Starship Asterisk*

University of Heidelberg:
How Did the Universe Begin: Hot Big Bang or Slow Thaw?

Did the universe begin with a hot Big Bang or did it slowly thaw from an extremely cold and almost static state? Prof. Dr. Christof Wetterich, a physicist at Heidelberg University, has developed a theoretical model that complements the nearly 100-year-old conventional model of cosmic expansion. According to Wetterich’s theory, the Big Bang did not occur 13.8 billion years ago – instead, the birth of the universe stretches into the infinite past. This view holds that the masses of all particles constantly increase. The scientist explains that instead of expanding, the universe is shrinking over extended periods of time.

More at:
http://www.uni-heidelberg.de/presse/new ... um_en.html

Hot big bang or slow freeze? Christof Wetterich
http://arxiv.org/abs/1401.5313

This idea represents a rather radical break with the generally accepted Big Bang model of the universe.

How likely is this new idea to become the preferred cosmological model? What would it take for it to become accepted by a majority of those astronomers
who now embrace the Big Bang model?

C. Wetterich, the author of the paper, wrote:
Despite the striking differences between the hot big bang and slow freeze pictures for the evolution of geometry and temperature, our model is compatible with all present cosmological and experimental observations.

Let's assume, for the sake of the argument, that Wetterich's model is just as good as the currently accepted model at explaining the phenomena that have been cited as evidence of a primordial Big Bang. But let's assume, too, that Wetterich's hypothesis is no better at explaining these phenomena than the Big Bang theory. How likely is it that the new model would gain widespread acceptance if it explains things just as well as the current model, but it doesn't obviously do any better?

Ann

Why bother with those assumptions? Give it a couple of years and then see if it's been Swiss cheesed yet.

This view holds that the masses of all particles constantly increase.

Oh good, I was worried my expanding waistline was from too much cake and ale.

That just means it's expanding that much faster.

geckzilla wrote:That just means it's expanding that much faster.

Maybe, but do you really think it wise to fight nature?

Nature as a whole? Nah. Your own personal human nature? I don't know about you, but I battle with parts of mine on a daily basis.

Ann wrote:Let's assume, for the sake of the argument, that Wetterich's model is just as good as the currently accepted model at explaining the phenomena that have been cited as evidence of a primordial Big Bang. But let's assume, too, that Wetterich's hypothesis is no better at explaining these phenomena than the Big Bang theory. How likely is it that the new model would gain widespread acceptance if it explains things just as well as the current model, but it doesn't obviously do any better?

Not likely at all, I’d say. People can be very slow to accept the radically new, even putting up institutional barriers to such change. Without the new concept having obvious advantage, why change horses? Those whose careers have been built upon developing the standard model wouldn’t be quick to embrace the notion that the past century of cosmology has had things so totally backward. People don’t like admitting that they were wrong.

And don’t think that I’m on Witterich’s side here either. I’ll demonstrate the resistance myself. Constants are called constant for good reason. They’re constant.

geckzilla wrote:Why bother with those assumptions? Give it a couple of years and then see if it's been Swiss cheesed yet.

I was dismissive of the idea in a couple of seconds. As for poking holes, if the masses of all particles are continually growing, then how can the expanding orbit of the Earth’s Moon be explained? Oh, I guess the gravitational constant isn’t constant either??? I don’t think the idea is Swiss cheese. To me it smells more like Limburger.

Bruce

One interesting point made in the paper (which can be picked up at arxiv, if you haven't read it yet) is that this hypothesis (not a theory yet!) makes a specific prediction for the value of a certain parameter, which ΛCDM does not (cannot?) make. Then the authors issue the challenge: go and look and falsify this prediction if you can. That's the way science works, by either finding data to back up a hypothesis or data which falsifies it. Opinions one way or the other are not relevant.

Rob

BDanielMayfield wrote:

Ann wrote:Let's assume, for the sake of the argument, that Wetterich's model is just as good as the currently accepted model at explaining the phenomena that have been cited as evidence of a primordial Big Bang. But let's assume, too, that Wetterich's hypothesis is no better at explaining these phenomena than the Big Bang theory. How likely is it that the new model would gain widespread acceptance if it explains things just as well as the current model, but it doesn't obviously do any better?

Not likely at all, I’d say. People can be very slow to accept the radically new, even putting up institutional barriers to such change. Without the new concept having obvious advantage, why change horses? Those whose careers have been built upon developing the standard model wouldn’t be quick to embrace the notion that the past century of cosmology has had things so totally backward. People don’t like admitting that they were wrong.

And don’t think that I’m on Witterich’s side here either. I’ll demonstrate the resistance myself. Constants are called constant for good reason. They’re constant.

geckzilla wrote:Why bother with those assumptions? Give it a couple of years and then see if it's been Swiss cheesed yet.

I was dismissive of the idea in a couple of seconds. As for poking holes, if the masses of all particles are continually growing, then how can the expanding orbit of the Earth’s Moon be explained? Oh, I guess the gravitational constant isn’t constant either??? I don’t think the idea is Swiss cheese. To me it smells more like Limburger.

You may be instantly dismissive of it but not everyone will be. It's natural to doubt a new idea that challenges a longstanding one but if it truly offers an exactly equal explanation then there's no reason why it would not eventually be presented as an equal possibility alongside the BB. The likelihood of them being precisely equal counterparts to one another is the most improbable outcome, though.

rstevenson wrote:One interesting point made in the paper (which can be picked up at arxiv, if you haven't read it yet) is that this hypothesis (not a theory yet!) makes a specific prediction for the value of a certain parameter, which ΛCDM does not (cannot?) make. Then the authors issue the challenge: go and look and falsify this prediction if you can. That's the way science works, by either finding data to back up a hypothesis or data which falsifies it. Opinions one way or the other are not relevant.

Rob

Thanks, Rob!

Ann

[Prof] Wetterich stresses that this in no way renders the previous view of the Big Bang “invalid”.

... um, apart from bit about the "big bang". I'll (need to) leave it for minds brighter than mine to study this new model. If it does indeed turn out to be a valid alternative model of the Universe, then that's rather impressive. And if it offers the possibility of some kind of scientific breakthrough that the Big Bang model does not permit, then even better. I suppose it also offers a possibility that the Universe might be "reborn" after the Big Freeze (or heat death) fate currently predicted.

It seems like reality could be relative to the mathematics used to describe it.

Nitpicker wrote:... It seems like reality could be relative to the mathematics used to describe it.

I like that way of putting it.

Rob

rstevenson wrote:One interesting point made in the paper (which can be picked up at arxiv, if you haven't read it yet) is that this hypothesis (not a theory yet!) makes a specific prediction for the value of a certain parameter, which ΛCDM does not (cannot?) make. Then the authors issue the challenge: go and look and falsify this prediction if you can. That's the way science works, by either finding data to back up a hypothesis or data which falsifies it. Opinions one way or the other are not relevant.

Rob

Thank you , Rob, for clearly spelling out the scientific method!

I may even change my signature file one day to read
Find and examine the data:
"Opinions one way or another are not relevant"

Margarita

There is a 2013 arXiv paper, entitled A Universe without expansion by Professor Wetterich here
http://arxiv.org/abs/1303.6878/ where he first sets out his hypothesis.

This paper is discussed in Nature (the discussion isn't behind a paywall) here:

http://www.nature.com/news/cosmologist- ... ng-1.13379
...
Although the paper has yet to be peer-reviewed, none of the experts contacted by Nature dismissed it as obviously wrong, and some of them found the idea worth pursuing. “I think it’s fascinating to explore this alternative representation,” says Hongsheng Zhao, a cosmologist at the University of St Andrews, UK. “His treatment seems rigorous enough to be entertained.” ...

This Wikipedia article gives Professor Wetterich's curriculum vitae
http://en.wikipedia.org/wiki/Christof_Wetterich

And this University of Heidelberg webpage gives his research interests and publications:

http://www.thphys.uni-heidelberg.de/~wetteric/