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Showing posts from November, 2019

A Classic(al) Story of the Creation of the Universe

In his 1980 book Cosmos, Carl Sagan famously wrote, “If you wish to make an apple pie from scratch, you must first invent the universe.”

 If you follow their threads back in time, the ingredients for a deliciously satisfying apple pie - apples, flour, cinnamon, heat, etc. - wind their way back to before the observable universe. Existence was contained in a vacuum then, a void empty except for quantum fluctuations. 
 According to leading cosmological models, the vacuum was fairly stable and may have existed in this state for a very long time, but it had a weakness. When quantum fluctuations caused a region of space to spontaneously become more stable (to have lower energy) than its surroundings, a “bubble” of greater stability formed. According to cosmological models, this “bubble” of stability rapidly expanded at nearly the speed of light. Multiple bubbles may have occurred at the same time, coalescing and bringing the entire vacuum into a more stable existence. An existence in wh…

The New Playground of an Unexpected Bose-Einstein Condensate

Most playgrounds feature slides, swings, and other structures that encourage visitors to explore cause-and-effect, test their physical limits, and try new things. Scientists like to engage in these activities too, although their playgrounds don’t look quite the same...


In new research published in the American Physical Society’s journal Physical Review Letters, a team of researchers from the US and Canada have discovered what looks like a Bose-Einstein Condensate (BEC) in an unexpected place—a magnet based on the rare-earth element ytterbium.
 “This discovery provides a new playground for understanding Bose-Einstein condensation in magnetic systems, as well as how ytterbium breaks our expectations at low-temperatures in condensed matter systems,” says Gavin Hester, a graduate student working with Kate Ross at Colorado State University and one of the project leaders. 
 BECs are often called the fifth state of matter. It’s a state that can only be reached when a very dilute gas is coo…