If physics blogs were like economics blogs

I recently came across some interesting new work in computational cosmology, this time in a paper from Jan Ambjorn, Timothy Budd that lent itself to some rather beautiful 2-dimensional universes. Check out this video for some of these 2D universes embedded in 3D:

Causal dynamical triangulation may potentially be the long-sought quantum theory of gravity. It constructs universes from tiny triangles ("simplices"). Older but similar "brute force" approaches failed, producing universes with a low number of effective dimensions. However this approach assumes one extra ingredient: causality. Complexes with causality-violating simplices are forbidden, reducing the number of possible configurations. This results in universes with the "correct" number of effective dimensions.

Posted 07/14/2014 11:14am

Comments (13)

Ted A. Thomas III I've spent 30+ years as a manager of a piano moving company, so I think I know a thing or two about gravity. All I can say is that this isn't how gravity works in the real world. You have to apply force perpendicular to the ground plane in order to move objects along the z-direction.

Anonymous LOL this is completely wrong

jeffkeen22 This ignores what Aristotle said: everything moves toward its natural place.

Anonymous Ah, but Aristotle got heliocentrism wrong. 

jeffkeen22 Heliocentrism was the downfall our society. We're living in a dark age now. 

Anonymous You realize Aristotle was a geocentrist right?

unlearningphysics Newton knew about this all along. He's credited with discovering calculus but he used trigonometry in his Principia for a reason.

Paulite2000 You liberals think government can fix everything.

progman2000 It can!

StudentofPhilosophy I've long thought gravity is an illusion invented by physicists to keep ordinary people from being allowed to speak on the subject. Remember -- Newton's inverse square law is guilty of what Einstein called spooky action at a distance. Yet astrophysicists and aerospace engineers still use Newton's flawed equations to run our society. I was completely astounded when I saw this:

Physicists Pin Down Value Of Newton's Gravitational Constant

How can they pin down something that Einstein says is fundametally flawed? I was a philosophy major in college, so I am well trained in being able to spot the fundamental contradiction and circular logic.

oldisnewagain "Once upon a time a valiant fellow had the idea that men were drowned in water only because they were possessed with the idea of gravity. If they were to knock this notion out of their heads, say by stating it to be a superstition, a religious concept, they would be sublimely proof against any danger from water. His whole life long he fought against the illusion of gravity, of whose harmful results all statistics brought him new and manifold evidence. This valiant fellow was the type of the new revolutionary philosophers in Germany. "

https://www.marxists.org/archive/marx/works/1845/german-ideology/preface.htm

aphysicist Actually that may be more correct than you know -- gravity may be an entropic force and the local direction of the gravitational field is the direction of the holographic dimension.
http://en.wikipedia.org/wiki/Entropic_gravity

timecube4444 1000 dollars to anyone who can disprove the Harmonic Cube
http://www.timecube.com/


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PS This is kind of a half-baked joke, but apparently I was scooped in concept by John Cochrane of all people.
PPS I really think the CDT group is doing really neat stuff -- actually that is what I devoted my spare time to playing with before I took up the economics blogging. I was hoping to speed up the computations with GPU processing, but it appears they've already gotten there.