What Was The Universe Like Before The Big Bang?

What Happened Before the Big Bang

An artist’s illustration showing the patterns of signals generated by primordial standard clocks in different theories of the primordial universe. Top: Big Bounce. Bottom: Inflation. Credit: CfA/Zhong-Zhi Xianyu, Xingang Chen, Avi Loeb

A team of scientists has proposed a powerful new test for inflation, the theory that the universe dramatically expanded in size in a fleeting fraction of a second right before the Big Bang. Their goal is to give insight into a long-standing question: what was the universe like before the Big Bang?

Although cosmic inflation is well known for resolving some important mysteries about the structure and evolution of the universe, other very different theories can also explain these mysteries. In some of these theories, the state of the universe preceding the Big Bang – the so-called primordial universe – was contracting instead of expanding, and the Big Bang was thus a part of a Big Bounce.

To help decide between inflation and these other ideas, the issue of falsifiability – that is, whether a theory can be tested to potentially show it is false – has inevitably arisen. Some researchers, including Avi Loeb of the Center for Astrophysics | Harvard & Smithsonian (CfA) in Cambridge, Massachusetts, have raised concerns about inflation, suggesting that its seemingly endless adaptability makes it all but impossible to properly test.

“Falsifiability should be a hallmark of any scientific theory. The current situation for inflation is that it’s such a flexible idea, it cannot be falsified experimentally,” Loeb said. “No matter what value people measure for some observable attribute, there are always some models of inflation that can explain it.”

Now, a team of scientists led by the CfA’s Xingang Chen, along with Loeb, and Zhong-Zhi Xianyu of the Physics Department of Harvard University, have applied an idea they call a “primordial standard clock” to the non-inflationary theories, and laid out a method that may be used to falsify inflation experimentally. The study will appear in Physical Review Letters as an Editors’ Suggestion.

In an effort to find some characteristic that can separate inflation from other theories, the team began by identifying the defining property of the various theories – the evolution of the size of the primordial universe.

“For example, during inflation, the size of the universe grows exponentially,” Xianyu said. “In some alternative theories, the size of the universe contracts. Some do it very slowly, while others do it very fast.

“The attributes people have proposed so far to measure usually have trouble distinguishing between the different theories because they are not directly related to the evolution of the size of the primordial universe,” he continued. “So, we wanted to find what the observable attributes are that can be directly linked to that defining property.”

The signals generated by the primordial standard clock can serve such a purpose. That clock is any type of heavy elementary particle in the primordial universe. Such particles should exist in any theory and their positions should oscillate at some regular frequency, much like the ticking of a clock’s pendulum.

The primordial universe was not entirely uniform. There were tiny irregularities in density on minuscule scales that became the seeds of the large-scale structure observed in today’s universe. This is the primary source of information physicists rely on to learn about what happened before the Big Bang. The ticks of the standard clock generated signals that were imprinted into the structure of those irregularities. Standard clocks in different theories of the primordial universe predict different patterns of signals because the evolutionary histories of the universe are different.

“If we imagine all of the information we learned so far about what happened before the Big Bang is in a roll of film frames, then the standard clock tells us how these frames should be played,” Chen explained. “Without any clock information, we don’t know if the film should be played forward or backward, fast or slow, just like we are not sure if the primordial universe was inflating or contracting, and how fast it did so. This is where the problem lies. The standard clock put time stamps on each of these frames when the film was shot before the Big Bang and tells us how to play the film.”

The team calculated how these standard clock signals should look in non-inflationary theories, and suggested how they should be searched for in astrophysical observations. “If a pattern of signals representing a contracting universe were found, it would falsify the entire inflationary theory,” Xianyu said.

The success of this idea lies in experimentation. “These signals will be very subtle to detect,” Chen said, “and so we may have to search in many different places. The cosmic microwave background radiation is one such place, and the distribution of galaxies is another. We have already started to search for these signals and there are some interesting candidates already, but we need more data.”

Many future galaxy surveys, such as US-lead LSST, European’s Euclid, and the newly approved project by NASA, SphereX, are expected to provide high-quality data that can be used toward the goal.


“Unique Fingerprints of Alternatives to Inflation in the Primordial Power Spectrum” by Xingang Chen, Abraham Loeb and Zhong-Zhi Xianyu, 28 March 2019, Physical Review Letters.
DOI: 10.1103/PhysRevLett.122.121301
arXiv: 1809.02603

“Quantum primordial standard clocks” by Xingang Chen, Mohammad Hossein Namjoo and Yi Wang, 4 February 2016, Journal of Cosmology and Astroparticle Physics.
DOI: 10.1088/1475-7516/2016/02/013
arXiv: 1509.03930

34 Comments on "What Was The Universe Like Before The Big Bang?"

  1. There was no big bang the universe is electric it’s not expanding there’s no black holes there plasmids there’s no dark energy dark matter all buls#!t made up to keep the false hope of gravitic and nebula forming galactic buls#!t going no gas sun’s it’s call plasma and Electricity. Stop everyday some bs article comes out about more B’s they made up on a cpu model what a joke.

    • TechOmega08 | May 8, 2020 at 2:48 pm | Reply

      If you’re the next Einstein, why are you well known and why don’t you know how to form complete sentences with correct grammar? It’s hard to understand your argument when you’re only complaining about someone else’s but not offering any substatiating counter-claims.

  2. Another Earth | March 26, 2019 at 9:02 am | Reply

    Once we measure and prove exactly what happened at Big Bang, it will collapse universe’s wave function and the universe as we know it will disappear.

  3. Torbjörn Larsson | March 26, 2019 at 11:00 am | Reply

    “No matter what value people measure for some observable attribute, there are always some models of inflation that can explain it.”

    But the same generality can be said for general relativistic cosmology, it can always explain these expanding and/or collapsing universes, or for particle physics, it can always explain particles and their fields. And notably here, all these other cosmologies has exactly the same problem.

    The trick is as always, to compete theories instead of opinionate. Which is why currently inflation is – AFAIK – the consensus choice.

    @Sergio, AE: No. No evidence from you, no new believers for you. Meanwhile, please stop polluting comment threads with worthless opinion.

  4. @ Sergio,
    Is the Earth flat?

  5. Sergio, please do some real research and stop being a troll. From where I sit you look like one of those prick who acts stupid in order to give people who have an opinion you don’t agree with a bad name. No one can possibly have as poor grammar and lack of sense as you have displayed.

    Surprises me how any real theories can explain the universe before it became the universe. We don’t even know which laws of physics did or didn’t exist back then. And these theories are impossible to verify for certain without a time machine or magical crystal ball.

    • This is scitechdaily,not kjv only bible study group. Please keep your theology out of this science discussion. Also,Sergio, no just no

  6. My, my, my. Thank you folks for the sensible follow up and thoughts based on the article. Always a pleasure to listen to intelligent and learned people. As for Another Earth, do you have inside knowledge or experimental evidence of your theory? As to Sergio, I promote you to Tin Hat General.

  7. Ha ha. Ha ha. Ha ha. Ha ha ha ha. I laugh at you.

  8. The question “What was the universe like before the Big Bang?” presupposes the event BB. But has it been been conclusively proved yet?

  9. Michael Tomczyk | July 5, 2019 at 4:51 am | Reply

    What if we are essentially an exploding firecracker in a larger universe? We evolved chemically on one of the exploded bits of the firecracker like Tony mites we see on our world. We would not be able to see beyond our “universe” because we are on one of the bits that is expanding from the original firecracker explosion. We cannot see giants in the larger universe any more than a bacterium can see a human. Which once again begs the question, what existed before the firecracker and how can we wrap our minds around or explain the notion that at one time there was “nothing” that somehow became “something.”

  10. Once we find out the how we can work on the why.

  11. Neal Jacobsen | August 3, 2019 at 5:48 pm | Reply

    I believe that the universe was always there and the statement that there was some small particle that blew up causing this “Big Bang” is unfathomable. Not if your trying to tell me that right away there were 10 million galaxies. Some of the galaxies are really, really old and from before this big bang. Let’s get real with this. We haven’t seen the end of the universe so how can we really say it is contracting or expanding? Did time start with this big bang too? I think too many things are being taken for granted. I am not scientist but surely some of these ideas evade common sense.

  12. There was nothing material before the big bang…

  13. There is and was no big bang, no explosion can create order. The big bang also goes against the Laws of Thermodynamics, stop proposing this made up weird assumption as science. Also this false faith erases God and teaches people they all evolved from a rock and the universe is billions of years old. None of that is true, people are not animals, nothing evolved, there was no big bang, God created the heavens and the earth, and God created man. Jesus Christ is God .

  14. I didn’t get it.

  15. Ugh, Avi Loeb.

  16. Chris Matthewson | May 19, 2020 at 11:42 am | Reply

    Any theory that is neither provable nor negatable is just speculation. The genius is not coming up with a theory, but in proving or disproving it.

  17. Thomas E Hiles | May 19, 2020 at 12:53 pm | Reply

    Oh my God people who cares.

  18. Sanghesh Bhimte | May 24, 2020 at 1:31 pm | Reply

    Something can not be emarge from nothing,before the big bang matters were exist before atom elections,protons & neutrons and before them what were there? Of course letest theary of higs boson.so we need more & more knowledge.there is no limit.

  19. Robert Archuleta | July 15, 2020 at 12:10 am | Reply

    Before the universe God’s Spirit hoovered over the darkness (space) . He said with the words Let thier be light and thier was light (the big bang). He separated the light from the dark (sun’s and sunlight ).

  20. … the standard model assumes that the generations are all the time reversible, however that might not be the case in the very first stage of an early universe.
    That needs to be proven, too! …
    You know, beyond reasonable doubt………a
    The fact is that scientists have kicked few cans out of the way, and that is haunting modern world of physics.

  21. As Einstein wrote: For we convinced physicists, the distinction between past, present, and future is only a stubbornly persistent illusion. Then, when was big bang?

  22. It was a black hole in a state of critical mass!

  23. Quit acting as if the Big Bang was a “thing”. It is an idea. And there are other ideas. What if the red shift was misinterpreted. The notion that everything came into existence in a single moment for no discernable reason is the ultimate test for credulity. It is the least likely of all possibilities. How far will “scientist” go in the wrong direction to make their theories work. Dark matter? Multiple infinities and imaginary numbers and neuron stars. I was drawn in for decades after my science degree. Then one day I thought, ” This is preposterous ” and with the internet available I searched for alternative ideas. And there they were. Science is a religion. And my post is blasphemous. I don’t believe a word cosmologist say anymore. Just look at the science news. It is full of titles like, “Scientist puzzled by new data”, “what if there is no dark matter. They made it up to balance the equations to promote their theories.

  24. My God this is a lame excuse for a science article. With commentary that stretches back two years, the best they can do to counter the glaringly obvious fact that when you remove cause and effect you delve into magical thinking, & the standard model is exposed as religion not science; is rehash easily debunked nonsense using the core belief (and I don’t use that word lightly) of the standard model, ie: the universe is expanding. Well? Either it’s expanding or it’s contracting. You can’t have it both ways. They’re like clergymen trying to explain the trinity. It’s ####ing horse####!

  25. Hello everyone…..See the bitter fact is that Scientists are fooling us since the very start….. I have worked on this problem for the last 37 years along with my team of esteemed physicists and finally after years of sleepless nights i have found all the deep hidden answers and discovered the FINAL COSMOLOGICAL THEORY which describes every bit about universe and all the answers about universe,its origin,myth of big bang,illusion of time,what was there before our universe came into existence,myth of supernova and black holes,cosmic microwave backround,parallel universe,multiverse,branes and the ever idiotic standard model !!!!! And my theory is not just an idea like other models , every bit of my theory is testable and can be verified experimentally . But i cant reveal my theory for atleast next 8 months because its being peer reviewed and moreover its being submitted for detailed analysis and experimental verification by esteemed scientists / physicists . As my theory is in contention for this years NOBEL PRIZE IN PHYSICS i am ethically bound to not to publish it before that . But come october-2021 when we receive the Nobel Prize we will REVEAL IT TO THE WORLD and everything about physics and older outdated theories and Concepts like General and Special Theory of Relativity , String Theory , Superstring theory , Quantum Mechanics , Quantum Gravity will be thrown away to get Dumped in the Dustbin . We have found the Answers to Everything and it will be the ULTIMATE THEORY OF EVERYTHING !!  So i request you all to keep patience for just a few months to witness the greatest day in the history of mankind . But if anyone still cant keep patience , can contact me at my email or phone no but with a promise to not to reveal anything about the theory till we officially release it .

  26. Judging merely by the illustration, the universe appears to be FM.

  27. There is big blast universe has time limit ,start from big blast and end at critical merge point.

  28. cheese

  29. 🧀🧀🧀🧀

  30. BIDENSUCKS@$$ TRUE | November 15, 2023 at 4:03 pm | Reply


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