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Author Topic: Can you explain inflationary theory?  (Read 6195 times)

Offline annie123

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Can you explain inflationary theory?
« on: 15/08/2014 01:26:38 »
I know Alan Guth's theory about inflation after the Big Bang is VERY important and has been verified etc. but can someone out there explain in words that an ordinary person can understand what is so significant about this and how it differs from other Nobel prize winning discoveries like the acceleration of the universe by Brain Schmidt? Thanks.


 

Offline PmbPhy

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Re: Can you explain inflationary theory?
« Reply #1 on: 15/08/2014 02:33:45 »
I know Alan Guth's theory about inflation after the Big Bang is VERY important and has been verified etc. but can someone out there explain in words that an ordinary person can understand what is so significant about this and how it differs from other Nobel prize winning discoveries like the acceleration of the universe by Brain Schmidt? Thanks.
Basically the theory of inflation explains certain puzzles in physics such as the flatness problem etc. It's basically a theory which describes the expansion of the universe hyperfast such as what is to be expected from vacuum energy which causes antigravity.
 

Offline annie123

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Re: Can you explain inflationary theory?
« Reply #2 on: 15/08/2014 20:28:15 »
Thanks but what is vacuum energy? And antigravity? Am i naive in thinking I can find an explanation of these things without a physics degree?
 

Offline PmbPhy

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Re: Can you explain inflationary theory?
« Reply #3 on: 16/08/2014 00:21:42 »
Thanks but what is vacuum energy? And antigravity? Am i naive in thinking I can find an explanation of these things without a physics degree?
See the definition of vacuum energy at http://en.wikipedia.org/wiki/Vacuum_energy

Anti-gravity is a gravitational force that is repulsive rather than attractive like gravity usually is, e.g. on earth and in our solar system and other star systems.
 

Offline Bill S

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Re: Can you explain inflationary theory?
« Reply #4 on: 19/08/2014 21:15:05 »
Quote
Am i naive in thinking I can find an explanation of these things without a physics degree?

Annie, I think that depends to a great extent on what you mean by “find”.  I too lack a physics degree, and I believe it would be naïve for me to think I could work these things out for myself.  In my case, I also believe it would be naïve to think I could ever grasp most of the maths without a lot of patient help.  However, I don’t think it is naïve to expect someone with a physics degree to be able to present a complex idea in a way that is understandable to a lay person of reasonable intelligence.

A piece of advice I was given as a child was: "Never be satisfied with an answer you don't really understand, and never pretend you under stand it if you don't."  AT 74, I'm still trying people's patience by following that advice.  :)
 

Offline Ethos_

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Re: Can you explain inflationary theory?
« Reply #5 on: 19/08/2014 22:53:28 »

A piece of advice I was given as a child was: "Never be satisfied with an answer you don't really understand, and never pretend you under stand it if you don't."  AT 74, I'm still trying people's patience by following that advice.  :)
Very good advice Bill. Being 72 myself, I find that simple advice like that has become too little and too far between today.

Today's Physics has become very detailed and some might even say; "very complicated". But if the Physicist really understands the subject in question, it is usually possible to pass along the basics to a lay person. Even so, there remain issues physicists are dealing with today that they still have difficulty passing along to each other as well.  The possibility always remains that making an explanation to simple has the effect of leaving out important information. This can lead to false assumptions on the part of the less well educated and the lay person should always be ready to change their minds when faced with good evidence.
« Last Edit: 19/08/2014 23:00:31 by Ethos_ »
 

Offline Ethos_

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Re: Can you explain inflationary theory?
« Reply #6 on: 20/08/2014 00:20:06 »
Now to answer the question in as simple a way as I'm able:

Inflation theory says that from a time 10^-36 sec. after the Big Bang to around 10^-33 sec., the universe expanded exponentially.

When people state that this expansion was so fast that it violated the speed limit of light, they are mistaken. While the speed limit of light is 186,282 miles/sec. in our present space/time, there is no law of physics that restricts the space/time itself from expanding at any rate it so chooses.

Because it was space/time that expanded and not a particle within that space/time moving faster than light, inflation violates no law of physics.

You might want to check out Brian Green on Wiki, he is one of the leading authorities on the subject.
« Last Edit: 20/08/2014 00:27:37 by Ethos_ »
 

Offline Ethos_

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Re: Can you explain inflationary theory?
« Reply #7 on: 20/08/2014 23:01:16 »
Here are a few quotes from Albert Einstein that reflect his admiration for the simplest method for explaining things:

"Things should be made as simple as possible, but not any simpler."

"It should be possible to explain the laws of physics to a barmaid."

"Most of the fundamental ideas of science are essentially simple, and may, as a rule, be expressed in a language comprehensible to everyone."

"God always takes the simplest way."

IMHO, our friend Albert might be remembered as a philosopher if he hadn't become known for his scientific genius.



 
 

Offline yor_on

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Re: Can you explain inflationary theory?
« Reply #8 on: 25/08/2014 23:07:43 »
The idea is that you have some sort of point, 'marble' that at very high energies (as a whole subsequent universe comes to be from it, or several 'subsequent' dropping of the 'first', all depending on how you define it) behaves as a repulsive force (gravity) expanding faster than light into becoming a universe. It is a theory trying to explain both the flatness problem, why the universe seems perfectly balanced (density versus expansion) not flying apart, neither collapsing upon itself. As well as 'the horizon problem' which is a result of the Big Bang theory in which the universe need to have a initial almost perfect uniformity to give us the isotropic and homogeneous universe we see today.

As for how inflation theory agrees with a accelerating expansion I'm unsure, one idea suggests that dark energy is what causes it, making it evenly spread out through a universe.

What I find confusing with inflation is the idea of that initial 'marble' from where it is assumed to inflate, otherwise I think it highly plausible with 'faster than light' as described from a observer existing inside it. This 'marble' needs somewhere to exist. Alternatively there might be other models not needing a marble.
 

Offline Ethos_

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Re: Can you explain inflationary theory?
« Reply #9 on: 27/08/2014 02:30:42 »


What I find confusing with inflation is the idea of that initial 'marble' from where it is assumed to inflate, otherwise I think it highly plausible with 'faster than light' as described from a observer existing inside it. This 'marble' needs somewhere to exist. Alternatively there might be other models not needing a marble.
A quote from Brian Greene: "No object can move through space faster than the speed of light. But nothing in Einstein's ideas prevent objects from riding the swell of an expanding space itself."

This phenomenon is misunderstood by many. But as we speak, the inflationary theory of universal expansion is becoming well accepted among the scientific community in general.
 

Offline yor_on

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Re: Can you explain inflationary theory?
« Reply #10 on: 27/08/2014 15:30:12 »
Ethos, it's deeper than that to me. The marble, if one want to define it as a object, needs a 'place'. I prefer a inflation explained otherwise, through constants :)

and now you will have to figure out what I mean ::))
 

Offline JP

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Re: Can you explain inflationary theory?
« Reply #11 on: 27/08/2014 15:46:34 »
There's no need for a "marble."  The universe could be infinite in size all the way back in time, at least as far as our current theories can describe...  It's not intuitive, but when we're talking about the birth of the universe, why should we be able to picture it in terms of marbles?  :)
 

Offline yor_on

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Re: Can you explain inflationary theory?
« Reply #12 on: 27/08/2014 16:00:44 »
Heh, beats me too. I don't want a marble at all.
 

Offline Ethos_

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Re: Can you explain inflationary theory?
« Reply #13 on: 27/08/2014 17:05:23 »
Heh, beats me too. I don't want a marble at all.
Actually, most current theories don't use a marble either. The most popular among these are a few of which include:

1. A quantum fluctuation
2. A collision of membranes
3. An off budding from another universe in the multiverse concept

And less popular, those that require a genesis particle, which in simple terms parallels your marble idea:

1. An explosion of a white hole
2. The cyclical universe, one that contracts and bounces back in expansion
3. One that requires a creator to initiate a beginning

These last three examples have long since been abandoned by most of the scientific community.

 


 

Offline JP

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Re: Can you explain inflationary theory?
« Reply #14 on: 27/08/2014 17:17:47 »
God does not play marbles with the universe...?
 

Offline Ethos_

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Re: Can you explain inflationary theory?
« Reply #15 on: 27/08/2014 19:41:22 »
God does not play marbles with the universe...?
Ha, ha, ha,...........good one JP. And according to Albert Einstein, he doesn't play dice with it either!
 

Offline yor_on

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Re: Can you explain inflationary theory?
« Reply #16 on: 27/08/2014 23:47:59 »
Well, as long as we all have our marbles, I'm sure I should have one left at least, somewhere?
 

Offline yor_on

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Re: Can you explain inflationary theory?
« Reply #17 on: 27/08/2014 23:53:05 »
'So, I contradict myself, So what, I contain multitudes.' Doesn't really have anything to do with it, more than I think it to be a statement uttered once, which I'm sort of fond of. Should make a fitting epitaph to mankind too?
 

Offline Jybwee

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Re: Can you explain inflationary theory?
« Reply #18 on: 20/11/2015 02:25:28 »
Don't hurt me for bumping this year old thread but... :)

I am having major problems with WHY we need this inflation theory. Can't the 'flatness' be explained just in the expansiveness? Can't the uniformity around us be explained in the same way? I don't even understand how uniformity needs a theory.

Universe being so big, perhaps infinitely so, surely it seems 'globally' flat as we observe all the 'space' in-between. An observance of uniformity in an infinite universe wouldn't really mean anything yea?... We cannot possibly observe the entire expanse so how can we possibly make predictions of the universe as a whole?

Isn't that in some way in relation to people thinking the Earth is flat? Sure we see mountains and such near us, but look at this huge expanse of water.. can't even see the end... aka, globally flat most likely!

Everything around us is green and lush, same type of trees in all directions.... i'm losing my train of thought :P

I just want someone to hit me on the head and tell me i have everything wrong or that there's math out there i will likely never understand and THAT is why.

Edit: side question - How can a science forum have a 'bot test' that asks "What colour is the sky?" LOL... cuz.. well.. it depends...
 

Offline evan_au

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Re: Can you explain inflationary theory?
« Reply #19 on: 21/11/2015 09:29:19 »
 

Offline puppypower

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Re: Can you explain inflationary theory?
« Reply #20 on: 21/11/2015 12:37:45 »


What I find confusing with inflation is the idea of that initial 'marble' from where it is assumed to inflate, otherwise I think it highly plausible with 'faster than light' as described from a observer existing inside it. This 'marble' needs somewhere to exist. Alternatively there might be other models not needing a marble.
A quote from Brian Greene: "No object can move through space faster than the speed of light. But nothing in Einstein's ideas prevent objects from riding the swell of an expanding space itself."

This phenomenon is misunderstood by many. But as we speak, the inflationary theory of universal expansion is becoming well accepted among the scientific community in general.

The idea of space-time expanding faster than the speed of light is not something you can prove in the lab, even if this premise helps the math. You would need to be able to tweak space-time in a vacuum so no matter or energy is impacting the experiment. This premise also implies that space-time is an independent variable and that matter and energy is a dependent variable. Einstein's relativity has space-time the dependent variable and mass and mass velocity the independent variable that drives changes in space-time.

The net result is we need another way explain inflation, which does not contradict the independent and dependent variable hierarchy of relativity as outlined by Einstein. One possible way to do this is to assume that when inflation occurs, the affect is grounded on the reference of the primordial atom, and not the earth reference; aftermath.

To explain this, consider the twin paradox. One twin is stationary and the other twin is on a space ship moving near the speed of light, C. When the two twins meet on the earth, the moving twin is younger, due to time dilation and relativity.

In an inflation analogy, the earth reference is like the stationary twin. The inflation reference is like the moving twin. Since the inflation twin is younger, this implies the things in his reference appears to occur faster. He can go from here to there in less time, compared to us, because his watch slows down.

If you were sitting on the primordial atom, since that reference is the only reference in the  universe, expansion of the universe could be induced by simply slowing down from the speed of light via special relativity. If you looked out your window, the expanding reference looks, like an expansion of the universe, which is consistent with the abstraction of space-time leading, from the earth's reference.

But it is due to a slow down from C leading, stemming from the primordial atom reference; aging slower, which was the only show in town. Going from C  (point) to C-, (finite size) makes a huge difference in terms of relativity. After that things gets tighter.
« Last Edit: 21/11/2015 12:45:15 by puppypower »
 

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Re: Can you explain inflationary theory?
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