Forum menu
Please Mr ET - could you be hired for a hit on our planets most single biggest problem
Trump the lab test rat on destruction of planet earth
😜
There is an alien in our kitchen now, I can hear it muttering.
It came down to the shed last night moaning that it couldn't get the top off the silver pen.
It was my old pencil tyre pressure gauge!!!!
Hmm.
Lots of fancy stuff there about how things move apart at faster than light speeds. But it can be explained very simply with vectors.
Two planes fly away from each other in opposite directions, both maintaining 500mph. At what speed are they flying apart?
Follow up question, are either breaking the sound barrier?
Now, two galaxies are drifting apart in opposite directions, both maintaining 0.8c. At what speed are they drifting apart?
Follow up question, are either breaking the light barrier?
Unfortunately, at near to light speed you can't use Newtonian mechanics to calculate speed.
To turn the Squirrel King's question round, if the 2 galaxies moving in opposite directions at 0.8c each, but moving towards each other, their approach speed is NOT 1.6c as you'd expect. It more like 0.975c - this is the weird beauty of relativistic formulae for velocity.
You also have to bear in mind that you can't say the galaxies are both moving at 0.8c - that's only relative to a specific point of reference. If you moved your point of reference to be in one of the galaxies, one would appear stationary whilst the speed of the other would appear to be 0.975c.
And there's no one point in the universe that can categorically be identified as being "at rest". It's all relative. Which goes some way to seeing why Einstein was a genius.
Those videos are easily explained by optical means:
https://petapixel.com/2020/04/28/that-navy-ufo-footage-has-an-optical-explanation/