Imagine a world where you can only see in blue for the month of February. In July, the world is rose-tinted. In December, everything looks green. Sounds rather arbitrary, doesn't it? Well, that's how I feel about photons.

The electromagnetic spectrum runs from very long wavelengths to very small wavelengths. It's not continuous thanks to Mr. Planck but it might as well be to us since we aren't equipped to distinguish such inifinitesimal differences. What's arbitrary about photons is our eyes. We have receptors in there that see red, blue and green; rods and cones and all that high school stuff. When they fire in combination, our brain interprets them as various colours. But it's only a small section of the spectrum that our eyes are senstive to. Infrared and ultra-violet are out of our league. There are some insects who can see ultra-violet and some flowers look different in ultra-violet light. But, for us humans, we're confined to our narrow range of wavelengths.

Why this range of wavelengths? Well, our atmosphere blocks a whole lot of E/M radiation from getting down to the Earth's surface but it lets two large sections through, radio and visible. I suppose we could have evolved eyes that were sensitive to radio but then our resolution would be on the order of meters. Everything less than 50 cm would probably look like 50 microns does now. So, that's less than practical.

We have ears, they interpret air modulation. Our skin feels wind, the touch of another person, temperature. Our inner ear give us a sense of gravity. We can interface with the world on a wide array of levels. As such we have constructed for ourselves a fairly representative model of "how the world works". It seems to make pretty good predictions and keeps us on top of things.

But what about plants that can't interface with, say, sound, as we do. Does that mean sound is not a useful way of looking at the world because plants can't sense it? For us, it's a pretty useful tool to have at our disposal. So what does that signify about human perception? My question is: what interfaces with the universe are we oblivious to?

There is probably level of information out there that we just can't "see". It stands to reason that the universe has many many ways of being looked at and we are limited by the senses we developed locally. I would hope that these other methods of looking at the world around us can inferred from what we can perceive or perhaps we could one day build instruments to do so...

It's an old saying but it's probably true. The universe is not only stranger than we imagine, it's stranger than we can imagine.