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2146 -
Astronomy is Seeing History.
Because of the fixed speed of light everything that astronomers see happened a long time
ago. Who knows what it really looks like
today? A lot has happened since
then. The more distant you look the
further back in time you see.
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---------------------------------- 2146 -
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- Astronomy is the study of history. Because of the fixed speed of light
everything that these astronomers see happened a long time ago. Who knows what it really looks like
today? A lot has happened since
then. The more distant you look the
further back in time you see.
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- Astronomers today have technology that lets
them see back 3,800,000,000 years. Back
97% of the time since the big bang. One
new technology is called gravitational lensing.
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- Looking back to within 1 billion years after
the big bang astronomers have found over 300 galaxies. Much study remains but the hope is to find
the very first galaxies formed in the universe.
They must be getting close.
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- The first galaxies were composed of only hydrogen
and helium. The heavier elements beyond
hydrogen, helium and lithium had not yet
been created because the universe cooled down
too fast The stars themselves
fused the heavier elements in their hot nuclear cores. The 90 or so heavier elements
were to be spread throughout the
universe in supernovae explosions.
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- The first galaxies were not spiral
galaxies. And, they were only 1% the
size of the Milky Way Galaxy. Stars were
reproducing rapidly because so much was concentrated in a smaller volume of
space. Galaxies collided and merged into
larger galaxies more frequently as space expanded.
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- Today the universe has expanded even more and
galaxy growth through merging has slowed down.
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- That is the evolution picture astronomers
have today. The hope is that looking
back further may help define the story
in even more detail. Gravitational
lensing is our new magnifying glass to learn more about this early beginning.
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- Gravity bends light. Giant galaxy clusters have immense gravity
concentrations that bend the light that passes by them. Light from more distant galaxies directly in
the path of their star light is magnified as it is bent around this immense
gravity concentration.
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- In the early universe small, faint galaxies
were plentiful. But, they are very
difficult to find. Despite the
difficulty of the search, at least one galaxy has been discovered that existed
just 420,000,000 years after the big bang.
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- Because the universe is expanding the light
from these earliest galaxies is stretched far into the infrared wavelengths,
redshifted. Observations are made at
wavelengths spanning 0.4 to 1.7 microns in order to "see" this early
light. If the wavelength of hydrogen can
be detected the amount of redshift can be determined and the distance to the
light source can be calculated.
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- A redshift as high as 10 means that that
light is from a source that is only 3.5% the age of the Universe. A redshift of 11 means that source is only
400,000,000 years old.
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At 380,000 years after the big bang space and time had expanded and cooled
enough for the first atoms to form. When
neutral atoms formed light was set free to travel out of the electrically charged
soup. That is the cosmic microwave
background that we see today.
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- The afterglow of this happening we see as
microwave background radiation that has been traveling for 3,800,000,000 years. This light has been redshifted into the
longer microwave wavelengths. The first
stars formed perhaps 100,000,000 years after this happened.
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- Looking back in time ultimately we discover
our origins and ,ultimately , we find ourselves.
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- What we are learning is like picking up
pebbles of knowledge on the beach with a whole ocean of unknown before us as
far as the eye can see.
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- Other reviews on the big bang available upon
request:
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- 2065 -
The big bang antimatter mystery. The big
bang that produced the universe from nothing should have produced equal amounts
of matter and antimatter. Yet antimatter
is surprisingly rare
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- 1983
- What are some of the problems
explaining the big bang theory for the creation of our universe?
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- 1682
- The big bang theory is the
birth of the "observable universe".
We don't know the rest?
The
biggest mystery of all is that we are here to observe it.
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- 1128
- What evidence supports the big
bang theory? As part of this expanding
there is only a small window of time that life could form. Thank your lucky stars that you are live to
read this.
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1127 - Do you
have some questions about the big bang theory for creation? If you don't I still do.
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712 - Meet the
primeval atom. The problem that arises for
astronomers is that if you count all the matter you only have 4% of that needed
to explain the rate of expansion of the universe.
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671 - Mini-big
bangs we have here on Earth.
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652 - Lemaitre's
big bang theory. It took 70 years before
the prejudices were overcome and the community accepted the model worked out by
this Catholic priest and mathematician.
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634 - The first
3 minutes in the age of the universe.
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613 - The history
of energy in the universe.
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612 - The age
of the universe. How science came up with
3,800,000,000 years?
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376 The origins of existence. There are only twelve fundamental particles that
make up all the matter in the universe.
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42 - How the
universe began. The most incomprehensible
thing about the beginning of the universe is that we are here trying to comprehend
it.
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6 - The big
bang's first creations. Everything that happened
in the universe , except for gravity, is the result of combinations of seven force interactions with twelve
fundamental particles. Think about it! It does not get much simpler than that!
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- October 29, 2018.
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--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
-- email feedback, corrections, request for
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--- to:
------
jamesdetrick@comcast.net
------ “Jim Detrick” -----------
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--------------------- Monday, October 29, 2018 -------------------------
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