Sunday, July 27, 2014

How much do we see?

[Johnathan Clayborn]

Yesterday I was having one of my classical philosophical mind trips where I sit in awe at the nature of the universe. I was thinking about vision. We use our eyes to inform ourselves about so many things. For most of us, our vision is a very large part of how we perceive the world. We can see what time of day it is, what the weather is like, if there's danger approaching. We can observe our fellow humans and animals and see their behavior. For most of us, our eyes are critical to understanding our world. And yet, for all of the importance that we place on our vision and our eyesight, our eyes don't really see anything at all.

There are many different estimates of how far the human eye can see. A lot of it has to do with ambient light, elevation, etc. But, assuming that you are standing in an open field during the day and you are looking around you can see fairly large objects at distances up to 20 miles. Assuming that your line of sight is a radius and you could turn and look equally in every direction, then your total field of view would be calculated by π(20)^2. 3.14159265359 * 20 * 20 = 1256.637061436 Square Miles. That's how much you can see at any given time. The entire surface of the Earth is 139,430,000 square miles. This means that as much of the earth as you are seeing is still only 0.000901267% of the planet we call home. Even if we made a more liberal assumption that you could see 100 miles in every direction, you would still only see 0.022531684% of our home. If you round that to the nearest 10th, then that means that everything that you're looking at right now, everything you can see, is 0% of the Earth. You see nothing. All of the wonders and beauties of our planet account for an infinitesimally small fraction of our home, so small that it's less than 1/10th of 1/4 of 1% of the earth.

Not even close to 0% of the Earth. Photo Credit Ben Foley

Thinking about things from a different perspective let's talk about space for a moment. Just looking at stars in the sky, at best we can see about 8,479 stars unaided with a telescope on any given night, assuming average lighting conditions. There, according to the average estimates, 200 Billion stars in the Milky Way galaxy. That means that what you can see accounts for only 0.0000042395% of our home galaxy. A more realistic calculation is that we can see only 2,500 stars unaided with a telescope from any given point on the Earth at once. That's only 0.00000125% of our galaxy.

Milky Way Galaxy
Not even close to 0% of the Milky Way. Photo Credit National Geographic. 

Switching to a larger scale and talking about entire galaxies, the number is even smaller. Without the aid of a telescope you can see the Milky Way (our home galaxy), plus Andromeda, and the Large Magellanic Cloud, as well as the Small Magellanic Cloud. That makes a whopping total of 4 galaxies. There are, according to the most recent estimates, 500 Billion galaxies in the universe. That's 0.0000000008% of the universe. Even with the aid of the Hubble Telescope we can see only 10,000 galaxies at once. That's 0.000002% of the universe. All of the beauty and wonder of the galaxy, all of the planets, all of the stars, and the nebulae, and supernovas, and comets. Everything that we know, everything that we see accounts for nothing in comparison of the entire universe. We know 8 to the -10th power of the universe.

0% of the Universe as seen from the Hubble Telescope. Photo credit - NASA.

And what about what we do see? What we do see is in the form of visible light, which is a form of radiation that is part of the electromagnetic spectrum. It might surprise you to learn that, calculated on a linear scale, the amount of light, color, everything that you can see with your eyes accounts for only 0.0035% of the entire EM spectrum. We are completely blind to radio waves, microwaves, infrared waves, ultraviolet waves, x-rays, and Gamma Rays, all of which are part of the EM spectrum. Every flower, every bird, every piece of art, literally everything we see is only a tiny fraction of the actual amount of things that are theoretically able to be seen.

Our eyes are also completely unable to see any of the other invisible forces at work constantly around us; wind, barometric pressure, gravity, temperature, and so on. And while we can observe specific behaviors, we have no idea why those behaviors are occurring. We can't see other people's thoughts.

For all of the beauty and splendor and awe-inspiring things that we can see, when compared to the scope of reality, we see absolutely nothing. And yet, many of us still continue to rely so heavily on our eyes to make decisions for us instead of letting some of our other senses and feelings take over.

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These blogs represent my thoughts, ideas and opinions. They may be different from yours. You may not agree with them. While I do enjoy a good, polite debate on a topic (where points are countered with other points based on logic, reason and fact), I do not enjoy an argument (where you tell me that I am wrong simply because you disagree and cannot offer any reasons to support your position). I am very respectful of others, and I expect everyone on here to be respectful in return, not only to me, but to each other as well. Disrespectful posts will be deleted automatically. Feel free to share your ideas, but keep it civil, please.