On Astronomic Theory of Knowledge

How do we know the Milky Way is a spiral? | The Story of the Milky Way
Dr. Becky | 12.VI.2019
https://www.youtube.com/watch?v=yq0zyA6Yr7o

I

1:34 Note very well, Galileo was never condemned for what he observed and said about the Milky Way. Clavius, though, after verifying (it was Clavius whom St Robert charged with verifying, wasn't it?) suggested stars might be only part of it, and there may be non-star matter as well.

Moderns, I think, have added gas clouds to stars as components, right?

What you said earlier about philosophers considering Milky Way "in the background" as early as 5th C BC must refer to Milky Way being part of Fix stars, since the only stars moving visibly to naked eye in relation to Milky Way are planets.

Oh, not just gas clouds, but dust as well, right?

Chris Baker

@Hans-Georg Lundahl You either don't understand anything about astronomy and astrophysics or you are deliberately obfuscating the issue for some unknown reason. (unknown to us.)

Hans-Georg Lundahl

@Chris Baker I think I have read, though it was some years ago, that Galileo's observations were checked by Clavius, and that Clavius found some cloudy stuff besides stars in Milky Way.

As I recall it, between the stars in Milky Way, interstellar matter, which is now recognised to exist, consists not only of gas clouds but also dust clouds - am I wrong?

Or was the issue the other thing about how parallax is measured? In that case, first you ought to have said that, perhaps by quoting a salient part of relevant passage in my comment, and then be a bit more precise on what I am supposed to be obfuscating or not understanding.

Parallax and aberration are both so small they cannot be seen by the naked eye, and the only thing very ancient astronomers can have seen moving in relation to the Milky Way is therefore the "seven planets" - Moon, Mercury, Venus, Sun, Mars, Jupiter and Saturn, and occasionally a comet.

II

2:11 Not only did Kant and the other guy have no proof, but their unproven speculation was arguably very instrumental in popularising Heliocentric or rather Acentric / Newtonian cosmography.

Obviously, appealing to Aliens was also very important:

New blog on the kid : Continuing with Carter to 24:01
https://nov9blogg9.blogspot.com/2019/06/continuing-with-carter-to-2401.html

If you want to skim fast to the reference, scroll down very low to "3) Idiocentric model as illustrated by Robert Carter" and then a few paragraphs lower start with "Between Kepler and Herschel, Carter omitted the real propagandists for Heliocentrism."

III

dialogue

Hans-Georg Lundahl

5:08 Neither Cepheid's nor stellar statistics by Herschel are apt to actually prove stellar distances, unless you presume some kind of uniformity.

The one presumed by Herschel is partially already seen as wrong, the one presumed by Leavitt could be wrong too, and either way, any absolute distance has to start in some other way, like using parallax for trigonometry - which is only valid in a Heliocentric view of the "Solar System".

Chris Baker

They measured the distances to the "local" Cepheid Variables with Parallax so they have true distances. It's perfectly accurate out to a distance that I forget but it's far enough to measure interstellar distances. But it is several hundred light years. Probably getting further all the time as the technology improves.

That gives them a light curve to pulse time relative to absolute brightness, that apparently holds true throughout. However, there's no proof that the laws of physics don't change minutely or at all over extreme distance. The actual gravity distance may be a teensy tiny fraction of a percent less than the strict inverse distance square law that we believe holds true.

Hans-Georg Lundahl

@Chris Baker "They measured the distances to the "local" Cepheid Variables with Parallax so they have true distances."

You missed that Parallax only measures if we presume Heliocentrism (alternatively, even less intuitive, Geocentrism, but with stellar deplacements aligned in not only time but also distances with Sun).

Chris Baker

@Hans-Georg Lundahl It seems you don't understand how parallax is measured. Heliocentrism has nothing to do with it. The local star's apparent position against the more distant stars is the same function as watching fence posts next to a road go zooming behind your while the distant mountains stay the same for much longer. If you looked across the field to a fence post on the other side of the field and you measured the angles from 2 known points at right angles to the distant fence post and measured it's displacement against the mountains in the far distance behind you and used trigonometry to figure the distance you would be doing exactly the same thing the astronomers are doing to measure the distance to nearby stars. The only difference is the scale of the measurements. The distances are no more heliocentric than the distance to the fence post is Hans-centric. The distance would be the same whoever measured it if they do the math correctly.

Hans-Georg Lundahl

@Chris Baker "Heliocentrism has nothing to do with it. The local star's apparent position against the more distant stars is the same function as watching fence posts next to a road go zooming behind your while the distant mountains stay the same for much longer. "

Which presupposes you are in a moving car.

Heliocentrism is also known - perhaps better in the context - as Geokinetism, "Earth moving".

So, my observation can be restated "what if Earth isn't moving".

IV

dialogue

Hans-Georg Lundahl

6:01 So, Shapley considered the Milky Way as 100 000 light years in radius.

Now, with a distance 100 000 light years, you have a Distant Starlight Problem for Young Earth Creationism.

However, suppose the real distance was only 316 or 317 light years ... exactly what would Cepheid's require in different positioning for "close stars" like alpha Centauri? Instead of 4 light years, what?

And how far away would Andromeda be, on Curtis' observation, if Milky Way were only 316 rather than 100 000 light years away?

If we continue using square roots, I get 707 light years ... also no Distant Starlight challenge to Young Earth Creationism ....

Chris Baker

It seems pretty obvious that God created the universe in pretty much it's current state, 13.8 billion years or so old at the time of creation.

Otherwise we wouldn't be able to see all the things out there that proclaim the glory of God because the light wouldn't have had time to arrive. This in no way conflicts with the evolutionary view of the universe because it was created looking as though it actually had been born that long ago. There's nothing wrong with scientists finding out how it works and even how old it is because it really is 13.8 billion years old. Here's a thought, Prove to me it was not created last week. You can't. The evidence is that it was created much longer ago but there's no way to prove it. Fortunately religion does not deal with "HOW?" and instead deals with "WHY?". Science deals with "How?" quite nicely. As we learn more, the "HOW?" changes to explain what we know.

So my faith in a created universe, about 6,000 years ago, in no way conflicts with my scientific knowledge that it is 13.8 or so, billion years old.

Hans-Georg Lundahl

@Chris Baker "Otherwise we wouldn't be able to see all the things out there that proclaim the glory of God because the light wouldn't have had time to arrive."

My question was precisely on how we are supposed to know A N Y T H I N G is as far away as 13.8 billion light years.

What if certain assumptions are flawed?

"Here's a thought, Prove to me it was not created last week."

I have memories from years ago. To account for them with a creation last week would require God including traces of things happening before creation.

My point is, with "distant starlight" the problem is the same, S U P P O S I N G we know the furthest away we see is 13.8 billion or anything exceeding 8000 light years and even some 500 less away.

B U T if instead the very distant stars are a bad conclusion on a bad supposition, we don't need God creating traces of what wasn't there to see what we see and 7200 - 7500 years being the age of Cosmos.

V

dialogue

Chris Baker

Everything in the universe seems to have a inverse relationship between the size and the number of objects. From the smallest sub atomic particles to the largest galaxies. The larger they are, the fewer they are. I haven't read anything about any studies on how many true wanderers (planets) are in interstellar space. It seems there should be a LOT of them. We have a few gigantic stars, lot's of medium sized stars, a multitude of red dwarf stars and it seems a logical progression that there would be a much larger mega multitude of failed stars and even more giant planets and again even more smaller rocky planets although small gas planets could exist if they'd never been near enough to a star to evaporate their ices. and on and on throughout interstellar space and even intergalactic space. There would be more moon sized wanderers in and around the galaxy than there are stars by a huge amount. Has anyone studied this possibility? I would think that they could easily account for the so called "missing mass" without resorting to the mysterious "dark matter".

Hans-Georg Lundahl

And what if suppositions are flawed, and the sizes are wrong?

Chris Baker

@Hans-Georg Lundahl What suppositions and what sizes??? I asked questions about possibilities that seem to be logical. The whole point of my comment was to find out if anyone knows if any studies have been done or are being planned. So I really don't understand your question.

Hans-Georg Lundahl

@Chris Baker Suppositions like "aberration and parallax" being derived in two different ways from movement of Earth, and therefore supposed Trigonometry by parallax and therefore the very first stellar distances and sizes ("local" or "our part of the galaxy" I think I have heard them called) and therefore the other distances and sizes as well.

I don't see any lack of logic in this question, and if you mean it is physically impossible in your world view, how about learning sufficient philosophy to understand difference between physically impossible (as miracles seem to an Atheist) and logically impossible (as 2=2=5).

VI

9:00 You said Hydrogen was the most abundant element in the Universe, right?

Some guys have been denying "waters above the firmament" .... and what would Hydrogen best be described as in Biblical terms?

If we term it "instant water" (add Oxygen and a spark, you get an explosion and water), we can see why Moses would have called Hydrogen water rather than air.

Plus, if I recall correctly, second most abundant interstellar matter molecule after H2 is H2O.

VII

16:00 Kapteyn ... seriously Cup Tine and not Cup Tayn?

I'm not that good on Dutch I can confidently correct you, though.