For Questions That Don't Merit Their Own Thread

[AckSed]

I think of it as two similar instruments given similar but not identical roles. Kind of like two delivery lorries that are sent out to most of the same places, but one is available for the inner city routes, while the other is almost exclusively long-haul.

[SOXBLOX]

I was in a chat group online where they started talking about the universe's expansion for some reason, and I remember that Mr. JoeSchmuckatelli and I were interested in findings about inflation, dark matter and stuff. Someone dragged out a paper from May 11th of this year that discusses re-casting cosmology in Minkowski space to gain insights into current problems. It sounds like the author is proposing that we can interpret apparent expansion to be mass and distance scales changing over time, though I probably mis-interpreted that...

The math looks mind-killing to my untrained eyes, but I was hoping someone might be able to skim it, or see whether anyone they know of has something to say about how reasonable it is. Thanks in advance! 

[JoeSchmuckatelli]

10 hours ago, SOXBLOX said:

I was in a chat group online where they started talking about the universe's expansion for some reason, and I remember that Mr. JoeSchmuckatelli and I were interested in findings about inflation, dark matter and stuff. Someone dragged out a paper from May 11th of this year that discusses re-casting cosmology in Minkowski space to gain insights into current problems. It sounds like the author is proposing that we can interpret apparent expansion to be mass and distance scales changing over time, though I probably mis-interpreted that...

The math looks mind-killing to my untrained eyes, but I was hoping someone might be able to skim it, or see whether anyone they know of has something to say about how reasonable it is. Thanks in advance! 

Yark!  That's gonna take some brain twisting work.  Started reading it - then had to go back and review Minkowski for definitions of terms (within the framework of the discussion)... And yeah. 

Seeing as I'm hiking with the fam, that will have to wait for a while. 

Thanks for the post! 

[mikegarrison]

[SunlitZelkova]

When I was in the 6th grade, my science teacher told us energy goes into space when things die, and I recall reading somewhere that one of Tsiolkovsky’s religious ideas was that space travel was a necessary development to retrieve people’s energy, revive them, and become immortal.

But I can’t find a reference to this or Tsiolkovsky’s idea anywhere. Is it true or not?

Also, is there any book or website compiling Tsiolkovsky’s religious ideas or Russian cosmism in general? I’d like to incorporate elements of it into the world/multiverse I am creating.

[kerbiloid]

4 hours ago, SunlitZelkova said:

Also, is there any book or website compiling Tsiolkovsky’s religious ideas or Russian cosmism in general?

Yes, wiki. "Utopian philosophy of Tsiolkovsky"
https://ru-m-wikipedia-org.translate.goog/?_x_tr_sl=ru&_x_tr_tl=en&_x_tr_hl=ru&_x_tr_pto=wapp&_x_tr_hist=true#Утопическая_философия_Циолковского

It's far more than anyone usually has read from his ancestry.
Actually, it's nothing to read there, as he wasn't an educated person, and his ideas were randomly reflecting extreme ideas of his epoch.
Basically, it's just a marginal echo of then-mainstream mysticism and theosophy of Blavatskaya, Rerikh, Gurdzhiev, Vernadskiy, and a bunh of ortodox religious-phylosophic mysticists (unlike Tsiolkovskiyy, sent out from Soviet Russia).

In the USSR he was just an officially iconic figure, never studied farther than several basic quotes and portrait.

[LHACK4142]

I'm listening to the Feynman lectures for the first time, and in his ninth lecture he talks about calculating the positions of bodies in a solar system accounting for all the other bodies (which sounds a lot like n-body physics). He says that a computer could calculate a revolution of Jupiter, with all the perturbations and everything, in just 2 minutes. This was in the 60's- how is it that there's any argument over whether our computers today could easily do N-body physics in real time for KSP?

[kerbiloid]

The real planetary position calculation is not a real N-body physics. It's a set of empirical formulas and coefficients.

https://www.amazon.com/Astronomy-Personal-Computer-Oliver-Montenbruck/dp/3540672214

(With CD-ROM, it contains program sources.)

P.S.
And actually, it's very simplified. Real calculations include several GB large precalculated tables.

Edited July 11, 2023 by kerbiloid

[magnemoe]

4 minutes ago, LHACK4142 said:

I'm listening to the Feynman lectures for the first time, and in his ninth lecture he talks about calculating the positions of bodies in a solar system accounting for all the other bodies (which sounds a lot like n-body physics). He says that a computer could calculate a revolution of Jupiter, with all the perturbations and everything, in just 2 minutes. This was in the 60's- how is it that there's any argument over whether our computers today could easily do N-body physics in real time for KSP?

Problem with n-body in KSP is not CPU power, yes it can be if planning more advanced stuff like multiple gravity assists and modifying the planned vector or if you have lots of junk at high time warp. 
And most will never notice it outside of in their eyes weird effects. 

As for real world, we can only predict short periodic comets like Halley's 3-5 orbits forward in time, this is not cpu power limited but accuracy, because the very eccentric orbit it require very little force to change Ap and this changes how long an orbit last who changes of close it passed the large planets. who changes Ap for the next orbit, repeat. 

[mikegarrison]

On 7/11/2023 at 11:43 AM, LHACK4142 said:

calculating the positions of bodies in a solar system accounting for all the other bodies

This can't be done. Not accounting for *all* the other bodies. Every asteroid? Every comet? Every bit of human space debris? Every particle of dust? Every bird flying in the sky of Earth?

No, you are always going to end up accounting for only those that you think significantly affect the result you are trying to find.

[JoeSchmuckatelli]

Are calculations about expansion tied to estimates of the age of the universe? 

 

There is a new paper out arguing that the universe is twice as old as the general consensus. 

https://www.usatoday.com/story/news/nation/2023/07/14/universe-may-older-than-thought-study-shows/70411343007/

Just wondering, if true, whether a revised age challenges other assumptions beyond just how long stars have been forming galaxies 

[kerbiloid]

The modern view of the Universe structure is based on the views of the people, who were sure that Milky Way is the whole Universe till 1918, the atom is a pudding, consisting of protons and electrons (with no core) till 1914, having no ideas about isotopes till early 1920s, no idea of the neutron till 1932, no idea of spontaneous fission till 1938.

Nuff said.

Why not base the geology on the Athanasius Kircher's studies?

Edited July 19, 2023 by kerbiloid

[mikegarrison]

9 hours ago, kerbiloid said:

The modern view of the Universe structure is based on the views of the people, who were sure that Milky Way is the whole Universe till 1918, the atom is a pudding, consisting of protons and electrons (with no core) till 1914, having no ideas about isotopes till early 1920s, no idea of the neutron till 1932, no idea of spontaneous fission till 1938.

Nuff said.

Why not base the geology on the Athanasius Kircher's studies?

All of biology is based on the work of a guy who had no idea that DNA existed. So, what's your point?

[kerbiloid]

27 minutes ago, mikegarrison said:

All of biology is based on the work of a guy who had no idea that DNA existed. So, what's your point?

The biology is mostly about a knife and a magnifying glass. The DNA also can be touched and studied directly. No need to believe when you can just vivisect this.
And yes, your example is perfectly accurate. The DNA has been discovered in 1953, much later than that.

The Einstein's postulates. Just given without any explanation.

The empirical Hubble's law, to which the expansional model was pulled by ears.

The very idea of the Universe expansion, a perpetuum mobile.

The hydrodynamics which is a hybride of numerology and alchemy, because it's based on purely unexplained empirical magic numbers.

The Michelson-Morley experiment. A search for aethereal flow, made by the tools consisting of the same aether, so moving with the aether speed. It's like measure the wind speed, sitting on a balloon.
(I don't say, that the aether exists, but the experiment looks... strange.)

Edited July 19, 2023 by kerbiloid

[darthgently]

17 hours ago, JoeSchmuckatelli said:

Are calculations about expansion tied to estimates of the age of the universe? 

 

There is a new paper out arguing that the universe is twice as old as the general consensus. 

https://www.usatoday.com/story/news/nation/2023/07/14/universe-may-older-than-thought-study-shows/70411343007/

Just wondering, if true, whether a revised age challenges other assumptions beyond just how long stars have been forming galaxies 

My understanding is that most of the community of researchers have not come to the conclusion that the universe is twice as old as thought just yet.  They are waiting for more info, replication, consideration of other, perhaps theoretical or methodological reconsiderations before coming to a conclusion.  That said, perhaps coming to the consensual conclusion that the age was around 13.x B yo was premature in hindsight.  Don't know for sure

[kerbiloid]

How can the age stay same, when it was calculated before the Dark Matter had entered the room?

Stop. Wasn't the expansion model perfectly balanced without it?

Oops. Is the whole galaxy evolution model still relevant, if keep the Dark Matter?

And the stars. The first generation stars, the hydrogen giants.

The Dark Matter is 10 000 K hot?  Where is the thermodynamic equilibrium then?

Why is it not warming us to decrease the temperature gradient and let the entropy raise?

Edited July 19, 2023 by kerbiloid

[darthgently]

32 minutes ago, kerbiloid said:

How can the age stay same, when it was calculated before the Dark Matter had entered the room?

Stop. Wasn't the expansion model perfectly balanced without it?

Oops. Is the whole galaxy evolution model still relevant, if keep the Dark Matter?

Exactly.  We don't know.  As Musk (and many before) would say in one way or another: 

I'm certain I'm wrong.  Hopefully getting less wrong over time, but always necessarily wrong, because I'm always data and cogitation limited relative to the scale of what I am a mere miniscule subset

Edited July 19, 2023 by darthgently
syntax

[darthgently]

1 hour ago, mikegarrison said:

All of biology is based on the work of a guy who had no idea that DNA existed. So, what's your point?

And the basic 10k ft concepts of genetics and breeding from a monk black-boxing generational changes peas in the garden with no knowledge of DNA.  Mendel was reverse engineering deep genetics by feeling his way in the dark starting at outermost observable layer.  Major kudos earned

[sevenperforce]

On 7/19/2023 at 10:01 AM, kerbiloid said:

The Einstein's postulates. Just given without any explanation.

Not without explanation, just without derivation. But then proven to the most rigorous of standards by every possible test (and by some tests thought to be impossible at the time the postulates were postulated).

On 7/19/2023 at 10:01 AM, kerbiloid said:

The empirical Hubble's law, to which the expansional model was pulled by ears.

The very idea of the Universe expansion, a perpetuum mobile.

You're confusing observations with conclusions.

On 7/19/2023 at 10:01 AM, kerbiloid said:

The Michelson-Morley experiment. A search for aethereal flow, made by the tools consisting of the same aether, so moving with the aether speed. It's like measure the wind speed, sitting on a balloon.
(I don't say, that the aether exists, but the experiment looks... strange.)

You realize the Michelson-Morley experiment wasn't only done once, right?

The laser interferometers at LIGO are the new and improved versions of Michelson-Morley, and they do quite a good job at detecting motion in the "aether" that is spacetime. Confirmed optically, no less.

23 hours ago, kerbiloid said:

How can the age stay same, when it was calculated before the Dark Matter had entered the room?

Dark matter is directly observable via objects like the Bullet Cluster. It would exist regardless of overall cosmology. 

[kerbiloid]

1 hour ago, sevenperforce said:

But then proven to the most rigorous of standards by every possible test (and by some tests thought to be impossible at the time the postulates were postulated).

Axioms can't be proven or disproven. They define the area of proofability.

1 hour ago, sevenperforce said:

You're confusing observations with conclusions.

Previous conclusions were that perpetuum mobile is impossible, and entropy is growing.

The Hubble's law is a kind of observational astrology. Sometimes matches the result, but a law?
Why not Titius-Bode as well?

1 hour ago, sevenperforce said:

You realize the Michelson-Morley experiment wasn't only done once, right?

Many times and in different schemes. All of them were based on the idea that the tool is not a part of aethereal flow.

1 hour ago, sevenperforce said:

The laser interferometers at LIGO are the new and improved versions of Michelson-Morley, and they do quite a good job at detecting motion in the "aether" that is spacetime. Confirmed optically, no less.

If the light doesn't consist of aether as well. Otherwise the laser beam is also a part of balloon, drifting with wind.

1 hour ago, sevenperforce said:

Dark matter is directly observable via objects like the Bullet Cluster. It would exist regardless of overall cosmology. 

Iirc, the Universal equations were including average Universe density. So, 3/4 was missed, but the equilibrium stays same.

Edited July 20, 2023 by kerbiloid

[magnemoe]

On 7/19/2023 at 4:58 PM, darthgently said:

And the basic 10k ft concepts of genetics and breeding from a monk black-boxing generational changes peas in the garden with no knowledge of DNA.  Mendel was reverse engineering deep genetics by feeling his way in the dark starting at outermost observable layer.  Major kudos earned

Granted he was not discovered until later then breeding for traits was big business. 
I say its weirder that the tree of life with how  animals relate to each other was done before theory of evolution and it was mostly correct. 
 

[magnemoe]

10 hours ago, sevenperforce said:

Not without explanation, just without derivation. But then proven to the most rigorous of standards by every possible test (and by some tests thought to be impossible at the time the postulates were postulated).

Yes, Einstein understood the implication of speed of light being constant would have and its very counter intuitive, if you drop an bomb from an plane the planes velocity affect there it hit. 
Even if firing an cannon on an ship the shell will keep the velocity of the ship and this adds up for long range artillery fire. 
But theory of relativity checks out in all the tests and practical applications like gps. 

[JoeSchmuckatelli]

14 hours ago, sevenperforce said:

Dark matter is directly observable via objects like the Bullet Cluster. It would exist regardless of overall cosmology. 

To be intentionally contrarian... the Bullet Cluster is a bit of an anomaly.  And while it was the whip used to flog MOND enthusiasts in the Aughts... MoND refuses to die.

Science-in-progress: Did the Bullet Cluster withstand scrutiny? | Ars Technica

(Yes, article does not say that Bullet Cluster does not prove DM)

(How you like them doublenegatives???)

...

And for those interested in the latest 'proof' of DM: I bring you, the DarkStar!

Dark stars: JWST may have spotted enormous stars powered by dark matter | New Scientist

JWST Might Have Spotted the First Dark Matter Stars - Scientific American

 

[kerbiloid]

3 hours ago, magnemoe said:

But theory of relativity checks out in all the tests and practical applications like gps. 

GPS = 10⁵ km

Galaxy =  10⁵ ly

Universe Today = 10⁹ ly

It's a ~10¹⁶..10²⁰ times gap between the GPS and the Universe scales.

Like between the human scale and the elementary particles.

[magnemoe]

Yes, now we could probably measure it over longer distances who would still be inside the solar system,  gps is just an real life practical example, 
Now it could easy be other rules over long distances or long time same as the first time we ran into relativity was Mercury's orbit and how light appeared to have an fixed velocity or as you say atomic physic has other rules.