Beyond Hubble’s constant – “A new era of the universe”

Hubble's new deep field

“Eventually, we reach the maximum limits of our telescopes. There we measure shadows and search among phantom measurement errors for reference points that are hardly more substantial,” wrote Edwin Hubble in 1916, inventor of the famous “constant” that describes how fast The universe is expanding at different distances from a particular point in space, implying the existence of a time or age scale for the universe. New research by a team of astronomers employing a novel approach using known distances from 50 Earth galaxies has estimated the age of the universe at 12.6 billion years.

Hubble’s measurements of the current rate of expansion do not match the expected rate based on how the Universe appeared shortly after the Big Bang more than 13 billion years ago. In 2019, using new data from the NASA / ESA Hubble Space Telescope, astronomers have significantly reduced the chance that this discrepancy is a fluke.

Ghostly mistakes

“Hubble’s tension between the early and late Universe may be the most exciting development in cosmology in decades,” said lead researcher and Nobel Laureate Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University. “This mismatch has been growing and has now reached a point that is really impossible to rule out as a fluke. This disparity cannot plausibly occur by chance. “

Hubble reveals a mystery: “New physics is needed to explain the forces that shaped the cosmos”

The approaches to dating the Big Bang and the birth of the universe are based on mathematics and computational modeling, using distance estimates of the oldest stars, the behavior of galaxies and the rate of expansion of the universe. The idea is to calculate how long it would take for all objects to return to the beginning.

A recent technique for measuring the age of the universe uses observations of surplus radiation from the Big Bang, reports the University of Oregon: “It maps bumps and shocks in space-time (the cosmic microwave background, or CMB) and reflects the conditions in the early universe. as established by the Hubble constant. “

A new approach

A new approach reports James Schombert, professor of physics at the University of Oregon. In an article published July 17 in the Astronomical Journal, he and his colleagues recalibrated a distance measurement tool known as the Barly Tully-Fisher relationship regardless of the Hubble constant that solves the “distance problem” as known. , solving the “long distances to galaxies and signals that are weak and difficult to calibrate”.

Hubble’s paradox: “Constant in space, not time”

Schombert’s team recalculated the Tully-Fisher approach, using precisely defined distances in a linear calculation of the 50 galaxies as guides to measure the distances of 95 other galaxies. The universe, he noted, is governed by a series of mathematical patterns expressed in equations. The new approach more accurately explains the mass and rotation curves of galaxies to convert those equations into numbers like age and the rate of expansion.

Schombert’s team’s approach determines the Hubble constant, the rate of expansion of the universe, at 75.1 kilometers per second per megaparsec, plus or minus 2.3. A megaparsec, a common unit of space-related measurements, equals one million parsecs. A parsec is approximately 3.3 light years. All of Hubble’s constant values ​​of less than 70, his team wrote, can be ruled out with a 95 percent confidence level.

Measurement techniques traditionally used in the past 50 years, Schombert said, have set the value to 75, but CMB calculates a rate of 67. The CMB technique, although using different assumptions and computer simulations, should still arrive at the same estimate. , said. .

Physics of the Incomplete Universe

“The tension in the field is caused by the fact that it is not,” Schombert said, reflecting Adam Reiss’ comments above. “This difference is far outside the observation errors and produced great friction in the cosmological community.”

Calculations from observations of NASA’s Wilkinson microwave anisotropy probe in 2013 put the age of the universe at 13.77 billion years, which, for the time being, represents the standard model of Big Bang cosmology. The different constant Hubble values ​​of the various techniques generally estimate the age of the universe between 12 billion and 14.5 billion years.

“Nothing like ours” – Billions of years from now a new strange universe emerges

The new study, based in part on observations made with the Spitzer Space Telescope, adds a new element to how calculations can be established to achieve the Hubble constant, by introducing a purely empirical method, using direct observations, to determine the distance to the galaxies.

“Our resulting value is at the top of the different schools of cosmology, indicating that our understanding of the physics of the universe is incomplete in the hope of new physics in the future,” he said.

The image at the top of the page took researchers from the Canary Islands Institute of Astrophysics almost three years to produce. It is the deepest image of the universe taken from space, recovering a large amount of ‘lost’ light around the largest galaxies in the iconic Hubble Ultra Deep Field.

The Daily Galaxy, Max Goldberg, via University of Oregon