Physics

Understanding Dark Energy



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The definition of dark energy is a puzzle. Some claim to know what it is, some claim to know what it is not and some claim to know what it does or does not do. Defining dark energy is really an exercise in futility. Dark energy is in fact a synonym for our ignorance about our universe. It is a general term that at it core says, "We don't know." What don't we know? An awful lot.
If you choose to believe in the theory of the Big Bang, then dark energy is worth committing to memory. The universe, according to the Big Bang, began as a singularity in which all matter was confined into no space at all. Doesn't make sense but follow me. The tempreture of this ball of everything was over 100 billion degrees and had a density of a number which would be written as 1 with 72 zeros after it tons per cubic inch. At some moment, for some reason everything blew. A colossal explosion beyond anyone's understanding ensued and within three minutes, all matter in our world was in existance. The explosion was on a scale that is imperceptable to humans and it is still exploding. More stuff that doesn't make sense.
On June 30, 2001 the Wilkinson Microwave Anistropy Probe or WMAP was launched. Its mission was to study the cosmic background radiation that is ever present in our universe. The cosmic background radiation is left over light from the big bang that is in the form of non-visible light energy or microwaves. This radiation can be seen by anyone who has a television with rabbit ear antennas and turns to a channel that is not in use. That static is in fact a visual representation of the cosmic background radiation and can be read by applying mathmatics to it.
Edwin Hubble gained worldwide fame by his discovery that galaxies are moving apart. This ushered in the idea that the universe was expanding which added fuel to the Big Bang theory band wagon. Further, the modern study of supernovae has shown us even more about the expansion of the universe and proof of the Big Bang. Although these studies have shown us something no one expected.
When anything explodes, such as a firecracker or a pound of C4, it explodes outwardly in a somewhat uneven pattern. The WMAP mission saw this about the universe and that unevenness is called wrinkles in time. Also true about any explosion is that the speed at which it explodes gradually slows down after the charge detonates. For example, the outward force of a standard claymore mine is at its greatest at the very moment of detonation, as close to the charge as possible. If you were standing 10 feet away from the charge, it may still knock you down and cause pain but it would not be as bad as if you were standing on top of it. Further, if you were standing a mile away, you may hear it but you wouldn't feel any force. You can back up further and further until you are in another state, country, continent, planet or galaxy. The farther away you get, the less the force.
Apparently the Big Bang has not seen it fit to abide by this common sense rule of physics. The universe is expanding as observed several times over several years. The problem is that it is expanding faster now than it has ever been. How does that happen? How does the force of an explosion become greater as it explodes? Especially 15 billion years after the fact. The universe is filled with huge quantities of baryonic matter and dark matter that create gravity in space-time. These huge objects sit in the fabric of the universe and cause gravity so great in some cases that they can tear stars apart in the manner of a black hole. So there is all this gravity in our universe but that gravity is not holding the expansion back as it would on Earth with a teenager and an M80 on the 4th of July. The force of the Big Bang has kept the universe expanding but what is causing the speed up?
The answer to that is dark energy. Dark energy is a exotic and undetectable force that is working against gravity to increase the speed of universal expansion. At least that's the theory. There is no direct evidence of dark energy, only observations of other events from which we can infer that some force is at work. If the idea of dark energy is in fact true, then that could spell disaster for our wonderful universe.
If dark energy continues to pull galaxies apart and expand our universe at a faster and faster rate then the consequences could be dire. The theory of the Big Rip is new on the scientific stage and deals directly with dark energy. If dark energy continues to speed up the expansion of the universe then it will eventually pull all galaxies apart. This would throw the universe into a deep freeze. But beyond that, if dark energy continues its current increase in power then it will eventually gain enough energy to pull all stars and planets apart as well. Furthermore, as the energy increases dark engery will go so far as to pull matter apart on a molecular level. That includes everything from your computer to planets to stars to gasses to dust. As if that weren't enough, the energy will reach an even higher level to overcome quantum strong force and pull apart the atoms and the individual particles themselves to the level of quarks. Will it go further? We don't know becuase we don't know of anything smaller than quarks but it has been shown that this is possible if dark energy is what we think it is. No need to live in fear, however, the Big Rip is a good 50 billion years away give or take a billion.
Dark energy is a theoretical term for which we do not have physical proof. Its existance is theorized because of the observation of the rapidly expanding universe. Perhaps in the future, space exploration and technology will yield more results and better answers.

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