A 'Hubble Crisis'? New Measurement Confirms Universe is Expanding Too Fast for Current Models
"The universe is expanding faster than predicted by theoretical models," writes Phys.org, "and faster than can be explained by our current understanding of physics." There's now been new confirmation of this (published in The Astrophysical Journal Letters) by a team led by Dan Scolnic, an associate professor of physics at Duke University. And this means the so-called Hubble tension "now turns into a crisis," said Dan Scolnic, who led the research team... This is saying, to some respect, that our model of cosmology might be broken." Measuring the universe requires a cosmic ladder, which is a succession of methods used to measure the distances to celestial objects, with each method, or "rung," relying on the previous for calibration. The ladder used by Scolnic was created by a separate team using data from the Dark Energy Spectroscopic Instrument (DESI), which is observing more than 100,000 galaxies every night from its vantage point at the Kitt Peak National Observatory. Scolnic recognized that this ladder could be anchored closer to Earth with a more precise distance to the Coma Cluster, one of the galaxy clusters nearest to us. "The DESI collaboration did the really hard part, their ladder was missing the first rung," said Scolnic. "I knew how to get it, and I knew that that would give us one of the most precise measurements of the Hubble constant we could get, so when their paper came out, I dropped absolutely everything and worked on this non-stop." To get a precise distance to the Coma cluster, Scolnic and his collaborators used the light curves from 12 Type Ia supernovae within the cluster. Just like candles lighting a dark path, Type Ia supernovae have a predictable luminosity that correlates to their distance, making them reliable objects for distance calculations. The team arrived at a distance of about 320 million light-years, nearly in the center of the range of distances reported across 40 years of previous studies — a reassuring sign of its accuracy. "This measurement isn't biased by how we think the Hubble tension story will end," said Scolnic. "This cluster is in our backyard, it has been measured long before anyone knew how important it was going to be." The results? "It matches the universe's expansion rate as other teams have recently measured it," writes Phys.org, "but not as our current understanding of physics predicts it. The longstanding question is: is the flaw in the measurements or in the models? Scolnic's team's new results add tremendous support to the emerging picture that the root of the Hubble tension lies in the models..." And the article closes with this quote from Scolnic: "Ultimately, even though we're swapping out so many of the pieces, we all still get a very similar number. So, for me, this is as good of a confirmation as it's ever gotten. We're at a point where we're pressing really hard against the models we've been using for two and a half decades, and we're seeing that things aren't matching up," said Scolnic. "This may be reshaping how we think about the universe, and it's exciting! There are still surprises left in cosmology, and who knows what discoveries will come next?" Read more of this story at Slashdot.
"The universe is expanding faster than predicted by theoretical models," writes Phys.org, "and faster than can be explained by our current understanding of physics." There's now been new confirmation of this (published in The Astrophysical Journal Letters) by a team led by Dan Scolnic, an associate professor of physics at Duke University.
And this means the so-called Hubble tension "now turns into a crisis," said Dan Scolnic, who led the research team... This is saying, to some respect, that our model of cosmology might be broken."
Measuring the universe requires a cosmic ladder, which is a succession of methods used to measure the distances to celestial objects, with each method, or "rung," relying on the previous for calibration. The ladder used by Scolnic was created by a separate team using data from the Dark Energy Spectroscopic Instrument (DESI), which is observing more than 100,000 galaxies every night from its vantage point at the Kitt Peak National Observatory. Scolnic recognized that this ladder could be anchored closer to Earth with a more precise distance to the Coma Cluster, one of the galaxy clusters nearest to us. "The DESI collaboration did the really hard part, their ladder was missing the first rung," said Scolnic. "I knew how to get it, and I knew that that would give us one of the most precise measurements of the Hubble constant we could get, so when their paper came out, I dropped absolutely everything and worked on this non-stop."
To get a precise distance to the Coma cluster, Scolnic and his collaborators used the light curves from 12 Type Ia supernovae within the cluster. Just like candles lighting a dark path, Type Ia supernovae have a predictable luminosity that correlates to their distance, making them reliable objects for distance calculations. The team arrived at a distance of about 320 million light-years, nearly in the center of the range of distances reported across 40 years of previous studies — a reassuring sign of its accuracy. "This measurement isn't biased by how we think the Hubble tension story will end," said Scolnic. "This cluster is in our backyard, it has been measured long before anyone knew how important it was going to be."
The results? "It matches the universe's expansion rate as other teams have recently measured it," writes Phys.org, "but not as our current understanding of physics predicts it. The longstanding question is: is the flaw in the measurements or in the models? Scolnic's team's new results add tremendous support to the emerging picture that the root of the Hubble tension lies in the models..."
And the article closes with this quote from Scolnic:
"Ultimately, even though we're swapping out so many of the pieces, we all still get a very similar number. So, for me, this is as good of a confirmation as it's ever gotten. We're at a point where we're pressing really hard against the models we've been using for two and a half decades, and we're seeing that things aren't matching up," said Scolnic.
"This may be reshaping how we think about the universe, and it's exciting! There are still surprises left in cosmology, and who knows what discoveries will come next?"
Read more of this story at Slashdot.
