« Last post by LB7 on Yesterday at 14:36:55 »
I updated the program of the numerical integration:
bsge.png (101.95 kB . 567x847 - viewed 97 times)
bsge.png (101.95 kB . 567x847 - viewed 97 times)
In this article it is stated:I said it was the sum of two light travel distances, not suggesting that light traveled that distance. Those two object cannot see each other.
" This has one simple property: the distance in light years is never greater than the age of the Universe in years, avoiding at least one appearance of speeds greater than the speed of light."
However, you have just confirmed that the distance between two galaxies based on light travel distance is 26.6 BLY
"The redshift z is usually the only number in the whole story that is unambiguous and likely to be correct."Yes, this is the one empirical observation. Hard to contest it.
we can easily calculate the distance from a shift in a sound:Two measurements were taken there. You can't estimate the distance to the Blackbird if you only measure its redshift since you don't know when it was directly overhead. Could be 30 seconds or a week ago. But with galaxies, we know approximately when it was 'overhead', so we can make the calculation.
"If an SR-71 blackbird flies over at Mach 3 and you hear the sound 30 seconds later, then answer to the question "How far away is it?" is clearly not 30 "sound seconds" or 10 km."
They also addI never said otherwise.
"The Universe is homogeneous and isotropic, so it has no edge. Thus there cannot be a maximum distance."
Therefore, without an edge and in order to meet the requirement to homogeneous and isotropic it actually must be infinite or at least very, very big. Much bigger than that 92BLY.
In the article it is even stated that by using the redshift for light travel time distance we get disagrees with the Hubble law...They were concluding a problem with use of light travel distance, not Hubble law or BBT. The problems go away if you don't use light travel distance.
Hence, if it generally disagrees with the Hubble law than they have to understand that there is a problem with Hubble law (not with the redshift!!!)
As we discuss about a redsfit, I also see other sever contradiction between the redshift and the BBT:OK. No contradiction pointed out yet, mostly because there's no mention of light travel distance in all that.
Based on this article we can calculate the light travel time based on the redshift
So, if the redshift is 6 than:
The age at redshift z was 0.942 Gyr.
The light travel time was 12.779 Gyr.
If the redshift is 12
The age at redshift z was 0.372 Gyr.
The light travel time was 13.349 Gyr.
So, we can claim that we see the light from two galaxies at the early Universe.
One at the age of 0.942 Gyr while the other at the age of 0.372 Gyr.
Based on the BBT, at that time the universe was quite compact and small.
Therefore, those galaxies were located quite nearby.
However, the difference in their redshift is 12-6 =6.
So, two nearby galaxies in the early universe have already so severe difference in their redshift.
However, based on this calculation we know that the meaning of redshift 6 is:Sorry, you've suddenly introduced this 13BLY, a distance that is not 'nearby'. It seems you are using light travel distance, which, as the article shows, is easily driven to inconsistency.
The light travel time was 12.779 Gyr.
Therefore, if about 13BLY we could stand in one galaxy and monitor the redshift from the other nearby galaxy, we could find that we get a redshift of 6 which equivalent to light travel time of 12.779 Gyr.
So, how could it be that in a maximal early universe age of only one billion years, we could have a light travel time of 12.779 Gyr between two nearby galaxies?Already answered in prior posts. Read it instead of just posting distractions. Focus. Look at my picture which explains better than words. It shows the light path from what was once a 'nearby' object as it gets here only today. The object is not 'nearby' today, and has in fact passed well beyond the event horizon.
The post you link is talking about the size back then of what is now the observable universe, not the size of the whole universe.QuoteWe all know that the size of the whole Universe after the inflation was only 10,000 LY.[physicsforums]:
"It is very difficult to quantify the size of the observable universe after inflation ended."
You claim that the size of the universe at age 420MY should be 3BLY.I said it is generally considered to be unbounded. For our discussion, it matters not. We're discussing how some distant galaxy appears, not the size of the universe, just another detraction of yours.
Actually, if we increase the early universe at the speed of light, it should get to about 420MLY.Again, I said nothing about a 3BLY universe. We're talking about a galaxy with a redshift of 12, which yes, is receding far faster than 1c as measured in proper distance in a comoving coordinate system.
Therefore, in total we need to increase its size at 10 times the speed of light in order to get a 3BLY universe after 420MY.
What about the momentum?Momentum is absolute in comoving coordinate system. It is assumed that the distant galaxy has insignificant local velocity, else it would not be where we see it. All galaxies are pretty much stationary. Rather the space between us and them is expanding. Our galaxy is moving at about 0.002c in the comoving coordinate system, so it does have nonzero velocity and momentum, but not much.
If due to the expansion/inflation we get that kind of size increasing (10 times the speed of light), why it suddenly slow down?It doesn't suddenly slow down. If expansion is unvaried (it's actually accelerating due to dark energy), then anything increasing its distance from here at 10c would still be receding at that rate today. I don't understand that exactly, since the worldlines in my picture curve slightly upward, not downward, so it appears that receding things are actually slowing. GN-z11 seems to be on a 3c line now, but somewhat faster in the early years. I'd have to ask that question of people who can give a better answer. Regardless, there are no sudden changes in the slopes of any worldlines
Theoretically, if something is moving away from us faster than the speed of light, while the momentum law is very clear, than how can we ever see again its light?The light does not stay with the object, but moves away from it at speed of light relative to local stationary. If you do the integration, you'll see the light get to Earth, but only from a limited distance. If you can't do the integration, then just look at the picture which shows exactly the result of it. But if you can't do the mathematics, you're in no position to assert a different story.
How can we get any sort of star while the expansion rate is so high at the early universe?We didn't. Took hundreds of millions of years, not seconds like your example posited.
How the gravity could work under those ultra high forces.Expansion isn't a force. No acceleration involved. Acceleration of expansion does require force/energy, which is why dark energy is posited.
Do you agree that when the Universe was very compact and very dense, its internal gravity was maximal?Matter is distributed in every direction, so gravity pulls in every direction and (assuming flat spacetime) effectively cancels, causing no particular change to the expansion. Only local density variations causes matter to actually accelerate away from uniformity and begin to form clusters of matter bound by gravity. This is no different than multiple stars eventually forming out of what was once a fairly homogeneous cloud of gas.
Why the gravity at that time couldn't prevent the expansion + inflation process?
Think about it instead of just dismissing it because you already know a different answer.I see you didn't quote the thing I told you to think about, which means you're dismissing it. It explains the point exactly, so you dismiss it. I see little point in going on then.
I really try to understand how the BBT works. I'm ready to accept any answer.I was explaining why the most distant galaxies (most redshifted) appear larger than similar size objects less redshifted. You dismiss that. I was not explaining the BBT to you, for which you've demonstrated a consistent negative bias instead of actual interest. No, you don't really want to understand it. You've not shown that at all.
Don't you think that as "The redshift z is usually the only number in the whole story that is unambiguous and likely to be correct" than we should fix our theories to meet this redshift instead of the other way?The theories are entirely consistent with observed redshifts, so there's nothing to fix.
do we know which specific cold viruses were around during late last year and early 2020 and how many people were infected?Do you report it to anyone if you get a cold?
I think the Coronavirus is making us all a lot more touchy than normal.Not especially; I never did like it when people said derogatory untruths about me.
In what way has anyone here been a troll?Can't answer that. You need to speak for yourself
Bored Chemist and I don't correct people for personal amusement.Again, you need to speak for yourself
We correct people in order to make the truth clear.Again you need to speak for yourself. You will have a deeper aim than arriving at the truth. You will be doing so to make yourself feel good.
If people are upset or provoked by that, then they need to do some thorough self-examination and ask themselves if they are being rational.I guarantee you MOST people will be provoked by what you have been posting. It takes a huge amount of skill to criticize and not antagonize people ( even more to have them thank you for it). You don't have the required skill, and, worse, your criticisms are mostly baseless.