These 4 Pieces Of Evidence Have Already Taken Us Beyond The Big Bang
“There are other predictions of cosmic inflation, too. Inflation predicts that the Universe should be almost perfectly flat, but not quite, with the degree of curvature falling somewhere within 0.0001% and 0.01%. The scalar spectral index, measured to depart slightly from scale invariance, should “roll” (or change during the final stages of inflation) by about 0.1%. And there should be a set of not just density fluctuations, but gravitational wave fluctuations that arise from inflation. So far, observations are consistent with all of these, but we have not reached the level of precision necessary to test them.
But four independent tests are more than enough to draw a conclusion. Despite the voices of a few detractors who refuse to accept this evidence, we can now confidently state that we’ve gone before the Big Bang, and cosmic inflation led to the birth of our Universe. The next question, of what happened prior to the end of inflation, is now at the frontier of 21st century cosmology.”
Did the Universe really begin with a Big Bang? Although there’s an overwhelming suite of evidence in support of our modern Universe arising from a very hot, dense, expanding state a finite amount of time ago, the Big Bang is not the origin of our Universe. For decades, now, we’ve had multiple lines of evidence that demonstrate that no, you cannot extrapolate the Big Bang all the way back to arbitrarily high energies and densities: to a singularity. But a series of puzzles led to a spectacular idea: cosmic inflation, which could have set up and preceded the Big Bang. While inflation’s detractors frequently make the news, the scientific data is overwhelmingly in favor of it.
Inflation has made concrete predictions, and of the ones that have been tested, inflation is 4-for-4. Come learn what lies beyond the Big Bang today.
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!
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!
Ask Ethan: Are We Deceiving Ourselves By Searching For B-Modes From Inflation?
“I have a question about B-Modes. I’ve read Dr. Keating’s book, Losing the Nobel Prize. In the book, he details his team’s search for B-modes, and claims this would be smoking gun for inflation. Dr. Hossenfelder, in a blog post, says this isn’t true and there are other ways to produce B-modes. What is the correct view?”
Perhaps the greatest danger in science is to go out, look for a predicted effect, find it, and declare victory. Why is that such a danger? Because your idea for how the effect was generated might not be the only possibility, or even the most accurate one. If I have a wild new theory that predicts some far-distant star will have a habitable planet around it, the detection of that planet does not necessarily mean the wild new theory is correct. When it comes to the origin of the Universe, our leading theory is cosmic inflation, which predicts a B-mode polarization signature in the cosmic microwave background. Are there other ways to generate those B-mode signatures, though? And if we find them, does that mean that inflation is correct, or might that be a premature conclusion?
This is a key problem, and a hard problem, in theoretical physics. But we can say a whole lot that’s intelligent on this topic, and still be correct. Let’s find out.