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Radar Reflection

I was looking around on the internet last night, researching radar, radio and the like for a top secret mission, when I learned a very interesting concept. To most people this is probably elementary, but I don't remember knowing this little physics tidbit before.

3-sided half box

If you construct a 3-sided surface where the three sides are at 90? angles to each other, you will have an effective radar reflector. Basically, take a cube and rip it in half taking three of the six sides away, and you will have the shape I'm referring to. The interesting tidbit about this shape in relation to radar is that, if you point a radar signal (or any form of electromagnetic wave that is readily reflected) very close to where the three sides converge, your signal will be reflected back at the exactly the same angle, providing that the surfaces are perfectly flat and at 90? angles to each other. Since radar must be reflected back in order to be useful, this 3-sided shape aides in making something more detectable.

Amazingly to me, the half box works exactly like a mirror set precisely perpendicular to the viewer. Virtually everyone takes for granted that if a mirror is set in front of them, that it must be perpendicular to the sight of their eyes in order for the image of their face to appear on the mirror. If the mirror is rotated in any direction ever so slightly, the person's face will be replaced by whatever objects are fixed behind them. Duh! However, if a 3-sided mirror of this radar-reflecting construction is held somewhat close to the subject the image will always appear, at least in part, virtually any direction the mirror is rotated. Naturally if the image is rotated to where basically only one of the faces is visible or the backside (the "outside" of the box) is showing, the principle won't apply. This shape simply increases the chance that waves will be reflected back to the source. The bigger the box is, and the closer the signal, the more likelihood of signal reflection and reception. So a surface with several of these half boxes inset into the contour will be more detectable by radar, or so I've read. By the same virtue, stealth can be created by making angles that are more likely to disperse a signal and keep it from reflecting back to its source. Don't ask me what these angles are, but if you are close to a stealth fighter/bomber, you let me know!

hexagon of straight reflection

Well, at least I thought it was pretty cool! Even if you don't think it is cool, click here to see an animation demonstrating the principle. Notice how the rotating EsoCube is not at all distorted by the rotating mirror structure. No matter the direction, the reflected image remains intact. This proves that the structure reflects waves directly back at their source. So as long as a wave is pointed within the inner black outlined hexagonal area (blue for illustration purposes, the black lines are reflections of the black borders to the mirror structure), it will be reflected virtually straight back where it came from. Mesmerizing, isn't it? Ah, the marbles (marvels) of technology.

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