- #1
ChrisXenon
- 60
- 10
I'm getting older and dumber, it seems.
In his book "The Fabric of the Cosmos", from page 49, Green points out some basic vector thinking. Given a fixed speed over the ground, as you head more West of North, your speed North decreases, whilst your speed West increases. He suggests that this is analogous to our movement through space-time. As our speed through space increases, our speed through time slows down - i.e. time slows down.
From page 53, Greene develops the model of space-time being a block of slices of 2D space. In this model, the third dimension is time, the two dimensions of the page are space, and the entity as a whole is space-time.
Here's my problem, and it hits before we even get into the interesting stuff. He says that a photon, moving through space at light-speed, will experience no time. This would be analogous to moving across one of his bread slices without moving in the time dimension. However, in his end note 9, he says that something moving at light speed sweeps out a line at 45 degrees to the crust-to-crust axis of the loaf. So on the one hand, the angle is 90 degrees and on the other it's 45 degrees.
Where have I gone wrong?
Please be gentle )
In his book "The Fabric of the Cosmos", from page 49, Green points out some basic vector thinking. Given a fixed speed over the ground, as you head more West of North, your speed North decreases, whilst your speed West increases. He suggests that this is analogous to our movement through space-time. As our speed through space increases, our speed through time slows down - i.e. time slows down.
From page 53, Greene develops the model of space-time being a block of slices of 2D space. In this model, the third dimension is time, the two dimensions of the page are space, and the entity as a whole is space-time.
Here's my problem, and it hits before we even get into the interesting stuff. He says that a photon, moving through space at light-speed, will experience no time. This would be analogous to moving across one of his bread slices without moving in the time dimension. However, in his end note 9, he says that something moving at light speed sweeps out a line at 45 degrees to the crust-to-crust axis of the loaf. So on the one hand, the angle is 90 degrees and on the other it's 45 degrees.
Where have I gone wrong?
Please be gentle )