Please provide a rating, it takes seconds and helps us to keep this resource free for all to use
Welcome to our Physics lesson on Chronology of the First Microsecond, this is the third lesson of our suite of physics lessons covering the topic of Chronology of the Universe, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.
The history known so far of the first microsecond of the Universe, begins with Planck's time (10-44 s) after the Big Bang. Everything that occurred prior to this instant is a mystery for scientists. They are trying to prove that all the main interactions were unified prior to Planck's time. This means the four forces (gravitational, electromagnetic, strong and weak) were initially symmetrical and they have the same properties. At Planck's time it was gravitational force that first that broke the symmetry. This means it acquired different features from the other three forces. The density of matter at Planck's time was about 1090 kg/m3.
Nuclear (strong) force is the second force that left the group of unified interactions at t = 10-38 s after the Big Bang. It also acquired different features from the rest of the forces and therefore, the second break of symmetry took place. At this point, the Universe took a uniform shape in a very short time. This process is known as the inflation stage. We will discuss in more detail about this stage in the next tutorial.
During the inflation stage, there was a continuous alternation of particles creation and annihilation due to the very high amount of energy present in the Universe, which looked like a giant enlarging fireball. Massive elementary particles were mixed in a number of very strange ways, a number of which "froze" over time. Some of these particles may have preserved their original shape but others have split into lighter particles. Today, they are hardly detectable in the Universe and may form the invisible (dark) matter, for which we will discuss in the upcoming tutorial.
At t = 10-10 s after the Big Bang, there was the third symmetry break, where electromagnetic and weak interactions detached from each other. Each of them acquires distinct features. Even at the end of this stage, quarks and antiquarks could not connect because of their high energy, as explained in the solved example. Only at t = 10-6 s (1 microsecond) they can combine with each other to form protons, neutrons and the other hadrons.
All these processes together occurred in a very short time (less that one millionth of a second). However, it is a matter of fact that time has increased by 1038 times from Planck's time to the end of subatomic era.
You have reached the end of Physics lesson 22.11.3 Chronology of the First Microsecond. There are 6 lessons in this physics tutorial covering Chronology of the Universe, you can access all the lessons from this tutorial below.
Enjoy the "Chronology of the First Microsecond" physics lesson? People who liked the "Chronology of the Universe lesson found the following resources useful:
Please provide a rating, it takes seconds and helps us to keep this resource free for all to use
We hope you found this Physics lesson "Chronology of the Universe" useful. If you did it would be great if you could spare the time to rate this physics lesson (simply click on the number of stars that match your assessment of this physics learning aide) and/or share on social media, this helps us identify popular tutorials and calculators and expand our free learning resources to support our users around the world have free access to expand their knowledge of physics and other disciplines.