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The Webb and Hubble space telescopes confirm the universe's expansion rate, the puzzle continues

Web sightings provide new insights into a decade-long mystery

This image of NGC 5468, a galaxy about 130 million light-years from Earth, combines data from the Hubble and James Webb space telescopes. It is the most distant galaxy in which Hubble has detected variable Cepheid stars. These stars serve as important landmarks for measuring the expansion rate of the universe.
This image of NGC 5468, a galaxy about 130 million light-years from Earth, combines data from the Hubble and James Webb space telescopes. It is the most distant galaxy in which Hubble has detected variable Cepheid stars. These stars serve as important landmarks for measuring the expansion rate of the universe.

The expansion rate of the universe, known as Hubble's constant, is one of the basic parameters for understanding the evolution and ultimate fate of the universe. However, there is a persistent difference, called the Hubble stress, between the value of the constant measured by a wide variety of independent distance measures and its value predicted from the post-Big Bang glow. NASA/ESA/CSA's James Webb Space Telescope has confirmed that the sharp eye of the Hubble Space Telescope was right all along, erasing any remaining doubts about Hubble's measurements.

One of the scientific justifications for building the NASA/ESA Hubble Space Telescope was to use its observational power to provide an accurate value for the expansion rate of the universe. Before Hubble's launch in 1990, observations from ground-based telescopes yielded large uncertainties. Depending on the values ​​inferred for the expansion rate, the universe could have been between 10 and 20 billion years old. Over the past 34 years, Hubble has reduced this measurement to an accuracy of less than 13.8 percent, reaching an age of XNUMX billion years. This figure was obtained by updating the so-called 'cosmic distance scale' by measuring important landmarks known as Cepheid variable stars.

However, the Hubble constant is inconsistent with other measurements that suggest the universe expanded more rapidly after the Big Bang. These observations were made by ESA's Planck satellite, which mapped the cosmic background radiation - the blueprint for how the universe would develop after it cooled from the Big Bang.

The simple solution to the dilemma was to say that maybe Hubble's observations were wrong, as a result of some inaccuracy in his measurements of the depth gauges of space. Then came the James Webb Space Telescope, which allowed astronomers to check the results of the 'Hubble'. Webb's infrared observations of the cupids matched Hubble's visible light data. Webb confirmed that the sharp eye of the Hubble telescope was correct all along, erasing any remaining doubts about Hubble's measurements.

Bottom line, the bitter tension between what's happening in the near universe versus the expansion of the early universe remains a vexing mystery for cosmologists. There may be something hidden in the structure of space that we do not yet understand.

Does solving this mystery require new physics? Or is it measurement errors between the two different methods used to determine the rate of expansion of space?

Hubble and Webb have now collaborated to produce definitive measurements, strengthening the case that something else – not measurement errors – is affecting the rate of expansion.

"With the measurement errors ruled out, what's left is the possibility that we have a misunderstanding of the universe," said Adam Rees, a physicist at Johns Hopkins University in Baltimore. Rees holds the Nobel Prize for discovering the fact that the expansion of the universe is accelerating, thanks to a mysterious phenomenon now known as 'dark energy'.

As a cross-check, an initial observation by Webb in 2023 confirmed that Hubble's measurements of the expanding universe were accurate. However, hoping to ease Hubble's strain, some scientists have speculated that hidden measurement errors may grow and become visible as we look deeper into the universe. In particular, star clusters may systematically affect brightness measurements of more distant stars.

The SH0ES (Supernova H0 for the Equation of State of Dark Energy) team, led by Rees, obtained further observations with a 'web' of objects that are critical cosmic landmarks, called Cepheid variable stars, which can now be linked to the Hubble data.

"We have now deployed the full range of Hubble measurements and can rule out measurement error as the cause of the Hubble voltage with high confidence," Rees said.

The team's first Webb observations in 2023 were able to show that Hubble was on the right track in determining the reliability of the first rungs of the cosmic distance scale.

Astronomers use different methods to measure relative distances in the universe, depending on the object being observed. Collectively, these techniques are known as the Cosmic Distance Scale - each step or measurement technique relies on the previous step for calibration.

But some astronomers have suggested that, as we move out along the 'second phase', the cosmic distance scale may become shaky if cupid measurements become less accurate with distance. Such inaccuracies can occur because the light of a Cepheid star can blend with that of a nearby star—an effect that can become more pronounced with distance as the stars crowd together in the sky and become harder to tell apart.

The observational challenge is that Hubble images of the more distant cupids appear denser and more connected with nearby stars the greater the distance between us and their host galaxies, requiring careful calculations for this effect. In addition, dust increases the uncertainty of visible light measurements. Webb passes through the dust and naturally isolates the cupids from nearby stars because its vision is sharper than Hubble's at infrared wavelengths.

"A combination of 'Web' and 'Hubble' gives us the best of both worlds. "We find that the Hubble measurements remain reliable as we climb further along the cosmic distance scale," Rees said.

Webb's new observations include five host galaxies of eight type Ia supernovae containing a total of 1000 cupids, reaching as far as the most distant galaxy where cupids have been well measured - NGC 5468, 130 million light years away. "This encompasses the entire range in which we performed measurements with the Hubble. So we've reached the end of the second rung of the cosmic distance scale," said co-author Gagandeep Anand of the Space Telescope Science Institute in Baltimore, which operates the Webb and Hubble telescopes for NASA.

Together, Hubble and Webb's confirmation of Hubble's hoaxes allows other observatories to solve the mystery, including NASA's upcoming Nancy Grace Roman Space Telescope and ESA's recently launched Euclid mission.

Today it is as if the distance scale observed by 'Hubble' and 'Webb' has placed a firm anchor point on one bank of the river, and the glow after the big bang observed by Planck from the beginning of the universe is firmly placed on the other side. How the expansion of the universe changed in the billions of years between these two endpoints has yet to be directly observed. "We need to find out if we're missing something on how to connect the beginning of the universe with the present time," Rees said.

These findings were published in The Astrophysical Journal Letters.  

More of the topic in Hayadan:

10 תגובות

  1. All that remains to be said is that scientists are really not scientists! And it's a shame!

  2. Dear Shani,
    It is one thing to be ignorant or stupid (abbreviations: BOAT), and another thing is to insist and show it with rudeness and arrogance.
    In physics there are dozens of open problems, some of them relate to the fundamental theories and concepts, and most of them are weighty to the point of being critical.
    For the sake of demonstration, some of these problems are described in the following link: https://he.wikipedia.org/wiki/%D7%91%D7%A2%D7%99%D7%95%D7%AA_%D7%A4%D7%AA%D7%95%D7%97%D7%95%D7%AA_%D7%91%D7%A4%D7%99%D7%96%D7%99%D7%A7%D7%94
    The issue of open problems, as it takes shape in recent generations, comes in addition to fundamental philosophical problems in relation to materialistic physical research. In any case, it puts the question of the possibility of a coherent description of physical reality into serious doubt, and calls for alternative concepts, including those that question the purely materialistic nature of reality.
    As a historical fact, it should be noted that since the end of the 19th century, as physical knowledge expands and enriches, the number of these problems increases, and there are no signs that the severity of the problems is getting any easier. Even the technological success of the research products in physics does not solve the problem. It seems that in this context, physics, in its various branches, is in a deep theoretical conceptual crisis despite its predicted "progress", and there is no guarantee that further "advances" in the future will change the situation. It is very possible that the rational human capacity does not reach complete physical truths, especially not coherent fundamental truths. It is possible that such truths do not exist at all, and creation is a voluntary occurrence of some super-material being, if not a chaotic random occurrence. Since the second option is not reasonable, in light of the fact that the universe does reveal segments of apparent regularity, the first option remains as a possibility that is not unreasonable at the principle level.
    The fact that someone will call it a divine occurrence, should not lead to reactions of cancellation and ridicule of the type that characterizes BOTs, as you wrote in your response.

  3. Hahahahaha, sparrow, of course God created the world, hahahaha, nothing about the baboons, nothing will help!!! No sense, no worries

  4. Dror Israel, my fellow fools, haven't you learned that you don't establish a fact without necessity?
    You or your fellow believers have no necessity that God created the world.
    And when you say God, do you mean our God? Because there are many types of God in many religions throughout history and they all thought and think that their God is the strongest of all.
    Arthur Schopenhauer the German philosopher said
    "Religion is the masterpiece of the art of taming animals."

  5. "With the measurement errors ruled out, what remains is the possibility that we have a misunderstanding of the universe,"
    No Shit Sherlock
    Maybe someone created the universe after all

  6. My dear father
    This is how you write in this article
    “…. It is possible that there is something hidden in the structure of space that we do not yet understand…”
    It's not that there might be something hidden, you just ignore the one who created the world and put the stars in their shifts..
    It's not bad, it's only a matter of time before the scientists and astrophysicists will admit it. And much shorter than it looks at first glance.
    Happy Matan Torah holiday

  7. The lonely hearts of the cosmos. One of the best books I've ever read, if not the best

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