DIR Return Create A Forum - Home
---------------------------------------------------------
Gunny Publications Incorporated
HTML https://gunnypubs.createaforum.com
---------------------------------------------------------
*****************************************************
DIR Return to: The Intelligence Corps
*****************************************************
#Post#: 2753--------------------------------------------------
Is Dark Energy the new Name for the 19th Century's Luminiferous
Æther
By: Thorgrimm Date: May 9, 2014, 1:08 pm
---------------------------------------------------------
The folks who have read the rules I made, called The Game of
Nation!, will realize that I use the concept of the Luminiferous
Æther from the 19th century as a way to have non-Newtonian
spaceflight. Moreover, I am sure most of you think that is a
load of fantasy. Is it? Or is it something that just could not
be detected till now? ;)
Here is a link that explains a bit about what Dark Energy is.
HTML http://physicsworld.com/cws/article/print/19419
HTML http://physicsworld.com/cws/article/print/19419
Below is the link I use to direct folks to when they ask why I
use the concept of the Æther. Below the link is the article en
toto.
HTML http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/dark_energy.html
HTML http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/dark_energy.html
[quote]The discovery in 1998 that the Universe is actually
speeding up its expansion was a total shock to astronomers. It
just seems so counter-intuitive, so against common sense. But
the evidence has become convincing.
The evidence came from studying distant type Ia supernovae. This
type of supernova results from a white dwarf star in binary
system. Matter transfers from the normal star to the white dwarf
until the white dwarf attains a critical mass (the Chandrasekhar
limit) and undergoes a thermonuclear explosion. Because all
white dwarfs achieve the same mass before exploding, they all
achieve the same luminosity and can be used by astronomers as
"standard candles." Thus by observing their apparent brightness,
astronomers can determine their distance using the 1/r2 law.
By knowing the distance to the supernova, we know how long ago
it occurred. In addition, the light from the supernova has been
red-shifted by the expansion of the universe. By measuring this
redshift from the spectrum of the supernova, astronomers can
determine how much the universe has expanded since the
explosion. By studying many supernovae at different distances,
astronomers can piece together a history of the expansion of the
universe.
In the 1990's two teams of astronomers, the Supernova Cosmology
Project and the High-Z Supernova Search, were looking for
distant type Ia supernovae in order to measure the expansion
rate of the universe with time. They expected that the expansion
would be slowing, which would be indicated by the supernovae
being brighter than their redshifts would indicate. Instead,
they found the supernovae to be fainter than expected. Hence,
the expansion of the universe was accelerating!
In addition, measurements of the cosmic microwave background
indicate that the universe has a flat geometry on large scales.
Because there is not enough matter in the universe - either
ordinary or dark matter - to produce this flatness, the
difference must be attributed to a "dark energy". This same dark
energy causes the acceleration of the expansion of the universe.
In addition, the effect of dark energy seems to vary, with the
expansion of the Universe slowing down and speeding up over
different times.
Astronomers know dark matter is there by its gravitational
effect on the matter that we see and there are ideas about the
kinds of particles it must be made of. By contrast, dark energy
remains a complete mystery. The name "dark energy" refers to the
fact that some kind of "stuff" must fill the vast reaches of
mostly empty space in the Universe in order to be able to make
space accelerate in its expansion. In this sense, it is a
"field" just like an electric field or a magnetic field, both of
which are produced by electromagnetic energy. But this analogy
can only be taken so far because we can readily observe
electromagnetic energy via the particle that carries it, the
photon.
Some astronomers identify dark energy with Einstein's
Cosmological Constant. Einstein introduced this constant into
his general relativity when he saw that his theory was
predicting an expanding universe, which was contrary to the
evidence for a static universe that he and other physicists had
in the early 20th century. This constant balanced the expansion
and made the universe static. With Edwin Hubble's discovery of
the expansion of the Universe, Einstein dismissed his constant.
It later became identified with what quantum theory calls the
energy of the vacuum.
In the context of dark energy, the cosmological constant is a
reservoir which stores energy. Its energy scales as the universe
expands. Applied to the supernova data, it would distinguish
effects due to the matter in the universe from those due to the
dark energy. Unfortunately, the amount of this stored energy
required is far more than observed, and would result in very
rapid acceleration (so much so that the stars and galaxies would
not form). Physicists have suggested a new type of matter,
"quintessence," which would fill the universe like a fluid which
has a negative gravitational mass. However, new constraints
imposed on cosmological parameters by Hubble Space Telescope
data rule out at least simple models of quintessence.
Other possibilities being explored are topological defects, time
varying forms of dark energy, or a dark energy that does not
scale uniformly with the expansion of the universe. [/quote]
So maybe the concept of the Luminiferous Æther is not so far
fetched. ;D
Cheers, Þórgrímr
*****************************************************