To the Moon and Back in 2.5 ms

The round trip transit time for light between the Earth and the moon is about 2.5 s, not 2.5 ms.

No, no Steve - 'ms" means "median seconds" - just joking! :) Tx, it was a "duh" on my side - must obviously be seconds!

Has anyone tried one of those laser tape measures at lowes? How accurate would that be?

Lowes sells ultrasonic tape measures with a laser pointing device. They are worthless.

Stanley makes the FatMax, but to my knowledge you will not find it at stores (I had to go online to buy one) It is a true laser tape measure. It is accurate to within 1/4 inch at its maximum range of 100 ft (over 50 feet you will probably need a reflective target, a sheet of white paper will do). It goes for $100 (compared to $300 to $800 for longer range products made by others).

I find it handy. It can do things like measuring ceiling height in tall rooms, that otherwise could be impractical to get. It is also very fast for things like measuring room dimensions.

A negative is that the location of the buttons for various functions (area, volume, units, front or rear reference to the unit) are easy to accidently engage, especially when trying to make an awkward measurement. It would be nice if they were recessed or had a cover of some sort.

It is a palm size hand held device. It is hard to hold steady on the target at distances. Outside, over 50 feet, the laser mark can be hard to see. For the more expensive devices with greater range, a tripod and some type of sighting device would seem to be essential.

FARO Technologies Company in Lake Mary, FL makes a laser like you're talking about. Actually three of them. The distance on these systems is up to 20m, 40m, and 80m, respectfully. Here's the page: Jason Zehnder Sales Research & Marketing LASER PHOTONICS CORPORATION a Division of FONON TECHNOLOGIES 41 Skyline Drive, Suite 1009 Lake Mary, FL 32746 407-804-1000x249 407-804-1002 FAX jzehnder@laserphotonics.com

Sorry guys, that link didn't come out right, this repost should work---FARO Technologies Company in Lake Mary, FL makes a laser like you're talking about. Actually three of them. The distance on these systems is up to 20m, 40m, and 80m, respectfully. __________________________________________________ _______________ Jason Zehnder Sales Research & Marketing LASER PHOTONICS CORPORATION a Division of FONON TECHNOLOGIES 41 Skyline Drive, Suite 1009 Lake Mary, FL 32746 407-804-1000x249 407-804-1002 FAX jzehnder@laserphotonics.com __________________________________________________ _______________ Here's the page: http://www.iqvolution.com/en/Products/Laserscanner s.php/