Dark Matter and Dark Energy
WHAT IS DARK MATTER?
Dark matter is a hypothetical form of matter in existence which accounts 85% of the total mass of the universe. This form of matter is different from what we generally observe around us as it does not appear to interact with normal matter and radiations such as light which makes it invisible to the naked eye and thus making it extremely difficult to detect using usual astronomical equipment. It is thought to be composed of some undiscovered atomic or sub-atomic particles. It is also said that even Black holes are made up of Dark Matter as they too are invisible. Evidences for dark matter include observations of light bending around the gravity of unseen matter and also calculations that show many galaxies would fly apart instead of rotating in the universe due to very low mass as the observable matter in just 15% so its pretty sure that they contain large quantities of unseen matter. Till now there are no signs of observation of dark matter as it barely reacts with matter. Many experiments are being actively undertaken to detect and study dark matter particles but none has succeeded till now.
We know much more about what dark matter cannot be than we know it can be. Firstly the name dark is given because it is not in the form of normal matter made up of particles called Baryons that we see daily. We know this because the dark matter neither does emit any kind of radiations nor it does react to matter and radiations. Secondly it is not in the form of stars and planets, observations show that there is too little matter visible compared to what is not visible. Third, Dark matter is not Antimatter as it does not produce any kinds of Gamma rays that are produced when it reacts with matter. However, at this point there are still a few dark matter possibilities that are viable. These possibilities are known as Massive Compact Halo Objects (MACHOs) but the most common possibility is that it is made up of other more exotic particles like Axions or WIMPS ( Weakly Interacting Massive Particles).
WHAT IS DARK ENERGY?
Dark Energy is an unknown form of energy which is known to permeate the all of space. We know how much dark energy there is because we know how it effects the universe's expansion and the rest is complete mystery but an important one. It is known that the total mass-energy content of the universe contains 68% Dark Energy, 27% Dark matter and 5% visible matter and energy, thus dark energy and dark matter constituting 95% of the universe's mass-energy content. There are many explanations and possibilities of Dark Energy.
One explanation states that Dark Energy is a property of space on which the expansion of universe depends. Space has amazing properties and many of which are just beginning to be understood. Albert Einstein was the first to realize that empty space is not nothing. One version of Einstein's relativity theories that contains cosmological constants suggests that "Empty Space" can possess its own energy which is what called now as Dark Energy.
Another explanation for dark energy is that it is a new kind of dynamical energy fluid, something that fills all of space but whose effects on the expansion of the universe is opposite of that of matter and normal energy. Some scientists have named this "Quintessence". But if quintessence is also an answer, we still don't know what it is like, what it interacts with or why it exists
Another explanation for how space acquires energy comes from the quantum theory of matter. In this theory "Empty Space" is actually full of temporary particles that continually form and then disappear. But when physicists tried to calculate how much energy will be required by this empty space to continuously form and disappear, the answer came out wrong. The number came out 10210 times too big. It's very hard to prove it correct if the answer goes that bad.
A last possibility is that the dark energy would not only effect the expansion of the universe but would also effect how the normal matter in galaxies behave. If this is a fact then the solution of dark energy problem would be a new gravity theory, but if it does not turn out that a new gravity theory is not needed then what kind of energy would that be? what kind of theory would it be? How could it correctly describe the motion of the bodies in the Solar System as Einstein theory does? Though there are many candidate theories, but none are compelling.
We just know how much dark matter and dark energy constitutes and till now many theories, explanations and possibilities were suggested by scientists and they are trying hard to examine dark matter and dark energy experimentally but nothing has been done as for now. But as we know there's a lot to come and the mystery still continues.....
Comment your Views and Suggestions:)
Dark matter is a hypothetical form of matter in existence which accounts 85% of the total mass of the universe. This form of matter is different from what we generally observe around us as it does not appear to interact with normal matter and radiations such as light which makes it invisible to the naked eye and thus making it extremely difficult to detect using usual astronomical equipment. It is thought to be composed of some undiscovered atomic or sub-atomic particles. It is also said that even Black holes are made up of Dark Matter as they too are invisible. Evidences for dark matter include observations of light bending around the gravity of unseen matter and also calculations that show many galaxies would fly apart instead of rotating in the universe due to very low mass as the observable matter in just 15% so its pretty sure that they contain large quantities of unseen matter. Till now there are no signs of observation of dark matter as it barely reacts with matter. Many experiments are being actively undertaken to detect and study dark matter particles but none has succeeded till now.We know much more about what dark matter cannot be than we know it can be. Firstly the name dark is given because it is not in the form of normal matter made up of particles called Baryons that we see daily. We know this because the dark matter neither does emit any kind of radiations nor it does react to matter and radiations. Secondly it is not in the form of stars and planets, observations show that there is too little matter visible compared to what is not visible. Third, Dark matter is not Antimatter as it does not produce any kinds of Gamma rays that are produced when it reacts with matter. However, at this point there are still a few dark matter possibilities that are viable. These possibilities are known as Massive Compact Halo Objects (MACHOs) but the most common possibility is that it is made up of other more exotic particles like Axions or WIMPS ( Weakly Interacting Massive Particles).
WHAT IS DARK ENERGY?
Dark Energy is an unknown form of energy which is known to permeate the all of space. We know how much dark energy there is because we know how it effects the universe's expansion and the rest is complete mystery but an important one. It is known that the total mass-energy content of the universe contains 68% Dark Energy, 27% Dark matter and 5% visible matter and energy, thus dark energy and dark matter constituting 95% of the universe's mass-energy content. There are many explanations and possibilities of Dark Energy.
One explanation states that Dark Energy is a property of space on which the expansion of universe depends. Space has amazing properties and many of which are just beginning to be understood. Albert Einstein was the first to realize that empty space is not nothing. One version of Einstein's relativity theories that contains cosmological constants suggests that "Empty Space" can possess its own energy which is what called now as Dark Energy.
Another explanation for dark energy is that it is a new kind of dynamical energy fluid, something that fills all of space but whose effects on the expansion of the universe is opposite of that of matter and normal energy. Some scientists have named this "Quintessence". But if quintessence is also an answer, we still don't know what it is like, what it interacts with or why it exists
Another explanation for how space acquires energy comes from the quantum theory of matter. In this theory "Empty Space" is actually full of temporary particles that continually form and then disappear. But when physicists tried to calculate how much energy will be required by this empty space to continuously form and disappear, the answer came out wrong. The number came out 10210 times too big. It's very hard to prove it correct if the answer goes that bad.
A last possibility is that the dark energy would not only effect the expansion of the universe but would also effect how the normal matter in galaxies behave. If this is a fact then the solution of dark energy problem would be a new gravity theory, but if it does not turn out that a new gravity theory is not needed then what kind of energy would that be? what kind of theory would it be? How could it correctly describe the motion of the bodies in the Solar System as Einstein theory does? Though there are many candidate theories, but none are compelling.
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| "FIGURE SHOWS THE EXPANSION OF UNIVERSE OVER TIME" |
We just know how much dark matter and dark energy constitutes and till now many theories, explanations and possibilities were suggested by scientists and they are trying hard to examine dark matter and dark energy experimentally but nothing has been done as for now. But as we know there's a lot to come and the mystery still continues.....
Comment your Views and Suggestions:)
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