Sep 20, 2023
Paradox-free time travel is ‘logically’ possible, say physicists
Posted by Shailesh Prasad in categories: physics, time travel
Grandfathers, take heart. You’ll survive the paradox that’s been gunning for you since the 1930s.
Grandfathers, take heart. You’ll survive the paradox that’s been gunning for you since the 1930s.
“Lightning” system connects photons to the electronic components of computers using a novel abstraction, creating the first photonic computing prototype to serve real-time machine-learning inference requests.
Computing is at an inflection point. Moore’s Law, which predicts that the number of transistors on an electronic chip will double each year, is slowing down due to the physical limits of fitting more transistors on affordable microchips. These increases in computer power are slowing down as the demand grows for high-performance computers that can support increasingly complex artificial intelligence models. This inconvenience has led engineers to explore new methods for expanding the computational capabilities of their machines, but a solution remains unclear.
Potential of Photonic Computing.
Is time travel possible, and if it is, what sort of civilizations would result? We’ll explore the science that might permit it as well as the classic science fiction examples to see if they make sense.
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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 https://www.youtube.com/watch?v=79LciHWV4Qs) and Penrose’s Conformal Cyclic Cosmology https://www.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.
Continue reading “Before the Big Bang 11: Did the Universe Create itself? The PTC model” »
Whether you find yourself laying awake at night crippled with anxiety regarding the embarrassing errors of your past, or just love Christopher Nolan’s non-linear storytelling, you may be shocked to learn about the latest scientific discovery. According to a recent write-up from Science Alert, time travel may actually be achievable, using the powerful time dilation of interstellar wormholes.
Scientists claim they’ve calculated a potential new method of time travel involving a theoretical object called a ring wormhole.’ Here are the details.
Theoretical physicists have a lot in common with lawyers. Both spend a lot of time looking for loopholes and inconsistencies in the rules that might be exploited somehow.
Valeri P. Frolov and Andrei Zelnikov from the University of Alberta in Canada and Pavel Krtouš from Charles University in Prague probably couldn’t get you out of a traffic fine, but they may have uncovered enough wiggle room in the laws of physics to send you back in time to make sure you didn’t speed through that school zone in the first place.
Shortcuts through spacetime known as wormholes aren’t recognized features of the cosmos. But for the better part of a century, scientists have wondered if the weft and warp instructed by relativity prescribe ways for quantum ripples – or even entire particles – to break free of their locality.
Astrophysicist Geraint Lewis of the University of Sydney in Australia recently authored a study about time dilation and said that Doctor Who’s description of time travel is accurate, as we truly don’t yet understand the limitations of time (via Reuters).
Sci-fi shows like Doctor Who can usually rely on the audience’s suspension of disbelief when diving into heady concepts, and the science doesn’t always have to be accurate — though it is much cooler when a show gets the science right. Apparently, the long-running BBC series can take pride in the fact that the Doctor’s description of time as ‘wibbly-wobbly, timey-wimey stuff, is co-opted by real-life astrophysicists.
In other words, theoretical concepts like time travel and warp drives could be possible, or they may not be. Maybe a Time Lord out there uses a British police box to travel through time. Okay, so Doctor Who probably isn’t right about that part, but there technically is still a chance that it is!
Nothing prepared me for the disconnection from Earth that distorted my perception of time while submerged.
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 https://www.youtube.com/watch?v=79LciHWV4Qs) and Penrose’s Conformal Cyclic Cosmology https://www.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.
Continue reading “Before the Big Bang 11: Is the Universe a Time Machine?” »