At the present time, the only way we know of that light can get shifted
toward the blue end of the spectrum is the Doppler effect ... wavelengths
appear shorter than they should be when the source is moving toward us.
IF that's true in the case of the Andromeda galaxy, it means the galaxy is
moving toward us.
We use the same reasoning to conclude that all the galaxies whose light is red-shifted are moving away from us. That includes the vast majority of all galaxies that we can see, and it strongly supports the theory of the big bang
and the expanding universe.
If somebody ever comes along and discovers a DIFFERENT way that light
can get shifted to new, longer or shorter wavelengths, then pretty much all
of modern Cosmology will be out the window. There's a lot riding on the
Doppler effect !
Answer: A, B, and D,
C is incorrect because continental drift takes several centuries to move the tectonic plates witch is not an immediate impact leaving you with A,B, and D.
Answer:
a) b = -5
b) slope = 3/2
Explanation:
a) The equation of a line is given as y = mx + b, where m is the slope of the line and b is the intercept on the y axis.
Given that y = 3x + b and it passes through the point (2, 1). Hence when x = 2, y = 1. Therefore, substituting for x and y:
1 = 3(2) + b
1 = 6 + b
b = 1 - 6
b = -5
b) The equation of a line passing through two points (
) and
is given by:

The equation of the line passing through the two points (0,3) and (4,9) is:

Comparing y = (3/2)x + 3 with y = mx + b, the slope (m) is 3/2
By Hubble theory in which universe is expanding,