The unfolding of time is typically described as a sequence of spatial regions: one region of space gets realized, and then another, and then another. For example: consider a region…
Can Time Unfold in the Wrong Direction?
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How to Create a Closed Timelike Curve
Time along the vertical axis; space along the horizontal…. Voila! And now, how to travel to the past…. Soul Physics is authored by Bryan W. Roberts. Thanks for subscribing. Want…
Why does matter follow geodesics?
In the very first lessons on General Relativity, we learn that free particles follow geodesics — the equivalent of straight lines in curved spacetimes. Why? Well, it’s easy to show…
Geneva Summer School in Philosophy of Physics
Read About It Here. The Geneva Summer School in Philosophy of Physics, 2008 was a 1-week intensive summer school in the middle of the Swiss alps. This year, scholars and…
Rotating Discs in GR: Part I
Introduction. Craig Callender (2001) and Jeremy Butterfield (2004) have recently suggested that the Rotating Disc Argument (RDA) fails in General Relativity. I argue that this conclusion is wrong: two recharged…