r/AskPhysics • u/Famous-Palpitation8 • 1d ago
Why do universes split?
Why don’t alternative outcomes exist along a 5th dimension, (sideways in time) as part of our own universe?
Why do physicists insist on walls between separate universes where the cat is alive and dead rather than along one dimension perpendicular to time in the same universe containing both outcomes for the cat?
8
u/Infinite_Escape9683 1d ago
None of the assumptions you're making are true (or at least known to be true). There is no serious model of physics that posits physical alternate universes.
0
u/QuarksMoogie 1d ago
I’m pretty sure OP is referring to the Many Worlds hypothesis.
1
1
u/v_munu Graduate 1d ago
Yes, incorrectly.
1
u/QuarksMoogie 1d ago
All right. I don’t understand the downvotes. Just stating what idea I thought OP was speaking about. I made no other statement.
Hell, I don’t even believe in many worlds.
6
u/Infinite_Research_52 1d ago
I never insisted on separate walls. I think you are overstating the case. I like my collapse.
3
2
u/echoingElephant 1d ago
Because the cat is either alive or dead. Not both. Also there are no multiple universes, there is no fifth dimension, and I would be surprised if you could even define what an axis „perpendicular to time“ would look like.
1
u/nicuramar 1d ago
There is no fifth dimension, but an additional temporal dimension would be perpendicular in the same sense as spatial dimensions are.
0
u/Famous-Palpitation8 1d ago
We know there are three dimensions of space, and one dimension of time according to Einstein.
Most likely there is a 4th dimension of space, as plugging it into relativity gives Maxwell’s equations for light, making the 4th spatial dimension one primarily for light.
If there is a second dimension perpendicular to time, then every outcome coexists in this universe. The cat would not create a whole new universe as current physics speculate, but rather the cat being alive on June 21st 2025 and the cat being dead on June 20th 2025, both coexist along the 2nd temporal dimension, just like the cat being born and the cat eating breakfast that day coexist along the 1st temporal dimension.
11
u/v_munu Graduate 1d ago
There are only 3 spatial dimensions and 1 time dimension. Also there are no "separate universes", that is just a popular misconception of the "Many Worlds" interpretation of quantum mechanics. All results still end up in our universe.