The I-35 bridge collapsed because of a design flaw. (Mostly. The inspection engineers had a case of tunnel vision.)

You mean besides the Emergency Alert System, which is required by law to be supported by a wide variety of radio transmitters.

One of the more mind blowing things I read in 2008 was the discovery of a third type of visual receptor besides rods and cones. Essentially there's a third type of receptor that only detects sort of gross levels of light, and feeds directly into the system which regulates your circadian rhythm and is used for some other purposes.

Those are the photosensitive retinal ganglion cells. In addition to driving the circadian rhythm generators, they also control pupil size in response to light. IIRC, research in cats found that they do connect to the visual cortex, although how the signals are perceived is not yet known.