

Study finds possible alternative explanation for dark energy - afthonos
http://phys.org/news/2014-12-alternative-explanation-dark-energy.html

======
btilly
This should be subtitled, "A biologist opines on cosmology and fails to
understand physics."

They have an alternate theory of relativity that they point out agrees with
the usual one for many types of data. However their theory does not include a
theory of gravity, and an extension of their theory to a theory of gravity
seems unlikely to give us some of the odder confirmed effects of general
relativity, like frame dragging.

Until you have an actual theory of gravity that matches those experiments (and
not just special relativity), you can wave your hands all you want, but you
have no real business discussing things like why cosmologists believe that a
contribution from dark energy to the stress energy tensor creates the
acceleration of the universe that is the simplest explanation of current
observation.

See [http://en.wikipedia.org/wiki/Lambda-
CDM_model](http://en.wikipedia.org/wiki/Lambda-CDM_model) for a random
starting place that can actually inform you.

~~~
PhantomGremlin
Maybe this article isn't the answer to the mysteries of the Universe. Maybe
the article is complete bullshit. But IMO right now the reality is that
physicists don't really have a fucking clue about how 95% of the universe
works. E.g. consider this[1], yes I know it's just Wikipedia, but the general
idea should be correct:

    
    
       Dark matter is a kind of matter that accounts for
       most of the matter in the entire universe. Dark
       matter is one of the greatest mysteries in modern
       astrophysics.
       ...
       the total mass–energy of the known universe
       contains 4.9% ordinary matter, 26.8% dark matter
       and 68.3% dark energy. Thus, dark matter is
       estimated to constitute 84.5% of the total matter
       in the universe, while dark energy plus dark matter
       constitute 95.1% of the total content of the
       universe.
    

So maybe physicists should be grasping at straws, maybe they should even be
considering ideas from mere "biologists", because (to steal a line from Dr.
Peter Venkman) "the usual stuff isn't working".

And it doesn't get any better at the subatomic level. I've previously [2]
commented on that. How about a theory combining general relativity with
quantum mechanics? The best attempt I've seen so far is from slashdot:

    
    
       Your momma so fat even if I'd entangle
       with her no information would be able
       to leave her event horizon.
    
          Nobody has managed to put gravitation
          and QM together yet, and you want to
          do it in a your-momma-so-fat-joke? Wow.
    

[1]
[https://en.wikipedia.org/wiki/Dark_matter](https://en.wikipedia.org/wiki/Dark_matter)
[2]
[https://news.ycombinator.com/item?id=8715315](https://news.ycombinator.com/item?id=8715315)

------
iaw
I'm a little confused. If I understood the article correctly the argument is
that the rate of expansion isn't increasing but staying constant while the
rate time passes is slowing.

Given that the rate of expansion is a measure of distance over time wouldn't
the net effect be identical?

I guess the argument is that dark energy is in fact a manifestation of the
physical rules of our universe, but in the end doesn't that violate the laws
of energy conservation? Effectively if we observe acceleration of distant
parts of the galaxy due to present time traveling slower relative to historic,
where does the energy that causes the acceleration come from?

This is reminiscent of Feynman's explanation about magnetism [1] in that it
leads back to the original question.

[1]
[https://www.youtube.com/watch?v=MO0r930Sn_8](https://www.youtube.com/watch?v=MO0r930Sn_8)

~~~
gliese1337

        I guess the argument is that dark energy is in fact a manifestation of the physical rules of our universe, but in the end doesn't that violate the laws of energy conservation?
    

Yes, but that's OK because energy is only conserved to the extent that the
laws of physics are time-translation invariant.

    
    
         Effectively if we observe acceleration of distant parts of the galaxy due to present time traveling slower relative to historic, where does the energy that causes the acceleration come from?
    

From the alteration of the laws of physics (in this case, the rate of time).

------
rd108
Here's original article
[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0115550)

------
ars
> time dilation in response to movement is directional, with only the moving
> object undergoing time dilation.

What?

Maybe the reporter messed up, but this flies directly in the face of
relativity which states there is no such thing as absolute movement.

And saying:

> Absolute Lorentz Transformation ... "preferred reference frame" ... linked
> to centers of gravitational mass.

Doesn't help in the slightest because it is completely wishy-washy. There is
no limit to the centers of gravitational mass.

There is the center of my body, my house, the earth, the solar system, the
galaxy, (the universe too?? possibly not). What makes one center more
important than another?

~~~
rd108
The PLOS paper brings up that question, too. Overlapping fields of PRF
proposed:
[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...](http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0115550#s1)

