Category: inflation

Don’t Believe These 5 Myths About The Big Bang

1.) The Big Bang is the explosion that began our Universe. Every time we look out at a distant galaxy in the Universe and try to measure what its light is doing, we see the same pattern emerge: the farther away the galaxy is, the more significantly its light is systematically shifted to longer and longer wavelengths. This redshift that we observe for these objects follows a predictable pattern, with double the distance meaning that the light is shifted by twice as much.

Distant objects, therefore, appear to be receding away from us. Just as a police car speeding away from you will sound lower-pitched the faster it moves away from you, the greater we measure an object’s distance to be from us, the greater the measured redshift of its light will be. It makes a lot of sense, then, to think that the more distant objects are moving away from us at faster speeds, and that we could trace every galaxy we see today back to a single point in the past: an enormous explosion.”

The Big Bang is not an explosion, it doesn’t have a center point that we can trace the expansion back to, it never reached an infinitely hot-and-dense state, it doesn’t imply that the Universe began from a singularity, and it doesn’t take you back to a moment where space, time, and the laws of physics all spontaneously emerged. Do you believe any of these statements? Do you know why they’re not true? 

Here’s the real physics behind what we know about our Universe’s origin, with the scientific evidence to back it all up!

The Universe Really Is Fine-Tuned, And Our Existence Is The Proof

“Whenever we run into an unexplained phenomenon, where two seemingly unrelated physical quantities match up either perfectly or almost perfectly, it’s our duty to seek out an explanation. Perhaps the outcome truly is a coincidence, but that should only be a conclusion we reach if we cannot find any other scientific explanation. The key is to tease out novel and unique predictions that can be put to the experimental or observational test; without it, our attempts at theorizing will remain divorced from reality.

The fact that our Universe has such a perfect balance between the expansion rate and the energy density — today, yesterday, and billions of years ago — is a clue that our Universe really is finely tuned. With robust predictions about the spectrum, entropy, temperature, and other properties concerning the density fluctuations that arise in inflationary scenarios, and the verification found in the Cosmic Microwave Background and the Universe’s large-scale structure, we even have a viable solution. Further tests will determine whether our best conclusion at present truly provides the ultimate answer, but we cannot just wave the problem away. The Universe really is finely tuned, and our existence is all the proof we need.”

When we examine the expansion rate of the Universe, we get a particular value, which ought to correspond to a particular energy density for the Universe when we apply General Relativity. When we go ahead and measure that energy density, adding up dark energy, dark matter, normal matter, radiation and all the other forms of energy, we get exactly the same answer. And I mean exactly, as if we extrapolate back in time, they match to more than 20 significant figures! When two unrelated quantities match so well without a known explanation, we call that a fine-tuning problem, and find ourselves compelled to seek a reason why. 

Here’s how to do it scientifically, rather than ideologically, and how to use that scenario to learn something profound about the Universe we inhabit.

This Is How Quantum Physics Creates The Largest Cosmic Structures Of All

“If not for quantum physics, the Universe would have been born perfectly smooth, with every region of space having the exact same temperature and density as every other region. As time went on, we would still have matter win out over antimatter, form the light elements through nucleosynthesis, and then create neutral atoms as the Universe expanded and cooled.

But we wouldn’t form stars and galaxies the way our Universe did. It would take many billions of years for even the first ones to form: many hundreds of times longer than we actually see. The existence of enormous galaxy clusters and a large-scale cosmic web would be forbidden, as the seeds of structure wouldn’t be there for them to grow. And dark energy would be the final nail-in-the-coffin, preventing the largest structures from ever forming.

The only reason we have them at all is because of the quantum nature of our Universe. It’s only because of the connection between the smallest and the largest scales — the quantum and the cosmic — that we can make sense of our Universe at all.”

Have you ever looked at maps of the Universe on the largest scales and seen galaxies clumped and clustered together along filamentary lines, with enormous nexuses separated by vast cosmic voids? That’s known as the large-scale structure of the Universe. Have you ever wondered why it looks the way it does?

Believe it or not, the answer to that lies in the quantum physics that occurred during the inflationary epoch that preceded the Big Bang. Come get the story for yourself.

What Really Put The ‘Bang’ In The Big Bang?

So what is it that put the “bang” in the hot Big Bang? It’s the end of inflation. There is a state prior to the start of the hot Big Bang that set it up and provided it with the initial conditions of being spatially flat, the same energy density everywhere, always below a certain threshold temperature, and uniform with quantum fluctuations superimposed atop it on all scales.

When this inflationary state ended, the process of cosmic reheating transformed that energy — which had previously been inherent to the fabric of space itself — into particles, antiparticles and radiation. That transition is what put the “bang” in the hot Big Bang, and led to the birth of the observable Universe as we know it. The details of this were first worked out in the 1980s, back when inflation was just a theoretical idea, and have been confirmed by observations taken in the 1990s, 2000s, and 2010s. For decades, scientists have known what put the “bang” in the Big Bang. At last, now the general public can share in that knowledge, too.

Last week, a story came out that claimed to discover what put the “bang” in the Big Bang. Only, the actual study talked about what occurs in a conflagration or an explosion, which is completely unrelated to anything that occurs in the earliest moments of the hot, dense state that kicked off our Universe as we know it. Fortunately, we don’t have to wonder about what put the “bang” in the Big Bang; this is something scientists have known for decades.

The answer? It’s the cosmic reheating that occurs at the end of inflation that gives rise to the first moments of the hot Big Bang. Come get the real, hype-free story today.

What Came First: Inflation Or The Big Bang?

“In fact, our entire observable Universe contains no signatures at all from almost all of its pre-hot-Big-Bang history; only the final 10^-32 seconds (or so) of inflation even leave observably imprinted signatures on our Universe. We do not know where the inflationary state came from, however. It might arise from a pre-existing state that does have a singularity, it might have existed in its inflationary form forever, or the Universe itself might even be cyclical in nature.

There are a lot of people who mean “the initial singularity” when they say “the Big Bang,” and to those people, I say it’s long past due for you to get with the times. The hot Big Bang cannot be extrapolated back to a singularity, but only to the end of an inflationary state that preceded it. We cannot state with any confidence, because there are no signatures of it even in principle, what preceded the very end-stages of inflation. Was there a singularity? Maybe, but even if so, it doesn’t have anything to do with the Big Bang.”

Have you heard that our Universe began some 13.8 billion years ago with the start of the Big Bang? There’s a good chance that some version of that story has made it to you, but it unfortunately has probably gotten to you the same way it got to me: with an error that’s many decades out of date. 

What if I told you that you couldn’t extrapolate the Universe back to a singularity, where all the matter and energy was consolidated into a space so tiny that the laws of physics break down?

What if I told you that we have a verified, validated theory of what happened before the Big Bang, and it has (for decades, now) superseded and replaced the idea of an initial singularity as the earliest stages of the Universe?

Meet cosmic inflation, the pre-origin of our Universe that set up and gave rise to the Big Bang, and learn why the naysayers are out of legs to stand on.

Was Dark Matter Really Created Before The Big Bang?

“So if that’s what the observational data points towards, what can we say about where dark matter comes from? A recent headline that made quite a splash claimed that dark matter may have originated before the Big Bang, and many people were confused by this assertion.

It might seem counterintuitive, because the way most people conceive of the Big Bang is as a singular point of infinite density. If you say the Universe is expanding and cooling today, then you can extrapolate it back to a state where all the matter and energy was compressed into a single point in space: a singularity. This corresponds to an initial start time for our Universe — the beginning of our Universe — and that’s the Big Bang.

So how could something that exists in our Universe, like dark matter, have originated before the Big Bang? Because the Big Bang wasn’t actually the beginning of space and time.”

Last month, a paper came out claiming that dark matter may have been created before the Big Bang. Although it might sound implausible, it’s absolutely a possibility that we cannot rule out, although it might be an idea that’s extraordinarily difficult to test when we compare it up against the other options. We have to keep every scenario that hasn’t been ruled out in mind, and understand that despite all we don’t know about dark matter, there’s a ton of indirect evidence brought to us by the full suite of observations at our disposal.

Could dark matter have been created before the Big Bang? Yes, but three other possibilities are maybe even more viable. Come find out why today.

Ask Ethan: Can We Really Get A Universe From Nothing?

“One concept bothers me. Perhaps you can help. I see it in used many places, but never really explained. “A universe from Nothing” and the concept of negative gravity. As I learned my Newtonian physics, you could put the zero point of the gravitational potential anywhere, only differences mattered. However Newtonian physics never deals with situations where matter is created… Can you help solidify this for me, preferably on [a] conceptual level, maybe with a little calculation detail?” 

You’ve very likely heard two counterintuitive things about the Universe before. One of them is that the Universe arose from nothing, and this defies our intuition about how it’s impossible to get something from nothing. The second is that we have four fundamental forces in the Universe: gravity, electromagnetism, and the strong and weak nuclear forces. So how, then, do we account for the fact that the Universe’s expansion is accelerating? Isn’t this clearly evidence for a fifth force, one with negative gravity?

Guess what? These two counterintuitive aspects of reality are related. If you understand them both, you’re one step closer to making sense of the Universe.

Could Parallel Universes Be Physically Real?

“Inflation may give us an enormously huge number of Universes that reside within a greater multiverse, but there simply aren’t enough of them to create an alternate, parallel you. The number of possible outcomes simply increases too fast for even an inflationary Universe to contain them all.

In all the multiverse, there is likely only one you. You must make this Universe count, as there is no alternate version of you. Take the dream job. Stand up for yourself. Navigate through the difficulties with no regrets, and go all-out every day of your life. There is no other Universe where this version of you exists, and no future awaiting you other than the one you live into reality. Make it count.”

Our observable Universe, as vast and enormous as it may be, is still finite. There are a finite number of galaxies containing a finite number of atoms and particles that have existed for a finite amount of time since the Big Bang. There’s an idea in quantum physics call the many-worlds interpretation, where all the various quantum outcomes that are possible actually do occur, but they simply occur in parallel Universes: where the Universe was identical to our own until a critical moment when a particular quantum decision occurred.

Does the existence of a multiverse mean there’s a Universe out there where you also exist, but made different decisions? The answer is probably no. Here’s why.

Ask Ethan: How Well Has Cosmic Inflation Been Verified?

“To what margin of error or what level of statistical significance would you say you say inflation has been verified?”

So, you’ve got an alternative theory to our best mainstream scientific ideas? Well, guess what: those are the same shoes that every scientific idea we accept today were wearing at one point in the distant past. The thing that separates them from the ideas that fell by the wayside were three remarkable feats:

1. They reproduced all the earlier successes of the previous prevailing model.
2. They resolved or explained puzzles or problems that the previous model had no sufficient answer for.
3. And, perhaps most importantly, they made new predictions that we could go out and test about the Universe, and those predictions were proven correct by the appropriate experimental or observational test.

Although most people don’t appreciate it, inflation has hurdled all three bars, and has no fewer than four spectacular predictions that have since been confirmed. Come learn how well cosmic inflation has been verified today!

This Is Why The Multiverse Must Exist

“This picture, of huge Universes, far bigger than the meager part that’s observable to us, constantly being created across this exponentially inflating space, is what the Multiverse is all about. It’s not a new, testable scientific prediction, but rather a theoretical consequence that’s unavoidable, based on the laws of physics as they’re understood today. Whether the laws of physics are identical to our own in those other Universes is unknown.

If you have an inflationary Universe that’s governed by quantum physics, a Multiverse is unavoidable. As always, we are collecting as much new, compelling evidence as we can on a continuous basis to better understand the entire cosmos. It may turn out that inflation is wrong, that quantum physics is wrong, or that applying these rules the way we do has some fundamental flaw. But so far, everything adds up. Unless we’ve got something wrong, the Multiverse is inevitable, and the Universe we inhabit is just a minuscule part of it.”

Skeptical about the Multiverse? You’re not alone. After all, how can you be confident that something must exist if the experimental, measurable, or observational evidence that’s required to validate its existence isn’t located within our observable Universe? It’s a reasonable thought, but there are ways to know something that go beyond verifying the exact phenomenon we’re looking for. This is why theoretical physics is so powerful: it not only allows you to draw conclusions about things you have not yet observed, but about things you cannot observe at all.

Come find out how, and learn why the Multiverse really must exist.