{"id":114,"date":"2010-05-14T01:42:02","date_gmt":"2010-05-14T00:42:02","guid":{"rendered":"http:\/\/www.quantum-bits.org\/?p=112"},"modified":"2015-08-10T16:09:39","modified_gmt":"2015-08-10T15:09:39","slug":"smarter-than-tony-stark","status":"publish","type":"post","link":"https:\/\/www.quantum-bits.org\/?p=114","title":{"rendered":"Smarter than Tony Stark"},"content":{"rendered":"\n\n
\nWell, I wish I were… Anyhoo, I went to the movies and saw Iron Man II<\/a> a few hours ago. Slightly disappointing, maybe because I was expecting much from Don Cheadle<\/a> and Mickey Rourke<\/a>, and, well, because the french speaking scenes were so totally weird (I had no idea that people from Monaco were speaking with such a strong Qu\u00e9b\u00e9cois<\/a> accent…).<\/td>\n\n
qbits-post.png<\/div>\n<\/td>\n<\/tr>\n<\/table>\n

But that is not the point of this post. I saw the film through my geeky eyes, and I was stricken by a particular scene.<\/p>\n

Okay, this is just a small detail that caught my attention. I’m weird. I know. I (kind of) assume it.<\/p>\n

Usually, the laws of physics don’t apply in Hollywood movies, and especially in superhero<\/a> movies, including this one. But, at one point, Tony Stark<\/a> is given by Nick Fury<\/a> a suitcase containing a few old films and notes from his father (Howard Stark<\/a>)<\/p>\n

Here’s a shot from the film, focusing on the notes :<\/p>\n

<\/div>\n

 <\/p>\n

The circled formula is what caught my eyes and triggered an intense googling effort to find this shot and check if I was indeed crazy (or not). It reads as follows:<\/p>\n

\nR_{\\mu\\nu} = K \\left(T_{\\mu\\nu} - \\frac{1}{2} T g_{\\mu\\nu}\\right)<\/div>\n

which is accurate, as it is a “trace-reversed” form of actual Einstein’s field equations:<\/p>\n

R_{\\mu\\nu} = \\frac{8\\pi G}{c^4} \\left(T_{\\mu\\nu} - \\frac{1}{2} T g_{\\mu\\nu}\\right)+\\Lambda g_{\\mu\\nu} <\/div>\n

where the Cosmological Constant<\/a> (\\Lambda) would have been omitted.<\/p>\n

Usually, Einstein’s field equations are written under this form:<\/p>\n

\n\n\n
G_{\\mu\\nu} + \\Lambda g_{\\mu\\nu} = \\frac{8\\pi G}{c^4} T_{\\mu\\nu} <\/td>\n where <\/td>\nG_{\\mu\\nu} = R_{\\mu\\nu} - \\frac{1}{2} Rg_{\\mu\\nu}<\/td>\n<\/tr>\n<\/table>\n<\/div>\n

or under this simpler and incredibly beautiful form (neglecting the cosmological constant):<\/p>\n

G_{\\mu\\nu} = \\frac{8\\pi G}{c^4} T_{\\mu\\nu} <\/div>\n

The rest of the notes apparently deal with the conservation of energy-momentum T^{ab};b = 0 and other simple properties of General Relativity<\/a>.<\/p>\n

Whatever the meaning of all these equations is (got one post on General Relativity in preparation), what is truly remarkable is that:<\/p>\n