dark matter trap
(Credit: University of Nottingham)

Scientists Devise a New Strategy for Solving the Mystery of Dark Matter: They Want to Trap It

The existence of dark matter, an enigmatic and essentially invisible material that scientists can neither see nor detect but instead infer through indirect observation of the way gravity behaves throughout the cosmos, remains one of the most perplexing mysteries of modern astrophysics.

The notion that a mysterious form of nonluminous matter may proliferate throughout the universe, void of any interactions with light or electromagnetic fields, still remains controversial in some circles. Hence, scientists’ opinions remain divided about whether it really exists, or if our understanding of the universe requires a fundamental revision instead.

Now, scientists have proposed a novel method of potentially detecting dark matter, as well as a possible means of exploring dark energy: by using a 3D-printed vacuum system to “trap” dark matter using ultra-cold lithium atoms.

The experiment, if successful, could lead to potentially crucial new insights into what is behind the acceleration observed by astrophysicists that are driving the universe’s expansion.

Building a Dark Matter Trap

The team behind the effort, comprised of scientists from the University of Nottingham’s School of Physics, plans to reduce the density of gas with the vacuum, after which they will add extremely cold lithium atoms as a means of attempting to detect dark walls

“Ordinary matter that the world is made from is only a tiny fraction of the contents of the universe, around 5%, the rest is either dark matter or dark energy, – we can see their effects on how the universe behaves but we don’t know what they are,” says Professor Clare Burrage from the School of Physics.

“One way people try to measure dark matter is to introduce a particle called a scalar field,” says Burrage, one of the lead authors of a new study detailing the work.

Burrage says that dark matter can be likened to being “missing mass” in most galaxies, whereas dark energy can potentially explain the acceleration observed in the expansion of the universe if it can be detected.

“The scalar fields that we are looking for could be either dark matter, or dark energy,” Burrage said in a recent statement describing the work she and her team have undertaken. “By introducing the ultra-cold atoms and examining the effects it produces we may be able to explain why the expansion of the universe is accelerating and whether this has any effects on Earth.”

The vacuum system the team designed is based on current theories related to light scalar fields, which are believed to undergo density-driven phase transitions. Burrage explains that this process leads to the formation of domain walls.

“As density is lowered defects form – this is similar to when water freezes into ice, water molecules are random and when they freeze you get a crystal structure with molecules lined up at random, with some lined up one way and some another and this creates fault lines,” Burrage recently explained. “Something similar happens in scalar fields as the density gets lower.”

Burrage says the fault lines produced can’t be observed visually. However, if a particle crosses paths with these lines, its trajectory could be changed, providing a clue about the potential existence of these fields.

“These defects are dark walls and can prove the theory of scalar fields – either that these fields exist or don’t.”

Absolute Zero in a Dark Matter Trap

As to how one spots the kinds of defects the team is searching for, the vacuum they have created will mimic the movement from a dense environment to one that is less dense. Lithium atoms cooled using laser photons to temperatures nearing absolute zero, the team says, will allow them to achieve quantum properties that will help to make their analysis more predictable, as well as more precise.

“The 3D printed vessels we are using as the vacuum chamber have been constructed using theoretical calculations of Dark Walls, this has created what we believed to be the ideal shape, structure, and texture to trap the dark matter,” said Lucia Hackermueller, an Associate Professor at University of Nottingham’s School of Physics.

Hackermueller, who led the design of the team’s experiment, says that successfully trapping dark walls will require allowing a cold atom cloud to pass through them, which should cause the cloud to be deflected. Hackermueller compared this process to “slowing down an elephant using snowballs.”

Hackermueller says that whether or not the team proves that dark walls exist, their experiment marks a significant step toward obtaining a better understanding of dark energy and dark matter and offers an example of how “a well-controlled lab experiment can be designed to directly measure effects that are relevant for the Universe and otherwise cannot be observed.”

The team’s new paper, “Detecting dark domain walls through their impact on particle trajectories in tailored ultrahigh vacuum environments,” by Kate Clements, Benjamin Elder, Lucia Hackermueller, Mark Fromhold, and Clare Burrage, appeared in the 14 June 2024 edition of the journal Physical Review D.

Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.