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Experts Doubt the Sun Is Burning Coal (1863)

scientificamerican.com

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Re: Experts Doubt the Sun Is Burning Coal (1863)

#81

Post by pishpash »

asveikau wrote: post #71
robotbikes wrote: post #35

In fact when Cecilia Payne proposed that the Sun and other stars were composed of Hydrogen and Helium in her Doctoral thesis in 1925 the conclusion was rejected by her advisor because of the conventional wisdom of the time that the earth and the sun were composed of the same elements. https://en.m.wikipedia.org/wiki/Cecilia_Payne-Gaposchkin

I thought helium was named for the sun (Helios), by spectral analysis of sunlight. In hindsight it's weird that they can know that in the 19th century (per Wikipedia of Helium) and the next conclusion has to wait until 1925, with controversy.

They probably thought it was an inert atmosphere found on the Sun but having nothing to do with the operation of the Sun. Without nuclear physics, it wouldn't be an unreasonable conclusion.

Re: Experts Doubt the Sun Is Burning Coal (1863)

#82

Post by perl4ever »

gerdesj wrote: post #69
tempestn wrote: post #57

Earlier quoted context omitted.

I wouldn't even say it's nonsense. Edit: just realized the precise word you used was in fact 'bollocks'. I wouldn't say it's that either. The logic behind the sun not burning a fuel like coal is entirely sound. From there an alternate theory is proposed based on the limits of understanding of the time. Not as fact, but as a best guess theory that fits the evidence at that point. The theory was wrong of course, but it…

"The logic behind the sun not burning a fuel like coal is entirely sound" That is precisely why I called it "reasoned bollocks" - perhaps a bit colourful for HN. As you say the theory was wrong but the article was describing current theory at the time and is of course ... science. I really am praising a long running science magazine as best I can. I am a massive fan.

It seems very anachronistic to describe it like that. Like calling the Apple I a failure for selling a couple hundred and ridiculously underpowered for not even having a 1 GHz processor. People make comments like that now and then, and it's just odd.

Re: Experts Doubt the Sun Is Burning Coal (1863)

#83

Post by tlb »

Just checkin' the math:

  >>> sun_output = 3.828e26 # watts
  >>> sun_mass = 2e30 # kg
  >>> coal_energy_density = 30e6 # W*s/kg
  >>> year = 365*86400
  >>> sun_mass * coal_energy_density / sun_output / year
  4970.1868313110635
So (assuming a magical supply of oxygen) a lump of coal the mass of the sun could burn with the brightness of the sun for 4970 years

Numbers from https://en.wikipedia.org/wiki/Sun and https://en.wikipedia.org/wiki/Energy_density

Re: Experts Doubt the Sun Is Burning Coal (1863)

#84

Post by Geee »

throw_away wrote: post #66
whymauri wrote: post #55

Earlier quoted context omitted.

My older brother has founded two separate isotope dating companies, one for C-14 dating and the other for rare isotopes. At this point, he has about 15 years of experience in the field and a decent clientele. He believes the Earth is 6000 years old, though. He rationalizes the science he works on as (the biblical) God testing his faith. My father, who works at his C-14 company, also believes this. I will never unders…

How do they reconcile when they give customers answers > 6000 years and the whole "thou shalt not lie" bit?

It's not a lie. When God created everything, he made it seem it was older.

Re: Experts Doubt the Sun Is Burning Coal (1863)

#86

Post by gojomo »

When I was a child, my father had a 'Scientific American' monthly magazine subscription for our household.

I always got a kick out of the regular features, "50 years ago" and "100 years ago", where they excerpted their own actual articles from exactly that long ago. Definitely gave me a sense of perspective on the march of scientific understanding.

(By 1995, they were able to add "150 years ago", as they'd been in existence since 1845.)

Re: Experts Doubt the Sun Is Burning Coal (1863)

#87

Post by saagarjha »

gerdesj wrote: post #80
tialaramex wrote: post #59

Earlier quoted context omitted.

I'm not sure it's helpful to describe this 1863 article as "reasoned bollocks" In this same timeframe Kelvin supposes the Earth cannot possibly be billions of years old because it's warm underground. You can measure and verify that the Sun can't be keeping the Earth this warm, if it was just down to the Sun this place would be uninhabitable. Nothing could be this warm after cooling down for billions of years with jus…

Assume a spherical planet. OK an ablate spheroid. OK a ... Now assume Lord Kelvin is talking bollocks. Just because you invent "really cold, bordering on quite nippy" doesn't mean you can overlook things like half lives and red shift. If Lord Kelvin lived now I suspect he might have other conclusions - he evaluated the evidence available at the time. I was deliberately provocative and I'm glad I was. I've got far bet…

> I was deliberately provocative and I'm glad I was. I've got far better responses as a result.

I would tend to argue that this isn’t something we need on Hacker News. (Also, it’s “oblate”. To “ablate” is to erode.)

Re: Experts Doubt the Sun Is Burning Coal (1863)

#88

Post by saagarjha »

litoE wrote: post #51
gerdesj wrote: post #36

Earlier quoted context omitted.

[Please move away from the DV button - I like to encourage discussion around here] You forgot the conclusion. The prevailing opinion about the world's age is not 6000 years. I think some fundamentalist Christians might try for 4004 BC so 6000 years ... ish but I don't even know anyone who subscribes to that nonsense. I'm sure there are some who do but they are not my mates. They are certainly not general population.

I've heard the argument that God did create everything about 6,000 years ago in HIS reference frame but that due to relativistic time dilation/contraction its been 13+ billion years in OUR reference frame.

God must’ve been a hadron shot out of a particle accelerator then, because He’s going pretty fast…

Re: Experts Doubt the Sun Is Burning Coal (1863)

#89

Post by yongjik »

tialaramex wrote: post #59
gerdesj wrote: post #15

I had absolutely no idea that SA is so old. New Scientist - https://en.wikipedia.org/wiki/New_Scientist is a mere whippersnapper. It doesn't matter that the article is bollocks. It is reasoned bollocks. That is basically what science is all about! I would prefer if there was some more working shown to back up the article but it seems to imply that some might be available rather than just simple assertions. We live in…

I'm not sure it's helpful to describe this 1863 article as "reasoned bollocks" In this same timeframe Kelvin supposes the Earth cannot possibly be billions of years old because it's warm underground. You can measure and verify that the Sun can't be keeping the Earth this warm, if it was just down to the Sun this place would be uninhabitable. Nothing could be this warm after cooling down for billions of years with jus…

> You can measure and verify that the Sun can't be keeping the Earth this warm, if it was just down to the Sun this place would be uninhabitable.

This is somewhat misleading because the Sun is pretty much the sole energy source for keeping the surface of the Earth warm:

> Despite its geological significance, this heat energy coming from Earth's interior is actually only 0.03% of Earth's total energy budget at the surface, which is dominated by 173,000 TW of incoming solar radiation. [1]

The problem posed by Kelvin was the the interior of the Earth was too warm, which may affect long-term habitability because plate tectonics plays a role in regulating the atmosphere's CO2 levels (or so I've heard), but of course nobody at Kelvin's time knew that. Kelvin wasn't asking "Why isn't the Earth a dead planet?"

[1] https://en.wikipedia.org/wiki/Earth%27s_internal_heat_budget

Re: Experts Doubt the Sun Is Burning Coal (1863)

#90

Post by AareyBaba »

philipkglass wrote: post #60

Here is the longer original article, scanned by Google Books and hosted by the HathiTrust project: "Age of the Sun -- Force and Heat" Scientific American Vol IX -- No. 7 August 15 1863 https://babel.hathitrust.org/cgi/pt?id=uva.x001601382&view=1...

Interesting to read. The Sun is referred to as 'he' and people were just beginning to understand how heat energy and mechanical energy could be transformed into one another.

"He has enlightened our globe from one generation to another without any apparent diminution of strength, and we have formed the instinctive belief that no limit in the past or any in the future can be assigned to his functions. No proof of progress or decay has been detected ; and it has been thought that nothing but the fiat of the Almighty can quench his rays. Principles have now been recognized, however, which enable us to assign limits, and to show that he has not shone from a past eternity, and that he has a limited existence as an incandescent body. This limit assigned to the solar system forces us to recognize the hand of a Creator."

"The meteoric stones that sometimes fall to our earth may be regarded as balls, but moving with much greater velocity. They strike against our atmosphere with so much force that the force is converted into heat, so intense that they glow or become incandescent. .... Assuming that the heat of the sun has been kept up by meteoric bodies falling into it, and proof has been given of such fall, it is possible from the mass of the solar system to determine approximately the period during which the sun has shone as a luminary"

"Limits can be set to the fuel of the solar system, and therefore limits can also be assigned to the existence of the sun as our luminary. The limits lie between 100 millions and 400 millions of years. These are enormous periods, but still they are definite. The mass is so great,and the cooling is so slow, that, even on the supposition that no fuel was added, it might be five or six thousand years before the sun cooled down a single degree."

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