Chapters:
0:00 – Summary of metastability
1:33- Intro to energy potentials
4:08 – The shocking behavior of quantum particles
5:57 – Why a metastable universe could destroy us
7:21 – Why the Higgs potential is special
7:34 – Higgs mechanism
8:06 – Why we think the universe is metastable
8:38 – False vacuum state of Higgs
9:54 – What we would see with Higgs at true vacuum
10:31 – Why isn’t everyone panicking?
11:53 – Audible offer for Arvin Ash viewers
Cited paper on lifespan of metastable universe: https://journals.aps.org/prd/pdf/10.1103/PhysRevD.97.056006
Summary:
Could the universe be in a metastable, or false vacuum state? Could there be a looming vacuum catastrophe waiting to happen? Is the universe doomed?
This is related to the Higgs boson and the heaviest fundamental particle we know of, the top quark. All systems tend to minimize energy. Just as in the case of atoms forming molecules to lower overall energy of the system, particles also have a propensity to lower their potential energy.
A very simply potential energy diagram looks like a simple parabola. The Y axis is potential energy, and the X axis represents a parameter by which potential energy varies, such as position, energy, and field value. There’s a minimum, or lowest point at 0 energy on the x-axis.
What if we had two minima, where one minimum was at a higher energy state than the other minimum. A physical system trying to minimize energy would always seek to fall into the lowest possible minimum. But the key is that in order to do this, it has to overcome the barrier.
This is the classical picture of how potential energy works. But the world is fundamentally quantum mechanical, not classical. The Heisenberg’s uncertainty principle tells us that in quantum mechanics the position and momentum of a particle is not something we can know exactly, no matter how hard we try. This means a quantum particle is not like a little ball. It’s wavy, its position and momentum is uncertain. Because we don’t exactly know the position and momentum, we can no longer be certain whether the particle will stay at the high minimum or overcome the barrier and drop to the lower minimum.
Because of this uncertainty the particle is no longer in a stable state, but a metastable state. Quantum tunneling could allow it to escape from the higher minimum to the lower minimum. Quantum tunneling is a feature of the probabilistic nature of quantum mechanics.
Our universe could also not be in its lowest possible minimum, meaning that it may also be metastable. We believe this because of the mass ratios of the Higgs boson and top quark. which theoretically puts the universe in a metastable state.
As the matter particles that make up our universe interact with the Higgs potential, they obtain mass and become massive. Without the Higgs there would be no massive fundamental particles. However, if the true Higgs potential is lower than where it is now, then it would change the mass of all fundamental particles, taking the universe from its current state to a completely different state.
For example, Electrons would not have any mass. And without massive electrons, atoms would not be stable. This is because electrons wouldn’t be able to stick to atoms, or more simplistically, be able to orbit them. The latest research shows that the Higgs potential may not currently be in its lowest minimum. It is metastable.
If you create a high enough energy event, you can, in theory, overcome the barrier, and universe collapses. Or the higgs potential could tunnel to the lower energy minimum.
If this were to happen, what would we see? Simulations show that the transition would happens initially locally in a small volume, nucleating a small bubble of the vacuum in space. The bubble would quickly reach the speed of light, any destroying everything in its way. The scary part is that we would not see it coming because it would be propagating at the speed of light, so any light from this nucleating region would reach us at the speed of light. In other words, we would be incinerated at the very moment we saw it. There would be no warning.
#metastable
#vacuumdecay
So why isn’t everyone panicking? Our physics could be wrong, and it will likely not happen for a long time. in a 2018 paper researchers calculated that the lifespan of our metastable universe is anywhere from 10^88 to 10^241 years. So that is many orders of magnitude longer than the current age of the universe.
