On Wednesday, January 22, 2025 at 10:32:58 AM UTC-7 Dirk Van Niekerk wrote:

Sorry rear door closed and then opened...typo. D

On Wednesday, January 22, 2025 at 9:30:29 AM UTC-8 Dirk Van Niekerk wrote:

Forgive me if this was already done but I would like to clarify the 
experiment. Let's assume a covered bridge with two sliding doors. The 
bridge is 10 m in length. There is also a car 12 m in length. The front 
sliding door is closed and the car drives onto the bridge until the front 
almost touches the door and stops. The driver of the car and the bridge 
operator both agree that the back of the car sticks out 2 m at the rear. 
They propose an experiment. The driver will drive through the bridge at 
near the speed of light. When the front of the car is almost at the front 
door the bridge operator will quickly close and then open the front door. 
And when the back the car is just inside the bridge he will do the same 
with the rear door. They complete the experiment and compare notes. 

The bridge guy says that when he was about to close the front door he 
noticed that the rear of the car has already passed the rear door, so he 
opened and closed both doors at the same time. The driver disagrees. He 
sped up to the front door and saw it close and then open. He noticed in his 
rear view mirror that that back door was still open and the car still 
outside the bridge. As he sped through the front door (now open again) he 
notice the rear of the car moving past the rear gate, which then opened and 
closed behind him. To resolve the APPARENT paradox they have to account for 
length contraction and time dilation. The doors opened and closed 
simultaneously in the garage operator's frame but not the driver's 

Dirk


*All you've proven, if anything, is that the car fits from the pov of the 
garage frame, but doesn't fit from the pov of the car frame, AT THE SAME 
TIME. So what?  I don't see how this resolves the paradox?  Presumably they 
disagree about fitting at small or large different times. Same car. Same 
paradox. AG*

-- 
You received this message because you are subscribed to the Google Groups 
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion visit 
https://groups.google.com/d/msgid/everything-list/2292f57a-75fa-4cfb-9869-f4689a049db1n%40googlegroups.com.

Reply via email to