Researchers launched what looks like a white, cooler-sized fridge to the International Space Station in March 2018.

In that box is a $100 million facility known as the Cold Atom Laboratory, which enables atomic physics experiments to be conducted at freezing temperatures in zero-g space.

Scientists have now produced tiny bubbles of extremely cold gas atoms under those unique conditions, putting them on the cusp of quantum physics.

The achievement, which was only possible in microgravity and at a millionth of a degree above absolute zero, the minimum temperature of the universe, would have been impossible on Earth.

Researchers who made the ultracold bubbles remotely - that is, on the ground - published their new research in Nature last week, showing that they made them with an experimental apparatus that beams lasers into a sealed vacuum chamber to cool gas atoms.

Magnetic fields and radio waves were then used to cast them into hollow, egg-shaped blobs. It provides insight into the quantum realm and has applications in other areas of physics as well.

“I find it exciting to see the atoms take on these new shapes and to observe the new behaviors when gravity is removed," says David Aveline, one of the authors of the study and a member of NASA's Jet Propulsion Laboratory's Cold Atom Lab team in Pasadena, California.

At ultracool temperatures, atoms of gases-in this case, rubidium-don't behave as they do at room temperature, zipping around like microscopic billiard balls.

When the gas cools, the atoms slow down, but they do not turn into a liquid or solid as a vapor would. When they're chilled close to absolute zero, they begin clumping together, causing the wavelengths associated with the gas particles to become longer and overlap.

Atoms start acting strangely at such extremely cold temperatures. Together, they coalesce into a substance with quantum properties, behaving both like particles and like waves.

In essence, they are quantum paradoxes, almost like a new state of matter, called a Bose-Einstein condensate, named after the Indian and German physicists of a century ago.

In any case, while quantum phenomena usually need powerful microscopes to be observed, the bubbles can be inflated to a size significantly greater than the width of a human hair.

“Our study makes quantum mechanics and strange physics behavior visible just by using objects up to a millimeter in size, allowing us to make quantum mechanics visible to the naked eye," says Nathan Lundblad, an atomic physicist at Bates College in Maine and lead author of the study.

In addition to quantum physics, this research may have applications in other fields. NASA is interested in such work because it could lead to greater precision in gyroscopes and accelerometers, Aveline says.

A bubble of ultracold atoms could also provide insight into the rapid expansion of the baby universe following the Big Bang.

Although these physicists and their colleagues have studied ultracold atoms on Earth for decades, gravity still tugs on the atoms, despite it being nature's weakest force.

On the ground, if scientists try to nudge atoms into round blobs or bubbles, they end up dropping, creating a concave shape more like a contact lens.

Researchers have still been able to manipulate them into other shapes, such as needles, rings, and pancakes. Since an ultrathin layer of carbon can be made into graphene, for example, atoms can have geometry.

But to make bubbles of ultracold gas atoms that stay spherical or ellipsoidal and don't flatten out, gravity must be removed. This is where the ISS comes in.

CAL's Cold Atom Lab includes experiments such as Lundblad and Aveline's super cool one. CAL, unlike a research lab at a university, contains hardware that allows six teams to conduct a variety of experiments.