- X} is:
timelike if g ( X , X ) < 0 {\displaystyle \,g(X,X)<0} null or
lightlike if g ( X , X ) = 0 {\displaystyle \,g(X,X)=0}
spacelike if g ( X , X )...
- forward-in-time pointing,
lightlike,
normal directions. For example, a (spacelike)
sphere in
Minkowski space has
lightlike vectors pointing inward and...
- {\displaystyle v>c} . Δs2 = 0: In this case, the two
events are said to be
lightlike separated. This
implies that | Δ x / Δ t | = c {\displaystyle \vert...
- can be
classified into spacelike,
lightlike and
timelike separations. Only if two
events are
separated by a
lightlike or
timelike interval can one influence...
-
determined by the lay of the
lightcones – that
determines the
trajectories of
lightlike geodesics, and
hence their causal relationships. The
importance of Penrose's...
-
vector is
timelike if c2t2 > r2,
spacelike if c2t2 < r2, and null or
lightlike if c2t2 = r2. This can be
expressed in
terms of the sign of η(v, v), also...
- at a
spacetime point) can be
distinguished is
whether it is spacelike,
lightlike or timelike. The
space of
special relativity (Minkowski space) is an example...
-
inhomogeneous Lorentz group. The
first equation (or the
second restricted to
lightlike separation)
leads to a yet
larger group, the
conformal group of spacetime...
-
leads to a
measurement of
proper distance rather than
proper time. For
lightlike paths,
there exists no
concept of
proper time and it is
undefined as the...
-
something moving at the
speed of
light is zero. Such an
interval is
termed lightlike or null. A
photon arriving in our eye from a
distant star will not have...
