Is a larger initial size for the universe possible?

In summary: In this case the argument that we are the only universe that can support life because we have the correct physical constants would be wrong. In summary, the conversation discusses the possibility of the universe expanding from a larger initial size and the implications it would have on various aspects such as the horizon problem, dark energy, and the presence of other universes with different physical constants. The conversation also touches on the role of mathematics in understanding these theories and the potential limitations in our current paradigm. Ultimately, the conversation raises metaphysical questions about the nature of the universe and the role of science in understanding it.
  • #1
kurious
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Is it possible for the universe to expand from a very large initial size such as 10^25 metres instead of from the usual 10^-35 metres.
Could the universe have a high enough temperature at 10^25 metres?
Would nucleosynthesis of the elements give the right abundances?
My motivation for asking this is as follows:

(1) Wouldn't a large initial radius for the universe overcome the horizon problem?

(2)A large initial radius would explain why the dark energy density and
the baryonic matter density are so similar today.

These are not unreasonable questions given that there is so little evidence for the theory of inflation.
 
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  • #2
I think it is a very interesting question in the case that there can be infinitely many different Plank-like constants, where each constant is the initial unit of another universe.

In this case we can ask if there can be any connection between two universes, which are based on different Plank-like constants.
 
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  • #3
with metaphysical questions kurious?

Is it not a metaphysical question to suppose the universe had a beginning?
Should we ask that question in a scientific forum?
Is it not that question part of the reason why our prevailing paradigm is askew?

Regards

EP
kurious said:
Is it possible for the universe to expand from a very large initial size such as 10^25 metres instead of from the usual 10^-35 metres.
Could the universe have a high enough temperature at 10^25 metres?
Would nucleosynthesis of the elements give the right abundances?
My motivation for asking this is as follows:

(1) Wouldn't a large initial radius for the universe overcome the horizon problem?

(2)A large initial radius would explain why the dark energy density and
the baryonic matter density are so similar today.

These are not unreasonable questions given that there is so little evidence for the theory of inflation.
 
  • #4
You would probably find a fair percentage of theorists believe the universe has always been infinite in size.
 
  • #5
Would an infinite Creator create a finite universe?

Regards

EP
Chronos said:
You would probably find a fair percentage of theorists believe the universe has always been infinite in size.
 
  • #6
Epsilon Pi said:
Is it not a metaphysical question to suppose the universe had a beginning?
Should we ask that question in a scientific forum?
Is it not that question part of the reason why our prevailing paradigm is askew?

If its a metaphysical question or not doesn’t really matter. If you haven’t noticed these are the question physicists deal with everyday.

Unless you agree with the Popes advice given to physicists in a conference in 1981 that we should not inquire into the big bang itself because that was the moment of creation and thus the work of god.
 
  • #7
It is only a metaphysical question like every other question until experimental evidence is found for it.I think dark energy holds the key to how big,small old and young the universe gets.If the issue of dark energy is resolved in the next few years we will be
privileged to be living at a time when some of the questions that people have asked
for thousands of years are answered.
 
  • #8
Hi kurious,

Please look at post #2.
 
  • #9
Paraphrasing Chronos I would say:

You would probably find a fair percentage of theorists and physicists are working with metaphysical questions, as they gave up given a mathematical description of their theories.

Regards

EP
Vast said:
If its a metaphysical question or not doesn’t really matter. If you haven’t noticed these are the question physicists deal with everyday.

Unless you agree with the Popes advice given to physicists in a conference in 1981 that we should not inquire into the big bang itself because that was the moment of creation and thus the work of god.
 
  • #10
Epsilon Pi said:
as they gave up given a mathematical description of their theories.

All their theories are based on mathematics, it's philosophers who need mathematical experience to understand these theories…
 
  • #11
Lama:
I think it is a very interesting question in the case that there can be infinitely many different Plank-like constants, where each constant is the initial unit of another universe.

In this case we can ask if there can be any connection between two universes, which are based on different Plank-like constants.

Kurious:
I would suspect that two universes with different Planck constants couldn't interact,
if each universe had the same particles in it.This is because the energy levels of atoms in each universe would be different and so phenomenoa such as absorption of photons from one universe by electrons in atoms of another would not occur.
Also, we would expect anisotropies in microwave background if other universes could contribute to our microwave background.However, a Planck constant that varies with time in our universe is a possibility, provided the other constants of nature vary too.
 
  • #12
Existence... then logic... then science?
 
  • #13
What about if their mathematical descriptions are askew, as is the prevailing paradigm? Their conclusions will be metaphysical in this stage of science; they do not agree in their cosmological point of view, as we have seen lately
What is a mathematical experience? I thought mathematics were a tool invented by human mind to interpret and describe, in the case of physicists, the physical world

Regards
EP
Vast said:
All their theories are based on mathematics, it's philosophers who need mathematical experience to understand these theories…
 
  • #14
kurious said:
I would suspect that two universes with different Planck constants couldn't interact.
I agree with you. In that case we can think about a universe which its initial plank-like constant is in the size of our universe.
 

1. What is the initial size of the universe?

The initial size of the universe is currently unknown. Scientists estimate that the universe began as a singularity, an infinitely dense and hot point, and has been expanding ever since the Big Bang approximately 13.8 billion years ago.

2. How do scientists determine the initial size of the universe?

Scientists use various methods, such as measuring the cosmic microwave background radiation and the expansion rate of the universe, to estimate the initial size of the universe. However, these methods only provide approximations and the exact size is still unknown.

3. Can the initial size of the universe be measured?

No, the initial size of the universe cannot be directly measured. The universe was extremely dense and hot in its early stages, making it impossible to obtain accurate measurements. Scientists can only make estimations based on various observations and theories.

4. Has the initial size of the universe changed over time?

Yes, the initial size of the universe has changed over time. The universe has been expanding since the Big Bang, and its size continues to grow. The rate of expansion has also changed, with the universe expanding faster in the past than it is currently.

5. Is the initial size of the universe infinite?

It is currently unknown if the initial size of the universe was infinite or not. Some theories suggest that the universe could be infinite, while others propose that it has a finite size. However, due to the expansion of the universe, its current size is much larger than its initial size.

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