
20220720: What If We Live in a Superdeterministic Universe?
 08:18: Let’s play out the Bell test on something called a spacetime diagram  with one dimension of space only on the x axis and time on the y.


20210224: Does Time Cause Gravity?
 02:09: We can show this with our old friend the spacetime diagram.


20210210: How Does Gravity Warp the Flow of Time?
 07:36: We can see that when we use a spacetime diagram to show how the traveler tracks the passage of time back on Earth.
 07:52: Here’s the spacetime diagram for our rotating lab.


20210119: Can We Break the Universe?
 04:07: The best way to see this is on a spacetime diagram.
 04:33: ... the spacetime diagram, the set of simultaneous events for a motionless observer lie on a ...
 05:12: ... the spacetime diagram, that’s whenever one of these lines of constant time extending from ...
 06:20: But to see why we need a much weirder version of the spacetime diagram.
 09:46: Again, the best way to see this is on a spacetime diagram.
 11:12: The answer is in our looped spacetime diagram.


20200615: What Happens After the Universe Ends?
 04:41: This is a spacetime diagram.


20190403: The Edge of an Infinite Universe
 05:40: As a quick review: start with a graph of space versus time – a spacetime diagram – then compactify.


20181107: Why String Theory is Right
 03:34: On a spacetime diagram, time versus one dimension of space, this is called its world line.
 04:32: When strings move on a spacetime diagram, they trace out sheets or columns.


20180404: The Unruh Effect
 01:26: We just need a little special relativity and a spacetime diagram.
 01:34: A spacetime diagram has two axes, time and, well, space, with time on the vertical axis.
 02:04: On the spacetime diagram, this is a line with a 45degree angle from the vertical axis.


20170816: Extraterrestrial Superstorms
 12:41: To prove this to yourself, try drawing a spacetime diagram, time on the yaxis and space on the xaxis.


20170329: How Time Becomes Space Inside a Black Hole
 05:19: On our ever popular spacetime diagram, we see a sharp division between the two.


20170322: Superluminal Time Travel + Time Warp Challenge Answer
 01:23: We'll do this in flat space, so we need a flat or Minkowski spacetime diagram.
 04:43: Let's see what that looks like on the spacetime diagram.


20170308: The Race to a Habitable Exoplanet  Time Warp Challenge
 00:51: In that episode, we talked about the spacetime diagram and how it transforms between observers traveling at different speeds.
 01:35: ... respect to x and to equal zero as contours, then we can transform the spacetime diagram into a 3D graph, in which causality must always flow ...
 03:29: To answer this, you'll need to draw a spacetime diagram showing the world lines of the two ships.
 04:43: Submit your answers with full explanations and spacetime diagrams within two weeks of the release of this video to be in the running.


20170215: Telescopes of Tomorrow
 11:39: ... wondered about the relationship between the geometry I depicted on the spacetime diagram and the geometry that comes from mass and energycurving ...
 11:49: The spacetime diagram I showed is for flat or Minkowski space.


20170202: The Geometry of Causality
 02:49: To preserve our sanity, we represent this on a spacetime diagram plotting time and only one dimension of space.
 03:03: There is no standing still on a spacetime diagram.
 04:51: First, we need to draw the spacetime diagram from the perspective of one of the other travelers.
 06:27: That comes from insisting that we all see the same speed of light, 45 degrees on the spacetime diagram.
 09:40: In fact, the nearest downhill contour defines the forward light cone for anyone anywhere on the spacetime diagram.
 10:08: ... spacetime diagram we looked at today was for a flat or Minkowski space, in which faster ...


20161208: What Happens at the Event Horizon?
 02:08: It's a special type of spacetime diagram designed to clarify the nature of horizons.
 02:15: But first, a quick refresher on basic spacetime diagrams.
 02:30: With the right choice of space and time units, the speed of light becomes a diagonal line on the spacetime diagram.
 03:01: Let's drop a black hole onto our spacetime diagram.
 03:48: The problem with the regular spacetime diagram is that the path of light and the shape of the light cone changes as spacetime becomes warped.
 04:10: It transforms the regular spacetime diagram to give it two powerful features.
 04:48: ... as with a regular spacetime diagram, blue verticalish lines represent fixed locations in one dimension of ...


20160217: Planet X Discovered?? + Challenge Winners!
 04:11: The best way to illustrate this is with a spacetime diagram.
 04:21: So a photon clock that stationary on the spacetime diagram moves straight up.


20150819: Do Events Inside Black Holes Happen?
 00:37: ... technical terms like "geodesic" or "flat spacetime" and if I can draw a spacetime diagram or ...


20150729: General Relativity & Curved Spacetime Explained!
 01:54: ... think about it, on the flat spacetime diagrams of inertia observers, the world lines of other inertial observers are ...
 05:44: On a flat spacetime diagram the world lines of those photons should be parallel and congruent.


20150715: Can You Trust Your Eyes in Spacetime?
 01:22: Our principle tool for exploring flat spacetime geometry will be something called a spacetime diagram for representing physical events.
 04:34: ... spacetime diagrams are great for visualizing cool phenomena like time dilation, or length ...
 04:51: Because here's the thing, the answer is not clear a priori since you can't trust your eyes in spacetime diagrams.
 05:19: ... spacetime diagrams preserve the spacetime interval between points with its weird minus ...
 07:25: But that interpretation doesn't work on a spacetime diagram.
