Even though it may sound like something out of science fiction,
Dark Energy is very much a part of the universe and may indeed hold the answers to many of the universe’s as yet uncovered mysteries.
The theoretical composition of the universe consists of three components –
- Dark Energy,
- Dark Matter and,
- Normal Matter
Long periods of study have enabled scientists to confirm the rough percentage of this composition as well -
- 68% dark energy,
- ~27% dark matter,
- ~5% normal matter
As the largest percentage in the composition of the universe, dark energy works in apparent opposition to the known laws of gravity.
While for several decades, physicists and scientists had been observing the unique phenomenon of the expansion of the universe, it had been believed that the universe would eventually either slow down in its spread or reverse and collapse.
However, careful studies of the light that reaches us from exploding supernovae have long revealed that the rate of expansion of the universe and its galaxies has only increased over time. And the reason seems to be the unknown variable, Dark Energy.
Einstein had postulated that
- The apparently empty spaces of the universe were not, in fact, empty, but were filled with an unquantifiable energy with unique properties of its own.
- He had also predicted that gravity can repel as well as attract, but only under very specific circumstances.
- This repulsive gravity uses dark energy, which seems to have negative energy that pushed things away as opposed to pulling them together, like Earth’s gravity does to anything that falls.
Further studies and observation in recent years, however, have led to an improved understanding of dark energy, based on the rate of expansion of the universe.
Scientists now know that the sum of all the dark energy in the universe must constitute more than 70 percent of the total contents of the universe. Some have even theorized that this energy must be hiding, but further experimentation of several types, on atomic structures that may mimic the properties of dark energy, have not yet provided any positive results.
A final possibility being considered is the inefficiency of Einstein's theory of gravity.
- Any change in this theory, however, would affect not just the expansion of the universe, but also our current understanding of how normal matter present in the universe behaves.
- Till date, Einstein’s theory of gravity is the only one that accurately describes how our own Solar System operates. It has also, thus far, proved correct as regards the different prediction for the universe that we need.
What is required, therefore, is to be able to decide between dark energy possibilities. But in order to identify it as anything – a property of space-time, a new theory of gravity or a new dynamic fluid – more data is yet be discovered.