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Did Time Start at the Big Bang?

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Did Time Start at the Big Bang?

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Our universe started with the big bang. But only for the right definition of “our universe”. And of “started” for that matter. In fact, probably the Big Bang is nothing like what you were taught.
A hundred years ago we discovered the beginning of the universe. Observations of the retreating galaxies by Edwin Hubble and Vesto Slipher, combined with Einstein’s then-brand-new general theory of relativity, revealed that our universe is expanding. And if we reverse that expansion far enough – mathematically, purely according to Einstein’s equations, it seems inevitable that all space and mass and energy should once have been compacted into an infinitesimally small point – a singularity. It’s often said that the universe started with this singularity, and the Big Bang is thought of as the explosive expansion that followed. And before the Big Bang singularity? Well, they say there was no “before”, because time and space simply didn’t exist. If you think you’ve managed to get your head around that bizarre notion then I have bad news. That picture is wrong. At least, according to pretty much every serious physicist who studies the subject. The good news is that the truth is way cooler, at least as far as we understand it.


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What Happened Before the Big Bang?

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We actually have a pretty good idea of what might have happened before the Big Bang. That is, as long as we define the Big Bang as the extremely hot, dense, rapidly expanding universe that is described by Einstein’s equations. That picture of the universe is very solid down to about a trillionth of a second after the supposed beginning of time. We can make good guesses down to about 10^-30th of a second. But before that?

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What Came Before the Big Bang?

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What Came Before the Big Bang? – Second Thought

Modern science seems to agree that our universe began with a monumental explosion, but do we know what came before the Big Bang? Watch to find out!

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The Beginning of Everything -- The Big Bang

How did everything get started?

Has the universe a beginning or was it here since forever? Well, evidence suggests that there was indeed a starting point to this universe we are part of right now. But how can this be? How can something come from nothing? And what about time? We don't have all the answers yet so let's talk about what we know.

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The Beginning of Everything -- The Big Bang

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What Came Before The Big Bang? A Time Before Time

Astronomers are pretty sure what happened after the Big Bang, but what came before? What are the leading theories for the causes of the Big Bang?

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About 13.8 billion years ago the Universe started with a bang, kicked the doors in, brought fancy cheeses and a bag of ice, spiked the punch bowl and invited the new neighbors over for all-nighter to encompass all all-nighters from that point forward.
But what happened before that?

What was going on before the Big Bang? Usually, we tell the story of the Universe by starting at the Big Bang and then talking about what happened after. Similarly and completely opposite to how astronomers view the Universe... by standing in the present and looking backwards. From here, the furthest we can look back is to the cosmic microwave background, which is about 380,000 years after the big bang.

Before that we couldn't hope to see a thing, the Universe was just too hot and dense to be transparent. Like pea soup. Soup made of delicious face burning high energy everything.
In traditional stupid earth-bound no-Tardis life unsatisfactory fashion, we can’t actually observe the origin of the Universe from our place in time and space.

Damn you… place in time and space.

Fortunately, the thinky types have come up with some ideas, and they’re all one part crazy, one part mind bendy, and 100% bananas.
The first idea is that it all began as a kind of quantum fluctuation that inflated to our present universe.

Something very, very subtle expanding over time resulting in, as an accidental byproduct, our existence.
The alternate idea is that our universe began within a black hole of an older universe.
I’m gonna let you think about that one. Just let your brain simmer there.

There was universe “here”, that isn't our universe, then that universe became a black hole… and from that black hole formed us and EVERYTHING around us. Literally, everything around us. In every direction we look, and even the stuff we just assume to be out there.

Here’s another one. We see particles popping into existence here in our Universe. What if, after an immense amount of time, a whole Universe’s worth of particles all popped into existence at the same time. Seriously… an immense amount of time, with lots and lots of “almost” universes that didn't make the cut.

More recently, the BICEP2 team observed what may be evidence of inflation in the early Universe.
Like any claim of this gravity, the result is hotly debated. If the idea of inflation is correct, it is possible that our universe is part of a much larger multiverse.
And the most popular form would produce a kind of eternal inflation, where universes are springing up all the time. Ours would just happen to be one of them.


It is also possible that asking what came before the big bang is much like asking what is north of the North Pole. What looks like a beginning in need of a cause may just be due to our own perspective.
We like to think of effects always having a cause, but the Universe might be an exception. The Universe might simply be. Because.

You tell us. What was going on before the party started? Let us know in the comments below.


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Did time begin at the big bang?

The question of what happened before the Big Bang is an interesting one: Did time actually start then or was there a pre-Big Bang universe? Brian Greene explores some possible answers to this question.

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What Was There Before The Big Bang? | Earth Unplugged

The common theory is that the universe began with the big bang, but what was there before?

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1. The beginning of the universe .. the big bang

The first in a series of videos aimed at explaining why we exist and exploring possible meaning. It is under 10 minutes so will not take too much of your time!! Designed for web viewing. To view a pdf explaining some of the key concepts please go to
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Astronomy: The Big Bang (13 of 30) Plank Era: The Beginning of Time

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In this video I will explain the Plank Era where all four forces are unified into a super force.

Why The Big Bang Isn't The Beginning Of The Universe — It's The End Of Something Else

The Big Bang is not the beginning of the universe, it is the end of our theoretical understanding of space and time. Prior to the Big Bang, we just don't know what existed. It's possible that our universe came from another universe entirely.

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What existed before the Big Bang?

Scientists have a few theories.

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What’s Wrong With the Big Bang Theory? | Space Time | PBS Digital Studios

There's a problem with the Big Bang Theory.

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Now that we have a primer on the aspects of the Big Bang Theory that we know definitely happened, let’s look further into what we don’t yet know, and how the theory could progress in the future. Since there is a discrepancy between general relativity and quantum mechanics, we continue to search for a grand unifying theory... one which may finally lead to a description of the actual moment of the Big Bang! On this week's Space Time, Matt describes what specifically needs fixing within the current theory, and the reasons why.

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Electroweak Era

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Does the Big Bang affirm a creator?

Leslie Wickman explains in 'God of the Big Bang'

EXCLUSIVE: Stephen Hawking on What Existed Before the Big Bang

In this exclusive clip, Tyson asks Hawking your standard softball interview question: what was around before the big bang? In other words, what happened before the moment the universe began? Check out Hawking’s answer:

“The boundary condition of the universe...is that it has no boundary,” Hawking says.

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Ripples From The Big Bang: Listening to the Beginning of Time

In March, a major breakthrough in understanding the origin of universe took the scientific community–and the general public–by storm. A team lead by astronomer John Kovac, using a powerful telescope at the South Pole, reported evidence of ripples in the fabric of space time produced by the big bang, a long-sought prediction of our most refined approach to cosmology, the inflationary theory. Amidst the worldwide celebration, though, some have been quietly suggesting that the champagne has been uncorked prematurely. Join a singular conversation, among the world’s most respected pioneers in cosmological theory and observation, that will explore the state of the art in the ongoing quest to understand the beginning of the universe.

This program is part of the Big Ideas Series, made possible with support from the John Templeton Foundation.

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Original Program Date: May 30, 2014
Host: Brian Greene
Participants: Andrei Linde, Alan Guth, Amber Miller, John Kovac, Paul Steinhardt

Brian Greene's Introduction. 00:12

Participant Introductions. 20:34

Can we confirm that there are ripples in the fabric of space? 22:19

What did you find with BICEP2? 26:05

What is the inflationary theory? 31:46

What is making the universe accelerate? 37:33

What were the main issues with the inflationary theory? 44:42

What is chaotic inflation? 51:22

How do we calculate density motivations? 59:00

Looking for cosmic fluctuation. 1:03:40

How close were the predictions to the observations? 1:09:03

How confident are you that the swirls are coming from quantum fluctuations? 1:14:40

What are the concerns about the inflationary theory? 1:23:49

Final thoughts. 1:29:33
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What Caused the Big Bang?

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Every astronomy textbook tells us that soon after the Big Bang, there was a period of exponentially accelerating expansion called cosmic inflation. In a tiny fraction of a second, inflationary expansion multiplied the size of the universe by a larger factor than in the following 13 and a half billion years of regular expansion. This story seems like a bit of a … stretch. Is there really any mechanism that could cause something like this to happen? What what we’re covering today – the real physics of cosmic inflation.

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The Quantum Vacuum and Hawking Radiation Playlist


Most cosmologists buy some variation of the inflation hypothesis. It seems to very neatly solve some of the biggest questions in cosmology. Those being: why is matter and energy so smoothly spread out across the entire observable universe? And why is the geometry of the universe so flat? Neither should be expected unless the universe expanded much more rapidly early on. We explored these problems in an earlier video – worth a look if you really want to get inflation. Another problem fixed by inflation is the absence of magnetic monopoles – strange particles predicted to have been produced in the early universe. We’ll come back to those another time.


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Why the Big Bang Definitely Happened | Space Time | PBS Digital Studios

How physics lets us rewind time to the beginning of the universe.

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We pretty much know for sure that the universe was once extremely small, and extremely hot. And we know that something set it in motion, expanding rapidly and continuing to do-so today. But the actual moment of ‘the Big Bang’ is still a bit of a grey area within physics. The theories of general relativity and quantum mechanics disagree on this pivotal “beginning of time,” and physicists continue to search for an all-encompassing theory to unify the study of our universe. On this week’s Space Time, we begin to discuss the current state of the Big Bang Theory, and where it could go from here.

FURTHER READING:

Overview of Big Bang theory


Timeline of the Big Bang


MinutePhysics made a truly superb video on what the Big Bang really is:


Kurzgesagt does a great job describing some of the events of the very early universe:


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Before the Big Bang 5: The No Boundary Proposal

In this film Stephen Hawking, James Hartle and Thomas Hertog explain their model of the early universe: The No Boundary Proposal. In the 1960’s and 70’s Hawking and Penrose showed that according to classical general relativity, given some minimal assumptions the origin of an expanding universe is a singularity: a point of infinite density and spacetime curvature. But this and other singularity theorems do not take into account the strange world of quantum mechanics. So in the 1980’s Hawking and collaborators started to build a model of the big bang that included quantum effects.The result is the No Boundary Proposal, a model that may be able to explain some of the deepest mysteries of the cosmos such as, is there a multiverse? how is there an arrow of time and what really happened a the big bang?
This is the fifth in a series of films exploring competing models of the early universe. To see the other films click here:

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Presenter: Monica C
Sound:William Corbet
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For this film we hope you will notice a significant improvement in quality and this is very much down to 1185 films who co produced the film to ensure it has a beautiful cinematic look, feel and sound. To see more of their work click here:



Timeline of topics discussed:
00-1:19 intro
1:19 Singularity theorems
3:44 Hawking’s work on black holes and what they mean for the origin of the universe
4:11 Introducing the No Boundary Proposal in 1981
5:13 The key concept is the wave function
5:39 Feynman’s sum over histories
6:15 Explaining the concept of a path integral
6:40 What is Euclidean Spacetime?
7:36 Imaginary numbers and imaginary time
9:12 Explaining the Formula for the No Boundary Wavefunction
10:19 The shuttlecock
11:59 Inflation and the No Boundary Proposal
14:22 Predictions of the the theory
16:20 Falsification
16:55 Bottom Up versus Top Down
20:12 Eternal Inflation and the Multiverse
22:46 The No Boundary Proposal implies Inflation is not fine tuned
23:31 The No Boundary Proposal and the Cosmological Constant problem
25:33 Measure Problem, there’s a simpler way of doing it
26:532 Fine tuning and probability
27:16 Weinberg’s prediction of the cosmological constant and The No Boundary Proposal
28:30 Could the constants of nature be necessary?
29:25 Is the multiverse science?
31:03 The Boltzman Brian Problem
32:53 Stephen, Jim and Thomas’s latest work : holography and the No Boundary Proposal
35:18 Next Steps in Making the No Boundary Wave function more precise
37:14The Ground State
38:18 The Arrow of Time
39:27 Roger Penrose
39:50 A Big Bounce?
40:14 Aron Wall claims the No Boundary Proposal is eternal into the past
42:14 More on the Big Bounce
43:50 Alex Vilenkin alternative to the No Boundary Wavefunction
46:41 String theory
46:37 Unifying the Dynamics and the initial conditions of the universe
47:14 George Lemaitre in the multiverse in the 1930’s
47:58 Summing up

Before the Big Bang 6: Can the Universe Create Itself?

Richard Gott , co author with Neil De Grasse Tyson of Welcome to The Universe argues the key to understanding the origin of the universe may be the concept of closed time like curves. These are solutions to Einstein's theory that may allow time travel into the past. in this film, Richard Gott of Princeton University explains the model he developed with LIxin Li . Gott explores the possibility of a closed time like curve forming in the early universe and how this might lead to the amazing property of the universe being able to create itself. Gott is one of the leading experts in time travel solution to Einstein’s equations and is author of the book “Time Travel In Einstein’s Universe”.
This film is part of a series of films exploring competing models of th early universe with the creators of those models. We have interviewed Stephen Hawking, Roger Penrose, Alan Guth and many other leaders of the field. To see other episodes , click on the link below:


We would like to thank the following who helped us are this movie:
Animations:
Morn 1415
David Yates
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M Buser, E Kajari, and WP Schleich
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Ziri Younsi

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Photography Rob, Speakers Corner Uk


Thanks to:
University College London
Princeton University Press
Howard Walwyn Fine Antique Clocks

Timeline:
00:00 Introduction
1:07 Working with Penzias and Wilson
1:42 relativity and time
2:58 the block universe
4:00 time travel in Einstein’s universe
4:54 Godel and time travel into the past
5:54 Cosmic Strings
7:43 Cosmic inflation
8:50 Bubble Universes
9:56 Lixin Li
12:11 The Gott Li self creating universe model
14:17 Jinn Particles
14:35 How to escape a time loop
16:14 Experimental test
20:05 Hawking’s Chronology Protection Conjecture
23:46 The Arrow of Time
29:00 The Second Law
33:00 Answering Hiscock’s criticisms
40:07 fine tuning
40:46 Boltzmann Brains
44:37 Quantum Entanglement and Wormholes
46:04 Uncertainty
47:11 A Universe from Nothing
50:25 Summing Up

Before the Big Bang: What Happened? - Space

The universe was born 13.7 billion years ago with the Big Bang. But what was there before? Scientists are starting to get an answer thanks to the time-travelling Planck mission.

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