What Would Happen If Everyone on Earth Pointed Lasers at the Moon

As part of their ongoing “What If?” series, Randall Munroe of xkcd and Henry Reich of MinutePhysics looked at what might happen if every person on Earth pointed a laser at the moon and if it would change color.

This question comes from Peter who asks if every person on Earth aimed a laser pointer at the moon at the same time would it change color. The answer is, not if we use regular laser pointers.

He further explained is that everyone would need a much more powerful laser device that would ultimately vaporize the Earth before ever getting to the moon.

The most powerful laser on Earth is the confinement Beam at the National Ignition Facility, a fusion research laboratory. It’s an UltraViolet laser with an output of 500 ter but it fires only in pulses lasting …let’s imagine we somehow find a way to power it and fire it continuously, give one to everyone and point them at the Moon. Unfortunately the lasers turn the atmosphere to plasma instantly igniting the Earth’s surface and killing us all.