Cosmologist claims Universe may not be expanding

http://www.nature.com/news/cosmologist-claims-universe-may-not-be-expanding-1.13379

by xd • 13 years ago

58 61 13 years ago

kghose• 13 years 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_SDT2• 13 years 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• 13 years ago

What about a test over time?

I'd guess the time scale required is a bit long....

Zikes2• 13 years 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• 13 years ago

If time is relative, and mass is relative, and space is relative ... then what's the point of science?

ollysb• 13 years ago

Could you give an example of something that can be measured absolutely?

onezeno• 13 years 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 :)

roc• 13 years ago

What about astronomical objects that are distorted by gravitational lensing? Even if the mass of everything is increasing, couldn't we still note any otherwise-anomalous universal change in the presentation of many such systems?

glogla• 13 years 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 :)

aneth44• 13 years 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

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• 13 years ago

[...] light losing energy to radiation [...]

Light is radiation. So we are are talking about radiating radiation...

lisper2• 13 years 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.

aneth44• 13 years 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.

Florin_Andrei• 13 years ago

red shift as the result of light losing energy to radiation as it travels

Yet another incarnation of the old so-called "tired light" idea. Just google it. Or start here:

http://en.wikipedia.org/wiki/Tired_light

You run very quickly into all sorts of problems once you assume light gets "tired" as it travels.

While the theory seems to be collecting dust, I've not found anything to fully discredit it.

Start here:

http://hep.ucsb.edu/people/bmonreal/Null_Physics_Review.html

I've not found anything

Odd, since a simple google search for "null physics" returns several strong rebuttals on literally the first page. Maybe you haven't actually looked?

EDIT: Oh boy, this "null physics" thing shows all the signs of crackpot "science". The author working on it "for decades". Studies physics, but becomes "disenchanted" and switches to engineering. Is a "visiting scientist" at a "university" nobody has heard about. His theory is not published in journals because journals "help the establishment". Compares himself with Ben Franklin, Bill Gates, and Faraday. The only thing he's published is this book; no articles, no nothing. On and on and on. There are literally hundreds of woo peddlers out there like this guy, and all of them are made in the exact same image.

http://www.ourundiscovereduniverse.com/pages_author.php

That page lit up the pseudo-science detector, firing up another alarm at each and every sentence. The only thing amazing about this guy is how well he fits the stereotype. It's surreal.

Brilliant quote from a link I posted above:

Much crackpot literature gives the impression of an old grudge being played out: "I learned quantum mechanics from some book that made me feel dumb; thinking up Quantum Aethro-Gyromechanics on my own made me feel smart." The sad thing is, this illustrates a sort of can-do spirit that's admirable in fields other than science. Stubbornly defying a swimming coach ("You'll never be an Olympian, kid") or editor ("Your manuscript 'Harry Potter and the Philosopher's Stone' does not meet our needs at this time") or venture capitalist ("Forget it, Mr. Fred Smith, there is no market for nationwide express delivery"), turns out to actually work sometimes; the people who pull this off are praised as heros. But science isn't like that. Whereas coaches, editors, and entrepreneurs have to rely on (fallible, human) gut instinct for many of their evaluations, science relies on explicit, rigorous go/no-go tests. I think that the dissonance between the value of stick-to-it-iveness in entrepreneurship, versus the value of mathematical rigor in science, is the root cause of a lot of physics crackpottery.

aneth44• 13 years ago

I agree it seems like pseudoscience.

Actually I did look for information to discredit the theory about a year ago. There appears to be more out there now. At that time I did lose interest after reading about problems with tired light.

Regardless, it's an interesting theory from a philosophical perspective, even if it has major problems.

aneth44• 13 years ago

That UCSB review is extremely amusing as is the other one linked.

Thank you for those.

http://hep.ucsb.edu/people/bmonreal/Null_Physics_Review.html

http://homepages.ihug.co.nz/~fiski/ouu_review.html

lukifer• 13 years ago

Honest question: how you do you prevent your pseudo-science detector from succumbing to confirmation bias? I'm willing to wager that if you gathered up every single so-called crackpot on the planet and looked at their ideas in 50 years, there's at least a single person that will have turned out to be right.

Love the quote, by the way.

omegant2• 13 years 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?

cpleppert5• 13 years 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.asp...

omegant2• 13 years 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.

cpleppert5• 13 years 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• 13 years 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.

cpleppert5• 13 years 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.

fargolime8• 13 years 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-obvia.... It also solves the flatness problem, a major problem in cosmology.

phaemon5• 13 years ago

That page doesn't actually explain why the galaxies appear to be moving away from each other.

fargolime8• 13 years 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.

cpleppert5• 13 years ago

That doesn't make sense at all. The whole point of cosmological expansion is to explain relations between redshift and distance. That is what was suggested to Hubble back in the 1920's when he plotted this relationship. If you don't hypothesize any global relationship between these two values then every galaxy just happens to have a larger velocity depending on distance. The link doesn't explain why this would happen.

I'm a little concerned about some of the other stated problems that the 'theory' tries to solve. For instance,

>They believe that sufficiently large objects stretch or break apart, and proffer explanations as to why smaller objects, like galaxies, don’t do likewise.

Spacetime isn't an object! I think gravity is a great explanation why galaxies don't break apart..

fargolime8• 13 years ago

The link doesn't explain why this would happen.

Physics doesn't answer why on anything. Hubble's observations still apply. He didn't try to explain why the observational data is what it is.

Spacetime isn't an object!

Where was the opposite claimed? I don't see it.

I think gravity is a great explanation why galaxies don't break apart..

That's fine, but you still have a flatness problem that also needs an explanation. If you don't need your explanation (by obviating the expanding space paradigm) the flatness problem vanishes.

gizmo686• 13 years 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• 13 years ago

Consider yourself stumbled. The paper is here: http://arxiv.org/abs/1303.6878/

rprospero• 13 years 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.

swombat2• 13 years 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• 13 years ago

How do we measure frequency (or time) precisely if the emission spectra are changing?

swombat2• 13 years 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...

aufreak3• 13 years ago

Haven't read the paper, but another problem that occurred to me - if the mass of all particles is increasing over time, over whose time is it increasing. The rate of progress of time depends on the frame of reference, right?

lcedp• 13 years ago

If the mass of everything — including the official kilogramme — has been growing proportionally over time, there could be no way to find out.

?! Actually the gravity would increase. Quadraticly, cause you mass would increase and Earth's as well.

xanderstrike• 13 years 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• 13 years ago

My cosmetologist told me I was gaining mass too. She recommended a diet though - not further research.

drzaiusapelord• 13 years ago

Ah yes, I've also been to the "Girl, your ass is gettin big" symposium.

mtdewcmu• 13 years ago

It's interesting that you clicked on it anyway.

vital• 13 years 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• 13 years 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• 13 years 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.)

Cosmologist claims Universe may not be expanding

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