Astronomy domine is a song much played in philosophy, not just by Pink Floyd, ever since there are men, and they observe. (Homo Erectus probably observed the last fabulous Galactic Core Eruption, two million years ago.)
Before feeding the pocketbooks of the greedy, science feeds the imagination of poets.
Astronomy has been at the forefront of physics, at least since Buridan (14th Century). Buridan applied his notion of impetus to explain that planets went around in circles from what we now call inertia. In Greek Antiquity, a large, wagon sized meteorite landed in Northern Greece, and was visited for centuries (it may have been a piece of Halley’s comet, which whizzed by spectacularly close in 466 BCE).
A Place Of Great Eruptions, Past & Future. Eta Carinae Nebula, At Least A Couple of Giant Stars, The Lightest One At Least 30 Sun Masses, the Largest Maybe As Much As 220 Solar Masses, 7,500 Light Years Away. Five Million Times The Luminosity Of the Sun. Stellar Natures & Explosions Are Far From Fully Understood!
Supernova explosions are awesome: the most luminous one ever detected had a peak luminosity 570 BILLION times the luminosity of the Sun (yes, (570) 10^9 Suns; that was seen in 2015).
Supernovae are us. Supernovae create most of chemistry: the extremely high temperatures of their explosions enable light nuclei to smash into each other, and fuse, making most elements of the periodic table.
There are two main types of stars which explode as supernovae: white dwarfs and massive giant stars. In the so-called Type Ia supernovae, gases falling onto a white dwarf raise its mass until it nears a critical level, the Chandrasekhar limit, resulting in an explosion when the mass approaches exactly 1.44 Solar Mass. In Type Ib/c and Type II supernovae, the progenitor star is a massive star which runs out of fuel to power its nuclear fusion reactions and collapses in on itself, reaching astounding temperatures as it implodes, and then explodes.
Supernova science is very far from finished knowledge. Even the nature of the Crab Nebula supernova, which was seen to explode in 1054 CE, is not clear (it is known it was a big star, more than 8 Solar Masses; it left a pulsar).
Even the Crab was philosophically interesting in devious ways: the explosion was duly recorded by Europeans and Chinese. However the Muslims tried very hard not to see it (a mention was recently found). Indeed, the heavens, for desert savages, are supposed to be messages from God, and God playing games with stars was apparently not kosher…
Type Ia supernovae have completely changed our idea of the universe in the last two decades. (According to your modest servant, other types of supernovae may change our view of the universe even more dramatically. See the conclusion!)
Eta Carinae is the only star known to produce ultraviolet laser emission!
There is some philosophy to be extracted from Eta Carinae: if a star, or a system of gravitationally bound stars, can be that exotic, how sure are we from the astrophysics we think we know?
I am not the only one who thought of this. The teams who determined the accelerating acceleration of the universe (“Dark Energy”), had to exclude weird, sort-of Type Ia Supernovae… from their statistics (pre-selecting the population of explosions they would apply statistics on…). There are now other ways to detect Dark Energy (and they give the same results as the pre-selected Type Ia supernovae studies). So the results have been confirmed.
However my position is more subtle, and general. How sure are we of the astrophysics we have, to the point that we can claim that stars are unable to create all the known elements? In the proportion observed?
I am no specialist of astrophysics. But, as a philosopher, I have seen the science evolve considerably, so I think we cannot be sure that we absolutely need the hellish temperatures of the Big Bang to generate all observed elements.
Very large stars (600 Solar masses) have now been observed. They don’t live very long. I don’t see why stars thousands of Solar Masses, living only for a few hundred years, before exploding, are not possible. During these so-far-unconceived apocalypses, nucleogenesis could well follow unexpected ways.
And that could well remove one of the main arguments for the Big Bang.
Patrice Ayme’
Tags: Astrophysics, Dark Energy, Explosions, Nucleogenesis, Supernovae, Type Ia
Patrice Ayme's Thoughts 
April 6, 2016 at 11:08 pm |
Big Booms will replace the Big Bang!
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April 7, 2016 at 12:10 am |
Exactly. Stick with what we know. I mean we have observed exploding stars, not exploding universes…
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April 8, 2016 at 6:25 am |
Could ETA Carinae go nova?
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April 8, 2016 at 5:47 pm |
Eta Carinae was seen to explode a bit in the 19C, releasing apparently 30 Solar Masses… So I would say it could go bad any time. Although it’s generally considered it (one of its components) should become a red supergiant first. But then the usual theory does not predict the eruption of the 19C…
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April 8, 2016 at 8:54 pm |
Definite thumbs up on that. I would think the time scale of the Big Bang should also be a give away that all is not right. It’s like trying to explain the history of the earth in 6000 years.
We have seen what appear to be mature galaxies and large scale galaxy clusters as far out as we can see.
FQXI put me up a thread on this some years ago and I’ve added to it over the years;
http://fqxi.org/community/forum/topic/1578
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April 9, 2016 at 5:18 am |
Some say giant walls and voids of galaxies did not have the time to appear in only 14 billion years.
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April 9, 2016 at 5:06 pm |
It says a lot about group psychology that these complications don’t get any attention. I have noticed the premise of the multiverse is starting to draw some skepticism.
Possibly it is just one extrapolation too far, combined with an age that is growing increasingly distrustful of the voices of authority.
They will keep shoehorning everything into this timeframe though, like cavemen riding dinosaurs.
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April 9, 2016 at 7:34 pm |
The Multiverse is an explanation in search of an impossible problem.
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April 9, 2016 at 7:33 pm |
BA & Brodix: Yes the Big Bang is a simple idea. The large scale structures in the space of all galaxies, something else…
For decades, there was strong evidence for Dark Matter, all over the place. It was ignored by Main Stream Cosmologists (MSC). However, a few professionals were vociferous about the fact something was wrong… And they were right.
DM, BTW, contradicts the BB.
… Because how come it appeared recently (I have an explanation for this as DM is just Quantum debris in my theory… So it piles up, over time!)
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April 9, 2016 at 11:33 pm |
Patrice,
All we really know about gravity is the effect, not the cause. Is it simply the presence of mass/matter?
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April 10, 2016 at 4:36 am |
Well, mass has clearly to do with gravity.
For the rest, indeed… Einstein’s theory of gravitation is a bit of a tautology. A force shows up by varying the distance of geodesics (Riemann’s idea ~ 1864). Thus, it shows up as curvature. Thus, indeed, these geodesic gymnastics do not stand under the force.
There is NO under-standing. And “virtual particles” exchanges don’t help either. They are just terms in expansion. Waves seem more real, as they explain the Casimir effect (at least so I think).
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April 10, 2016 at 9:50 am
Patrice,
“Waves seem more real”
Then if mass is an effect of gravity, it would be wave contraction, which starts with the photon effect/quantization. So galaxies hold together because they are ultimately wave expansion/contraction. i.e., radiation out and gravity in.
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April 10, 2016 at 2:49 am |
I am not quite so convinced about dark energy, or at least the accelerating universe. A local cosmologist and others have analysed the data and the conclusion was that for the moment the data are unreliable beyond red shift – 1. Before that, the data cannot resolve between dark energy and no dark energy.
It has also been shown that there are two classes of 1A supernovae, which depend to some extent on metallicity, and the low metallicity ones are dimmer. (What we see tends to depend on the outer shell of the explosion because that tends to be the last radiator, which in turn depends on the partner star.) Now, my guess is there will actually be a continuous change between them, rather than two subsets, and of course the olde the stars, the lower the metallicity on average.
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April 10, 2016 at 4:24 am |
I am aware. Yet the accelerating boys say there are now 4 or 5 other ways to demonstrate acceleration. There maybe 2 types of type Ia, but it’s pretty sure that a subclass can be used as standard candle due to the apparition of the Quantum degeneracy at 1.44 solar mass, and thus explosion, always the same. I have gone through the computation, long ago. Classic Chandrasekar, from the 1930s… He, also got the Nobel for that. Mathematician Segal had found an acceleration, already way back in the 1960s, BTW….
This said, I have a theory of Dark Matter, from my subquantic theory, but Dark Energy eludes me. A reason is that not enough is known about it to start to theorize (quintessence, or not quintessence, etc…) So, in a sense I agree with you….
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April 10, 2016 at 9:58 am |
Ian, Patrice,
Dark energy is proposed to explain why the rate of redshift doesn’t slow at a steady degree from the edge of the visible universe, where it appears galaxies are receding at the speed of light, but slows rapidly, then levels of to a more stable decline. Which needs dark energy to sustain this stable level, since it isn’t explained by the initial event.
Now if redshift is an optical effect, that compounds, it would start off slowly, from our point of view, then eventually go parabolic, to the point galaxies do appear to recede at the speed of light. Which would create a horizon line for visible light, but having simply shifted completely into the black body spectrum, would be the source of the CMBR. Which would be the solution to Olber’s paradox; why we don’t see the light of infinite sources. It would also explain the faint irregularities, since it comes from specific sources.
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April 11, 2016 at 9:35 pm |
Source?
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April 11, 2016 at 10:02 pm |
That is an interesting question. My observation is based on how it was initially described, back in 89, that it was assumed the rate of redshift dropped off at a constant rate, but the measurements by Perlmutter et al, showed it dropped off rapidly than stabilized at about half the age of the universe/7 billion years.
Yet any popular descriptions of it today only say it “accelerated” during the last half;
https://en.wikipedia.org/wiki/Dark_energy
Which makes no sense, as that implies the recent/closer is greater than the distant, yet the most distant appears to recede at close to the speed of light.
The original assumption what all this expansion was due to the initial event and gravity slowed it down, but if it flattened out and then decreased at a steadier pace, that would require the extra energy to sustain.
One of the theories this effect has been compared to is Einstein’s Cosmological Constant, which was originally proposed to balance gravity. Now given gravity is the inward curvature of space, mostly into galaxies, then logically the CC would be an outward curvature between them.
To use the rubber sheet analogy, where the ball warps the sheet, add the idea of the sheet over water, so that while the weight of the ball would push the sheet down, the corresponding pressure would push it up in the surrounding areas, so there is an “outward” curvature to match the inward curvature of gravity.
Such that the light which only traveled in between galaxies would cover this outward curvature and as it is redshifted the effect would compound on itself and go parabolic.
Which makes more sense to me, than just saying the redshift appears to have accelerated recently. Which completely contradicts the fact that redshift does increase proportional to distance, just not at the regular rate originally assumed, but at an accelerating rate.
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April 12, 2016 at 5:19 am |
Hmmm… It looks like I need to make a drawing… I think I covered that in my “100 billion years universe”…
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