Rethinking the theories that explain some supernovae
The uncertainty of science: New data now suggests that the previous consensus among astronomers that type Ia supernovae were caused by the interaction of a large red giant star with a white dwarf might be wrong, and that instead the explosion might be triggered by two white dwarfs.
If this new origin theory turns out to be correct, then it might also throw a big wrench into the theory of dark energy.
The evidence that twin white dwarfs drive most, if not all, type Ia supernovae, which account for about 20% of the supernova blasts in the Milky Way, “is more and more overwhelming,” says Dan Maoz, director of Tel Aviv University’s Wise Observatory, which tracks fast-changing phenomena such as supernovae. He says the classic scenario of a white dwarf paired with a large star such as a red giant “doesn’t happen in nature, or quite rarely.”
Which picture prevails has impacts across astronomy: Type Ia supernovae play a vital role in cosmic chemical manufacturing, forging in their fireballs most of the iron and other metals that pervade the universe. The explosions also serve as “standard candles,” assumed to shine with a predictable brightness. Their brightness as seen from Earth provides a cosmic yardstick, used among other things to discover “dark energy,” the unknown force that is accelerating the expansion of the universe. If type Ia supernovae originate as paired white dwarfs, their brightness might not be as consistent as was thought—and they might be less reliable as standard candles.
If type Ia supernovae are not reliable standard candles, then the entire Nobel Prize results that discovered dark energy in the late 1990s are junk, the evidence used to discover it simply unreliable. Dark energy might simply not exist.
What galls me about this possibility is that it was always the case. The certainty in the 1990s about using type Ia supernovae as a standard candle to determine distance was entirely unjustified. Even now astronomers do not really know what causes these explosions. To even consider them to always exhibit the same energy release was just not reasonable.
And yet astronomers in the 1990s did, and thus they fostered the theory of dark energy upon us — that the universe’s expansion was accelerating over vast distances — while winning Nobel Prizes. They still might be right, and dark energy might exist, but it was never very certain, and still is not.
Much of the fault in this does not lie with the astronomers, but with the press, which always likes to sell new theories as a certainty, scoffing over the doubts and areas of ignorance that make the theories questionable. This is just one more example of this, of which I can cite many examples, the worst of all being the reporting about global warming.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
The uncertainty of science: New data now suggests that the previous consensus among astronomers that type Ia supernovae were caused by the interaction of a large red giant star with a white dwarf might be wrong, and that instead the explosion might be triggered by two white dwarfs.
If this new origin theory turns out to be correct, then it might also throw a big wrench into the theory of dark energy.
The evidence that twin white dwarfs drive most, if not all, type Ia supernovae, which account for about 20% of the supernova blasts in the Milky Way, “is more and more overwhelming,” says Dan Maoz, director of Tel Aviv University’s Wise Observatory, which tracks fast-changing phenomena such as supernovae. He says the classic scenario of a white dwarf paired with a large star such as a red giant “doesn’t happen in nature, or quite rarely.”
Which picture prevails has impacts across astronomy: Type Ia supernovae play a vital role in cosmic chemical manufacturing, forging in their fireballs most of the iron and other metals that pervade the universe. The explosions also serve as “standard candles,” assumed to shine with a predictable brightness. Their brightness as seen from Earth provides a cosmic yardstick, used among other things to discover “dark energy,” the unknown force that is accelerating the expansion of the universe. If type Ia supernovae originate as paired white dwarfs, their brightness might not be as consistent as was thought—and they might be less reliable as standard candles.
If type Ia supernovae are not reliable standard candles, then the entire Nobel Prize results that discovered dark energy in the late 1990s are junk, the evidence used to discover it simply unreliable. Dark energy might simply not exist.
What galls me about this possibility is that it was always the case. The certainty in the 1990s about using type Ia supernovae as a standard candle to determine distance was entirely unjustified. Even now astronomers do not really know what causes these explosions. To even consider them to always exhibit the same energy release was just not reasonable.
And yet astronomers in the 1990s did, and thus they fostered the theory of dark energy upon us — that the universe’s expansion was accelerating over vast distances — while winning Nobel Prizes. They still might be right, and dark energy might exist, but it was never very certain, and still is not.
Much of the fault in this does not lie with the astronomers, but with the press, which always likes to sell new theories as a certainty, scoffing over the doubts and areas of ignorance that make the theories questionable. This is just one more example of this, of which I can cite many examples, the worst of all being the reporting about global warming.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
That puts a wrench in a lot of things.
And then there are the superluminous supernova (astronomers are running out of words), and the FBOTs (astronomers have indeed run out of words!) Fast Blue Optical Transients. They just discovered them the other week. Immediately it was suggested that perhaps it is some kind of gigantonormous superstar that suddenly detonates and devastates everything all around it. That’s the 1A school book explanation reused, again. Given the vast amount of dots up there in the black at night, this should work at least once.
“- James, would you mind having a look through the lens tonight?
– Yes, no, I mean yes sir. Why try to upset our beautiful theory by collecting more data? Who knows what that could bring about. Can’t we just wait for the JWST another lifetime? I like it here in the observatory library of past discoveries and beautiful theories of those twinkling dots in the blackness.
– Myself, I never look up. I only read Ptolemy. And according to him it is your turn tonight. Unless you find some star to contradict his horoscope.”
(Astronomers are actually the most honest and bright gang of guys I know of. They are not in it for the money or some crazy preconceived idea, they are genuinely curious and open minded.)
Have we even figured out what, exactly, are Quasars?
David M. Cook: Astronomers presently believe they are supermassive black holes. Do a search on BtB for “quasars” and you will get a lot interesting stuff to read.