January 25th, 2016


Noisemaking weapons

During combat operations, the Canadian Forces are trained to use suppressing fire. This consists of shooting in the general direction of the opposing force, so they have to take cover and cannot aim to shoot accurately at the Canadian forces. This is effective, but all those stray rounds keep flying for great distances, and can hit civilians far from the area. It also uses up a lot of ammunition very quickly, which increases the risk of running out at a bad time.

This ammunition is being fired off to give an audible message meaning, "Warning! I am pointing a gun at you, please duck". So, why not skip the ammunition and go straight to the audible message?

Let's suppose we mount a pair of speakers on the rail of the C7, in forward-facing tubes, playing irritating tones of slightly different frequencies. When the barrel is pointing towards you with the speakers playing, you'd hear a really loud beat frequency, rattling like a machine gun. As the barrel swings away to either side, the noise would drop off rapidly. With a few seconds of observation, people would learn to hear when they are being targeted, and would duck accordingly.

So, instead of suppressing fire, the first step would be to click on the speakers and point weapons at the opponents. Actual ammunition would only be fired if the opponents did not duck. The Canadian Forces would save ammunition, and civilians would have fewer stray projectiles punching through the walls of their houses. Fewer opponents would be shot, but shooting opponents isn't the primary goal of suppressing fire anyway.

Glass-fibre reinforced concrete


Epoxy is fairly strong, but it becomes even stronger and durable when you mix in glass fibres to make fibreglass. You can also mix glass fibres with concrete to make a stronger, lightweight material that is used for decorative building materials.

Why aren't we mixing glass fibres with concrete used for all other purposes? It would add a bit to the cost, but it would help prevent cracking, spalling, and other common failure modes of concrete. Glass has about the same density as the gravel and sand used for concrete aggregate, so even with bulk pours there wouldn't be a risk of it separating out. Am I missing something here, or is this an opportunity to make more durable concrete structures?