Light Cone Laffs

I must confess: I love light cones! They appear so simple, but what they represent is stupendously complex. Just for one example - these cones represent causality. What happens within the cone can have a causal relationship with the object of the light cone (remember, everything has a light cone, or, a sphere of influence), both past and future. Something outside the cone has no direct causal connection.

The past is defined as that which causally impacted the now, and the future is defined as that which can be causally impacted by now. "Now" is an ever moving center of these two cones at which point space/time is manifested on a flat plane we call existence. This plane influences the object of the light cone, causing it to move this way or that - the red squiggly line, or "wordline" in the drawing at top. These squiggles represent movement, and - dig this - graphically represent time travel, in that any deviation from a straight line is a deviation from "light" time, and thus a time traveler (future or past). This time deviation is Einstein's General Theory of Relativity, which states that time is relative to the motion of the observer (in part). The famous example used to illustrate this effect is if you were to blast off in a space ship going close to the speed of light, a year for you on board the craft might be 100 years to the folks left back on Earth. For both of you, time would seem normal, but when you returned to Earth, you'd find everything you know long gone even if you were away for but a few years. Time travel!

OK! Now for some laffs:

Get it?

Everything is funny when presented on a hipster faux trucking cap.