Talk:Spacetime
Summaries of earlier Talk (see [1])
Space-time vs. Spacetime
Examples of use of spacetime:
- Weisstein's encyclopedia http://www.treasure-troves.com/physics/
- D. J. Griffiths' Introduction to Electrodynamics (Upper Saddle River, N. J.: Prentice-Hall, 1989)
- numerous books with spacetime in title
- E. F. Taylor and J. A. Wheeler, Spacetime Physics (San Francisco: W. H. Freeman, 1966)
- Caltech class: "Spacetime 101"
- .edu matches online are almost exclusively for spacetime
Examples of use of space-time:
- Brehm & Mullin, Introduction to the Structure of Matter (ISBN: 047160531X)
- Merriam-Webster http://www.m-w.com
- space-time about four times as many hits as spacetime on AltaVista
The Spacetime four vector
The space-time four vector is:
[x y z ct]
the use of the vector as:
[x y z ict]
was common about 40 years ago or so, but it is now considered archaic and the former notation is prefered.--BlackGriffen
However, there are certainly physicists who prefer the i notation, including Dr. Jack Sarfatti.
The Wikipedia should present the mainstream state of a field as much as possible, presenting relevant dissenting views as such when they arise. The use of the i is just a lazy way to make finding the "length" squared of a four vector feel like finding the length of any other vector (dot product the vector on to itself). It is, however, just as easy to define a new "length" operator for four vectors that doesn't require complex numbers.
And if bandying about names is the game, a quick look at the Feynmann Lectures on Physics explanation of four vectors shows nary an i, even though he had a discussion of using c=1.--BlackGriffen
I concur: both 'space-time' and the 'i' notation appear to be common early usage, and physicists everywhere seem now to have standardised on both 'spacetime' and the 'i'-less notation -- The Anome