Next Argument:

Pictures from space?

See this? This is a picture of Pluto taken by the New Horizons spacecraft. I don’t know about you, but I wondered exactly how they got this picture. Yeah, yeah, I know, “The satellite took the picture and transmitted it back to Earth”. Yeah, I got that. But exactly how did it do that? The usual explanation is that the satellite took the picture, digitized it, shows you how old I am that I even mention this step, and sent it back to the Earth via radio waves. That! That is the part I want to know about. Have you ever seen what Earth looks like from Pluto? Well I tried to find a picture of it but the best I could do was a picture from Saturn, which is a heck of a lot closer to Earth than Pluto is. Anyway, the Earth is really, really tiny compared to the entire sky when looking from that far away. So just how did those radio waves make it to this really tiny point in the sky from there? Well the answer that I grew up with was that the satellite has an antenna that created an electromagnetic field through which the radio waves traveled back to Earth. Well, that seemed logical until I realized that there is a transmitter on top of the Empire State Building transmitting radio waves that only go at best a few hundred miles. And that transmitter is 50,000 watts. I don’t remember ever seeing a giant transmitter on a satellite. Certainly not one big enough to send a signal all the way from Pluto. So, I looked it up. Turns out that the transmitter on the New Horizons satellite that took that picture is 12 watts. That’s about 6 times more powerful than the transmitter in my iPhone. My iPhone can barely get a signal in places in Queens NY let alone from a billion miles away. So, how am I supposed to believe that that transmitter created an electromagnetic field strong enough to not only go all the way from Pluto to the Earth, but to go that distance in all directions from that satellite? Because if it didn’t go in all directions, then the signal would probably miss the really, really, tiny spot that is the Earth from there. Let’s take a moment to look at this problem.

Since you were a kid you’ve probably played with magnets. You may have even done the thing where you put iron filings on a piece of paper over a magnet and saw that they all lined up in lines from the north to the south pole of the magnets. If you didn’t do it personally, your science teacher probably did it for you. The teacher probably also told you that the magnet created a magnetic field that caused the filings to line up like that. Pretty cool huh? An invisible field that did things to iron. You probably also felt this magnetic field when you tried to force two of the same poles of a magnet together. You felt them push apart. Well, at least I did. Anyway, later on you may have learned that you could create a magnet by wrapping a coil of wire around a nail and connecting that wire to a battery. That showed you that electricity and magnetism were somehow related, even if you didn’t get it at the time. That may be where your interest in electromagnetism ended until you learned about radio waves. Radio waves were those same types of things that caused the iron filings to line up, only depending on your age, they carried music or made your telephone work. It may have not occurred to you that radio waves needed an electromagnetic field to work.

So, I told you that I would let you know when I wasn’t sure of something, well this is one of those times. I am only 99% certain of the following information. I can’t remember which of the books I read this in.

Now, back to the original problem, how does a 12 watt transmitter create an electromagnetic field that reaches all the way back to Earth in order to transmit that picture? It turns out that it doesn’t. You see, there are not many electromagnetic fields being created here and there by various means. It turns out there is just one electromagnetic field that permeates the entire universe. Just like a giant ocean surrounding everything. All the transmitter has to do is disturb that field and the waves will ripple through it just like waves rippling across the water. Now here is the part I am not sure of. Remember how I told you we were moving all the time? Well I am pretty sure that the field does not move like we do. I’m pretty sure it’s stationary, relative to us. The reason I say this is because if it were moving the radio waves would never make it to us. They would be carried along on a field that moved as we do and basically just vibrate in place. I could be wrong about this, but I don’t think so.

So, the idea here is that there is a field out there which the entire universe is moving through. How do I know it’s throughout the entire universe? It turns out that light also travels through this field. No field, no light.