Scientists believe they have discovered a new method to pinpoint how fast our universe is expanding over time.
In a new study, a team of researchers at the University of Chicago discovered that the study of gravitational waves emitted by cosmic collisions could lead to more determined predictions about how quickly the universe is expanding.
Scientists are so confident in this method that they say they could have an "accurate measurement" of the expansion rate of the universe in about five to ten years.
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The researchers discovered that studying the gravitational waves emitted by cosmic collisions could lead to more determined predictions about how quickly the universe is expanding
STARS OF NEUTRON
Neutron stars are the small, dense remains of a once-massive star that exploded like a powerful supernova at the end of its natural life.
They often spin very fast and can sweep regular pulses of radiation toward Earth, like a beacon light that seems to turn on and off as it rotates.
These pulsars & # 39; They can be found in stellar pairs, with the neutron star cannibalizing their neighbor.
This can cause the neutron star to spin faster and high-energy X-ray pulses from the hot gas to be channeled into magnetic fields towards the neutron star.
Courtesy: The University of Chicago
Previously, scientists have relied on a variety of methods to test the exact expansion rate of the universe, also known as the Hubble constant, which first developed in 1929 and is named after the famous astronomer Edwin Hubble.
They have coupled the Hubble constant with other methodologies, such as measuring the brightness differences between variable stars and supernovas, to estimate how fast the universe is expanding.
Another method is to examine the cosmic microwave background, or the pulse of light created at the beginning of the universe.
However, like the method mentioned above, it tends to spit distressingly different results, "explained the University of Chicago.
One says that the universe is expanding almost 10 percent faster than the other, according to the researchers.
"This is an important question in cosmology right now," said Hsin-Yu Chen, lead author of the study.
Detecting the exact speed of expansion of the universe could consist in studying a revolutionary collision between two neutron stars, observed for the first time in 2017.
In a new article published in the scientific journal Nature, scientists at the University of Chicago say that the collision could be a new way of calculating the Hubble constant.
The collision, observed for the first time on August 17, 2017, marked the first detection in the world of two distant neutron stars colliding, causing a massive explosion that spread through the fabric of space and time.
To detect the exact speed of expansion of the universe could be to study a revolutionary collision between two neutron stars, observed for the first time in 2017
This image shows an artistic illustration of two neutron stars that merge. Ligo, the largest gravitational wave observatory in the world, captured the gravitational waves emitted by the explosion.
Ligo, the largest gravitational wave observatory in the world, captured the gravitational waves emitted by the explosion.
It happened about 130 million light-years away, but given the speed with which the researchers observed the collision of the star, it could give them a "very accurate measurement" of the Hubble constant over the next five to ten years, according to the study. .
The gravitational waves, or ripples through the space-time frame predicted by Albert Einstein a century ago, could be the key to determining a more accurate Hubble constant.
"When two massive stars collide with each other, they send waves in the fabric of spacetime that can be detected on Earth," said the University of Chicago.
& # 39; By measuring that signal, scientists can obtain a signature of the mass and energy of the colliding stars.
"When you compare this reading with the force of gravitational waves, you can infer how far away you are."
The collision of 2017 marked the first detection in the world of two distant neutron stars colliding, causing an explosion that spread through the fabric of space and time (artist's impression)
WHAT ARE THE GRAVITATIONAL WAVES?
Scientists consider that the universe is formed by a "tissue of space-time".
This corresponds to the General Theory of Relativity of Einstein, published in 1916.
The objects in the universe fold this fabric, and the more massive objects bend it more.
Gravitational waves are considered ripples in this tissue.
They can occur, for example, when black holes orbit with each other or by merging galaxies.
It is also believed that gravitational waves occurred during the Big Bang.
If found, they would not only confirm the Big Bang theory, but also offer knowledge about fundamental physics.
For example, they could shed light on the idea that, at one point, most or all of the forces of nature merged into a single force.
In March 2014, a team operating the Bicep2 telescope, based near the South Pole, believed they had found gravitational waves, but it proved that their results were inaccurate.
Scientists say that measuring gravitational waves could serve as a "cleaner" way of inferring how fast the universe is expanding.
However, there is concern about the frequency with which scientists can catch these cosmic collisions and the robustness of the data.
They predict that once scientists have detected 25 readings of neutron star collisions, they can measure the expansion of the universe with a surprising accuracy rate of 3 percent.
With 200 readings, that is further reduced to 1 percent, according to the University of Chicago.
"It was a big surprise for me when we got into the simulations," Chen said.
"It was clear that we could achieve precision and that we could reach it quickly."
The planned improvements for the Ligo should mean that the sensitivities of the detectors will be much stronger.
This could potentially lead to the amount and distance of the "astronomical events" they can pick up and which scientists can use to affirm their hypothesis about how fast the universe is expanding.
"With the collision we saw last year, we were lucky, it was close to us, so it was relatively easy to find and analyze," said Maya Fishbach, another author of the article.
"Future detections will be much farther away, but once we have the next generation of telescopes, we can also find counterparts for these distant detections."