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Dark energy makes up about 70 percent of the universe, but we don't know anything about it.
About 25 percent of the universe is the equally mysterious dark matter, leaving only five percent for everything we can see and touch – matter that consists of atoms.
Dark energy is the designation of the temporary name that scientists have given to the unknown force, which means that the universe expands faster and faster over time.
But some recent cosmic instructions have been taken away about the leading theory for this phenomenon, which could ultimately mean that humanity will have to reconsider our understanding of the universe.
And with various new telescopes that focus on the problem, scientists hope to have some concrete answers quickly.
This is what you need to know about what many scientists have mentioned the greatest mystery in the universe.
So what exactly is dark energy?
Nobody knows. It is invisible and it does not interact with matter or light.
And it can't even exist.
This story starts – just like everything else – about 13.8 billion years ago with the Big Bang, when the universe first started to expand.
Since then there has been “Cosmic Tug-of-War” between two mysterious forces, to Joshua Frieman, a theoretical astrophysicist at the University of Chicago, AFP said.
It is thought that dark matter draws galaxies together, while dark energy pushes them apart.
During the first nine billion years of the universe, “Dark Matter was a win,” she formed galaxies and everything else, said Friseman.
Then dark energy got the upper hand and the expansion of the universe began to accelerate.
For the most part of history, however, scientists had little idea that this almighty between was going on. They thought that the expansion of the universe would just start to slow down because of gravity.
Everything changed in 1998 when two separate groups of astronomers noticed that distant exploding stars called Supernovae were further away than they should be.
This led to the discovery that the universe not only grows – it is so faster and faster.
So what can this acceleration cause? They gave this strange force a name: dark energy.
What are the most important theories?
The leading theory has long been that empty space itself produces dark energy.
Think of a cup of coffee, Frieman said.
“When I remove all the particles from the cup of coffee, there is still energy in what we call the quantum vacuum,” he said.
This energy of empty space is known as the cosmological constant. It is the theory used in the standard model of cosmology, Lambda-CDM, which is our best gamble for how the universe works.
But in recent years, various scientific results seemed to support a rival theory – called evolving dark energy – that questioned the standard model.
On Wednesday, new results from the Dark Energy Spectroscopic instrument offered the latest signs that Dark Energy could actually weaken over time.
However, the scientists behind the research emphasize that there is no definitive evidence yet.
If it is proven well, it would exclude that dark energy is a cosmological constant.
It cannot be “the energy of empty space – because empty space does not change,” Frieman explained, a leading supporter of the theory.
To change dark matter, it would probably require existence of an incredible light, so far an unknown particle.
Another possibility is that there is something wrong with our calculations – or our understanding of gravity.
The theory of relativity of Einstein has passed an incredible amount of scientific control over the past century and has always been proven.
There is no evidence that Einstein was wrong, but there is “a bit of room” to change his theory when it comes to the largest scales of the universe, Frieman said.
When can we know more?
Soon. The best way to understand dark energy is by looking at an enormous amount of heaven and to record as many galaxies as possible with as much data as possible.
And a number of new telescopes work there to do.
On Wednesday, Europe's Euclid Space Telescope released its first astronomical data since the launch in 2023 – but any dark energy results have been removed a few years.
Nasa's Nancy Grace Roman Space Telescope, planned for launch in 2027, and the Vera Rubin Observatory in Chile of the lower classes in Chile will also be aimed at the problem.
It is an exciting time for dark energy, Friseman said, adding that he expected a “final answer” in the coming years.
There is no time to waste, Frieman said.
“Every minute we wait, galaxies disappear from sight.”
(Except for the headline, this story was not edited by NDTV staff and has been published from a syndicated feed.)
