I should also like to note that Erik Verlinde, from the Institute for Theoretical Physics at the University of Amsterdam, has an interesting new paper available On the Origin of Gravity and the Laws of Newton (PDF), in which as he has said he argues that “Gravity exists because of a difference in the concentration of information in the empty space between two masses and its surroundings […] On the smallest level Newton’s laws don’t apply, but they do for apples and planets. You can compare this to the pressure of a gas. Molecules themselves don’t have any pressure, but a barrel of gas does” ~ because as Abraham Lincoln said, “For those who like this sort of thing, this is the sort of thing they like”. From the abstract:
Starting from first principles and general assumptions Newton’s law of gravitation is shown to arise naturally and unavoidably in a theory in which space is emergent through a holographic scenario. Gravity is explained as an entropic force caused by changes in the information associated with the positions of material bodies. A relativistic generalization of the presented arguments directly leads to the Einstein equations. When space is emergent even Newton’s law of inertia needs to be explained. The equivalence principle leads us to conclude that it is actually this law of inertia whose origin is entropic.
In section 6.1 of Verlinde’s paper, he writes, “Gravity has given many hints of being an emergent phenomenon, yet up to this day it is still seen as a fundamental force. The similarities with other known emergent phenomenon, such as thermodynamics and hydrodynamics, have been mostly regarded as just suggestive analogies. It is time we not only notice the analogy, and talk about the similarity, but finally do away with gravity as a fundamental force”. If Verlinde’s conjecture is true, and if his particular derivation of equation 5.34 in his paper
is valid, then it’s hugely significant. On the other hand, if not, then as Aristotle said, “It is the mark of an educated mind to be able to entertain a thought without accepting it”.
Your Reader Tips are, as always, welcome in the comments.