The universe consists of mysterious and powerful forms of energies and matters that are yet to be fully explained scientifically. Even though we can’t approach this phenomenon physically, it is speculated that the universe is made up of dark matter and dark energy.
Dark Matter vs Dark Energy
The main difference between dark matter and dark energy is that dark matter slows down the expansion of the universe by keeping it together whereas dark energy is a repulsive force of energy that has been accelerating the expansion of the universe. Compared to dark matter, dark energy is far more dominant.
Dark Matter is a speculated, invisible form of matter that comprises approximately 27% of our universe. Practically or theoretically, there is no clear proof of what exactly dark matter is. The definitions may only be partially ideal based on various experiments conducted over the decades.
Dark Energy is a confirmed yet invisible form of energy that comprises approximately 68% of our universe. It is a form of anti-gravitational or repulsive force that has been the major cause of our universe’s accelerating expansion. However, everything else about dark energy is a complete mystery.
Comparison Table Between Dark Matter and Dark Energy
| Parameters of Comparison | Dark Matter | Dark Energy |
| Definition | It is a form of matter. | It is a form of energy. |
| Distribution | It comprises 27% of the universe. | It comprises 68% of the universe. |
| Force | It is an attractive force. | It is a repulsive force. |
| Impact | It holds the galaxies intact. | It accelerates the expansion of the universe. |
| Existence | It exists in space only. | It exists in both space and time. |
What is Dark Matter?
Dark Matter is a speculated, invisible form of matter that comprises approximately 27% of our universe. Practically or theoretically, there is no clear proof of what exactly dark matter is. The definitions may only be partially ideal based on various experiments conducted over the decades.
In the 1930s, Fritz Zwicky, an astronomer researched thousands of galaxies and while he was studying some images, he made a surprising discovery. The galaxies he studied were moving so fast that they should have distorted from each other into different directions but they didn’t. He concluded that some form of invisible dark matter held them together.
Scientifically, dark matter has never been physically detected as it simply does not absorb, reflect or emit light. It is partially evident that dark matter provides the galaxies extra mass, which results in the induction of extra gravity. As a result, the galaxies stay intact.
Scientists are much more sure of what dark matter is not than what it is. Ruling out various scenarios and possibilities, dark matter works like an attractive force that glues our universe together. Thus, Dark matter slows down the expansion of the universe. It interacts with gravity but is unaffected by light energy.
What is Dark Energy?
Dark Energy is a confirmed yet invisible form of energy that comprises approximately 68% of our universe. It is a form of anti-gravitational or repulsive force that has been the major cause of our universe’s accelerating expansion. However, everything else about dark energy is a complete mystery.
In late 1998, a team of astronomers aimed to calculate the expansion rate of the universe in the form of a constant value, known as the Hubble Constant. They were studying supernovas in distant galaxies and they discovered that distant galaxies were drifting away from us much faster than the nearby galaxies. They realized that the universe wasn’t expanding at a consistent rate but an accelerating rate of pace. Hence, the concept of the Hubble Constant was contradicted.
Albert Einstein was the first person to state that space is not empty, and it consists of some invisible force. He gave the property of space that it was capable to expand beyond reach. Dark energy is evenly distributed throughout the universe, not only in space but also in time. Scientifically, dark energy has never been physically detected but only its effect on the universe has been proved to exist. It is a far more dominating force compared to dark matter and directly results in the expansion of the universe.
Main Differences Between Dark Matter and Dark Energy
- Dark matter is a form of invisible matter or mass whereas dark energy is a form of energy.
- Dark matter slows down the universe’s expansion whereas dark energy accelerates the expansion.
- Dark matter exists in space only whereas dark energy exists in both space and time.
- When compared to dark matter, dark energy is a far more dominating force in the universe.
- Dark matter is ideal for the co-existence of galaxies and the sustainability of the universe whereas dark energy is non-ideal.
Conclusion
The universe is mysterious. Every element of the universe that science is aware of including everything around us, planets, stars, milky-way galaxy, etc., comprises only 5% of the whole universe. The rest of the universe is known to be comprised of dark matter and dark energy.
The energy generated from the Big Bang drove the universe’s early expansion but in its early stages, this expansion was minimal. With the 1998’s study by astronomers, it was observed that this expansion is accelerating at a serious pace. This identified dark energy as a far more dominant force than dark matter. Dark energy now comprises about 68% of the universe, and various theories suggest that this percentage will keep on rising with time.
Scientists have not been able to figure out what dark matter and dark energy exactly are, their characteristics, their properties, etc. Nevertheless, the two are separated by their impact on the universe. Dark matter slows down the expansion of the universe by keeping it together whereas dark energy is a repulsive force of energy that has been accelerating the expansion of the universe. Dark matter is ideal for the co-existence of galaxies and the sustainability of the universe whereas dark energy is non-ideal.
References
- https://journals.aps.org/prd/abstract/10.1103/PhysRevD.79.015014
- https://arxiv.org/pdf/1103.5870