Raindrops as lenses and data storage devices

[Evil Captor]

I'm not sure MPSIMS is the right place for this thread -- I'm not sure it's pointless, or meaningless -- but then, I'm not sure it's NOT pointless or meaningless. So here it goes. But if a mod has an opinion, I'm cool with that.

While sitting in the car the other day, there was a light rain falling, and I was watching the process of the raindrops landing on the windshield, spattering into many small raindrops, and then sliding downward to collide with other small raindrops until they form raindrops so big that they side down the windshield in a rush, leaving a streak.

I noticed that every raindrop was acting as a lens, albeit a distorting lens -- inside every raindrop was a tiny inverse reflection of what was visible outside the windshield. My eyes aren't sharp enough to pick up more than the horizon line most of the time, but I'm sure there's a lot of detail in those drops I can't see.

What I'm not sure of is how much detail there is. If I could put a giant macro lens on any raindrop on the windshield, would I see a very detailed image of the world outside the windsheild, with individual blades of grass discernable, that sort of thing? I mean, the human eye is a pretty tiny lens, but it admits huge amounts of data to the back of the eyeball. Since the raindrops are presumably forming a reflective surface at the molecular level, the degree of resolution of the raindrop could be very high.

Maybe some optics guys could figure it out.

That line of reasoning got me to thinking about the level of data processing and storage needed to present a realistic image of a windshield in the rain at the same level of detail present in nature. You'd have to represent every raindrop lens in full detail, distorting the image to match the distorted shape of the raindrops. Hey, suppose you animate it, changing the image to reflect the changing shapes of the raindrops as the hit the windshield and slide down? That's gotta represent a lot of data.

What's more, as the raindrops fall they're presumably tiny sphere that reflect everything around them, including the other raindrops which are also reflecting them.

I read an SF novel once which considered the universe as a huge data storage device. I'm thinking that if that's true, raindrops are a pretty nifty hack.

Well, that's it. Your mind sure can come up with stuff while your wife is in some store or other. Probably a lot of crime and lunacy could be prevented by making such activities illegal.

[NoClueBoy]

These are a few of my favorite things.

[Nangleator]

As a 3D animator and artist, I have pondered wistfully over the resolution and frame rates of reality.

Reality has real-time ray tracing, multi-bounce radiosity and caustics. Reality has no need of bump or texture maps: It's all done in geometry. Ah, the power!

Windshields with raindrops can be modeled fairly accurately. But the resolution capacity of the human eye, which you have noted, is limited. So are our image display media.

I can model a windshield and render out an image, but I must choose a resolution, and there's no point in picking a resolution larger than what I can display it on. For print media, you won't get much more than 300 dots per inch of resolution. Print that windshield at 20 feet across, and the raindrops are still pretty small. You'll see that they refract their environment, but not much more.

Computer display is much lower resolution. Video is piss-poor.

In my computer, I can move the camera closer to an item of interest in my scene. The data (the world within a raindrop) doesn't really exist until I get the camera close enough to resolve it. The same practical effect is achieved with your eyes. If you can't resolve it, move your head closer. If you can't move your head closer, the data doesn't matter.

[SmackFu]

Originally posted by NoClueBoy
These are a few of my favorite things.

Ha! The "data storage devices" part doesn't quite fit though. Drop the "data" though....

[Evil Captor]

Raindrops as lenses and storage devices
Lands on cold pavements and they turns to ices
They help some alien do its computing
Along with a bevy of wet super strings!

When the rain drops
Hit the windsheilds
That's when data flows
And we'd know the secrets of the universe if we only knew where
It goes!

[Stage Manager]

Damn. NoClueBoy beat me to it.

[Q.E.D.]

Originally posted by Evil Captor
What's more, as the raindrops fall they're presumably tiny sphere that reflect everything around them...

Almost. They are shaped more like little fat pancakes, with the top surface convex and the bottom surface slightly concave. The larger the drop, the more pronounced is this flattening. Very tiny drops are almost, but not quite spherical as they fall. This shape is the result of several forces acting on the drop, including surface tension, air pressure and friction.