By: Brian Greene, read in 2004
29  Newton: Space is the sensorium of God  
79  A "self-evident truth" that I doubt: that two birds are distinct  
91  We don't know how to envision what QM probability waves are.  
99  Bohr: reality = things we can measure  
119  Wave function collapse does not emerge from QM math!  
128  Conscious experience of time  
130  Unwarranted assumption: That we are "all within space-time" and never "outside".  
131  Not true! What about dreams?  
131  Consciousness embodies what science has been unable to find.  
138  All of space-time exists - not just the "now-slice".  
139  Conscious experience moves through time.  
140  A discussion similar to my "What Might be Going On(?)"  
141  He makes my case for additional temporal dimensions.  
141  Einstein on the problem of "now" being beyond science.  
141  Good discussion demonstrating the separateness of experience & physical laws.  
154  Entropy - the definition is incomplete and meaningless without involving consciousness (See Encyclopaedia Britannica  11-258b for a good discussion of entropy, information, thought, brains and life.)  
203  Stage 1/Stage 2 QM sounds like Cartesian duality.  
216  Needed: time-asymmetric solution to the measurement problem with entropy decreasing toward the past.  
220  Error: Cubes are also symmetric wrt diagonal axes for rotations of 120 degrees.  
226  Wheeler: "Time is nature's way of keeping everything...from happening all at once".  
232  The pennies-on-balloon analogy doesn't account for constant penny size or for the extra (large!) dimension of space it requires.  
236  Greene dodges the extra-dimensional implication calling it "meaningless".  
237  His explanation of fixed penny size. Suppose the pennies grow. From page 46 and 229, stretching speed per mile of separation = 5.5 million mph / 100 million light years = 9.27X10-15 mph/mile [should double check these calculations.] = .0000052 inches per year per mile! That would be easy to overlook.  
242  I don't think a "saddle" shape is "completely symmetric"; curvature is different for different directions.  
253  Inconsistency with note 2 p517. Confusing order and symmetry.  
286  Leibniz: "Why is there something and not nothing?"  
310  Greene: Logic alone predicting physics is a "pipe dream".  
314  Entropy-as-order seems unjustified to me.  
317  Is chicken feed more "ordered" than a chicken? I doubt it.  
321  Good, short, summary of inflationary cosmology.  
333  While we're at it, why not consider "space itself" to be an embedded manifold?  
355  Super-symmetry or super string theory ~ integer and half integer spin symmetry.  
359  String theory requires 10 space-time dimensions.  
360  Greene claims that Theodor Kaluza was German. Not Swedish?  
361  Kaluza's insight re Einstein's & Maxwell's equations.  
361  Greene: Inability to detect hyperspace is a "problem".  
361  Kaluza learned to swim by reading a book.  
361  Oops! It was Klein who was Swedish.  
362  Tightrope analogy is bad: "easy to see", by whom? Philippe? worm? distant observer?  
362  The tightrope's surface is a manifold and not a dimension.  
363  Fibers do not have "circular dimension" except as a new set of basis vectors defined on a manifold.  
365  Not quite! The circles on the tightrope have no extension in any dimension of the tightrope; in Fig 12.7 they have extension in one of the dimensions of the fabric.  
365  Implication that curled-up dimensions are necessary to escape detection.  
366  The answer to "why the universe [has 11] dimensions" may be that we are at that point in cosmic evolution. The number of dimensions, along with cosmic complexity, may be evolving.  
369  Calabi-Yau spaces.  
372  Particle properties depend on C-Y spaces. I say why not as C-Y manifolds?  
372  "Since we don't see the extra dimensions, they must be small".  
373  The significance of the number of holes in a C-Y space.  
374  Extra dimensions may hold the key to the deepest mysteries.  
374  Inflation may have been asymmetric wrt dimensions.  
382  Kaluza showed that 5 dimensions unifies gravity and electromagnetism.  
383  "historical pattern of achieving unity through more dimensions"  
383  "The known equations are still unable to nail down the sizes or shapes of extra dimensions".  
385  Strings (1-manifolds) necessarily include gravity where points (0-manifolds) = electrons, photons, etc.  
392  "Why don't we see the three-brane...?" We do; that's all we see.  
393  YES!! That's what I've been saying all along! We shouldn't expect to be able to see extra dimensions!  
394  Giant leap to assume "everything we've ever seen" is "everything".  
412  Greene: There may be much more to reality than 4D space-time.  
441  Assumption that consciousness is seated in the brain.  
441  In a human body, a trillion atoms are replaced every microsecond.  
452  Greene: an observer following a static world line is not logical. I think it is.  
475  The "need" to curl up extra dimensions.  
475  If the particular "size and shape" of dimensions in Type IIA and Type IIB theory were seen as manifolds and not dimensions, then their geometries would naturally differ if seen as orthographic projections. That explanation would seem to be a lot more natural and simpler.  
477  Re two observers using different string theories and concluding that space has a different size and shape for each, he says: "Note too, that it's not that they would be slicing up spacetime in different, equally valid ways, as in special relativity." I say, Why not? That would seem to be a better interpretation to me.  
478  Definition of 'entropy' requires an observer with assumptions on acuity.  
479  I suspect that this line of reason is fallacious.  
479  I thought so!  
480  This paragraph sounds like baloney.  
481  Sounds to me like Greene has described a manifold and not a hologram.  
482  Yes. That's another way of saying we live in a 3D manifold embedded in 4D space.  
483  Tacit declaration that string theory requires curled-up dimensions.  
483  Interesting! This suggests a possible mechanism for evolving a cosmos of successively more spatial/temporal dimensions along the lines that I envisage.  
484  Yes! Just as a manifold and its boundary are on equal footing!  
485  Yes! It suggests the possibility of cosmic evolution with increasing number of dimensions.  
487  "background-independent" formulation ~ spaceless-timeless formulation  
490  Could the "loops" be information storage delay loops? This could possibly lead to a fractal generation of the fabric.  
491  Do "relative  relationships" have any meaning in the absence of consciousness? I don't think so.  
492  Maybe not: Individual experience may frame space and time!  
496  Maxwell's equations.  
498  Einstein's field equations.  
499  Greene: Spacetime = manifold + metric.  
505  The Minkowski space-time metric.  
506  Time reversal and CPT asymmetry of weak interaction.  
512  Schroedinger's Wave Equation  
516  Calculations of light travel along null geodesics of the metric  
526  The assumption that all known fields exist "everywhere" is either unwarranted or misleading. It is possible a field may exist only in a particular manifold. e.g. ocean waves exist only on the surface.  
526  A dead-calm ocean is different from no ocean.  
527  The time variable disappears when GR is transformed in a straight-forward way by QM!! This suggests to me that the temporal dimension we "experience" might, in reality, be another spatial dimension which is part of our 4D manifold and which  is traversed, in a higher temporal dimension, by a conscious agent.  
529  Strings conform to infinite symmetry groups. Higher-D branes conform to finite symmetry groups. Greene implies this is a negative; I think it is a positive feature.  
530  I believe Dr. Dick has proved that any consistent formulation of a description of fundamental reality must conform to QM rules.  
530  I suspect that "winding" is not a good explanation for T-duality. It seems more likely that the brane is spherical so the duality is due to the interchangeability between inside and outside. If R is the inside radius, then 1/R is the antipodal radius.  
534  I don't buy this demonstration of additivity of entropy. This would hold if there remained a partition between the two tupperware containers, but not otherwise.  
535  It seems to me you would have to admit (astronomically) large extra spatial dimensions to be able to talk about "light sheets". in this way.  
536  This either sounds like nonsense, or it begs a definition of "spatial infinity".  
©2005 Paul R. Martin, All rights reserved.