
Light Cone
1908 CE
The Speed Limit of Cause
The sunlight on your skin left the Sun a little over eight minutes ago. Light's finite speed turns every event into the point of an hourglass. Inside the Light Cone are events that could exchange cause and consequence with that point; outside are spacelike events that would require a signal faster than light. The diagram is not one prison built around the universe. Every event carries its own boundary of past influence and future reach.
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The sunlight on your skin left the Sun a little over eight minutes ago. Light's finite speed turns every event into the point of an hourglass. Inside the are events that could exchange cause and consequence with that point; outside are spacelike events that would require a signal faster than light. The diagram is not one prison built around the universe. Every event carries its own boundary of past influence and future reach.






























































