Low-Tech Solution

Some "technology" doesn't look like a new computer gadget or piece of software, it looks like garbage shoved into a roof. A man in Brazil has figured out a way to light his home during the day without spending money on electricity, using discarded water bottles and water (with a little bit of bleach to keep algae out) - check it out.

It isn't perfect, bot'tle do :)

This bottle-lamp works through the refraction property of water, which is an idea you've seen before - probably with a pencil in a cup. Light is a wave, and waves change whenever they change mediums ("medium" in this case means "the material that the wave moves through," not the spiciness of your Mexican food).

Couldn't find a gif of this unfortunately

You've heard a wave change mediums before, when you hear someone speaking from the other side of a wall or door: their voice is distorted and muffled because the vibrations that started in their throat have gone through air, then through the solid surface, before returning to air again on the other side. Each change causes a distortion of the original signal.

You could win a bet with this trick by claiming you can change the direction of an arrow without touching the paper

Notice that the arrow also changes location a bit - that's "refraction," which means the changing of the direction of a wave because it changes mediums (in this case the mediums are air, water, and glass). The changing direction is called reflection - BOTH can happen at the same time, just like when you see your reflection on a still pond and can also see the fish underneath the surface.

Birds that dive for fish under the water have to adapt to this, because when a fish is seen from outside  it's never actually where you see it! The light from the sun has bounced off the fish and changed directions when the light wave moved from water to air. Birds that didn't adapt to this would die of starvation in a hurry, so they have adjusted:

I don't have anything to add here, this is just freaking cool

Refraction also allows you to take pictures like this one:

This picture is upside down so that the image inside is right side up!