{"id":2962,"date":"2021-10-06T10:00:00","date_gmt":"2021-10-06T10:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=2962"},"modified":"2021-09-24T02:56:04","modified_gmt":"2021-09-24T02:56:04","slug":"unexplained-dark-matter-experiment-results-may-be-signs-of-dark-energy","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/unexplained-dark-matter-experiment-results-may-be-signs-of-dark-energy\/","title":{"rendered":"\u201cUnexplained\u201d Dark Matter Experiment Results May Be Signs of Dark Energy"},"content":{"rendered":"\n

I won\u2019t fault you for being unfamiliar with dark matter<\/em> and dark energy<\/em>. I\u2019m certain most astronomers and astrophysicists would sit along with you. This is because both entities are so elusive that we probably know more about what they\u2019re not<\/em> compared to what they are<\/em>.<\/p>\n\n\n\n

For some time now, astronomers and astrophysicists have pondered on the anomaly that is the total mass of galaxies. Galaxies are rotating at such high speeds that the mutual gravity that binds the stars inside them should not have been enough to hold a galaxy together; galaxies should have torn themselves apart. Approximating the forces required to keep galaxies together reveals that there appears to be much more mass in a galaxy than it appears to have\u2014that is, the total estimated mass of all matter that we can see doesn\u2019t match up to the value that we expected to come out of the calculations.<\/p>\n\n\n\n

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The computed mass of all visible matter in galaxies like this one seem to be disproportionate to the calculated amount needed for it to keep itself together with its own gravity; the presence of dark matter is said to be the culprit behind this discrepancy. (Canva\/Getty Images) <\/figcaption><\/figure><\/div>\n\n\n\n

It appears that there\u2019s something out there, invisible to the electromagnetic spectrum as we can\u2019t spot it with any of our telescopes and imaging equipment, that accounts for the rest of the \u201cmissing mass.\u201d Scientists call this mysterious source of gravity \u201cdark matter.\u201d It\u2019s \u201cdark\u201d in the sense that it doesn\u2019t interact with any part of the electromagnetic spectrum; yet it is definitely there, since the stability of galaxies proves it.<\/p>\n\n\n\n

To detect the presence of dark matter, scientists have created detectors such as the XENON1T<\/em> dark-matter detector<\/em>, a 1,300-kg (2,800-lb) vessel containing pure liquid xenon (Xe) that\u2019s been buried some 1.5 km (1 mi) below the surface of the Gran Sasso mountains of Italy. This detector was designed to detect even the smallest interactions of any particles that pass through the liquid xenon vat; it was placed underground in a cryostat together with cosmic ray shielding to eliminate as many false positive detections from other free particles as possible.<\/p>\n\n\n\n

Last year, however, XENON1T encountered some \u201cunexplained results\u201d in one of its recent runs. It appears that, according to the researchers, the detector instead got a hint of what may be dark energy instead of what it was supposed to detect. Their findings were published in the journal Physical Review D<\/em>.<\/p>\n\n\n\n

Dark energy, in simple terms, is another mysterious cosmic entity that is said to comprise about 68% of the universe. Dark energy is said to exert a repulsive force that is responsible for the accelerating expansion of the universe, as discovered by astronomer Edwin Hubble decades ago.<\/p>\n\n\n\n

According to Sunny Vagnozzi, physicist from the Kavli Institute for Cosmology at the University of Cambridge, \u201clarge-scale experiments like XENON1T have been designed to directly detect dark matter, […] but dark energy is even more elusive.\u201d<\/p>\n\n\n\n

Vagnozzi and team discovered the odd signal as an unexpected excess over the usual background data obtained during one of XENON1T\u2019s runs. These excesses are usually flukes, yet according to Frascati National Laboratories researcher Luca Visinelli, \u201conce in a while, they can also lead to fundamental discoveries.\u201d
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Models were conceptualized and designed to try and make sense of what produced the excess in the background; this time around, however, they explored that the excess could be due to dark energy instead of the experiment\u2019s original dark matter target. In order to do so, the scientists looked at gravitational interactions within the structures of the detector, as this tends to be how dark energy interacts with the rest of the universe.<\/p>\n\n\n\n

The model that they ended up with used what is known as \u201cchameleon screening<\/em>;\u201d what came out as a result \u201cshuts down the production of dark energy particles in very dense objects, avoiding the problems faced by solar axions<\/em>,\u201d according to Vagnozzi. (Solar axions were among the first possible reasons to be proposed as sources of the excess, being hypothetical particles possibly produced in environments like inside our own Sun; however, the amount of axions needed to fulfill the data registered as excess would undermine common understanding of stellar evolution<\/a>, according to the research team)<\/p>\n\n\n\n

\u201cIf XENON1T actually saw something, you\u2019d expect to see a similar excess again in future experiments, but this time with a much stronger signal,\u201d according to Visinelli. Vagnozzi aldo added: \u201cIt was really surprising that this excess could in principle have been caused by dark energy rather than dark matter. When things click together like that, it\u2019s really special.\u201d<\/p>\n\n\n\n

The original excess obtained from measurements still needs to be confirmed with further detections and experiments. As Visinelli put it: \u201cWe first need to know that this wasn\u2019t simply a fluke.\u201d Despite this, the calculations they had already obtained using their new model suggest that detection experiments like XENON1T are capable of detecting dark energy.<\/p>\n\n\n\n

(To learn more about how dark matter may influence our cosmic neighborhood, check out our piece on how the gravity of a galactic cluster bent incoming light from a supernova<\/a>.)<\/p>\n\n\n\n

References<\/h2>\n\n\n\n