DARK MATTER AND DARK ENERGY MAY BE THE SAME THING
I am fascinated by dark matter as well as dark energy, and this is the first time I have come across a suggestion that they may be the same thing. An article at the website of SPACE by Robert Roy Britt explores the possibility. I learned the following from the article.
The article asserts that dark matter and dark energy comprise 96% of all mass and energy in the universe. Imagine how this limit our ability to study the whole universe. We are not able to study very much of the universe at all. Scientists don't know what either dark energy or dark matter is. The astronomer Robert Scherrer suggests that they are caused by the same phenomenon.
Dark matter was imagined decades ago to solve the question of why galaxies stay together, given that being made of normal matter alone they would fly apart. Scientists theorized that there must be some unknown matter that forms invisible objects that hold galaxies together with their gravity. Dark energy, on the other hand, was concieved of in the last decade. It was imagined to be a force like the opposite of gravity, that must be pushing all objects apart. This theory was accepted because it had become known that the universe expanding at an ever-faster rate.
Robert Sherrer has a theory to explain both dark matter and dark energy. He suggests that there is a form of energy called a scalar field. It has energy and pressure and a magnitude, much like a magnetic field. As the previously mentioned article from SPACE states, "A scalar field has no direction. A scalar field is thought to have been behind inflation, the less-than-a-second period after the Big Bang when the universe expanded many billions of times before settling into a more reasonable rate of growth."
He suggests the presence of what other astrophysicists have theorized as being a kind of kinetic energy, called K-essence. K-essence in Scherrer's theory clumps early on to help form galaxies, and now forces the universe apart. According to the article at SPACE, "'Dark matter has a density that decreases as the universe expands', Sherrer explained, 'while dark energy has a density that stays constant as the universe expands. That means that at very early times, the dark matter 'piece' of the k-essence is the dominant one,' Scherrer said. 'As the universe expands and the density of the dark matter 'piece' of the k-essence decreases, it eventually falls below the density of the dark energy 'piece,' and the k- essence behaves more like dark energy.'"
Now this part is really fascinating. Imagine a fifth dimension of other universes alongside ours.
Sherrer suggests confining our universe to a four-dimensional plane known as a membrane, that is in between other membranes of other universes. And imagine that gravity belongs to a fifth dimension that's perpendicular to our universe's plane/membrane. Dark matter would be the gravitational influence of other membranes on ours. It has also been suggested that membranes give a new explanation of the Big Bang. According to this theory another membrane collided with ours, releasing energy and heat and leading to the expansion of our universe. The popular String Theory suggests that dark matter is not related to dark energy but is rather an exotic form of matter known as supersymmetric perticles. And this is very exciting: In 2007, a particle accelerator called the Large Hadron Collider will produce supersymmetric particles, if they exist. I can't wait to report on that.
I am fascinated by dark matter as well as dark energy, and this is the first time I have come across a suggestion that they may be the same thing. An article at the website of SPACE by Robert Roy Britt explores the possibility. I learned the following from the article.
The article asserts that dark matter and dark energy comprise 96% of all mass and energy in the universe. Imagine how this limit our ability to study the whole universe. We are not able to study very much of the universe at all. Scientists don't know what either dark energy or dark matter is. The astronomer Robert Scherrer suggests that they are caused by the same phenomenon.
Dark matter was imagined decades ago to solve the question of why galaxies stay together, given that being made of normal matter alone they would fly apart. Scientists theorized that there must be some unknown matter that forms invisible objects that hold galaxies together with their gravity. Dark energy, on the other hand, was concieved of in the last decade. It was imagined to be a force like the opposite of gravity, that must be pushing all objects apart. This theory was accepted because it had become known that the universe expanding at an ever-faster rate.
Robert Sherrer has a theory to explain both dark matter and dark energy. He suggests that there is a form of energy called a scalar field. It has energy and pressure and a magnitude, much like a magnetic field. As the previously mentioned article from SPACE states, "A scalar field has no direction. A scalar field is thought to have been behind inflation, the less-than-a-second period after the Big Bang when the universe expanded many billions of times before settling into a more reasonable rate of growth."
He suggests the presence of what other astrophysicists have theorized as being a kind of kinetic energy, called K-essence. K-essence in Scherrer's theory clumps early on to help form galaxies, and now forces the universe apart. According to the article at SPACE, "'Dark matter has a density that decreases as the universe expands', Sherrer explained, 'while dark energy has a density that stays constant as the universe expands. That means that at very early times, the dark matter 'piece' of the k-essence is the dominant one,' Scherrer said. 'As the universe expands and the density of the dark matter 'piece' of the k-essence decreases, it eventually falls below the density of the dark energy 'piece,' and the k- essence behaves more like dark energy.'"
Now this part is really fascinating. Imagine a fifth dimension of other universes alongside ours.
Sherrer suggests confining our universe to a four-dimensional plane known as a membrane, that is in between other membranes of other universes. And imagine that gravity belongs to a fifth dimension that's perpendicular to our universe's plane/membrane. Dark matter would be the gravitational influence of other membranes on ours. It has also been suggested that membranes give a new explanation of the Big Bang. According to this theory another membrane collided with ours, releasing energy and heat and leading to the expansion of our universe. The popular String Theory suggests that dark matter is not related to dark energy but is rather an exotic form of matter known as supersymmetric perticles. And this is very exciting: In 2007, a particle accelerator called the Large Hadron Collider will produce supersymmetric particles, if they exist. I can't wait to report on that.
posted by Caroline at 3:21 PM
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