Our Milky Way Galaxy and the Universe –“Are Ringing Like a Bell”

 

Milky Way Galaxy

 

“Our part of the Milky Way is ringing like a bell,” said Brian Yanny, with the Fermi National Accelerator Laboratory in 2012. “But we have not been able to identify the celestial object that passed through the Milky Way. It could have been one of the small satellite galaxies that move around the center of our galaxy, or an invisible structure such as a dark matter halo.”

“The perturbation need not have been a single isolated event in the past, and it may even be ongoing.” added Adds Susan Gardner, professor of physics at the University of Kentucky. “Additional observations may well clarify its origin.”

Past as Prelude — “Milky Way Collided With a Small Galaxy or Massive Dark Matter Structure 100 Million Years Ago”

“We have found evidence that our Milky Way had an encounter with a small galaxy or massive dark matter structure perhaps as recently as 100 million years ago,” said Larry Widrow, professor at Queen’s University in Canada. “We clearly observe unexpected differences in the Milky Way’s stellar distribution above and below the Galaxy’s midplane that have the appearance of a vertical wave — something that nobody has seen before.”

Today, Scientific American reports that in the beginning, in the immediate aftermath of the Big Bang, “all of space rang like a bell.”

The infant universe was filled with plasma—an energetic soup of particles and radiation with slight density and pressure gradients that pushed material around, says Lloyd Knox, a cosmologist at the University of California, Davis, “and when stuff gets pushed around, those are sound waves” that rang the infant cosmos like a bell.

The ringing happened everywhere, so intensely that we can still sense it 13.8 billion years later, writes Corey Powell, author of God in the Equation: How Einstein Transformed Religion, in today’s Scientific American. “New studies of the oldest light and sound in the cosmos suggest novel physics—rather than systematic errors in Hubble’s Constant—could explain an unsolved scientific mystery: why space is not ringing the way they expected that could lead cosmologists to previously unknown physics, potentially revealing a whole new aspect of reality.”

Knox and his co-authors explore that enticing possibility in a new study slated to appear in .The Astrophysical Journal .“Over the past two years,” he says, “I’ve evolved from thinking, ‘There must be something they did wrong’ to thinking, ‘Wow, maybe they haven’t done anything wrong.’ Maybe this is the clue I’ve been waiting for!”

“Overlooked” — Hubble’s Constant: A Key Mechanism That Drives the Cosmos

“Potentially where this is leading us is to a new ingredient in the ‘dark sector,’” Knox says, referring to cosmologists’ catch-all term for invisible components of the universe that do not interact with radiation in any way.

The divergent measurements of the Hubble constant, continues Powell, “may be the first sign of the existence of a third dark component, Knox argues—a “dark turbo,” perhaps, that added to the energy of the early universe, hastening its expansion and changing the pitch of its sounds. A related possibility is dark energy has more than one form, or changes over time in complicated ways. A recent study of 1,598 distant quasars using NASA’s Chandra X-Ray Observatory offers intriguing, if preliminary, evidence for the latter interpretation.”

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The first accurate 3D map of our galaxy shown at the top of the page reveals its true shape: warped and twisted. Astronomers from Macquarie University and the Chinese Academy of Sciences have used 1339 ‘standard’ stars to map the real shape of our home galaxy in a paper published in Nature Astronomy today. Artist’s impression above of the warped and twisted Milky Way disk. (Chen Xiaodian)

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