-
2121 - The Expanding
Universe. - Dark Matter is the gravitational energy that
brakes the expansion of the Universe.
Dark Energy, on the other hand, is the anti-gravity, the vacuum
repulsive force that accelerates the expansion of the Universe. Overtime the proportions of each effect has
changed.
---------------------------------- 2121 - Expanding
Universe
-
-
The Universe is still expanding. This Review explains why astronomers think that
is the case. The Universe started out to
be very small, the size of a single atom. We can call it the primeval atom. Primeval
means the first age.
-
-
This atom that existed during the first
age was hot, dense, and with energy beyond belief. This atom of energy created the matter and
began to expand and cool dissipating its energy as it expanded. The matter created was approximately 80%
hydrogen and 20% helium.
-
- The primeval atom was later renamed with the
misnomer, the Big Bang. But, the name stuck. It is a misnomer because the Universe is
expanding; it is not exploding. The matter in the expansion is actually standing
still. It is the space in between all the
matter that is expanding. The expanding
space drags the matter along with it.
-
- As the Universe expands matter gets spread
out thinner and thinner through the vacuum of space. The density of matter gets less and
less. As the density gets less the
gravity needed to stop the expansion becomes less and less powerful.
-
-
The matter in the form of galaxies are
accelerating faster the more distant they are from us. Another way to look at this expansion is to
decide if the accelerating galaxies have reached the velocity greater than the
escape velocity for the total amount of the gravity in the Universe.
-
- Astronomers have calculated the amount of
density to have the amount of gravity to prevent the galaxies from continuing
to accelerate outside the Observable Universe.
This density, called the Critical Density, is equal to 1 proton per
cubic meter. This does not seem like
much matter but remember there is a lot of space out there. At the exact Critical Density, 1 proton / m^3,
the Universe expansion would slowly come
to a stop after an infinite amount of time.
-
- The problem that quickly arises for
astronomers is that if they count all the matter they can see, they come up with only 4% of that Critical
Density, 1 proton / m^3. All the stars
and planets are only 0.5% of the Critical Density needed. To stop the never ending expansion of the Universe
we need a lot more mass. All the
galaxies are moving at a velocity far above the escape velocity and will
ultimately fly outside the Observable Universe.
-
- The next problem astronomers encountered was
a counter balance to this first problem.
When the rotational velocities of galaxies is studied the rotational
velocities are constant no matter how far from the center of the galaxy the
measurements are made. The laws of
physics require that the far out objects must have slower velocities than those
close in objects if they are to remain in orbit.
-
-
( For
example: Neptune has a rotational
velocity of 12,080 miles per hour.
Mercury has a rotational velocity of 107,152 miles per hour. ) The only way for astronomers to explain a
“constant rotational velocity” in galaxies is that there is a much higher
amount of mass in the galaxy than what we can see. Galaxies appear to have a halo of “Dark
Matter” that is 90% of the mass of the galaxy.
-
- We could tell Dark Matter exists although we
cannot see it because we do see the effect of gravity. Imagine that the Earth was always and
everywhere covered by clouds we would never see the Moon to know that it
exists. However, astronomers could study
the tides and conclude that a moon exists and know big it has to be. The math tells us the reality.
-
- So we need to add this Dark Matter to the
Ordinary Matter to calculate the density relative to the Critical Density. Doing this astronomers again can only come up
with 30% of the Critical Density. 70%
must be something else.
-
- One source of data for the expanding Universe
came from Type 1A Supernovae that were true explosions observed some
10,000,000,000 lightyears away. Astronomers
use the known luminosity of these explosions to determine the distance away
from us. Then, they use the redshift of
the receding light source to determine its velocity.
-
- ( An analogy here is similar to standing in a
perfectly dark, straight highway and observing a car’s red taillights fade the
distance as the car speeds away. We can
measure the redshift of the red taillights to determine the velocity of the car
to be 60 miles per hour. But, how can we
tell how far the car is away at that moment?
We can’t unless we know the intrinsic brightness of the taillight. If we know we are observing a 10 watt light
bulb, we know exactly how much light it produces at the source, and, we can
calculate the distance to the light source by how much dimmer they known light
appears at a distance.)
-
- The same process as our analogy is used for
the Type 1A supernovae. We know that
this type supernovae explodes with a critical mass of 1.4 Solar Mass. We therefore can calculate its absolute
luminosity. With this we calculate the
distance to be 10,000,000,000 lightyears.
We calculate the velocity with the redshift of the starlight. The Hubble Constant then becomes 70
kilometers/second per mega parsec and the age of the Universe becomes
13,700,000,000 years.
-
- After some 300 of these supernova
measurements scientists conclude the Universe is expanding at an accelerating
rate. The Dark Energy, or Vacuum Energy,
needed to explain this expansion rate comprises 74% of the mass of the Universe. Dark Matter comprises 22% and the rest is
Ordinary Matter.
-
-
Dark Matter is the gravitational energy
that brakes the expansion of the Universe.
Dark Energy, on the other hand, is the anti-gravity, the vacuum
repulsive force that accelerates the expansion of the Universe. Overtime the proportions of each effect has
changed. Here is the data over 54.8
billion years of this tug-of-war :
-
-------- Age of Universe -------------- Dark
----------- Ordinary
------------- Vacuum
-------- Billions of years -------------- Matter
----------- Matter
------------- Energy
-
-------- 3.4
--------------------------
75% ----------- 20% ------------- 5%
-------- 6.7
--------------------------
60% ----------- 15% ------------- 25%
-------- 13.7 today ------------------ 22%
----------- 4% ------------- 74%
-------- 27.4 -------------------------- 2%
----------- 1% ------------- 97%
-------- 54.8-------------------------- 1%
----------- .5%
------------- 98.5%
-
- Summary:
The primeval atom started out with the creation of all matter that is in
the Universe. As the matter spreads out
the Observable Universe has less and less matter in it. The density of the Universe becomes a greater
and greater proportion of Vacuum Energy of space with little matter left.
-
-
We need to learn what Dark energy is? What forces create this vacuum repulsive
energy? If the amount of vacuum energy
is constant then the density of vacuum energy in an expanding Universe will
decrease and eventually what little matter is left will have the gravity pull
needed to slow down the acceleration, stop expansion, and put the Universe
is reverse for a “ Big Crunch”.
-
- On the other hand , if the density of vacuum
energy is constant then the universe will continue to accelerate in its
expansion and we end up in a “ Big Chill”.
A cold, dark, lifeless Universe.
We need to learn more before we can decide the fate of the
Universe. A Big Crunch or a Big
Chill? Will there ever be another Big
Bang? When matter changes into energy
according to
E = mc^2, where does gravity go? Are matter and energy really the same things?
-
-
I love it when we end up with more questions
than answers. I don't ever want to stop learning.
Our knowledge is but a pebble on the beach
with a whole ocean of unknown in front of us.
-
- October 14, 2018
----------------------------------------------------------------------------------------
----- Comments appreciated and Pass it on to
whomever is interested. ----
--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for
copies or Index of all reviews
--- to:
------ jamesdetrick@comcast.net ------
“Jim Detrick” -----------
- https://plus.google.com/u/0/ -- www.facebook.com -- www.twitter.com
--------------------- Thursday, October 11, 2018 -------------------------
-----------------------------------------------------------------------------------------
No comments:
Post a Comment