Video Transcript
When the universe began, was it at
a higher pressure, a lower pressure, or the same pressure as it is today?
To begin, recall that the universe
includes everything that exists, all of the galaxies, stars, planets, space, and
time. We should also recall that the
universe is about 14 billion years old and that it’s expanding as time goes on. Today, the universe is incredibly
large and matter is spread out over a great area.
Interestingly, throughout its
entire existence, the universe has always included the same amount of matter and
energy. But at the very beginning of the
universe, everything was condensed into a single point. This is what’s known as the Big
Bang.
Back then, the universe was very
different from how it is today. When it began, a great amount of
matter and energy was packed into a very small area. Thus, the early universe was
extremely hot and dense, and it was at a very high pressure. Because of this, the universe
initially expanded really rapidly, and it’s been expanding ever since, although it
expands at a much lower rate now. This expansion over billions of
years has allowed matter to spread out. And so the universe today is much
cooler, less dense, and less pressurized.
The question though is asking about
the pressure when the universe began. The universe began with the Big
Bang, when all energy and matter was crammed together at a single point. Therefore, when the universe began,
it was at a higher pressure than it is today.
