This cool video shows the SawStop safety device at work:
The SawStop system uses electrical conductivity to tell the difference between wood and human flesh, allowing it to cut the first, but not the second. The technology is impressive, but the most jaw-dropping section of the video is the super slow-motion demonstration where the inventor places his own finger into the path of the saw to show how well it works.
I personally think that it was unnecessary risk for the inventor to take. But there is a similarity to the scene in Atlas Shrugged where Hank Rearden and Dagny Taggart had sufficient confidence in their judgment to ride the first train on rails made of Rearden Metal.
More information on the technology can be found at the SawStop website.
(Via Maximizing Progress.)