Question Where moment of inertia came from? Interaction with primordial matter that may be dark matter?

[vagor]

How big bang and inflation from singularity result in introduction of spin to as-formed matter?
This question was posted in https://www.space.com/largest-spinn...13f4afda3b088cde8254df9cfe0c9576ff1d31b319a04 .

What if we consider big bang akin to a grenade explosion. All particles including products of chemical reaction shall fly away in straight lines without spin. However, spin may be introduced if these particles experience interactions with surrounding matter.
If big bang happened within primordial space filled with matter that obeys different physics, but interacting with our matter in certain way, say gravitationally only, we shall see introduction of spin into our expanding matter.
This may explain dark matter and dark energy as manifestation of properties of primordial space.

 

[rabsal]

That's a great article and thanks for posting it, I saw it a few days ago and was to busy to comment. This article shows that spin is inherent in our universe and coincides with my theory that the inflation expansion that happened first is what causes the dense areas of our visible universe to drag from the differences in the speed of expansion between our visible universes expansion and the inflation field. The drag causes spin, mass, time and consciousness....I win!

 

[Catastrophe]

It seems to me that there is some confusion between rotation about an axis (spin) (applied to one body) and rotation about another external point (orbiting)(applied to more than one body).
Unfortunately this confused use of language seems universal.

Cat

 

[vagor]

It seems to me that there is some confusion between rotation about an axis (spin) (applied to one body) and rotation about another external point (orbiting)(applied to more than one body).
Unfortunately this confused use of language seems universal.

Cat

I agree that word "spin" was a poor choice. In that context I meant just rotation, not a quantum number. However, in multibody environments rotation occurs around common centers of mass. The latter can be easily defined for two-body systems and very problematic for analytical solution in case of multi (more than three)- body systems. If one component of a multibody system interacts with an external component, the motion disturbance will gravitationally couple with all components. If a component of "primordial universe" that obeys different laws of physics, in this context dark matter, interacts with expanding "new-born" Universe obeying our laws, but interacting gravitationally only (no electromagnetic, strong or weak), a particle of our laminar expending Universe will gain rot (in mathematical terms.)

 

[Catastrophe]

I am particularly concerned about this nomenclature. Spin can only be relative (I am talking about planets, not atoms). There was some talk about space spinning, but this is only possible in Newtonian physics. According to Einstein-Mach, spin is relative.

Cat

Vide The meaning of absolute:
Quote
. . . . . . , the Einstein/Mach viewpoint holds that rotation is not relative to space, but rather is defined relative to the matter in the universe. If this viewpoint is correct, you would never see any precession of the pendulums because the bulk of the matter in this experimental universe is the planet itself, so it basically defines the frame of zero rotation.
Quote

 

[vagor]

I am not sure that spin is relative. Frame of reference within spinning body is described as non-inertial coordinate system and as such it introduces behaviors that not present in inertial systems, i.e. centrifugal forces and associated coriolis acceleration.

 

[Catastrophe]

You need an outside observer to observe spin. Therefore spin is relative to the observer. If you had an observer spinning in fixed orbit, always over the same mark on the sphere, then that observer would observe no spin. Have another observer, not in simultaneous orbit, and the sphere will appear to be spinning. Have 50 other observers on different locations (planets, moons, etc.,) and each 50 will observe the spin of the original body according to their separate motions.

If you take the imaginary situation where you remove the whole of the Universe, then you have the Einstein-Mach situation above,

There can be no doubt whatsoever that spin is relative.

But of course you have every right to an opinion.

Cat

I did not mean to overstate that. What you describe is the Newtonian viewpoint. If you prefer that to Einstein-Mach, that is your prerogative.

 

[vagor]

Do you need an outside observer to measure force? What happens if you are standing on a platform that may be brought in rotation by flip of a switch and suddenly start feeling the force. To explain this using Mach's principle someone would have to assume that the entire Universe "knew' when you are about to flip the switch and will start rotating stars around you, which is equivalent to existence of God who knows everything before it happens ,or Matrix.

 

[Catastrophe]

Is rotational motion relative to space? - Physics Stack Exchange

https://physics.stackexchange.com › questions › is-rotati...

The Newtonian viewpoint holds that yes, rotation is relative to space. If this view is correct, and the isolated planet were rotating relative to space, you would see your pendulums (pendula?) precessing at a nonzero rate, and you could solve for the planet's rotational velocity.

On the other hand, the Einstein/Mach viewpoint holds that rotation is not relative to space, but rather is defined relative to the matter in the universe. If this viewpoint is correct, you would never see any precession of the pendulums because the bulk of the matter in this experimental universe is the planet itself, so it basically defines the frame of zero rotation. In our universe, of course, there is a much larger distribution of matter to define a nonrotating rotational reference frame. Mathematically, this results from a phenomenon in GR known as frame dragging.

 

[Catastrophe]

From Wiki:

Quote
Rotation period
From Wikipedia, the free encyclopedia
Jump to navigationJump to search
Animated rotation of asteroid 433 Eros
The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) is as its sidereal rotation period the time that the object takes to complete a single revolution around its axis of rotation relative to the background stars, meassured in sidereal time.
Quote

My emphasis

Cat

 

[Catastrophe]

There is a serious problem here with the English language. Let me be very clear - I am referring to the English language, and not to any individual person.
I have to mention that OP in #1 stated "How big bang and inflation from singularity result in introduction of spin to as-formed matter?" I mention this only to point out that OP correctly referred to the article which IMHO used the word "spin" incorrectly.

I am proposing a way around this verbal difficulty. If one body is in question, then the word spin is correct. A body spins around its axis.
If two bodies are concerned, one (or both) orbits the other. Each body may individually spin on its axis.
Rotates is used in both cases, but to mean different things.

 

[vagor]

My original post was structured around the origin of spin/rotation that was apparently introduced shortly after the Big Bang event. However, I was more interested in finding an explanation of dark matter. The latter was hidden as second layer in original query.

I was not planning to get into discussion of classical vs Einstein-Mach conjecture as this is largely of philosophical nature. However, if we are to assume that laws of physics as we know them were defined by events taking place in the early Universe, than both Newtonian and Einstein formulations were the derivatives of those early events. Furthermore, if expansion starts from singularity, than at least originally it would have to be laminar. And yet, we see the galaxies spinning and even, as pointed out in sited article, huge galaxy clusters are also spinning. Where this spin came from?
Second: if we are to assume that our Universe was expanding into space filled with primordial matter obeying different laws of physics but gravitationally interacting with our expanding Universe, than such spin on galactic scale may be explained. It may also suggest that dark matter is a substance of primordial space into which we are expending.

 

[Catastrophe]

The following are taken from The New Collins Concise Dictionary:

ROTATE vb

• to turn or cause to turn around an axis; revolve or spin.
• to follow or cause to follow a set sequence.

ROTATION n

• the act of rotating; rotary motion
• a regular cycle of events in a set order or sequence
• etc

Note that “rotate” here seems to favour the “spin” description, but from the noun rotation there seems to be an opening for a wider interpretation.

SPIN vb

• to rotate or cause to rotate rapidly, as on an axis.
• to draw out and twist … as fibres etc..

ORBIT n

• Astron. The curved path followed by a planet, satellite, etc., in its motion around another celestial body.
• a range or field . . . etc.,

ORBIT vb

• to move around (a body) in a curved path
• etc.,

I think it clear from these definitions that rotate can be ambiguous. To avoid any ambiguity the words SPIN and ORBIT can (should ?) be used to signify *one body spinning on its axis* and *one body orbiting another body* respectively. Orbit can, of course, also refer to two bodies orbiting a common centre of gravity, which can be between the bodies and not within either.

It seems clear to me that, if one body only is involved, the correct word is SPIN; if more than one body is involved, then one body can ORBIT another. In the second case, each body may spin separately on its axis, as well as the one orbiting the other.

Cat

 

[Catastrophe]

vagor, rather than invoking complexities, I would ask you to consider posts #10 and #13 which are in straightforward English.

I don't know about you, but English is my native language and I have also edited and written for Marcel Dekker, a US scientific publisher.

Cat

P.S. I meant only whether your native lingo is English English, or US English, just in case there are transatlantic shades of meaning?

 

[Catastrophe]

My original post was structured around the origin of spin/rotation that was apparently introduced shortly after the Big Bang event. However, I was more interested in finding an explanation of dark matter. The latter was hidden as second layer in original query.

I was not planning to get into discussion of classical vs Einstein-Mach conjecture as this is largely of philosophical nature. However, if we are to assume that laws of physics as we know them were defined by events taking place in the early Universe, than both Newtonian and Einstein formulations were the derivatives of those early events. Furthermore, if expansion starts from singularity, than at least originally it would have to be laminar. And yet, we see the galaxies spinning and even, as pointed out in sited article, huge galaxy clusters are also spinning. Where this spin came from?
Second: if we are to assume that our Universe was expanding into space filled with primordial matter obeying different laws of physics but gravitationally interacting with our expanding Universe, than such spin on galactic scale may be explained. It may also suggest that dark matter is a substance of primordial space into which we are expending.

I am sorry if I took you off the beaten track but the word "spin" was used imho incorrectly (not by you) in the very first line.
I have no wish to enter complicated philosophical discussions - though I will if YOU wish - my only concern is the correct use of words. Is there a basis for agreement here? Cat

 

[Catastrophe]

My original post was structured around the origin of spin/rotation that was apparently introduced shortly after the Big Bang event. However, I was more interested in finding an explanation of dark matter. The latter was hidden as second layer in original query.

I was not planning to get into discussion of classical vs Einstein-Mach conjecture as this is largely of philosophical nature. However, if we are to assume that laws of physics as we know them were defined by events taking place in the early Universe, than both Newtonian and Einstein formulations were the derivatives of those early events. Furthermore, if expansion starts from singularity, than at least originally it would have to be laminar. And yet, we see the galaxies spinning and even, as pointed out in sited article, huge galaxy clusters are also spinning. Where this spin came from?
Second: if we are to assume that our Universe was expanding into space filled with primordial matter obeying different laws of physics but gravitationally interacting with our expanding Universe, than such spin on galactic scale may be explained. It may also suggest that dark matter is a substance of primordial space into which we are expending.

Would it help if I ask, very politely, about what axis does a galaxy spin? You see, I don't think spin is the correct word here.

 

[vagor]

Catastrophe,
As you correctly guessed, English is not my native language, it is Russian instead.
My background is in physics and control systems with some involvement in neurophysiology. Let's stick to your definitions of rotation and spin as posted in #13 with one clarification:
It looks like spin should never be used in physics discussion as there is no fully isolated body in the Universe and all objects spin around something and not around their axis following a complex cycloid-like trajectory.

 

[vagor]

I am sorry if I took you off the beaten track but the word "spin" was used imho incorrectly (not by you) in the very first line.
I have no wish to enter complicated philosophical discussions - though I will if YOU wish - my only concern is the correct use of words. Is there a basis for agreement here? Cat

Agreed!

 

[vagor]

Would it help if I ask, very politely, about what axis does a galaxy spin? You see, I don't think spin is the correct word here.

Clusters of galaxies form tubes while revolving around a common axis

 

[Catastrophe]

vagor. I am so pleased that we have reached agreement. May I say that your English is really excellent. I had assumed you were English or American. It is phenomenal - I have tried learning a little Russian and I know how different the languages are. You are really to be congratulated,

I am so glad not to follow up the philosophical line of considering the Earth alone in the Universe. I know the differences between Newtonian and Einstein-Mach models and it is difficult to reconcile.

Best wishes,

Cat

 

[Catastrophe]

Clusters of galaxies form tubes while revolving around a common axis

OK - a tube can have an axis

 

[vagor]

vagor. I am so pleased that we have reached agreement. May I say that your English is really excellent. I had assumed you were English or American. It is phenomenal - I have tried learning a little Russian and I know how different the languages are. You are really to be congratulated,

I am so glad not to follow up the philosophical line of considering the Earth alone in the Universe. I know the differences between Newtonian and Einstein-Mach models and it is difficult to reconcile.

Best wishes,

Cat

Thank you Catastrope,
I love philosophy and would very much like to get engaged into philosophical discussion. It just appeared that that was not the best way to address the specific question.
Thanks again,
V

 

[Catastrophe]

Catastrophe,
As you correctly guessed, English is not my native language, it is Russian instead.
My background is in physics and control systems with some involvement in neurophysiology. Let's stick to your definitions of rotation and spin as posted in #13 with one clarification:
It looks like spin should never be used in physics discussion as there is no fully isolated body in the Universe and all objects spin around something and not around their axis following a complex cycloid-like trajectory.

Just to clear up a few small points . . . . . . "and all objects spin around something and not around their axis following a complex cycloid-like trajectory."

Did you mean 'all objects orbit around something' because all (most) objects do spin around their separate axis (plural) relative to the background stars (post #10)/

 

[Catastrophe]

vagor, if you look under Misc Space you will find a thread:

Various scientific and philosophical matters pertaining to space

which you are very welcome to join in. It is intended to keep good discussions away from specified topics where they do not really fit. In other words, if something interesting happens in a topic about something else, there is a home for it here, without mixing up the parent topic.

Cat

 

[vagor]

Just to clear up a few small points . . . . . . "and all objects spin around something and not around their axis following a complex cycloid-like trajectory."

Did you mean 'all objects orbit around something' because all (most) objects do spin around their separate axis (plural) relative to the background stars (post #10)/

Yes, sorry for throwing the wrong word again. It is funny how brain works .. it is very difficult to root out an image that was already associated with a linguistic element