "picture" as exact as many things astronomers have observed.
> in situations where the shrouds of two colliding galaxies separate from the galaxies themselves
That’s the first time I’ve read that. Sounds interesting, have you got any links?
Sounds like he's talking about the bullet cluster...
Although that's a colliding pair of galaxy clusters. I'm not currently aware of any examples of this effect being observed for just two galaxies.
Awesome, thanks for the link!
I only have up to university quantum (so no GR), but my understanding was that dark energy was believed to be equally distributed throughout all of space.
How would a GEODE produce such an effect?
When I was doing cosmology, the scales we were talking about were absurd - "model this galaxy cluster as a point" scales. So it seems conceivable to me that enough GEODEs, well-distributed, could look uniform on this scale.
I haven't done any physics past high school but isn't dark energy basically "Our equations don't work out, let's give our error term a name and act like it's all good"?
I'm sure this is oversimplified or outright wrong, can anyone correct me?
>"Our equations don't work out, let's give our error term a name and act like it's all good"
Not really. People make this argument for both dark energy and dark matter, and some people try to solve both of these (not necessarily at the same time) by trying to modify general relativity.
The problem is that we have observational evidence for both of them, and no alternative theory has come close to the level of accuracy and precision as GR has.
That isn't to say that we shouldn't be looking at potential alternative explanations to DM/DE, and the fact that there isn't scientific consensus on them at current doesn't mean that they're wrong (Wegener basically ended up losing his career over proposing continental drift was a thing), but at present, scientific consensus is overwhelmingly in favor of both DE and DM existing because we have more evidence for them than anything else, and the models that incorporate them are more accurate and precise than anything else.
That's not to say there isn't room for improvement in GR/SR/QM, etc. And there are some things where the math breaks down and we do sort of just shrug. Topically, black holes are among them - at least when it comes to the singularity and infinite density. In reality, the black holes we see out in the universe almost certainly don't have a point of infinite density.
In the high atmosphere, a bunch of floating bacteria have figured out physics-- kinetic energy, electromagnetism, momentum, electric potential, etc --but they have no notion of gravity, being high up and feeling the turbulent forces of air with a much greater strength than the pull downward.
Eventually, their astrophysicists say "Look, the cosmos behaves very similarly to how our models predict, except there seems to be an extra force or energy that pulls everything in one direction. If we just add one term to every potential energy equation we have, it all makes sense, but we have no idea where that energy actually comes from."
The reality is closer to:
We have a lot of observational evidence that the equations are very accurate.
But when we put all the mass we know about into the equations, the result of the equation doesn't match our observations.
Since we have a lot of evidence that the equations are very accurate, then it's more likely that there's more mass we haven't accounted for.
(at least for dark matter)
That's dark matter, dark energy is something else entirely, with much flimsier data and evidence.
whoops, I thought they said dark energy/matter
Dark energy has a bit of a weird history. Initially Einstein included it (or rather something like it) in his equations for general relativity because it fitted nicely and otherwise a static universe would eventually implode, only later it became clear that the universe was expanding and Einstein famously called this parameter his biggest mistake, except that in the current theory the value is very much not 0 (although annoyingly it's a lot closer to 0 than quantum physics says it ought to be, so much so that this has been called the worst prediction in physics).
So yeah, the debate about dark energy is responsible for 'Einstein's biggest mistake' and 'the worst prediction in physics'. Either way it wasn't simply a case of "let's just give our error term a fancy name and call it a day".
"Our equations don't work out, let's give our error term a name and act like it's all good"
Much more true for dark matter and still not really. The cumulative body of evidence suggests that this is due to real mass-energy out there.
You make it sound like the scientists are doing something shady, which is completely untrue... plenty of good science has been done on dark energy / dark matter. This is simply a prime example of how it looks when important observations aren't fully understood.
So that's a problem with your wording.
I was wondering the same thing. My thought was that if there are enough GEODEs evenly distributed, they would account for it.
My mental model of this is that if there were a lot of GEODEs created early, they explain acceleration (DE) with simple gravitational attraction. LET ME KNOW IF I'M CRAZY!
One consequence of this study is that the growth rate of the universe provides information about what happens to stars at the end of their lives. Astronomers typically assume that large stars form black holes when they die, but this is not the only possible outcome. In 1966, Erast Gliner, a young physicist at the Ioffe Physico-Technical Institute in Leningrad, proposed an alternative hypothesis that very large stars should collapse into what could now be called Generic Objects of Dark Energy (GEODEs). These appear to be black holes when viewed from the outside but, unlike black holes, they contain Dark Energy instead of a singularity.
A shower thought after watching some recent PBS Space Time videos: if the (hypothetical) inflaton field of the early universe is associated with certain high energy density conditions, could the interior of a black hole (specifically the region near what would be the singularity under vanilla general relativity) reproduce those conditions and return the inflaton field to the inflation-era state?
Related thought: what would it look like from the outside if a patch of the universe returned to inflation? Does it make any difference from the observer’s POV if this change occurs inside or outside an event horizon?
Dark energy is a placeholder word to explain a phenomena scientists can't understand. Before Einstein they didn't know what the medium was for light waves. For water waves it is obviously water, what does light use to travel through? They created this phrase called "ether" light traveled through "ether". Dark energy and dark matter are exactly the same case.
Physicists don't actually call it dark energy, that word is for journalists. Physicists call it the cosmological constant.
For the last few days I've been trying to make as many associations as possible between (the big bang, the progression of the universe, and the end of the universe) and a black hole's progression. For some reason this makes me think yet again that the universe might be inside a black hole.
You're not the only one that has proposed this idea :)
Is that black hole inside another black hole?
turtles all the way down ....
What is meant here by "exotic crust" of the black hole. I assume it's something inside the event horizon
Near the boundary anyway. The headline is poorly worded, but the argument is that some of these objects aren't black holes at all. I don't think the "event horizon" term really applies to GEODEs. I also don't think they have too clear an understanding of what this crust would consist of, or if they do the article fails to mention it.
These objects would no longer be black holes, and would not have event horizons.
LIGO and other detects are not able to tell the difference. Black holes are assumed based on the mass, event horizons have never been detected, just [mathematically] assumed.
Does this not count as detection of an event horizon? Or is it just considered strong circumstantial evidence?
No, that is not evidence of an event horizon, it's not circumstantial evidence either because it pre-supposes the existence of one.
Despite the name, no event horizon was directly photographed. Partly because event horizon's are not actually visible LOL.
The photo taken can not distinguish between a true black hole, and a super massive object of the same mass.
We just assume that if you have that much mass there is no force that is capable of preventing it from becoming a black hole.
But, that's not proof that such a force does not exist.
Generic Objects of Dark Energy... Is this exotic matter with negative energy?
Just a clarification, the article states that GEODEs are not black holes, they just look similar from the outside since they are almost dense enough but not quite.
Anyone have access to E.B. Gliner's 1966 paper describing a GEODE?
I think this is it: http://www.jetp.ac.ru/cgi-bin/dn/e_022_02_0378.pdf
Topically, black holes are among them - at least when it comes to the singularity and infinite density - https://www.guccibagshk.com/replica-gucci-handbags