Hubble's 'Magnum Opus': a 30-Year Analysis of the Universe's Expansion (newatlas.com) 16
"NASA has released a huge new report that astronomers are calling Hubble's magnum opus," reports New Atlas.
"Analyzing 30 years of data from the famous space telescope, the new study makes the most precise measurement yet of how fast the universe is expanding." Astronomers have known for the better part of a century that the universe is expanding, thanks to the observation that galaxies are moving away from us — and the farther away they are, the faster they're traveling. The speed at which they're moving, relative to their distance from Earth, is a figure called the Hubble constant, and measuring this value was one of the primary missions of the space telescope of the same name.
To measure the Hubble constant, astronomers study distances to objects whose brightness is known well — that way, the dimmer it appears, the farther away it is. For relatively close objects within our galaxy or in nearby ones, this role is filled by Cepheids, a class of stars that pulse in a predictable pattern. For greater distances, astronomers use what are called Type Ia supernovae — cosmic explosions with a well-defined peak brightness....
For the new study, a team of scientists has now gathered and analyzed the most comprehensive catalog of these objects so far, to make the most precise measurement of the Hubble constant yet. This was done by studying 42 galaxies that contained both Cepheids and Type Ia supernovae, as imaged by the Hubble telescope over the last 30 years.
"This is what the Hubble Space Telescope was built to do, using the best techniques we know to do it," said Adam Riess, lead scientist of the team. "This is likely Hubble's magnum opus, because it would take another 30 years of Hubble's life to even double this sample size."
The article points out that these detailed real-world observations of the Hubble "constant" now show a small discrepancy, which suggests "new physics could be at work."
And it's the new James Webb Space Telescope that will now be studying these same phenomena at an even higher resolution.
"Analyzing 30 years of data from the famous space telescope, the new study makes the most precise measurement yet of how fast the universe is expanding." Astronomers have known for the better part of a century that the universe is expanding, thanks to the observation that galaxies are moving away from us — and the farther away they are, the faster they're traveling. The speed at which they're moving, relative to their distance from Earth, is a figure called the Hubble constant, and measuring this value was one of the primary missions of the space telescope of the same name.
To measure the Hubble constant, astronomers study distances to objects whose brightness is known well — that way, the dimmer it appears, the farther away it is. For relatively close objects within our galaxy or in nearby ones, this role is filled by Cepheids, a class of stars that pulse in a predictable pattern. For greater distances, astronomers use what are called Type Ia supernovae — cosmic explosions with a well-defined peak brightness....
For the new study, a team of scientists has now gathered and analyzed the most comprehensive catalog of these objects so far, to make the most precise measurement of the Hubble constant yet. This was done by studying 42 galaxies that contained both Cepheids and Type Ia supernovae, as imaged by the Hubble telescope over the last 30 years.
"This is what the Hubble Space Telescope was built to do, using the best techniques we know to do it," said Adam Riess, lead scientist of the team. "This is likely Hubble's magnum opus, because it would take another 30 years of Hubble's life to even double this sample size."
The article points out that these detailed real-world observations of the Hubble "constant" now show a small discrepancy, which suggests "new physics could be at work."
And it's the new James Webb Space Telescope that will now be studying these same phenomena at an even higher resolution.
The Accelerating Expansion is Not Settled Science. (Score:5, Informative)
https://arxiv.org/abs/1506.013... [arxiv.org]
https://arxiv.org/abs/1703.093... [arxiv.org]
etc.
We might be in for some interesting results.
Re: (Score:2)
A lot of cosmological map based theories, like the non-baryonic dark matter theories, are based on extrapolations of very limited data taken at extreme distances from long, long ago in the universe's history. That data is extrapolated to deduce luminosities of remote supernova, whose distance and red shift is then measured and women into a complex 3D map of the universe. But the original data are so uncertain that deducing extraordinary cosmological configurations such as non-baryonic dark matter, equivalen
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Ya, the astrophysicists couldn't possibly have thought through your "objections". You should send them your papers on the subject, I'm sure they'll listen to you.
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Many have, and do, think about such suggestions. It's difficult to get funding or get a thesis signed in cosmology today without exotic forms of dark matter proposed, despite the lack of concrete evidence for it. Rejecting exotic matter is as popular as designing hardware without speculative execution, even though it inevitably is discovered as a security risk and needs to be disabled.
Boundless hope and endless frustration (Score:4, Interesting)
My line of work is different from pure astronomy, but similar in one key way:
Sensor technology is always improving, and the quality of data coming from stuff built in the last decade or two is leaps and bounds better than what preceded it. This lets you imagine all kinds of new science and new capabilities.
But all that imagination runs into the following brick wall: to do real science when developing new capabilities, you either need to make apples-to-apples comparisons with previous measurements (these don't exist) or else you need a long baseline of very precise high quality measurements (which also don't exist).
It's frustrating to know that your shiny new toy is just the beginning of something that will pay off in a decade (or longer), even if it's exciting to speculate about what that payoff would look like.
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tl;dr
Hubble crew doesn’t know their ass from their elbow
Hubble has a crew? Shouldn't we send Elon up to give them a change of shift?
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Never underestimate the power of delegation. [youtube.com]
I believe this guy doesn't sleep much.
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Elon pwning the libs while forgetting who actually buys Teslas. (Not conservatives).
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As of 4/20/22.. [tesla.com] 310,048 vehicles delivered in Q1 2022. Q1 2021 181,800 or a 70% increase YoY.
YMMV
So how fast *is* it expanding? (Score:2)