I’m currently hard at work analyzing the depiction of projectile motion in Portal 2. What started as a quick, one minute video has turned into a veritable research paper on the accuracy of projectile motion’s representation in the game. Keep an eye out for some hardcore physics nerdiness in the next few days.
In the meantime, here’s an interesting discussion on Reddit about the physics of a rod stuck between two moving portals.
The rod should oppose the motion of the portals in this diagram until it breaks. Increasing the distance between the portals would require stretching the rod, in which case the applied force would in some way be proportional to the tensile strength of whatever material makes up the rod. This begs a few questions, of course. What about the air between two moving portals such as these? Would moving portals create suction? Would a moving portal have to also apply a force to oppose air resistance? Would vertical portal movement (in this diagram) be possible? In a vacuum with no rod present, would you still have to apply a force to change the separation between the portals?
I recently read Chad Orzel’s fun book, “How to Teach Relativity to Your Dog,” which has put me in the relativistic mindset. I can’t help but think that a situation involving moving wormholes would experience significant effects from general relativity in ways that may not be immediately apparent (or allow this kind of situation in the first place). We’re looking at a moving spacetime connection between two distance places, which hurts my brain.
Anyone have any thoughts? I’d love to hear.
Physics with Portals 