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Category: time travel – Page 7

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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Credits:

Continue reading “Time Travel” | >

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.

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.”

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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.

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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.

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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!

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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.

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.”

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The research uses the genomes of 241 species.

A species is a group of living organisms that share a set of common characteristics and are able to breed and produce fertile offspring. The concept of a species is important in biology as it is used to classify and organize the diversity of life. There are different ways to define a species, but the most widely accepted one is the biological species concept, which defines a species as a group of organisms that can interbreed and produce viable offspring in nature. This definition is widely used in evolutionary biology and ecology to identify and classify living organisms.

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