T = Tsource = 1 second

BLUESHIFT

REDSHIFT

shift z

−0.5

−0.1

1

10

Distance of B source from A

β source (NNM)

−1.00

−0.11

0.50

0.91

d: distance of emission of B from O

−0.5 c T

−0.91 c T

λ: distance from B to A

(0.5 c) T

(0.9 c) T

Length traveled by photon B:

T observed/Tsource = (1 + z)

0.5

0.9

2

11

L: Length traveled using Tobs

c (0.5 T)

c (0.9 T)

0.5 c T

0.91 c T

Difference δ

0

0

0

0