# Multiple time dimensions

Two dimensional time 6.1

.

Physics

Special relativity describes spacetime as a manifold whose metric tensor has a negative eigenvalue. This corresponds to the existence of a “time-like” direction. A metric with multiple negative eigenvalues would correspondingly imply several timelike directions, i.e. multiple time dimensions, but there is no consensus regarding the relationship of these extra “times” to time as conventionally understood.

Philosophy

An Experiment with Time by J.W. Dunne (1927) describes an ontology in which there is an infinite hierarchy of conscious minds, each with its own dimension of time and able to view events in lower time dimensions from outside. His theory was often criticised as exhibiting an unnecessary infinite regress.

— Wikipedia on Multiple time dimensions

.

.

2010.02.11 Thursday ACHK

# The Open Cage

.

Have you ever noticed that when animals are let out of cages, they don’t always realize at first that the door’s open? Often they have to be poked with a stick to get them out. Something similar happened with blogs. People could have been publishing online in 1995, and yet blogging has only really taken off in the last couple years. … it just took eight years for everyone to realize the cage was open.

— Paul Graham

.

.

.

2010.02.11 Thursday $ACHK$

# 兩種天份

（安：甚至他不知道有頭十一步。你的第十二步，其實是他的第一步。）

（安：所以如果用這個準則在衡量老師的好壞，根據自然定律，好的老師是極少數。那是因為要一個人本身學養高，機會已經很小。而同時要他教學技巧好，機會就更小。）

— Me@2010.02.10

2010.02.10 Wednesday (c) All rights reserved by ACHK