Recent content by PRH

DocAI, I was thinking that the instrument on the moon gets the information as a series of light 'pulses' from when the laser flashes over the instrument. For those flashes to communicate information faster than the speed of light, the physical direction of the laser on Earth would need to varied...

DocAI, I was imagining that there was an instrument sitting on the moon that detects flashes of laser light, like blips of Morse code. But for the information to flow faster than light, the laser itself, back on Earth, would need to be physically twitched back and forth faster than light, which...

Thanks for "not really a thing" and the scissors topic. So what I was describing is called 'phase velocity' and can exceed the speed of light. And the example of twitching a laser dot across the surface of the moon at greater than light speed might suggest that we can transfer information at...

Hi, I have two topics: 1) Suppose a propeller is spinning very fast (say it's in a vacuum, no drag) and we arbitrarily lengthen its blades. Eventually the velocity of the tips of the propeller will approach the speed of light. That should be a speed limit, but that implies that the blades of...