To actually determine the exact size of the universe is beyond our means as humans right now. But that won’t stop me from trying.
Also, in considering the size of the universe we must define “universe”. The first result at Dictionary.com for “universe” reads “the totality of known or supposed objects and phenomena throughout space” (Based on the Random House Unabridged Dictionary, Random House, Inc. 2006). We’ll use this definition for our calculations.
So, when the Big-Bang occurred it sent matter and energy in essentially every direction. Light is furthest from the center because it’s traveling faster than anything else in the universe. Though in quantum theories light and matter may exist and interact in other dimensions, we’re going to limit our calculations to just the three well-known space dimensions.
Using Google, I searched for “Light travels at” (with the quotes) and got 186,000mps. Though this isn’t a precise figure, we’ll use it in our calculations anyway.
I also searched for “the universe is” “years old” (with the quotes) and read the previews for some of the web pages that were generally in agreement, concluding that the universe is 13.4 billion years old.
Since we measured the speed of light in miles per second, let’s convert the age of the universe to seconds for convenience.
1.34*10^10*(60*60*24*365) = 4.22582*10^17
Now, having these figures we can begin to calculate the size of the universe.
The universe expands radially, making it’s shape spherical. We calculate the volume of a sphere using the following equation:
4/3*pi*r^3
pi (while lacking precision) is 3.14159
r is 4.22582*10^17 * 1.86*10^5 which is 7.86003*10^22
Now for the real math!
4/3 [1.33333]
* Pi [3.14159]
* r [7.86003*10^22] ^3
Comes to a whopping 2.03404*10^69 cubic miles!
This figure is based on the given numbers and assuming I did all the math right. I honestly have no way of knowing how accurate it is to any degree, but let me know if I miscalculated anywhere. Thanks.
For those of you who were hoping I’d talk about how endless the expanse is, I do have a little to say.
The universe itself is really endless. Anywhere the matter or energy is traveling just seems to me like the occupied space in the universe. Although I’m no longer using the official definition of the word, I perceive the universe as endless. Light will keep going out, and the “universe” will keep getting bigger. The light isn’t going to bounce off of anything, it won’t disappear, it won’t be absorbed, it won’t be changed in any way, and we won’t encounter a celestial critical error. There will ALWAYS be space beyond every photon traveling through space beyond our galaxies. They can’t stop or it will violate the conservation of energy. Every minute, immeasurable amount of energy that was created in the big bang still occupies the universe. Although unreachable, it has never left, nor will it ever leave. The universe will always be there for us to explore and further our knowledge. It will always enchant some people, and bore others. We will never know everything there is to know about it, but we’ll keep learning.
