Phil Halper (aka Skydivephil) | Before the Big Bang 11: Did the Universe Create itself ? The PTC model @PhilHalper1 | Uploaded April 2023 | Updated October 2024, 1 week ago.
What happened before the Big Bang? In two of our previous films we examined cyclic cosmologies and time travel universe models. Specially, the Gott and Li Model youtube.com/watch?v=79LciHWV4Qs) and Penrose's Conformal Cyclic Cosmology youtube.com/watch?v=FVDJJVoTx7s) . Recently Beth Gould and Niayesh Afshordi of the Perimeter Institute for Theoretical Physics have fused these two models together to create a startling new vision of the universe. In this film they explain their new proposal, known as Periodic Time Cosmology.
0:00 Introduction
0:45 NIayesh's story
1:15 Beth's story
2:25 relativity
3:26 Gott & Li model
6:23 origins of the PTC model
8:17 PTC periodic time cosmology
10:55 Penrose cyclic model
13:01 Sir Roger Penrose
14:19 CCC and PTC
15:45 conformal rescaling and the CMB
17:28 assumptions
18:41 why a time loop?
20:11 empirical test
23:96 predcitions
26:19 inflation vs PTC
30:22 gravitational waves
31:40 cycles and the 2nd law
32:54 paradoxes
34:08 causality
35:17 immortality in a cyclic universe
38:02 eternal return
39:21 quantum gravity
39:57 conclusion
Elizabeth Gould has asked to make this clarification in the written text " "Despite the availability of infinite time in the periodic time model, this doesn't lead to thermalization in a typical time-evolution scenario, and therefore doesn't, strictly speaking, solve the problem related to thermalization in the power spectrum. The reason for this is that, unlike bounce models with a net expansion each cycle, our model has an effective contraction during the conformal phases. Periodic time, therefore, has a unique character in which it reuses the power spectrum from the previous cycles, which is confined to a given form due to the constraints of the system, rather than removing the old power spectrum and needing to produce a new one."
What happened before the Big Bang? In two of our previous films we examined cyclic cosmologies and time travel universe models. Specially, the Gott and Li Model youtube.com/watch?v=79LciHWV4Qs) and Penrose's Conformal Cyclic Cosmology youtube.com/watch?v=FVDJJVoTx7s) . Recently Beth Gould and Niayesh Afshordi of the Perimeter Institute for Theoretical Physics have fused these two models together to create a startling new vision of the universe. In this film they explain their new proposal, known as Periodic Time Cosmology.
0:00 Introduction
0:45 NIayesh's story
1:15 Beth's story
2:25 relativity
3:26 Gott & Li model
6:23 origins of the PTC model
8:17 PTC periodic time cosmology
10:55 Penrose cyclic model
13:01 Sir Roger Penrose
14:19 CCC and PTC
15:45 conformal rescaling and the CMB
17:28 assumptions
18:41 why a time loop?
20:11 empirical test
23:96 predcitions
26:19 inflation vs PTC
30:22 gravitational waves
31:40 cycles and the 2nd law
32:54 paradoxes
34:08 causality
35:17 immortality in a cyclic universe
38:02 eternal return
39:21 quantum gravity
39:57 conclusion
Elizabeth Gould has asked to make this clarification in the written text " "Despite the availability of infinite time in the periodic time model, this doesn't lead to thermalization in a typical time-evolution scenario, and therefore doesn't, strictly speaking, solve the problem related to thermalization in the power spectrum. The reason for this is that, unlike bounce models with a net expansion each cycle, our model has an effective contraction during the conformal phases. Periodic time, therefore, has a unique character in which it reuses the power spectrum from the previous cycles, which is confined to a given form due to the constraints of the system, rather than removing the old power spectrum and needing to produce a new one."
