Real talk: radars aren't perfect. They're complex machines that can only give clues about what's going on in the scene. The physicists, mathematicians, and engineers who work on these systems take a cue from Agatha Christie and add some Hercule Poirot-style sleuthing to their data sets. Using the

• size of the object
• material it's made of
• direction of the radar energy

they can figure out exactly where something is. The only problem? They don't often magically know exactly what material an object is made of—or even how big said object is. It's like solving a mystery where half the clues are told in Old French, set to iambic pentameter. So…they need to take a couple of leaps sometimes. Estimates can usually get you where you need to go on the Radar Express, but sometimes you can end up with some big margins of error.

Good luck.

The science behind radars is really neat, but it's also really complicated. The most basic radars using single antennas to do both the transmitting and the receiving. They use very simple algorithms to detect and range objects by sending waves and waiting for them to return. Depending on what you're doing, that can be okay, but the simpler the algorithm, the more leaps you'll need to take.

Plus, we're still innovating on this stuff. We've gone from the simplest set-up to imaging radar, radar guns, over-the-horizon radar, multi-static radar, satellite radar, weather radar, medical radar, and who knows what else.

(Our prediction: quantum radar. Sure, it might not be able to tell you whether the cat's dead or not dead, but at least it can tell you where the cat is.)

Did we mention radars in your car can help cars park and even drive themselves? They can also detect and identify visitors or intruders in your house.

Sometimes the radar messes up, but it can also help do so many things.

Radars are still being improved to give better quality images of scenes. For example, using a two-dimensional system of antennas, a radar can image and scan objects through obstructions like buildings, clouds, trees, and even soil because the angles give a better sense of where those obstructions are.

Next step: radar goggles. Like X-Ray goggles, but less creepy. And less likely to cause cancer.