electroweak force

Spontaneous symmetry breaking

  • A good way to get an idea of what this is like is through water. Water has four different forms it could take depending on the conditions; frost, snow, ice and rime. Spontaneous symmetry breaking is sort of like this.
  • At the start of the big bang there was a single force which started off hot and as it expanded began to cool and in 1x10-46s (supposed to be scientific notation) gravity came into existence.
  • Now there is gravity and the force energy of the universe. This force energy then split into the strong nuclear force (SNF) at about 1x10-36s.
  • Then shorty after the massive inflation at 1x10-22s (where the universe expanded from about the size of a proton to that of a orange), the weak nuclear force and electromagnetic force (or electroweak force as we now know that they are the same) came into existence at the same time at 1x10-12s.
  • So from one force, in 1x10-12s all the different forces have fallen out.
  • In about 1x10-6 quark confinement would happen, from 3-20 minutes the nuclei would begin to form, there is still too much energy for the electrons to be bound to the nuclei. Atoms would not form for about 380,000 years.

Well this has been a brief and simple intro to spontaneous symmetry breaking, hope you guys liked it. 

A Brief Timeline of the Universe - The First Second [Part I]

We know where we are roughly in the universe- Earth, Solar System, Milky Way Galaxy- but when are we in the universe? “13.8 billion years!” I hear some of you saying. You’re right. But what’s happened in those billions of years; what led us to the universe we know today?

Originally posted by sulfur

Let’s take a quick trip through a timeline of the universe as we know it, beginning with… 

The first second of the universe.

  • 0 Seconds Old | Planck Epoch- The universe is tiny, tiny, tiny. Every known particle, every possible bit of energy, is condensed into one unimaginably dense, hot point known as a singularity. Its physics are thought to be dominated by a unified theory which brings quantum mechanics and gravity together.
  • 10−43   Seconds Old | Grand Unification Epoch - The universe cools to 1032 Kelvin, and gravity separates from the other forces collectively known as the electronuclear force.
  • 10−32 Seconds Old | Electroweak Epoch - The universe expands in a brief but intense period of inflation, becoming 1026 times bigger and cooling to 1022 kelvin. The Strong Force separates from the Electroweak Force.
  • 10−12 Seconds Old | Quark Epoch - The four forces - the Weak, Strong, Electromagnetic, and Gravitational Force- are now separated and distinct. It is still too hot for quarks to form into anything other than a quark-gluon plasma.
  •  10−6 Seconds Old | Hadron Epoch - The universe cools to 1010 Kelvin, cool enough for quarks to form hadrons (such as protons and neutrons).
  • 1 Seconds Old | Lepton Epoch - At 109 Kelvin now, many hadrons and anti-hadrons collide with and annihilate one another, with most Leptons (such as electrons and muons) and anti-Leptons left behind. Neutrinos stop interacting with matter, and gravity begins determining the expansion of the universe.

In short, the universe got a lot done in its first second of existence- separating forces, cooling, expanding, birthing new particles and quickly annihilating them, and whatnot. There’s more to come of course, and a more familiar universe will emerge from this timeline soon.

Part II- The Photon Epoch


Grand Unification may be a dead-end for Physics

“It may still turn out that grand unification is correct, and that it’s an important step on the road to a Theory Of Everything: the ultimate holy grail of many theoretical physicists. But it may also turn out that nature doesn’t unify at high energies, and that our biases towards simplicity, elegance and more unification is completely wrongheaded and has nothing to do with our physical Universe. In science, as in all things, we cannot afford to be driven by our own preconceptions of how things ought to be. Rather, we owe ourselves to view the Universe exactly as it is, and to listen to the story it tells us about itself.”

One of the greatest discoveries of the 20th centuries was not only that there were just four fundamental forces describing all of nature, but that two of them — the electromagnetic and the weak force — unify into a single “electroweak” force at high energies. Given the equivalences between electric charges in the strong nuclear force sector and the electroweak sector, could there be a grand unification between those as well? In a great theoretical development, Grand Unification Theories (GUTs) became all the rage, making bold predictions like additional bosons, flavor-changing neutral currents, and proton decay. But in the more than 30 years since their inception, the ideas of GUTs have all fallen flat, implying the question of whether the entire concept of unifying forces and interactions into larger groups and structures is completely wrongheaded.

Experiments and measurements don’t lie, but it’s up to the scientists who work on it to choose to go in a different direction. Perhaps it’s truly time.