Over the past 30 years, the Space Observatory has helped scientists discover and refine this accelerating rate — as well as revealing mysterious wrinkles that only new physics can solve.
Hubble has detected more than 40 galaxies that contain pulsars, as well as exploding stars called supernovae to measure greater cosmic distances. These two phenomena help astronomers determine astronomical distances as mile markers, which indicate the rate of expansion.
In their quest to understand how fast our universe is expanding, astronomers already made an unexpected discovery in 1998: “dark energy”. This phenomenon acts as a mysterious driving force that accelerates the rate of expansion.
And there is another development: an unexplained difference between the expansion rate of the local universe versus the expansion rate of the distant universe immediately after the big bang.
Scientists don’t understand the paradox, but they admit it’s strange and may require new physics.
“You get the most accurate measure of the expansion rate of the universe from the gold standard for telescopes and cosmic tilt markers,” said Adam Rees, Nobel Prize winner at the Space Telescope Science Institute and Distinguished Professor at Johns Hopkins University in Baltimore. . in the current situation.
“That’s what the Hubble Space Telescope was built for, using the best technology we know to make it. It’s probably the Hubble magnum, because it would take another 30 years of Hubble’s lifetime to double the size of this sample.”
decades of surveillance
The telescope is named after the pioneering astronomer Edwin Hubble, who discovered in the 1920s that distant clouds in the universe were actually galaxies. (died 1953).
Hubble built on astronomer Henrietta Swan-Levitt’s 1912 work to discover periods of brightness in pulsars called Cepheid variables. Cepheids act as cosmic tilt markers because they periodically light up and darken within our galaxy and beyond.
Hubble’s work led to the revelation that our galaxy was one of many that changed our perspective and our place in the universe forever. The astronomer continued his work and found that distant galaxies appear to be moving rapidly, suggesting that we live in an expanding universe that began with the Big Bang.
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Reiss continues to lead SHOES, short for Supernova, H0, for the dark energy equation of state, a scientific collaboration that investigates the expansion rate of the universe. His team is publishing a paper in The Astrophysical Journal providing the latest update on the Hubble constant, as the expansion rate is known.
unresolved contradiction
Measuring distant objects has created a “cosmic distance ladder” that can help scientists better estimate the age of the universe and understand its underpinnings.
Several teams of astronomers using the Hubble telescope arrived at a Hubble constant of 73 plus or minus 1 kilometer per second per megaparsec. (One megaparsec is equal to one million parsecs, or 3.26 million light-years.)
“The Hubble constant is a very special number,” he said. “It can be used to thread a needle from the past to the present to test a comprehensive understanding of our universe. This required an enormous amount of detailed work.” Lecia Verdi, a cosmologist at the Catalan Institute for Research and Advanced Studies and the Institute of Cosmology at the University of Barcelona, said in a statement.
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But the actual rate of expansion expected of the universe is slower than that observed by the Hubble telescope, according to astronomers using the Standard Cosmological Model of the Universe (a theory that refers to the components of the Big Bang) and measurements made by the European Space Agency. . Planck. work between 2009 and 2013.
The Planck Observatory, another space observatory, was used to measure the cosmic microwave background, or residual radiation from the Big Bang 13.8 billion years ago.
Planck scientists hit the Hubble constant of 67.5 plus or minus 0.5 kilometers per second per megaparsec.
It presents an exciting challenge for cosmologists who were once determined to measure the Hubble constant — and now wonder what additional physics might help them solve a new mystery about the universe.
“Actually, I don’t really care about the scale value specifically, but I like to use it to get to know the universe,” Reese said.
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