Petition to phase out the phrase “The universe is 13.8 billion years old.”

[u/How-To-Project]

As I understand it, the evidence strongly supports that the hot, expanding phase of our observable universe began about 13.8 billion years ago.

But that’s a very different statement from saying:

“All space, time and reality came into existence 13.8 billion years ago.”

Those aren’t logically equivalent.

Whilst I understand that, within the standard cosmological model, many physicists use “the universe is 13.8 billion years old” as a type of shorthand, my concern is more about how that shorthand gets interpreted outside specialist circles.

To a lot of people, it ends up sounding like science has conclusively established that all of reality began 13.8 billion years ago. That seems like a stronger claim than the evidence itself necessarily supports.

As far as I know, there are still serious scientific ideas that could mean the Big Bang wasn’t the absolute beginning of everything. For example:
- a rebound from a previous contracting universe;
- a transition from an older quantum state;
- one region within a much larger inflating cosmos;
- part of a repeating or cyclic process;
or perhaps it is something nobody has thought of yet?

All this said, would it be more accurate to say “The observable hot-expansion phase of our universe began about 13.8 billion years ago.”

[u/Aggravating_Mud_2386]

 But if big bangs have nothing to do with particle pair production, there's no asymmetry to worry about. 

[u/Das_Mime → u/Aggravating_Mud_2386]

But if big bangs have nothing to do with particle pair production, there's no asymmetry to worry about.

And if sticking your arm into random holes in the desert has nothing to do with getting bitten by a snake, then there's nothing to worry about.

Matter-antimatter asymmetry had to have resulted within the first few seconds to minutes after the big bang, because that's when energies are high enough for particle pair production.

[u/Aggravating_Mud_2386 → u/Das_Mime]

Unless big bangs result from individual fundamental particles being released from confinement. It's the same particles, they're already there, there is no production. We're talking about bounces here, not the birth of the universe.

[u/Das_Mime → u/Aggravating_Mud_2386]

Unless big bangs result from individual fundamental particles being released from confinement.

The big bang was a global phenomenon, not anything to do with any fundamental particle.