20 ms·

Cosmologist claims Universe may not be expanding

58 points by xd 13y ago

kghose 13y ago
I found this a rather good explanation (well written article). My favorite para is in the closer: "Others say that Wetterich’s interpretation could help to keep cosmologists from becoming entrenched in one way of thinking." I like this attitude. Science is about playing with hypotheses and trying out new ideas. The most important thing for me is for my viewpoint to be zipped around and turned on its head - just for fun. I think it makes the mind more nimble. Also, could a physicsy person elaborate a bit more on why we can't test increasing mass? Is it in the same class as 'we can't actually measure the increasing distance in the cosmic expansion, because locally, nothing is expanding'? Thanks
- Le_SDT 13y ago
  I am not sure to understand your question, it has been said in the article that if everything's mass was increasing proportionally we could not test it since we have to compare two things to see an increase. But I am no physicist I don't know if there would be another way actually to test mass increase without comparing two objects.
  - hga 13y ago
    What about a test over time? I'd guess the time scale required is a bit long....
    - Le_SDT 13y ago
      I know what you mean. But an object of 1Kg today would still be 1Kg in 1000 years since everything gained mass (that includes what you are using to calculate the mass)... but like I said in my first response I am in no way the best person to give an answer to this question (still I lost karma :P). It is just a subject I find interesting!
      - marcosdumay 13y ago
        > But an object of 1Kg today would still be 1Kg in 1000 years since everything gained mass Yes, but a 1m rule will get longer if everything gained mass, won't it? (I mean, the meter will get shorter, and the atoms should get bigger, even after compensating for the change on meter. Is there something I'm missing?)
- Zikes 13y ago
  Mass is relative, measured by a standard object of arbitrary mass to which we've given a value. What we consider a "kilogram" is determined by one specific object sitting in a vault somewhere, and if that object were to be halved or doubled without us realizing it, then the official value of the kilogram would be similarly halved or doubled. Since we determine the mass of things by comparing them against that object, if everything in the universe changes mass in precisely the same way at precisely the same rate then we would have no way of knowing. All we can do is compare them with each other, and relative to each other the masses would remain the same.
  - contingencies 13y ago
    If time is relative, and mass is relative, and space is relative ... then what's the point of science?
  - ollysb 13y ago
    Could you give an example of something that can be measured absolutely?
    - chimeracoder 13y ago
      I'm not sure if this is the answer you're looking for, but degrees/radians are considered dimensionless in that they're defined by the ratio of two lengths. There's no way for the value of 1 radian to magically 'double' without causing π radians to magically amount to a full circle, which would seriously warp Euclidean geometry as we know it.
  - onezeno 13y ago
    I didn't understand this part of the article. We can measure the mass difference because, according to the theory, that is what we are measuring when we see a redshift. Should we not be able to measure the redshift in a laboratory, given equipment of high sensitivity and a large enough time delta for the change to register? Edit: Looks like Le_SDT beat me to it :)
    - 13y ago
- glogla 13y ago
  This remind me of the "gravity is entropy because everything is holographic" hypothesis made by physicist whose name I can't remember, when he had his passport stolen and had to wait in Paris for a week before they make him a new one :)
aneth4 13y ago
I became extremely fascinated by null cosmology, which explains red shift as the result of light losing energy to [background] radiation as it travels. That [background] radiation becomes essential in the cosmological cycle involving the endless birth and death of galaxies via black holes. While the theory seems to be collecting dust, I've not found anything to fully discredit it. http://www.nullphysics.com/pages_cosmology.php http://www.nullphysics.com/pages_cosmology.php Update: I'm writing from my iPhone and haven't looked into this in a while. When I said radiation I was referring to low energy cosmic microwave background, which is easily scattered. Read the FAQ if you have questions. I do not claim to fully represent the theory in the above paragraph.
- danbruc 13y ago
  [...] light losing energy to radiation [...] Light is radiation. So we are are talking about radiating radiation...
- lisper 13y ago
  > light losing energy to radiation as it travels > I've not found anything to fully discredit it Well, for starters, there's the minor problem of light never having actually been observed to lose energy as it travels. If light loses energy to radiation as it travels, then this radiation should be detectable. Where is it? Then there's the slightly less minor problem of having to rewrite all the known laws of physics from scratch, starting with electromagnetism and quantum mechanics. (I presume that you're not going to toss out conservation of energy because the whole point of the exercise it to account for the cosmological red shift, yes?) But other than that, I can't think of anything that would discredit it either.
  - aneth4 13y ago
    At the very least you should probably look at the theory before claiming to discredit it. The "radiation" is lower energy microwaves which are quickly scattered. As for your other questions, these are addressed in the theory. How about reading that first.
    - 13y ago
omegant 13y ago
Is it possible to difereciate between a expanding universe due to the big bang?, or an expanding universe due to this part of universe coming out of a more compressed stream (like coming out of a 3d venturi tube). I don't know if that makes sense. And if red shifted light is not red due to the expansion, but due to some kind interaction with dark matter?. I suppose this questions are dumb, and surely they have been discarded and replyied lotsof times, but never found that info. Does any body know a place were this kind of thinks are explained?
- cpleppert 13y ago
  I would say not really! The real problem isn't the effect can't be replicated it is that replacing cosmological expansion with something else requires the something else to exactly mimic all the other things we can observe about the universe. Dark matter is a great example. Due to gravitational lensing this can mimic directly the redshift we can observe. But then you have to explain how all this dark matter is distributed(not to mention created) in a way that doesn't mimic cosmic expansion in one part of the sky but everywhere at once. I found the teaching company course on cosmology(from what I saw of it) to be absolutely fantastic as a general introduction: http://www.thegreatcourses.com/tgc/courses/course_detail.aspx?cid=1830 http://www.thegreatcourses.com/tgc/courses/course_detail.asp...
  - omegant 13y ago
    Thank you very interesting, I´ll check it. Some times I get the feeling that somehow in cosmology there is some kind of advanced modern day epicycle squeme that is giving correct predictions but is not really what is out there. I just love to follow the advances in cosmology.
cpleppert 13y ago
I'm not sure I understand how this effect actually works. Cosmological redshift isn't due to galaxies moving away from us but the expansion of the universe occurring underneath light as it travels in an expanding universe. So replacing velocity with mass increases doesn't actually work as far as I can tell because the mechanisms aren't equivalent. You actually need some physical mechanism that produces this mass increase over time that happens to be exactly the same as that observed by cosmological redshift.
- cma 13y ago
  Are you sure about that? There is blueshift and redshift as you move towards or away from light sources. While the speed of light doesn't ever change no matter your reference frame, the frequency/wavelength indeed does.
  - cpleppert 13y ago
    I'm not sure we disagree. Cosmological redshift doesn't rule out additional changes in observed frequency that compound due to the ones we observe by the expansion of the universe. Hubble originally explained his observed redshifts in other galaxies entirely due to the doppler effect but changed his mind when he observed a correlation between the distance of a receding galaxy and its redshift. If the doppler effect could explain cosmological redshift then galaxies would seem to have to 'know' how far they were from the observer! If you go back and see the original 46 galaxies that hubble plotted by comparing observed redshift to the distance hubble had observed you can see considerable 'scatter' in the observations. This scatter is due to the Doppler effect. The velocity distance relationship in hubble's law isn't due to the doppler effect but a model that relates recessional velocity to the general expansion of the universe.
fargolime 13y ago
A much simpler explanation that adds no new assumptions and shows that space itself need not be expanding to explain what we observe is at http://finbot.wordpress.com/2008/03/06/expanding-space-obviated/ http://finbot.wordpress.com/2008/03/06/expanding-space-obvia.... It also solves the flatness problem, a major problem in cosmology.
- phaemon 13y ago
  That page doesn't actually explain why the galaxies appear to be moving away from each other.
  - fargolime 13y ago
    Physics doesn't answer why on anything. For example, why does gravity hold me to my chair? Nobody knows. Physics explains only how gravity affects things.
    - phaemon 13y ago
      Of course it does. Gravity holds you to that chair because the mass of the earth is attracting the mass of you. This tells us that if you were sat on a chair on the moon, the hold on you would be less. Theory with prediction, see? That's what that page doesn't answer: Why do the galaxies appear to be moving away from us?
      - fargolime 13y ago
        > Gravity holds you to that chair... You've explained how the effects of gravity can be predicted, not why gravity holds me to the chair. What is the mechanism that causes the gravity that holds me to the chair? Is it undiscovered gravitons, or what? Likewise you wish to know the mechanism that causes the galaxies to move away from one another. We already know that objects have freedom of movement in space. So why the galaxies appear to be moving away from us can be simply because they are moving away from us. There doesn't need to be a deeper explanation. If you would like to explain the observation using the expanding space paradigm then tell me why space itself is expanding, without saying "it just is". Tell me the mechanism by which it expands. Otherwise you've answered one why question by making an assumption that is left wanting for its own explanation as to why. You've traded one problem for another.
gizmo686 13y ago
Neat idea. If/when the paper gets published I hope I stumble upon it. One thing that I don't get with the hypothesis is how it deals with conservation of energy. Its well understood that mass is a form of energy, so if atoms were to simply grow in mass, then that would either require some other energy source, or violate conservation of energy. Obviously, this is a huge an obvious problem that should preclude this hypothesis from serious consideration. The fact that this does not do so suggests to me that this issue is somehow resolved within the theory.
- JonnieCache 13y ago
  Consider yourself stumbled. The paper is here: http://arxiv.org/abs/1303.6878/ http://arxiv.org/abs/1303.6878/
- rprospero 13y ago
  Well, it doesn't have any more of a conservation of energy issue than the current theory already does. Loosely speaking, cosmology currently states that the acceleration of the galaxies away from each other comes from dark energy. However, if we don't use that dark energy for pushing the galaxies around, we should have enough left over to increase the rest mass of every particle in the universe. Neither theory has a good explanation as to what this dark energy is, but both theories have it.
swombat 13y ago
The article contradicts itself... The idea may be plausible, but it comes with a big problem: it can't be tested. Mass is what’s known as a dimensional quantity, and can be measured only relative to something else. For instance, every mass on Earth is ultimately determined relative to a kilogram standard that sits in a vault on the outskirts of Paris, at the International Bureau of Weights and Measures. If the mass of everything — including the official kilogramme — has been growing proportionally over time, there could be no way to find out. The way to measure the increase in weight is actually described in the article itself: observe a shift in absorption/emission spectra. Of course, such a shift may be infinitesimally small and undetectable over short timespans. However, this is precisely the sort of theory (like all the neutrino theories, for example) for which you set up a very long-term experiment. The experiment is simple: measure the absorption spectrum of hydrogen in space with an extreme level of accuracy and a bajillion measurements (that's the scientific term). Record that for posterity. In 10 years (the equivalent of observing something 10 light-years away), repeat the measurement. Keep doing this until you either observe a shift or have made a measurement that based on observations of the real world (i.e. galaxies drifting away). The experiment might take 100, 1000 or even 10'000 years, but eventually we'd have an answer! UPDATE: Heh. isomorphic points out that this is actually not feasible given that it's impossible to make these measurements accurately without relying on mass being constant... So much for this. retracts
- isomorphic 13y ago
  How do we measure frequency (or time) precisely if the emission spectra are changing?
  - swombat 13y ago
    We'd need to calibrate against some kind of effect that is more heavily influenced by forces other than mass. You're right actually, that might be a lot more tricky than it seems on the surface. If we're left with the Weak and Strong forces to play with, that makes experimental design pretty difficult (and perhaps impossible). Hmm...
    - 13y ago
xanderstrike 13y ago
I don't like how similar the words "Cosmology" and "Cosmetology" are. I was very confused upon first reading the title of this article.
- kenj0418 13y ago
  My cosmetologist told me I was gaining mass too. She recommended a diet though - not further research.
  - drzaiusapelord 13y ago
    Ah yes, I've also been to the "Girl, your ass is gettin big" symposium.
- mtdewcmu 13y ago
  It's interesting that you clicked on it anyway.
vital 13y ago
Say, you are deep inside a huge forest with your eyes closed all the time. Then, you blink once. Can you from the information received via that blink deduce if the forest is expanding or shrinking? Did it have a big bang or a small one? Just asking... On the other hand given the situation one needs to be extremely delusional and detached from any sense of reality to consider any bang fantasy seriously.
Steuard 13y ago
The research here is based on the interesting premise that "the masses of electrons and protons were smaller" in the early universe, leading to different emission spectra that we have thus far interpreted as an expanding universe. I have not read the original research article in detail, but it is my impression that all masses would have to scale at the same rate in order to avoid changes in fundamental physical behaviors. (This seems consistent with the article's premise that the effect comes from some sort of field redefinition in the Lagrangian.) As a particle physicist, I see this as highly unlikely. The first big obstacle that I see for such a theory to overcome is that electrons and protons get their mass from entirely different sources. As far as we know, electrons are fundamental particles: their mass is a fundamental parameter of the theory (presumably encoded as the electron coupling to the Higgs boson). But although protons are composed of three fundamental particles (two up quarks and a down quark), the quarks' fundamental masses are only a tiny fraction of the total proton mass. Instead, the vast majority of a proton's mass results from complicated non-linear QCD (strong nuclear force) self-interactions that draw on both the fundamental masses and things like the QCD interaction strength. We've had some success at simulating those QCD interactions in recent years, but there's no known way of just reading off the proton mass from a fundamental equation. So for the idea behind this proposal to work, it seems to me that both the fundamental particle masses and these complicated QCD effective masses would have to scale completely in parallel. I'm not at all clear on whether a field redefinition (as proposed here) would work that way. Maybe it would be more natural than it seems, but that's my first big concern with the proposal.
Tcepsa 13y ago
It seems to me that this should be able to be tested by checking whether the gravitational force between two objects of a given mass increases over time. If it does, then their mass has increased. If it doesn't, then their mass has not. (Of course, if the gravitational constant is correspondingly decreasing then this idea goes out the window.)

58 points by xd 13y ago

I found this a rather good explanation (well written article). My favorite para is in the closer: "Others say that Wetterich’s interpretation could help to keep cosmologists from becoming entrenched in one way of thinking." I like this attitude. Science is about playing with hypotheses and trying out new ideas. The most important thing for me is for my viewpoint to be zipped around and turned on its head - just for fun. I think it makes the mind more nimble. Also, could a physicsy person elaborate a bit more on why we can't test increasing mass? Is it in the same class as 'we can't actually measure the increasing distance in the cosmic expansion, because locally, nothing is expanding'? Thanks

Le_SDT 13y ago
I am not sure to understand your question, it has been said in the article that if everything's mass was increasing proportionally we could not test it since we have to compare two things to see an increase. But I am no physicist I don't know if there would be another way actually to test mass increase without comparing two objects.
- hga 13y ago
  What about a test over time? I'd guess the time scale required is a bit long....
  - Le_SDT 13y ago
    I know what you mean. But an object of 1Kg today would still be 1Kg in 1000 years since everything gained mass (that includes what you are using to calculate the mass)... but like I said in my first response I am in no way the best person to give an answer to this question (still I lost karma :P). It is just a subject I find interesting!
    - marcosdumay 13y ago
      > But an object of 1Kg today would still be 1Kg in 1000 years since everything gained mass Yes, but a 1m rule will get longer if everything gained mass, won't it? (I mean, the meter will get shorter, and the atoms should get bigger, even after compensating for the change on meter. Is there something I'm missing?)
Zikes 13y ago
Mass is relative, measured by a standard object of arbitrary mass to which we've given a value. What we consider a "kilogram" is determined by one specific object sitting in a vault somewhere, and if that object were to be halved or doubled without us realizing it, then the official value of the kilogram would be similarly halved or doubled. Since we determine the mass of things by comparing them against that object, if everything in the universe changes mass in precisely the same way at precisely the same rate then we would have no way of knowing. All we can do is compare them with each other, and relative to each other the masses would remain the same.
- contingencies 13y ago
  If time is relative, and mass is relative, and space is relative ... then what's the point of science?
- ollysb 13y ago
  Could you give an example of something that can be measured absolutely?
  - chimeracoder 13y ago
    I'm not sure if this is the answer you're looking for, but degrees/radians are considered dimensionless in that they're defined by the ratio of two lengths. There's no way for the value of 1 radian to magically 'double' without causing π radians to magically amount to a full circle, which would seriously warp Euclidean geometry as we know it.
- onezeno 13y ago
  I didn't understand this part of the article. We can measure the mass difference because, according to the theory, that is what we are measuring when we see a redshift. Should we not be able to measure the redshift in a laboratory, given equipment of high sensitivity and a large enough time delta for the change to register? Edit: Looks like Le_SDT beat me to it :)
  - 13y ago
glogla 13y ago
This remind me of the "gravity is entropy because everything is holographic" hypothesis made by physicist whose name I can't remember, when he had his passport stolen and had to wait in Paris for a week before they make him a new one :)

aneth4 13y ago

I became extremely fascinated by null cosmology, which explains red shift as the result of light losing energy to [background] radiation as it travels. That [background] radiation becomes essential in the cosmological cycle involving the endless birth and death of galaxies via black holes. While the theory seems to be collecting dust, I've not found anything to fully discredit it. http://www.nullphysics.com/pages_cosmology.php http://www.nullphysics.com/pages_cosmology.php Update: I'm writing from my iPhone and haven't looked into this in a while. When I said radiation I was referring to low energy cosmic microwave background, which is easily scattered. Read the FAQ if you have questions. I do not claim to fully represent the theory in the above paragraph.

danbruc 13y ago
[...] light losing energy to radiation [...] Light is radiation. So we are are talking about radiating radiation...
lisper 13y ago
> light losing energy to radiation as it travels > I've not found anything to fully discredit it Well, for starters, there's the minor problem of light never having actually been observed to lose energy as it travels. If light loses energy to radiation as it travels, then this radiation should be detectable. Where is it? Then there's the slightly less minor problem of having to rewrite all the known laws of physics from scratch, starting with electromagnetism and quantum mechanics. (I presume that you're not going to toss out conservation of energy because the whole point of the exercise it to account for the cosmological red shift, yes?) But other than that, I can't think of anything that would discredit it either.
- aneth4 13y ago
  At the very least you should probably look at the theory before claiming to discredit it. The "radiation" is lower energy microwaves which are quickly scattered. As for your other questions, these are addressed in the theory. How about reading that first.
  - 13y ago

omegant 13y ago

Is it possible to difereciate between a expanding universe due to the big bang?, or an expanding universe due to this part of universe coming out of a more compressed stream (like coming out of a 3d venturi tube). I don't know if that makes sense. And if red shifted light is not red due to the expansion, but due to some kind interaction with dark matter?. I suppose this questions are dumb, and surely they have been discarded and replyied lotsof times, but never found that info. Does any body know a place were this kind of thinks are explained?

cpleppert 13y ago
I would say not really! The real problem isn't the effect can't be replicated it is that replacing cosmological expansion with something else requires the something else to exactly mimic all the other things we can observe about the universe. Dark matter is a great example. Due to gravitational lensing this can mimic directly the redshift we can observe. But then you have to explain how all this dark matter is distributed(not to mention created) in a way that doesn't mimic cosmic expansion in one part of the sky but everywhere at once. I found the teaching company course on cosmology(from what I saw of it) to be absolutely fantastic as a general introduction: http://www.thegreatcourses.com/tgc/courses/course_detail.aspx?cid=1830 http://www.thegreatcourses.com/tgc/courses/course_detail.asp...
- omegant 13y ago
  Thank you very interesting, I´ll check it. Some times I get the feeling that somehow in cosmology there is some kind of advanced modern day epicycle squeme that is giving correct predictions but is not really what is out there. I just love to follow the advances in cosmology.

cpleppert 13y ago

I'm not sure I understand how this effect actually works. Cosmological redshift isn't due to galaxies moving away from us but the expansion of the universe occurring underneath light as it travels in an expanding universe. So replacing velocity with mass increases doesn't actually work as far as I can tell because the mechanisms aren't equivalent. You actually need some physical mechanism that produces this mass increase over time that happens to be exactly the same as that observed by cosmological redshift.

cma 13y ago
Are you sure about that? There is blueshift and redshift as you move towards or away from light sources. While the speed of light doesn't ever change no matter your reference frame, the frequency/wavelength indeed does.
- cpleppert 13y ago
  I'm not sure we disagree. Cosmological redshift doesn't rule out additional changes in observed frequency that compound due to the ones we observe by the expansion of the universe. Hubble originally explained his observed redshifts in other galaxies entirely due to the doppler effect but changed his mind when he observed a correlation between the distance of a receding galaxy and its redshift. If the doppler effect could explain cosmological redshift then galaxies would seem to have to 'know' how far they were from the observer! If you go back and see the original 46 galaxies that hubble plotted by comparing observed redshift to the distance hubble had observed you can see considerable 'scatter' in the observations. This scatter is due to the Doppler effect. The velocity distance relationship in hubble's law isn't due to the doppler effect but a model that relates recessional velocity to the general expansion of the universe.

fargolime 13y ago

A much simpler explanation that adds no new assumptions and shows that space itself need not be expanding to explain what we observe is at http://finbot.wordpress.com/2008/03/06/expanding-space-obviated/ http://finbot.wordpress.com/2008/03/06/expanding-space-obvia.... It also solves the flatness problem, a major problem in cosmology.

phaemon 13y ago
That page doesn't actually explain why the galaxies appear to be moving away from each other.
- fargolime 13y ago
  Physics doesn't answer why on anything. For example, why does gravity hold me to my chair? Nobody knows. Physics explains only how gravity affects things.
  - phaemon 13y ago
    Of course it does. Gravity holds you to that chair because the mass of the earth is attracting the mass of you. This tells us that if you were sat on a chair on the moon, the hold on you would be less. Theory with prediction, see? That's what that page doesn't answer: Why do the galaxies appear to be moving away from us?
    - fargolime 13y ago
      > Gravity holds you to that chair... You've explained how the effects of gravity can be predicted, not why gravity holds me to the chair. What is the mechanism that causes the gravity that holds me to the chair? Is it undiscovered gravitons, or what? Likewise you wish to know the mechanism that causes the galaxies to move away from one another. We already know that objects have freedom of movement in space. So why the galaxies appear to be moving away from us can be simply because they are moving away from us. There doesn't need to be a deeper explanation. If you would like to explain the observation using the expanding space paradigm then tell me why space itself is expanding, without saying "it just is". Tell me the mechanism by which it expands. Otherwise you've answered one why question by making an assumption that is left wanting for its own explanation as to why. You've traded one problem for another.

gizmo686 13y ago

Neat idea. If/when the paper gets published I hope I stumble upon it. One thing that I don't get with the hypothesis is how it deals with conservation of energy. Its well understood that mass is a form of energy, so if atoms were to simply grow in mass, then that would either require some other energy source, or violate conservation of energy. Obviously, this is a huge an obvious problem that should preclude this hypothesis from serious consideration. The fact that this does not do so suggests to me that this issue is somehow resolved within the theory.

JonnieCache 13y ago
Consider yourself stumbled. The paper is here: http://arxiv.org/abs/1303.6878/ http://arxiv.org/abs/1303.6878/
rprospero 13y ago
Well, it doesn't have any more of a conservation of energy issue than the current theory already does. Loosely speaking, cosmology currently states that the acceleration of the galaxies away from each other comes from dark energy. However, if we don't use that dark energy for pushing the galaxies around, we should have enough left over to increase the rest mass of every particle in the universe. Neither theory has a good explanation as to what this dark energy is, but both theories have it.

swombat 13y ago

The article contradicts itself... The idea may be plausible, but it comes with a big problem: it can't be tested. Mass is what’s known as a dimensional quantity, and can be measured only relative to something else. For instance, every mass on Earth is ultimately determined relative to a kilogram standard that sits in a vault on the outskirts of Paris, at the International Bureau of Weights and Measures. If the mass of everything — including the official kilogramme — has been growing proportionally over time, there could be no way to find out. The way to measure the increase in weight is actually described in the article itself: observe a shift in absorption/emission spectra. Of course, such a shift may be infinitesimally small and undetectable over short timespans. However, this is precisely the sort of theory (like all the neutrino theories, for example) for which you set up a very long-term experiment. The experiment is simple: measure the absorption spectrum of hydrogen in space with an extreme level of accuracy and a bajillion measurements (that's the scientific term). Record that for posterity. In 10 years (the equivalent of observing something 10 light-years away), repeat the measurement. Keep doing this until you either observe a shift or have made a measurement that based on observations of the real world (i.e. galaxies drifting away). The experiment might take 100, 1000 or even 10'000 years, but eventually we'd have an answer! UPDATE: Heh. isomorphic points out that this is actually not feasible given that it's impossible to make these measurements accurately without relying on mass being constant... So much for this. retracts

isomorphic 13y ago
How do we measure frequency (or time) precisely if the emission spectra are changing?
- swombat 13y ago
  We'd need to calibrate against some kind of effect that is more heavily influenced by forces other than mass. You're right actually, that might be a lot more tricky than it seems on the surface. If we're left with the Weak and Strong forces to play with, that makes experimental design pretty difficult (and perhaps impossible). Hmm...
  - 13y ago

xanderstrike 13y ago

I don't like how similar the words "Cosmology" and "Cosmetology" are. I was very confused upon first reading the title of this article.

kenj0418 13y ago
My cosmetologist told me I was gaining mass too. She recommended a diet though - not further research.
- drzaiusapelord 13y ago
  Ah yes, I've also been to the "Girl, your ass is gettin big" symposium.
mtdewcmu 13y ago
It's interesting that you clicked on it anyway.

vital 13y ago

Say, you are deep inside a huge forest with your eyes closed all the time. Then, you blink once. Can you from the information received via that blink deduce if the forest is expanding or shrinking? Did it have a big bang or a small one? Just asking... On the other hand given the situation one needs to be extremely delusional and detached from any sense of reality to consider any bang fantasy seriously.

Steuard 13y ago

The research here is based on the interesting premise that "the masses of electrons and protons were smaller" in the early universe, leading to different emission spectra that we have thus far interpreted as an expanding universe. I have not read the original research article in detail, but it is my impression that all masses would have to scale at the same rate in order to avoid changes in fundamental physical behaviors. (This seems consistent with the article's premise that the effect comes from some sort of field redefinition in the Lagrangian.) As a particle physicist, I see this as highly unlikely. The first big obstacle that I see for such a theory to overcome is that electrons and protons get their mass from entirely different sources. As far as we know, electrons are fundamental particles: their mass is a fundamental parameter of the theory (presumably encoded as the electron coupling to the Higgs boson). But although protons are composed of three fundamental particles (two up quarks and a down quark), the quarks' fundamental masses are only a tiny fraction of the total proton mass. Instead, the vast majority of a proton's mass results from complicated non-linear QCD (strong nuclear force) self-interactions that draw on both the fundamental masses and things like the QCD interaction strength. We've had some success at simulating those QCD interactions in recent years, but there's no known way of just reading off the proton mass from a fundamental equation. So for the idea behind this proposal to work, it seems to me that both the fundamental particle masses and these complicated QCD effective masses would have to scale completely in parallel. I'm not at all clear on whether a field redefinition (as proposed here) would work that way. Maybe it would be more natural than it seems, but that's my first big concern with the proposal.

Tcepsa 13y ago

It seems to me that this should be able to be tested by checking whether the gravitational force between two objects of a given mass increases over time. If it does, then their mass has increased. If it doesn't, then their mass has not. (Of course, if the gravitational constant is correspondingly decreasing then this idea goes out the window.)