I want to ask how a hardware-store laser rangefinder works. I have a Bosch GLM20 and it works very well and definitely has valid sub-inch resolution. I know everyone is going to explain to me that it's time of flight divided by c, etc, etc. The problem is that I find that hard to believe. Can they really build a tens-of-gigahertz timer into something that sells for so little money and runs on so little power?