Big Bang - doubts ?

[ravell]

According to the published data the Universe as a result of the Big Bang, expands at an increasing rate, with a speed  increase of about 70 (km / s) / Mpc, the same for all observed galaxies, regardless of their distance from the Earth. The radius of the observed Universe was set at about 13.7 billion light years. Based on the above data  the age of the Universe was estimated at about 13.7 billion years.

 From the modeled calculations in the Sagitarius BR program available at the link:

https://www.dropbox.com/s/a1cu74xj4ep9iyq/SagitariusBRprogramForCalculationsOfSpeedOfStars.xlsx?dl=0,

   one can draw contradictory conclusions regarding the age of the Universe and the Big Bang itself, namely:

1.    The Universe's expansion speed corresponding to the Hubble parameter H = approx. 70 (km / s) / Mpc, with the size of the Universe reached  R = about 13.7 billion light years, can be obtained with many different accelerations of expansion and  initial velocities Vo , after various time laps T for each case (3 examples in the table below). Thus, based on the Hubble parameter  H and the observed size of the Universe R, the age of the Universe can not be reliably determined.

 

2.     Observed , on the basis of the spectral shifts,  the increase in the velocity of the galaxies moving away  H = approx. 70 (km / s) / Mpc, the same for all galaxies,  regardless of their distance from  the Earth, contradicts the expansion of the Universe. The age of the observed galaxies is the younger the farther the observed galaxy is, which when the Universe expands should cause that the value of the observed parameter H, regardless of the expansion rate of the Universe, should  gradually decrease for galaxies becoming older, ie closer to Earth, and we do not observe this.

Is it correct  to conclude, therefore, that  the observed  increase in the redshift of spectra from  increasingly distant galaxies may result  from other unknown  reasons and not as the effect of the Big Bang and the expansion of the Universe?

The size of the Universe and  the Hubble parameter  H  for 3 examples  of expansion rates

Initial velocity	Acceleration of expansion	Elapsed time from BB	Radius of Universe after T1	Parameter H after time T1	Approximate age of the Universe at the time of observation	Value of parameter H after T2 years
Vo	a	T1	R	H1	T2	H2
km/s	m/sek2	billion years	billion ly	(km/s)/Mpc	billion years	(km/s)/Mpc
0	3,330E-10	28	13,72	69,9	55	35,6
100 000	2,997E-10	20,8	13,75	70,1	48	34,5
299 900	0,0	13,9	13,9	70,4	42	23,3

 

[Strange]

5 minutes ago, ravell said:

According to the published data the Universe as a result of the Big Bang, expands at an increasing rate, with a speed  increase of about 70 (km / s) / Mpc, the same for all observed galaxies, regardless of their distance from the Earth. The radius of the observed Universe was set at about 13.7 billion light years. Based on the above data  the age of the Universe was estimated at about 13.7 billion years.

This is horribly confused. 

Lets start with the Hubble constant which is, as you say, about 70 (km / s) / Mpc. If that were the same for all galaxies, then the the universe would NOT be expanding at an increasing rate. It would be expanding at the same rate for all galaxies, by definition.

However, it turns out (surprisingly) that the rate of expansion is not the same for all galaxies. In fact the rate of expansion started increasing a few billion years ago. 

The radius of the observable universe is about 45 billion light years, not 13.7 billion light years.

12 minutes ago, ravell said:

The Universe's expansion speed corresponding to the Hubble parameter H = approx. 70 (km / s) / Mpc, with the size of the Universe reached  R = about 13.7 billion light years, can be obtained with many different accelerations of expansion and  initial velocities Vo , after various time laps T for each case (3 examples in the table below).

It is hard to make sense of this sentence but you seem to be saying that if the  rate of expansion had changed over time then the age of the universe could be different. This ignores the fact that we can measure the rate of expansion at different times. This is how we know that the rate of expansion has started accelerating.

So are the expansion rates in your table supported by evidence?

14 minutes ago, ravell said:

Observed , on the basis of the spectral shifts,  the increase in the velocity of the galaxies moving away  H = approx. 70 (km / s) / Mpc, the same for all galaxies,  regardless of their distance from  the Earth, contradicts the expansion of the Universe.

This sentence is even harder to parse I'm afraid. The fact that the recessional speed of galaxies increases linearly with distance was one of the first, and the simplest, bits of evidence for the expanding universe. Can you explain why you think it isn't?

(Note that it was not the most convincing evidence. That came later in the form of the CMB.)

17 minutes ago, ravell said:

The age of the observed galaxies is the younger the farther the observed galaxy is, which when the Universe expands should cause that the value of the observed parameter H, regardless of the expansion rate of the Universe, should  gradually decrease for galaxies becoming older, ie closer to Earth, and we do not observe this.

I have absolutely no idea what you are trying to say here.

Why do you think the value of H should decrease for older galaxies? It is not a function of the age of galaxies.

18 minutes ago, ravell said:

Is it correct  to conclude, therefore, that  the observed  increase in the redshift of spectra from  increasingly distant galaxies may result  from other unknown  reasons and not as the effect of the Big Bang and the expansion of the Universe?

When this was the only evidence for the expansion of the universe, many other explanations were presented. Not all of these could be ruled out. Until the discovery of the CMB, and all the other evidence for the Big Bang model, at which point all the other models were discarded as they were not able to explain all the evidence.

[beecee]

5 hours ago, Strange said:

 The radius of the observable universe is about 45 billion light years, not 13.7 billion light years.

 Yes, that error stood out like the proverbial.... 

[Airbrush]

"The radius of the observable universe is about 45 billion light years..."

Yes and I think that means that the most distant galaxy visible is approx. 30 billion LY away, because the distance to the CMB is about 50% more distant than the most distant visible galaxy, right?

[Endy0816]

@ravell

The Universe has a radius greater than its age alone might suggest.

Need to also consider the time light takes to reach us. Galaxies will appear younger as a result.

[Strange]

1 hour ago, Airbrush said:

"The radius of the observable universe is about 45 billion light years..."

Yes and I think that means that the most distant galaxy visible is approx. 30 billion LY away, because the distance to the CMB is about 50% more distant than the most distant visible galaxy, right?

Not sure of the exact figures, but that sounds about right.

[Airbrush]

On ‎1‎/‎22‎/‎2018 at 10:49 AM, Strange said:

Not sure of the exact figures, but that sounds about right.

"GN-z11 is a high-redshift galaxy found in the constellation Ursa Major. GN-z11 is currently the oldest and most distant known galaxy in the observable universe.^[4] GN-z11 has a spectroscopic redshift of z = 11.09, which corresponds to a proper distance of approximately 32 billion light-years...

"The object's name is derived from its location in the GOODS-North field of galaxies and its high cosmological redshift number (GN + z11).^[6] GN-z11 is observed as it existed 13.4 billion years ago, just 400 million years after the Big Bang;^[2][7][8] as a result, GN-z11's distance is inappropriately^[9] reported as 13.4 billion light years, its light travel distance measurement.^[

https://en.wikipedia.org/wiki/GN-z11

 

[beecee]

On 1/22/2018 at 6:01 AM, ravell said:

   one can draw contradictory conclusions regarding the age of the Universe and the Big Bang itself, namely:    

The BB/Inflationary model of the evolution of spacetime/Universe, is by far the best model we have. The onus is on you to put up a better model for consideration, not just make a lengthy posts with errors and self opinionated unsupported notions.

So what is the model that you subscribe to to best describe the universe we observe?

[ravell]

On 21.01.2018 at 8:21 PM, Strange said:

Lets start with the Hubble constant which is, as you say, about 70 (km / s) / Mpc. If that were the same for all galaxies, then the the universe would NOT be expanding at an increasing rate. It would be expanding at the same rate for all galaxies, by definition.

The  value of Hubble parameter H is the same throughout the Universe for a given  comoving time .

On 21.01.2018 at 8:21 PM, Strange said:

The radius of the observable universe is about 45 billion light years, not 13.7 billion light years

Could you explain how we can see galaxies that are distant from Earth by 45 billion light years, while the age of the universe is only 13.8 billion years old? 

^{from   https://www.space.com/24073-how-big-is-the-universe.html :}

 „ Because of the connection between distance and the speed of light  this means scientists can look at a region of space that lies 13,8 billion light-years away. Like a ship in the empty ocean, astronomers on Earth can turn their telescopes to peer 13.8 billion light-years in every direction, which puts Earth inside of an observable sphere with a radius of 13.8 billion light-years. The word "observable" is key; the sphere limits what scientists can see but not what is there.”

On 21.01.2018 at 8:21 PM, Strange said:

It is hard to make sense of this sentence but you seem to be saying that if the  rate of expansion had changed over time then the age of the universe could be different. This ignores the fact that we can measure the rate of expansion at different times. This is how we know that the rate of expansion has started accelerating.

Could you provide information sources on how the expansion rate was measured for different periods,  in km / sec / Mpc, while the Hubble parameter H measured for today is 70km / s / Mpc and is approximately the same for all observed galaxies, regardless of their distance?

On 21.01.2018 at 8:21 PM, Strange said:

So are the expansion rates in your table supported by evidence?

 No, these are just only examples that the parameter H = 70km / s / Mpc , as it is today, can be obtained  at many different rates of the expansion of the universe

On 21.01.2018 at 8:21 PM, Strange said:

Why do you think the value of H should decrease for older galaxies? It is not a function of the age of galaxie

Sorry, it is.  If the expansion  of universe takes place, the parameter H in km/s/Mpc must decrease as the age of the observed galaxy increases, by definition.

From  https://en.wikipedia.org/wiki/Hubble%27s_law  :

 „ Since the Hubble "constant"  H is a constant only in space, not in time, the radius of the Hubble sphere may increase or decrease over various time intervals. The  H0  is  the value of the Hubble constant today. Current evidence suggests that the expansion of the Universe is accelerating), meaning that, for any given galaxy, the recession velocity dD/dt is increasing over time as the galaxy moves to greater and greater distances; however, the Hubble parameter is actually thought to be decreasing with time, meaning that if we were to look at some fixed distance D and watch a series of different galaxies pass that distance, later galaxies would pass that distance at a smaller velocity than earlier ones.

[Strange]

7 hours ago, ravell said:

Could you explain how we can see galaxies that are distant from Earth by 45 billion light years, while the age of the universe is only 13.8 billion years old? 

(Actually, we cannot see galaxies at that distance; it is the size of the observable universe. The furthest galaxies we can see are a bit closer than that. But we probably don't need to worry about that now.)

The most distant light we can see is actually the CMB. It was emitted when the universe was about 4.5 billion light years in radius. Since then the universe has been expanding so the light took more than 4.5 billion light years to get here. It is a bit like fish swimming against a current: as the light travels, the distance it has to go is continually increasing. So it took 13.8 billion light years to get here. Meanwhile the universe was still expanding so, by now, the radius is about 46 billion light years.

The Wikipedia page has a good explanation: https://en.wikipedia.org/wiki/Observable_universe#Size

7 hours ago, ravell said:

Could you provide information sources on how the expansion rate was measured for different periods,  in km / sec / Mpc, while the Hubble parameter H measured for today is 70km / s / Mpc and is approximately the same for all observed galaxies, regardless of their distance?

It is measured (mainly) by measuring the red shift at different distances. There are also indirect ways of measuring it, but that is beginning to get beyond what I understand...

It is approximately the same at all distances. It was assumed that it would be gradually reducing over time. But measurements show that it started increasing (relatively) recently. Hence the need for "dark energy" (whatever it is) to explain the acceleration.

7 hours ago, ravell said:

Sorry, it is.  If the expansion  of universe takes place, the parameter H in km/s/Mpc must decrease as the age of the observed galaxy increases, by definition.

It is dependent on the age of the universe, not the age of galaxies.