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age 22
visits member for 3 years, 1 month
seen Jun 30 at 12:30

Jul
2
awarded  Curious
Jun
5
awarded  Yearling
May
7
awarded  Notable Question
Feb
11
accepted Is it possible to escape from within event horizon?
Feb
10
asked Is it possible to escape from within event horizon?
Jan
14
awarded  Popular Question
Dec
8
awarded  Notable Question
Nov
25
accepted Is there a simple model explaining Faraday effect?
Jun
24
awarded  Popular Question
Jun
5
awarded  Yearling
Apr
28
awarded  Popular Question
Feb
5
comment Is rate of temperature change constant?
You should state clearly that this law is empirical and approximately valid just for certain substance.
Feb
4
comment How can the speed of light be a dimensionless constant?
@kojiro: Coordinate transformation does not happen within a coordinate system; it is the transform from one coordinate system to another. All four coordinates, in fact, should have the same dimension, in order for many geometric constructs, like metric tensor to make sense.
Feb
1
answered Charged quantum particle in a magnetic field - choosing a different gauge leads to different wavefunctions
Feb
1
comment Relativistic basic question - four vector, Lorentz matrix
@DaPhil: $L^{\mu}{}_{\nu}L_{\mu}{}^{\lambda}=L^{\mu}{}_{\nu}g_{\mu\rho}g^{\lambda\sigma}L‌​^{\rho}{}_{\sigma}=g_{\nu\sigma}g^{\sigma\lambda}=\delta_{\nu}^{\lambda}$, so the two transform matrix are inverse to each other.
Feb
1
comment Relativistic basic question - four vector, Lorentz matrix
@DaPhil: Maybe your texbook uses a different notation? Matching indices means that upper $\mu$ on the l.h.s must match the upper $\mu$ on the r.h.s. In your question you write $(a^\mu)'=L_{\mu\lambda}a^\lambda$, where $\mu$ on the left is upper and right lower.
Feb
1
comment Relativistic basic question - four vector, Lorentz matrix
@DaPhil: Then your book is wrong. The indices must match each other.
Feb
1
comment Relativistic basic question - four vector, Lorentz matrix
@DaPhil: Is your book using imaginary time? In that case as I said, there is no distinction between upper and lower indices.
Feb
1
answered Relativistic basic question - four vector, Lorentz matrix
Jan
24
comment What are the differences between indistinguishable and identical?
As far as I know, these are just two different names with the same meaning.