# More at 10 yottameters
Why is 10^{25} the largest view that we can represent with
accuracy? All of the main images in this site represent a 30 degree
field of view. Applying some basic trigonometry (the
exercise is left to the student...), we can show that the one meter
picture was taken from a height of a little less than 2 meters. Likewise,
the 1 thousand million (10^{9}) light year image is seen from
a distance of 2 thousand million light years. So if we take another
step backward (make that a *giant* step) we will have stepped out
to 20 thousand million light years -- outside our universe! I'm sorry,
but I don't know what that would look like....
Does it make sense to ask questions like "How big is the universe?",
or "How many quarks does the universe contain?" Well, yes
it does. The universe must have a finite volume -- it has been expanding
from the Big Bang at a certain rate for a certain time so the volume
is large but calculable. On the other hand, the universe is all there
is. There is no 'outside' -- there's no THERE there (as far as science
can tell). As the universe continues to expand the volume it occupies
just increases. Mathematically, the universe is finite but unbounded.
The question of the number of particles in the universe provides a
more concrete answer. Say there are 10^{12} galaxies each containing
10^{12} stars each with a mass equal to the Sun. The Sun has
a large but finite number of atoms. The mass of the Sun is about 10^{31}
kilograms. From basic chemistry a kilogram of hydrogen contains about
10^{27} atoms. If you multiply it all out using these numbers
you get about 10^{82} particles in the universe -- a (very)
large but finite number. Say that I have underestimated the number of
galaxies. Perhaps there are 10^{24} galaxies in the universe.
That would add another 12 zeros. The point is that it is still finite
and calculable. There is a number in mathematics called a googol
-- defined as 10^{100}. That's a 1 followed by 100 zeros. It
would appear that the universe contains less than a googol of quarks.
This website is about the effect of adding another zero. Enjoy your trip!
*Copyright © 2016 by Bruce Bryson* |