Cosmology


As reported on Creation-Evolution Headlines:

22 March 2009 (SPACE.com) – A massive star a million times brighter than our sun exploded way too early in its life, suggesting scientists don’t understand stellar evolution as well as they thought.

“This might mean that we are fundamentally wrong about the evolution of massive stars, and that theories need revising,” said Avishay Gal-Yam of the Weizmann Institute of Science in Rehovot, Israel.

According to theory, the doomed star, about 100 times our sun’s mass, was not mature enough to have evolved a massive iron core of nuclear fusion ash, considered a prerequisite for a core implosion that triggers the sort of supernova blast that was seen.

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Smithsonian.com, (August 12, 2008) – … Historians of science have long debated the exact nature of and motivations for Galileo’s trial. War, politics and strange bedfellows obscure science’s premier martyrdom story. Many of the documents historians use to try and untangle the mystery are mired in their own prejudices or were written long after the fact, or both.

Now the very first written biography of Galileo has been rediscovered. It offers a rare glimpse into what people thought about the trial only 20 years after Galileo’s death and even suggests a tantalizing new explanation for why he was put on trial in the first place

… If people know anything about Galileo’s trial, it’s usually that the church disapproved of his advocacy of the idea that the earth orbits the sun. In many people’s minds, Galileo is a kind of martyr figure for science and a cautionary tale against allowing religious authority to trump scientific inquiry.

“There’s been a very long discussion about the trial—what happened, who won—and to some extent that’s still going on today,” Wilding says. “The usual interpretation is that this was the great rift between science and religion. You’ve got this arrogant scientist up against a dogmatic church, and in that head-ramming, the pope’s going to win.”

Not that modern scholars give much credence to the traditional science-vs.-religion interpretation of the trial. Most Galilean researchers today agree that politics played a much bigger role than religious closed-mindedness, but there is spirited disagreement about the specifics. Some think the pope was angry at being parodied by Galileo’s character Simplicius in Dialogue Concerning the Two Chief World Systems­. Other scholars have suggested that church leaders felt Galileo had tricked them into granting him a license to write the book by not revealing its Copernican leanings. But “Salusbury’s explanation is kind of refreshingly new,” Wilding says…

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In 1933 Fritz Zwicky was the first to find a need to invoke the idea of missing mass or dark matter. He looked at eight Coma galaxies. By assuming visual equilibrium,* he calculated the mass-to-light ratio and determined that about 90% of the mass necessary to account for the observed ratio was missing and therefore invisible. or “dark.” Here, the apparent rapid velocities of the galaxies, with respect to their common center of mass, suggested that much more mass (than could be seen) was required to keep the galaxies from flying out of the cluster. (BSVD) *Visual equilibrium means that the amount of light (of stars) is proportional to amount of mass (number of stars).

In 1936 Sinclair Smith found similar evidence for the existence of invisible mass in the Virgo cluster.

In 1940 Oort estimated (based on the Mass-to-light ratio of spiral nebulae) that 90% of the mass in the local group of spiral nebulae is “missing.” Oort didn’t cite Zwicky’s 1933 paper (BSVD)…

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ScienceDaily (Nov. 5, 2007) – Not only has a large chunk of the universe thought to have been found in 2002 apparently gone missing again but it is taking some friends with it, according to new research at The University of Alabama in Huntsville (UAH). The new calculations might leave the mass of the universe as much as ten to 20 percent lighter than previously calculated.

The same UAH group that found what was theorized to be a significant fraction of the “missing mass” that binds together the universe has discovered that some x-rays thought to come from intergalactic clouds of “warm” gas are instead probably caused by lightweight electrons.

If the source of so much x-ray energy is tiny electrons instead of hefty atoms, it is as if billions of lights thought to come from billions of aircraft carriers were found instead to come from billions of extremely bright fireflies.

“This means the mass of these x-ray emitting clouds is much less than we initially thought it was,” said Dr. Max Bonamente, an assistant professor inUAH’s Physics Department. “A significant portion of what we thought was missing mass turns out to be these ‘relativistic’ electrons.” Traveling at almost the speed of light (and therefore “relativistic”), these feather weight electrons collide with photons from the cosmic microwave background. Energy from the collisions converts the photons from low-energy microwaves to high-energy x-rays…

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Mon Oct 29, 2007 (SPACE.com) – Two Canadian astronomers think there is a good reason dark matter, a mysterious substance thought to make up the bulk of matter in the universe, has never been directly detected: It doesn’t exist…

Last August, an astronomer at the University of Arizona at Tucson and his colleagues reported that a collision between two huge clusters of galaxies 3 billion light-years away, known as the Bullet Cluster, had caused clouds of dark matter to separate from normal matter. Many scientists said the observations were proof of dark matter’s existence and a serious blow for alternative explanations aiming to do away with dark matter with modified theories of gravity.

Now John Moffat, an astronomer at the University of Waterloo in Canada, and Joel Brownstein, his graduate student, say those announcements were premature.

In a study detailed in the Nov. 21 issue of the Monthly Notices of the Royal Astronomical Society, the pair says their Modified Gravity (MOG) theory can explain the Bullet Cluster observation.

Using images of the Bullet Cluster made by the Hubble, Chandra X-ray and Spitzer space telescopes and the Magellan telescope in Chile, the scientists analyzed the way the cluster’s gravity bent light from a background galaxy-an effect known as gravity lensing. The pair concluded that dark matter was not necessary to explain the results…

Moffat compares the modern interest with dark matter to the insistence by scientists in the early 20th century on the existence of a “luminiferous ether,” a hypothetical substance thought to fill the universe and through which light waves were thought to propagate.

“They saw a glimpse of special relativity, but they weren’t willing to give up the ether,” Moffat told SPACE.com. “Then Einstein came along and said we don’t need the ether. The rest was history.”…

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Rehashing old ideas?

ScienceNOW (5 July 2007) – A cosmologist has created a mathematical model that he says shows space-time, contrary to common wisdom, did not begin with the Big Bang. Instead, the model suggests a universe pretty much like the one we live in today existed before the event, except it was contracting instead of expanding. If ever proven, the idea could force a complete rethinking of the origins of the cosmos and perhaps even open a doorway to an endless future…

At the moment of the Big Bang, everything was thought to be crammed into a singularity–a space with no dimensions–that also contained infinite density. Einstein couldn’t explain how such a state could give rise to a universe of finite density and possibly finite dimensions. Theoretical physicist Sean Carroll of the California Institute of Technology in Pasadena put it more succinctly: “Everyone’s calculations show the universe started from a singularity,” he says, “but no one believes it.”

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Of course, it seems likely that if a model such as this one could once again be resurrected with enough support it would probably be easy for the scientific community to accept. While any other model of the origin of the universe (such as white hole cosmology) would be rejected pretty much out of hand on the grounds that we have so much “evidence” that the Big Bang theory is correct, one that could move the naturalistic community back to the idea of a universe that existed in infinite time would probably be accepted in an instant. After all, the only real way to avoid the idea of a Creator is to believe that all matter has always existed. Ex nihilo creation without a Creator is somewhat difficult to conceive of logically, so the only real alternative I can see for the naturalist is to posit matter and time itself as necessary causes (though even this is difficult to maintain).

August 7, 2006 (SPACE.com) – A project aiming to create an easier way to measure cosmic distances has instead turned up surprising evidence that our large and ancient universe might be even bigger and older than previously thought.

If accurate, the finding would be difficult to mesh with current thinking about how the universe evolved, one scientist said…

The finding, which will be detailed in an upcoming issue of Astrophysical Journal, suggests that the Hubble constant, a number that measures the expansion rate and age of the universe, is actually 15 percent smaller than other studies have found…

Scientists now estimate the universe to be about 13.7 billion years old (a figure that has seemed firm since 2003, based on measurements of radiation leftover from the Big Bang) and about 156 billion light-years wide.

The new finding implies that the universe is instead about 15.8 billion years old and about 180 billion light-years wide…

Lawrence Krauss, a professor of astronomy and chair of the Department of Physics at Case Western Reserve who was not involved in the study, said the idea of a significantly reduced Hubble constant would be hard to accommodate.

“Things fit right now very well for a Hubble constant of a low 70s,” Krauss said in a telephone interview. “It corresponds very well with the age of globular clusters as we’ve determined them and the age of the universe. It would be hard, although not impossible, to change things by 15 percent.”

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