Tag: Big Bang

Conflict in Hubble constant continues to confound astronomers

9:56 am

The uncertainty of science: In reviewing their measurements of the Hubble constant using a variety of proxy distance tools, such as distant supernovae, astronomers recently announced that their numbers must be right, even though those numbers do not match the Hubble constant measured using completely different tools.

Most measurements of the current acceleration of the universe (called the Hubble constant, or H0) based on stars and other objects relatively close to Earth give a rate of 73 km/s/Mpc. These are referred to as “late-time” measurements [the same as confirmed by the astronomers in the above report]. On the other hand, early-time measurements, which are based on the cosmic microwave background emitted just 380,000 years after the Big Bang, give a smaller rate of 68 km/s/Mpc.

They can’t both be right. Either something is wrong with the standard cosmological model for our universe’s evolution, upon which the early-time measurements rest, or something is wrong with the way scientists are working with late-time observations.

The astronomers are now claiming that their late-time observations must be right, which really means there is either something about the present theories about the Big Bang that are fundamentally wrong and that our understanding of early cosmology is very incomplete, or the measurements by everyone are faulty.

Based on the number of assumptions used with both measurements, it is not surprising the results don’t match. Some of those assumptions are certainly wrong, but to correct the error will require a lot more data that will only become available when astronomers have much bigger telescopes of all kinds, in space and above the atmosphere. Their present tools on Earth are insufficient for untangling this mystery.

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Astronomers detect water in the very very early universe

9:14 am

The uncertainty of science: Using the ALMA telescope in Chile, astronomers have detected the molecules of water and carbon monoxide in a galaxy thought to have formed only 780 million years after the Big Bang.

SPT0311-58 is actually made up of two galaxies and was first seen by ALMA scientists in 2017 at its location, or time, in the Epoch of Reionization. This epoch occurred at a time when the Universe was just 780 million years old—roughly 5-percent of its current age—and the first stars and galaxies were being born. Scientists believe that the two galaxies may be merging, and that their rapid star formation is not only using up their gas, or star-forming fuel but that it may eventually evolve the pair into massive elliptical galaxies like those seen in the Local Universe.

“Using high-resolution ALMA observations of molecular gas in the pair of galaxies known collectively as SPT0311-58 we detected both water and carbon monoxide molecules in the larger of the two galaxies. Oxygen and carbon, in particular, are first-generation elements, and in the molecular forms of carbon monoxide and water, they are critical to life as we know it,” said Sreevani Jarugula, an astronomer at the University of Illinois and the principal investigator on the new research. “This galaxy is the most massive galaxy currently known at high redshift, or the time when the Universe was still very young. It has more gas and dust compared to other galaxies in the early Universe, which gives us plenty of potential opportunities to observe abundant molecules and to better understand how these life-creating elements impacted the development of the early Universe.”

Need I say that there are many uncertainties with this result, including the assumption that the universe is only 780 million years old at location of this galaxy. That age is extrapolated from the galaxy’s red shift, a link that depends on some uncertain assumptions. Moreover, the discovery of these molecules so soon after the theorized Big Bang is unexpected. Cosmologists had assumed that at this early age the universe wasn’t old enough yet to form galaxies with such complex molecules.

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Galaxies in the early universe don’t fit the theories

9:33 am

The uncertainty of science: New data from both the ALMA telescope in Chile and the Hubble Space Telescope about six massive galaxies in the early universe suggest that there are problems and gaps in the presently accepted theories about the universe’s formation.

Early massive galaxies—those that formed in the three billion years following the Big Bang should have contained large amounts of cold hydrogen gas, the fuel required to make stars. But scientists observing the early Universe with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Hubble Space Telescope have spotted something strange: half a dozen early massive galaxies that ran out of fuel. The results of the research are published today in Nature.

Known as “quenched” galaxies—or galaxies that have shut down star formation—the six galaxies selected for observation from the REsolving QUIEscent Magnified galaxies at high redshift. or the REQUIEM survey, are inconsistent with what astronomers expect of the early Universe.

It was expected that the early universe would have lots of that cold hydrogen for making stars. For some galaxies to lack that gas is inexplicable, and raises questions about the assumptions inherent in the theory of the Big Bang. It doesn’t disprove it, it simply makes it harder to fit the facts to the theory, suggesting — as is always the case — that the reality is far more complicated than the theories of scientists.

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Astronomers chart the universe’s slow death

9:40 am

Using data gathered from more than 200,000 galaxies, astronomers have been able to measure the slow decline in the universe’s energy output since the Big Bang.

The fact that the Universe is slowly fading has been known since the late 1990s, but this work shows that it is happening across all wavelengths from the ultraviolet to the infrared, representing the most comprehensive assessment of the energy output of the nearby Universe. “The Universe will decline from here on in, sliding gently into old age. The Universe has basically sat down on the sofa, pulled up a blanket and is about to nod off for an eternal doze,” concludes Simon Driver.

I wish to note the significant uncertainty of this result. While this result is important and does strongly suggest that the universe is dying, 200,000 galaxies is hardly a significant representation of the universe’s galaxy population.

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Gravitational wave/inflation discovery literally bites the dust

9:24 pm

The uncertainty of science: The big discovery earlier this year of gravitational waves confirming the cosmological theory of inflation has now been found to be completely bogus. Instead of being caused by gravitational waves, the detection was caused by dust in the Milky Way.

Even while the mainstream press was going nuts touting the original announcement, I never even posted anything about it. To me, there were too many assumptions underlying the discovery, as well as too many data points with far too large margins of error, to trust the result. It was interesting, but hardly a certain discovery. Now we have found that the only thing certain about it was that it wasn’t the discovery the scientists thought.

Nor is this unusual for the field of cosmology. Because much of this sub-field of astronomy is dependent on large uncertainties and assumptions, its “facts” are often disproven or untrustworthy. And while the Big Bang theory itself unquestionably fits the known facts better than any other theory at this time, there remain too many uncertainties to believe in it without strong skepticism.

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Some scientists are now calling into question the BICEP2 results that confirmed the existence of inflation just after the Big Bang.

10:12 am

The uncertainty of science: Some scientists are now calling into question the BICEP2 results that confirmed the existence of inflation just after the Big Bang.

The biggest discovery in cosmology in a decade could turn out to be an experimental artifact—at least according to an Internet rumor. The team that reported the discovery is sticking by its work, however.

Eight weeks ago, researchers working with a specialized telescope at the South Pole reported the observation of pinwheel-like swirls in the polarization of the afterglow of the big bang, or cosmic microwave background (CMB). Those swirls are traces of gravitational waves rippling through the fabric of spacetime a sliver of a second after the big bang, argue researchers working with the Background Imaging of Cosmic Extragalactic Polarization 2 (BICEP2) telescope. Such waves fulfilled a prediction of a wild theory called inflation, which says that in the first 10-32 seconds, the universe underwent a mind-boggling exponential growth spurt. Many scientists hailed the result as a “smoking gun” for inflation.

However, scientists cautioned that the result would have to be scrutinized thoroughly. And now a potential problem with the BICEP analysis has emerged, says Adam Falkowski, a theoretical particle physicist at the Laboratory of Theoretical Physics of Orsay in France and author of the Résonaances blog. The BICEP researchers mapped the polarization of the CMB across a patch of sky measuring 15° by 60°. To study the CMB signal, however, they first had to subtract the “foreground” of microwaves generated by dust within our galaxy, and the BICEP team may have done that incorrectly, Falkowski reports on his blog today.

When the BICEP2 result was announced, the media went crazy over it. I however didn’t even post anything about it, as I know from experience that cosmological results such as this are very tentative and require confirmation. Too often, they turn out to be false results, with the scientists in charge fooled by the uncertain nature of their data.

The results from BICEP2 might still hold up. We need to wait a bit longer to find out.

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Cosmologists, using new data, are now reconsidering their theories on the manner in which the universe began organizing itself after the Big Bang.

9:08 am

The uncertainty of science: Cosmologists, using new data, are now reconsidering their theories on the manner in which the universe began organizing itself after the Big Bang.

Scientists call it the epoch of reionization, the period in which a newborn universe went from darkness to light as the first stars, galaxies and black holes began forming and radiating energy.

In a paper published Thursday in Nature, researchers are challenging one long-held conception about how quickly the universe began warming during this transition period. Based on observations of X-ray emissions from binary star systems, as well as new mathematical models, cosmologists at Tel Aviv University and Harvard say that heating of the universe progressed much more slowly, and uniformly, than previously thought.

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One scientist’s modeling of the early universe suggests to him that intelligent life could have evolved as early as 15 million years after the Big Bang.

9:23 am

Theories! One scientist’s modeling of the early universe suggests to him that intelligent life could have evolved as early as 15 million years after the Big Bang.

This is fun stuff, but entirely theoretical and not to be taken very seriously. We know with certainty as much about the early universe as a mouse understands Shakespeare. To predict accurately the nature or even existence of life at that time is stretching our knowledge considerably.

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Astronomers have found a dozen supernovae taking place closer to the Big Bang than ever detected.

10:18 pm

Astronomers have found a dozen supernovae taking place only a few billion years after the Big Bang.

[The results suggest that these types of supernovae] were exploding about five times more frequently 10 billion years ago than they are today. These supernovas are a major source of iron in the universe, the main component of the Earth’s core and an essential ingredient of the blood in our bodies.

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The most distant quasar ever found

9:04 am

Astronomers have found the most distant quasar ever, and are baffled by its existence.

The light from the quasar started its journey toward us when the universe was only 6% of its present age, a mere 770 million years after the Big Bang, at a redshift of about 7.1 [3]. “This gives astronomers a headache,” says lead author Daniel Mortlock, from Imperial College London. “It’s difficult to understand how a black hole a billion times more massive than the Sun can have grown so early in the history of the universe. It’s like rolling a snowball down the hill and suddenly you find that it’s 20 feet across!”

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