(CNN) – Measuring the expansion rate of the universe was one of the main goals of the Hubble Space Telescope when it launched in 1990.
For the past 30 years, the Space Observatory has helped scientists discover and increase the rate of this acceleration, as well as discovering mysterious wrinkles that only new physics can solve.
Hubble has detected more than 40 galaxies containing pulsars as well as stellar explosions called supernovae to measure greater cosmic distances. These two phenomena help astronomers define astronomical distances as mile markers, which indicate the rate of expansion.
In their quest to understand how fast our universe is expanding, astronomers made an unexpected discovery in 1998: “dark energy.” This phenomenon acts as a mysterious driving force that accelerates the rate of expansion.
And another development: an inexplicable difference between the rate of expansion of the local universe and the rate of expansion of the distant universe immediately after the Big Bang.
Scientists do not understand the paradox, but they admit that it is strange and may require new physics.
“The most accurate measurements of the expansion rate of the universe are obtained from the telescope’s gold standard and cosmic tilt markers,” said Adam Rees, Nobel Prize winner from the Institute of Space Telescope Science and Distinguished Professor at Johns Hopkins University in Baltimore. statement.
“That’s what the Hubble Space Telescope was built for, using the best technology we know to do it. This is perhaps Hubble’s greatest achievement, as it would take another 30 years for Hubble to double this sample size.”
decades of surveillance
The telescope is named after the pioneering astronomer Edwin Hubble, who discovered in the 1920s that the distant clouds in the universe are actually galaxies. (died 1953).
Hubble builds on the work of astronomer Henrietta Swan-Levitt, who in 1912 discovered periods of brightness of pulsars called Cepheid variables. Cepheids act as cosmic landmarks, periodically brightening and dimming in our galaxy and elsewhere.
Hubble’s work led to the revelation that our galaxy is one of many that have forever changed our perspective and place in the universe. The astronomer continued his work and found that distant galaxies appeared to be moving fast, suggesting that we live in an expanding universe that began with the Big Bang.
Discovery of the expansion rate of the universe contributes to the gift 2011 Nobel Prize in PhysicsAwarded to Saul Perlmutter, Brian P. Schmidt, and Riess “for discovering the accelerated expansion of the universe by observing distant supernovae.”
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. Your team published an article about Astrophysics Journal Which provides the latest update to the Hubble constant, since the rate of expansion 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 foundations.
Various teams of astronomers using the Hubble telescope have produced a Hubble constant of 73, plus or minus 1 kilometer per second per megaparsec. (One megaparsec is one million parsecs, or 3.26 million light years.)
“The Hubble constant is a very special number. It can be used to thread a needle from the past to the present to comprehensively test our understanding of the universe. This required an impressive amount of detailed work,” said Licia Verdi, a cosmologist at the Catalan Institute for Research and Advanced Studies and the Institute of Cosmology at the University of Barcelona, in a statement.
But the expected actual rate of expansion 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 suggests the components of the Big Bang) and measurements made by the Planck mission. . The European Space Agency between 2009 and 2013.
The Planck Observatory, another space observatory, was used to measure the cosmic microwave background, or radiation left over from the Big Bang 13.8 billion years ago.
Scientists on the Planck mission reached a Hubble constant of about 67.5 or more, or 0.5 kilometers per second per megaparsec.
The James Webb Space Telescope, launched in December, will be able to observe Hubble’s features at higher resolutions and at greater distances, which could help understand the difference between the two numbers.
This presents an interesting challenge for cosmologists who previously attempted to measure the Hubble constant and are now wondering what additional physics could help them unravel new mysteries about the universe.
“I don’t really care what the value of the scaling is specifically, but I like to use it to study the universe,” Reese said.
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