The baiscis of the universe expanding

2. 1) If the Universe were infinite and contained stars
everywhere then if you looked in any direction, your line-
of-sight would eventually fall on the surface of a star.
Although the apparent size of a star in the sky becomes
smaller as the distance to the star increases, the
brightness of this smaller surface remains a constant. if
the Universe were infinite, the whole surface of the night
sky should be as bright as a star. there are dark areas in
the sky, so the universe must be finite.
2) gravity is always attractive. Every object in the universe
attracts every other object. If the universe truly were
finite, the attractive forces of all the objects in the
universe should have caused the entire universe to
collapse on itself.

3. Using red shift it is possible to calculate the age
of the universe.
Red shift is the displacement of spectral lines
toward longer wavelengths (the red end of the
spectrum) in radiation from distant galaxies and
other objects. This is often interpreted as a
Doppler shift. The formula is given as V=HD.
The frequency of waves which sources are
moving away from us decrease so wavelength
increases.
So a light wave from a far away galaxy will have
a wavelength of light that shifts to the red end of
the visible light spectrum.

4. V = H x D Distance
Recessional velocity Hubble’s Constant
Age of the Universe = 1 / H
(Seconds) Hubble’s Constant (Mpc)
(1.62 x 10^-18)

5. The discovery of cosmic Microwave
Background further strengthened the
argument that the universe was
expanding.
You can see the remnants of the
expansion of the universe by detuning
your TV.

6. Open universe
The Universe will continue to expand forever no matter
what but will continue to slow down.
Flat Universe
the Universe will continue to expand but eventually
this expansion will rate will slow to zero after an
infinite amount of time.
Closed universe
Eventually the universe will stop expanding due
to Gravity and will Collapse in on its self. This
May then lead to another big bang.