Explaining Cosmic Inflation using analogies

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Discussion Overview

The discussion centers on using analogies to explain the concept of Cosmic Inflation, exploring various comparisons to help convey the scale and implications of this phenomenon. Participants examine the effectiveness of these analogies and question their accuracy in representing the actual inflationary process.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant proposes an analogy comparing the universe's growth from subatomic size to that of a tennis ball, questioning whether a football inflated at the same rate would approximate the size of the solar system or be much larger.
  • Another participant references an analogy from Space.com, suggesting that if the universe doubled in size 90 times, it could be compared to a football growing to a size around 10^25 meters in diameter, and asks if this calculation is correct.
  • A third participant agrees that the calculations seem to be in the right order of magnitude, emphasizing the incomprehensibility of the scale of inflation and noting that it is far larger than the Milky Way.
  • A summary post reiterates the analogy of the universe growing from subatomic to softball size and raises caution about the accuracy of these comparisons, suggesting that the observable universe's growth should be described as exponential and involving many regions.

Areas of Agreement / Disagreement

Participants express differing views on the accuracy and implications of the analogies presented. There is no consensus on the correctness of the analogies or the calculations involved, and the discussion remains unresolved regarding the best way to conceptualize Cosmic Inflation.

Contextual Notes

Some limitations include the potential oversimplification of complex concepts, the dependence on specific definitions of size and growth, and the unresolved nature of the calculations regarding the size comparisons.

Paolo 2008
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TL;DR
Cosmic Inflation might be explained to the average person using simpler analogies.
An analogy to understand Cosmic Inflation: If the universe grew in size from a subatomic size to the size of a tennis ball (or softball) in a tiny fraction of a second, then a football inflated at the same rate will grow to an approximate size of our solar system. Is this a correct analogy? Wouldn't the football grow to several billion times our solar system? Or just one solar system is more approximate to a plausible analogy?
 
Space news on Phys.org
Here is another analogy I found on Space.com "During this period, the universe doubled in size at least 90 times, going from subatomic-sized to golf-ball-sized almost instantaneously". So, I was wondering if we double a football 90 times, would it grow to be the size of the solar system? Or way larger, I calculated it to be something in the vicinity of 10^25 meters in diameter. Anybody agrees or am I miscalculating?
 
Without even doing any calculation I can see that it is definitely in the right ballpark in terms of orders of magnitude, which means it is MANY orders of magnitude larger than the milky way, to say nothing of being a bit larger than the solar system.

The magnitude of inflation is, to my mind, literally incomprehensible. It's just numbers. I don't mean to suggest that it's not correct, just that it is WAY far outside of human understanding as anything other than numbers.
 
Paolo 2008 said:
Summary: Cosmic Inflation might be explained to the average person using simpler analogies.

An analogy to understand Cosmic Inflation: If the universe grew in size from a subatomic size to the size of a tennis ball (or softball) in a tiny fraction of a second, then a football inflated at the same rate will grow to an approximate size of our solar system. Is this a correct analogy? Wouldn't the football grow to several billion times our solar system? Or just one solar system is more approximate to a plausible analogy?
Some caution. Would it not be better to rather say that the observable universe grew exponentially from subatomic size to a softball size in a tiny fraction of a second. There were probably many, even infinitely many such regions, making up the Universe. Then, without specifying times for simplicity, one can say that a phase transition happened, dumping some of that kinetic energy into particles of matter, bringing the inflation period to an end. From there on it was just decelerating expansion, until dark energy lately again started pushing the observable universe towards exponential expansion again.
 
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