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Madheart918

Can you witness the birth of the Universe?

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I remember watching a NGT documentary on Netflix, and he mentioned something abouto Photons and how the first ones, from the big bang, witnessed the big bang.

Or something about how when they are born, until they reach their destination, they see the birth and death of the universe. Would make for some sick go-pro footage i might add.

 

So in theory, if you could fold spacetime and "Beat" the photons in whatever direction they are heading, or just match their pace, you could look back into the universe and witness our universe be born.

Kind of like how if you instantly travel 65 million light years away, you could see earth be hit by an asteroid, killing the dinosaurs.

 

Also, i had this perspective in the back of my mind on the concept of death and what happens.

Once you die, your perception of time ends, so theoretically, the universe will end when you die, atleast from your perspective.

Since you aren't alive, then there is no concept of time, therefore, the universe you knew will simultaneously come to the end of its life span as you, yourself, die.

 

That's how i see it anyway. 

 

 

 

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The univers was opaque until about 300,000 years or so after the big bang. The photons that we detect as the cosmic microwave background date to that time. And they're from the whole universe, so they don't form an image.

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Hello Madheart918,

I think that light was not present at the very very first stages of the Big Bang. Also as is often mentioned on this forum, the big Bang does not describe the birth of the Universe, just it's rapid expansion from a very dense hot state.

I assume you watched Cosmos: A Spacetime Odyssey. Neil deGrasse Tyson often makes science sound poetic but in this process he makes his statements a bit ambiguous as well sometimes for dramatic purpose. (Also the asteroid didn't "kill the dinosaurs")

In regards to your last part, I wont touch upon it as it has more to do with the Philosophy section of this forum. :) 

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On 1/8/2018 at 1:12 AM, Madheart918 said:

I remember watching a NGT documentary on Netflix, and he mentioned something abouto Photons and how the first ones, from the big bang, witnessed the big bang.

Or something about how when they are born, until they reach their destination, they see the birth and death of the universe. Would make for some sick go-pro footage i might add.

 

So in theory, if you could fold spacetime and "Beat" the photons in whatever direction they are heading, or just match their pace, you could look back into the universe and witness our universe be born.

Kind of like how if you instantly travel 65 million light years away, you could see earth be hit by an asteroid, killing the dinosaurs.

 

Also, i had this perspective in the back of my mind on the concept of death and what happens.

Once you die, your perception of time ends, so theoretically, the universe will end when you die, atleast from your perspective.

Since you aren't alive, then there is no concept of time, therefore, the universe you knew will simultaneously come to the end of its life span as you, yourself, die.

 

That's how i see it anyway.

Photons did not exist until ~10 seconds after the Big Bang, after the universe cooled down from a billion degrees Kelvin to ~4,000°K, but the temperature is still too high for the binding of electrons to nuclei .  The Photon Epoch begins just after the leptons and anti-leptons annihilate each other during the Lepton Epoch, and will last until ~380,000 years after the Big Bang, or red shift z = 1,100.  It is during the Recombination Epoch, which lasts ~100,000 years, and occurs immediately after the Photon Epoch when the universe starts becoming transparent to photons.  By 380,000 years after the Big Bang the temperature of the universe cooled enough to allow nuclei and electrons to combine and create neutral atoms.  Which meant that photons no longer frequently interacted with matter, the universe became transparent.  This Recombination Epoch is something we have been able to image, because it is also known as the cosmic microwave background radiation.

Therefore, if you were to take a ride back in time on the very first photon created, your journey would end ~10 seconds after the universe began.

On an interesting side note, it was the 1964 discovery of the cosmic background radiation by Robert Wilson and Arno Penzias that convinced the overwhelming majority of astronomers that the "Big Bang" really did exist.  For 14 years the astronomer Fred Hoyle had argued, convincingly, that the universe was in a Static State.  It was Fred Hoyle who coined the term "Big Bang."  He meant it as derisive term, but the name stuck.  Fred Hoyle died never believing that the universe had a beginning.

Edited by T. McGrath

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4 hours ago, T. McGrath said:

Photons did not exist until ~10 seconds after the Big Bang, after the universe cooled down from a billion degrees Kelvin to ~4,000°K, but the temperature is still too high for the binding of electrons to nuclei . 

Surely they existed before ~10 seconds after the Big Bang, just not for very long; i.e. have you a reference?.

A few lucky photons probably survived from before neutral atoms existed, but probably not enough to observe.

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33 minutes ago, Carrock said:

Surely they existed before ~10 seconds after the Big Bang, just not for very long; i.e. have you a reference?.

What do you mean not for very long? Why/how would they just disappear?

You do understand that the BB is not an actual explosion right?

On 1/8/2018 at 12:13 PM, swansont said:

The univers was opaque until about 300,000 years or so after the big bang. The photons that we detect as the cosmic microwave background date to that time. And they're from the whole universe, so they don't form an image.

Also I am a bit confused swansont. As T. McGrath mentions, first photons were around 10 seconds after the BB. Yet you are mentioning that the universe was Opaque the first 300,000 years. I am sure you are both right but can you please elaborate? Were the first ones virtual photons? 

image.png.f8c5658b04858645a867c46c51befcf1.png

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2 hours ago, Silvestru said:

What do you mean not for very long? Why/how would they just disappear?

You do understand that the BB is not an actual explosion right?

Each photon would disappear when it interacted with a charged particle; there would be approximately as many photons then as there are now, but none of them would exist for long i.e. the mean free photon length was very short. Photons existed before nucleosynthesis stopped; i.e. during the first ten seconds.

 

Why do you think I think the BB is an actual explosion?

Edited by Carrock
clarification

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5 hours ago, Silvestru said:

What do you mean not for very long? Why/how would they just disappear?

You do understand that the BB is not an actual explosion right?

Also I am a bit confused swansont. As T. McGrath mentions, first photons were around 10 seconds after the BB. Yet you are mentioning that the universe was Opaque the first 300,000 years. I am sure you are both right but can you please elaborate? Were the first ones virtual photons? 

image.png.f8c5658b04858645a867c46c51befcf1.png

 

Notice how it says "more and more transparent to photons"?

photons couldn't travel very far through the plasma that was present. Not until the universe was cool enough for atoms to exist.

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10 hours ago, T. McGrath said:

.  Fred Hoyle died never believing that the universe had a beginning.

Sadly, an otherwise great scientist, who achieved great things such as the the theory of nuclear synthesis process undertaken in stars.

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12 hours ago, T. McGrath said:

Fred Hoyle died never believing that the universe had a beginning.

Actually he didn't. See

 

Mach's Principle and the Creation of Matter
Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences
Vol. 273, No. 1352 (Apr. 23, 1963), pp. 1-11

 

Hoyle used 'Steady State' in the conventional sense i.e. after startup transients have become negligible.

 

Confusion arises because Bondi and Gold beat Hoyle into print with an eternal rather than steady state universe.

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16 hours ago, Carrock said:

Surely they existed before ~10 seconds after the Big Bang, just not for very long; i.e. have you a reference?.

A few lucky photons probably survived from before neutral atoms existed, but probably not enough to observe.

Photons existed before electrons combined with nuclei to form neutral atoms.  Neutral atoms started to form when the universe cooled to 4,000°K.

When an electron in the high energy level is converted into a lower energy-level electron a photon is created and released.  When an electron in the lower energy level is excited into a higher energy-level a photon is absorbed and destroyed.

The universe was not "observable" in the sense that we can see anything, until neutral atoms were created and the universe became transparent for the first time during the Recombination Epoch.  At  z > 1,100 all matter is in excess of 4,000°K, ionized, optically thick, and strongly coupled to photons.   In other words, the photons are being scattered all the time. The Universe is completely opaque.

15 hours ago, Silvestru said:

What do you mean not for very long? Why/how would they just disappear?

You do understand that the BB is not an actual explosion right?

Also I am a bit confused swansont. As T. McGrath mentions, first photons were around 10 seconds after the BB. Yet you are mentioning that the universe was Opaque the first 300,000 years. I am sure you are both right but can you please elaborate? Were the first ones virtual photons?

Photons are created and released when an electron in the high energy level is converted into a lower energy-level electron.  Even before neutral atoms existed, when the universe was still an extremely hot plasma, there were still free electrons and this is where the first photons came from.  As the universe cools, neutral atoms begin to form and electrons are bound to nuclei for the first time, making the universe transparent.

While the universe was cool enough for photons to be created from free electrons ~10 seconds after the Big Bang, the universe did not cool enough to become transparent until ~380,000 years after the Big Bang, when neutral atoms were able to form.

 

8 hours ago, Carrock said:

Actually he didn't. See

 

Mach's Principle and the Creation of Matter
Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences
Vol. 273, No. 1352 (Apr. 23, 1963), pp. 1-11

 

Hoyle used 'Steady State' in the conventional sense i.e. after startup transients have become negligible.

 

Confusion arises because Bondi and Gold beat Hoyle into print with an eternal rather than steady state universe.

I'm familiar with Hoyle's work on the creation of matter.  It was the primary flaw in his Steady State theory.  Since we already knew the universe was expanding, thanks to Edwin Hubble, the only way the universe could be eternal (as Hoyle believed) was by continuously creating matter from nothing somewhere in the universe.  The paper you referenced was that attempt to explain how matter can be created from nothing.

You will also note that the paper was published the year before the cosmic microwave background radiation was discovered which vindicated Georges Lemaître and proved Fred Hoyle wrong.  Fred Hoyle died in 2001 never buying into the Big Bang theory.  He simply could not grasp that the universe had a beginning.

9 hours ago, beecee said:

Sadly, an otherwise great scientist, who achieved great things such as the the theory of nuclear synthesis process undertaken in stars.

I agree.  Hoyle was a brilliant astronomer.  He just got this one theory wrong.  It happens to the best of them.  Even Einstein blew it with his cosmological constant, because he too desired an eternal universe.  It is ironic that the term "Big Bang," which is used by everyone now, was created by someone who did not believe in the theory.

Edited by T. McGrath

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Your forgetting a critical detail on thermal equilibrium. electrons etc can form at higher temperatures but they quickly annihilate. Also temperature is part of the electromagnetic spectrum. 

photons do exist before electron decoupling their mean free path is still too short so while not decoupled they still form but with extremely short mean free path. I might be wrong but I think the detail you may be missing is how thermal equilibrium relates to expansion rate. ie how a particle decouples but the rate of expansion prevents its immediate annihilation. Individual particle species can form just not with any stability. For example from the following arxiv discussing boson/fermion particle species during the electroweak symmetry breaking.

"EW symmetry breaking arises, while one is retained in the one single dynamical charge neutral
Higgs component. In the massless stage, the SU(2)×U(1) theory has 4×2=8 gauge degrees of
freedom where the first coefficient is the number of particles (γ, Z, W±) and each massless gauge
boson has two transverse polarizations. Adding in 8c × 2s = 16 gluonic degrees of freedom we
obtain 4+8+16=28 bosonic degrees of freedom."

https://www.google.ca/url?sa=t&source=web&rct=j&url=https://arxiv.org/pdf/1311.0075&ved=2ahUKEwjRxNyr8tvYAhVmxVQKHQvjCtgQFjADegQIFRAB&usg=AOvVaw1kFMHLpDTJAcQS_fT7bFqF

Quoted section is under figure 4.

Seems to me the misconception is what is meant by decoupling and thermal equilibrium. It does not mean the SM particles are not present only that they haven't decoupled.

 

Edited by Mordred

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3 hours ago, T. McGrath said:

Even Einstein blew it with his cosmological constant, because he too desired an eternal universe. 

I think "desired" is a bit strong. It was just the standard assumption at the time. There was no reason to think otherwise.

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2 hours ago, Strange said:

I think "desired" is a bit strong. It was just the standard assumption at the time. There was no reason to think otherwise.

Actually, there was reason to think otherwise, and it was Einstein who provided that reason.  When Hubble demonstrated that the universe was expanding Lemaître used Einstein's equations to demonstrate that the universe had a beginning.  Einstein's own equations show that the universe must either be expanding or contracting, it cannot be static.  Einstein did not want to accept what his own equations were telling him, which is why he began work on his cosmological constant.  When Lemaître and Einstein met for the first time in 1927 Einstein said to Lemaître, "Your calculations are correct, but your physics are abominable."  However, by 1931 Einstein gave up on his cosmological constant and by 1933 commented that Lemaître's theory was “the most beautiful and satisfactory explanation of creation to which I have ever listened.”

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6 hours ago, T. McGrath said:

The paper you referenced was that attempt to explain how matter can be created from nothing.......

 

Fred Hoyle died in 2001 never buying into the Big Bang theory.  He simply could not grasp that the universe had a beginning.

It was actually a speculative discussion of initial boundary conditions (i.e. the beginning of the universe) as applied to the steady state theory.

As I've said, Bondi and Gold posited a 'perfect' universe which had been expanding 'unchanged' for infinite time, which Hoyle knew was impossible for basic mathematical reasons - it was formally disproved long before discovery of the CMBR.

From Mach's Principle and the Creation of Matter

 

Quote

If the C-field is not present, it seems that the universe itself is simply a 'transient' and the observed regularity is just 'chance'.

If the C-field is  present ... , it seems that the universe attains the observed regularity irrespective of initial boundary conditions.

The abstract and full conclusion make this even clearer.

You have to create a free account to read the whole paper.

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The earliest time we will ever be able to 'image' with EM radiation is approx. 300000 yrs after T=0.
 This is the CMB, before that photons had a very short MFP because they readily interacted with massive particles ( creation/annihilation ).

However, if we can find a way to 'image' neutrinos, we may be able to get much closer to T=0, as they interact extremely weakly.

And graviton imaging would get us to within the first second after T=0.
( don't know if that will ever be possible, but would that be close enough ? )

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