Questions on the big bang expanding universe.

[ratiocinator]

Oh, so it´s your gravity which causes water and mercury colums to rise and fall? So "gravtity" isn´t a constant force? Or is it that your gravity works both ways?

See: #1017. If you have a vacuum on one side, then you don't have air pressure on that side. Air pressure, of course, only exists because of gravity pulling it towards the Earth. If there was no gravity, you couldn't even have an atmosphere at all, why do you think the air doesn't just drift off into space?

As far as I know it´s only the atmospheric pressure and of course E&M which can work both ways.

What causes air pressure without gravity?

 

[Polymath257]

You¨re simply confusing the atomic E&M binding of particles as weight and then you´re confusing this weight to contain your illusive "gravity".

No, you are the one confusing weight (the force downward from gravity) as something produced by E&M effects. I have to say it is very unclear how you get that.

Oh, so it´s your gravity which causes water and mercury colums to rise and fall in changing atmospheric pressures? So "gravity" isn´t a constant force? Or is it that your gravity works both ways?

As far as I know it´s only the atmospheric pressure and of course E&M which can work both ways.

Already explained above.

Forces add to give the net force on an object. Gravity is one of the forces, but there are others as well (like friction, and the force from air pressure). Air pressure is usually balanced and gives no net effect. It does in a manometer because there is no pressure at the top from the vacuum, so it is no longer balanced.

 

[Polymath257]

See: #1017. If you have a vacuum on one side, then you don't have air pressure on that side. Air pressure, of course, only exists because of gravity pulling it towards the Earth. If there was no gravity, you couldn't even have an atmosphere at all, why do you think the air doesn't just drift off into space?

What causes air pressure without gravity?

Exactly. The weight of the air is the combined gravitational force on the mass of the air. That is what produces the air pressure.

 

[Native]

According to the link you provided; "Primordial nucleosynthesis is believed by most cosmologists to have taken place in the interval from roughly 10 seconds to 20 minutes after the Big Bang", so how does this impact on galaxy formation 400 million years later?

Did you study the posted image at all? Because galaxies are assumed to be the latest to be formed from gas and particles in 13.8 bill. year old BB Nucleosynthesis and not just about 400 mill. after a beginning.

This inconsistency in the BB Theory just accurs logically because the entire idea is nonsens in the first hand.

 

[Polymath257]

Did you study the posted image at all? Because galaxies are assumed to be the latest to be formed from gas and particles in 13.8 bill. year old BB Nucleosynthesis and not just about 400 mill. after a beginning.

This inconsistency in the BB Theory just accurs logically because the entire idea is nonsens in the first hand.

First, it is not an inconsistency with the BB theory. At worst, it is an issue about when and how galaxies form.

Second, once there are stars (see where it says 'first stars'?), galaxies can form. The galaxies on the left are the *modern* galaxies, not the first galaxies.

Third, nucleosynthesis is over on the far right. it has nothing to do with galaxy formation other than providing the raw materials from which stars are formed.

Fourth, you say the BB is nonsense while claiming things fall because of air pressure? REALLY? ( I notice you still haven't said what you expect to happen to an apple in a vacuum on Earth).

 

[Native]

Native said: ↑
You¨re simply confusing the atomic E&M binding of particles as weight and then you´re confusing this weight to contain your illusive "gravity".

No, you are the one confusing weight (the force downward from gravity) as something produced by E&M effects. I have to say it is very unclear how you get that.

Once again then:
I said:
Oh, so it´s your gravity which causes water and mercury colums to rise and fall in changing atmospheric pressures? So "gravity" isn´t a constant force? Or is it that your gravity works both ways?

How is it that you´re having difficulties including other natural phenomenons but "gravity"

 

[exchemist]

Yes, anything with z>1.46 corresponds to a recessional velocity >c. I think the current limit for a red shift for a galaxy is 11.1.

The following article is a bit technical, but goes into a lot of misconceptions that are around about the BB model:

https://www.cambridge.org/core/serv...uperluminal-expansion-of-the-universe-div.pdf

(Thanks to @ChristineM for the reference)

Many of the misconceptions are common in the popular literature. Some are even common among physicists. if you can push through it, this is a very good article to clear up confusion.

One big issue is the notion of co-moving coordinates. if we imagine the universe expanding, we can set up coordinates where objects moving with the expansion have a fixed spatial coordinate. This is not a 'true' distance coordinate, but it can simplify the math considerably. Many times, the picture simplifies in comoving coordinates and allows a better understanding of what is going on.

Aha, thank you very much. (Thanks also to @ChristineM )

I see that for relatively low redshifts, the Special Relativistic Doppler formula gives practically the same result as the (more correct) GR formula. Indeed it looks as if Hubble himself used the SR Doppler formula when he first came up with Hubble's Law (and his eponymous constant), back in 1929. So Hubble gave us the idea that the redshift indicated recession velocity, but it was only a bit later that this idea was re-interpreted, in the light of GR, as actually not being due to a relativistic Doppler shift after all.

The key point, as I now understand it, seems to be that SR forbids anything to move with a velocity >c in a given inertial frame of reference. However, the idea that space itself expands implies that objects far from an observer are not in the inertial frame of reference of the observer, so all bets are off as far as SR is concerned. So we can, in fact, see light from objects receding from us at >c, counterintuitive though this may seem.

I must say I have not fully taken in the meaning of the diagrams yet, but I get the general idea. I think.

P.S. @ben d , this may go some way to answering your earlier question to me that I could not answer before.

 

[Native]

First, it is not an inconsistency with the BB theory. At worst, it is an issue about when and how galaxies form.

I certainly also would call it an issue when at theory is contradicted.

All I do is to quote scientific article and so should you - if you dare to find articles in which the scientists themselves asks serious questions to the standing cosmology.

 

[Native]

See: #1017. If you have a vacuum on one side, then you don't have air pressure on that side. Air pressure, of course, only exists because of gravity pulling it towards the Earth. If there was no gravity, you couldn't even have an atmosphere at all, why do you think the air doesn't just drift off into space?

If I´ve not seen a circular argument before, I thank you for providing it now.

What about providing the answer to why your "gravity atmospheric pressure" is constantly changing?

 

[Polymath257]

Once again then:
I said:
Oh, so it´s your gravity which causes water and mercury colums to rise and fall in changing atmospheric pressures? So "gravity" isn´t a constant force? Or is it that your gravity works both ways?

The gravitational force is proportional to the masses involved. it is the air pressure that is producing a force *upwards*. That force upwards is countered by the gravitational force *downwards*. The point of balance happens when the gravitational force on the column balances the air pressure on the exposed liquid since there is no pressure at the top.

So, the weight of the column of liquid is equal to the weight of the air above the liquid.

How is it that you´re having difficulties including other natural phenomenons but "gravity"

I am not the one having difficulties. It seems you don't understand the basics of air pressure in addition to you lack of understanding of E&M and cosmology.

And, frankly, if your understanding of even the basics is this bad, then there is really no hope of you understanding anything done in the last 400 years in physics.

 

[Polymath257]

I certainly also would call it an issue when at theory is contradicted.

But that is my point. Nothing about the BB was contradicted. At worst, we have to change ideas about the formation of galaxies. But that is NOT part of the BB model.

All I do is to quote scientific article and so should you - if you dare to find articles in which the scientists themselves asks serious questions to the standing cosmology.

Actually, you have not quoted any scientific articles. You have quoted popular accounts. if you have questions about the BB model, look at the article I liked to above. It gives a fair amount of detail and clears up many misconceptions about the BB model.

 

[Polymath257]

If I´ve not seen a circular argument before, I thank you for providing it now.

Waht about providing the answer to why your "gravity atmospheric pressure" is constantly changing?

What makes you think it has to?

PS: I see what you are saying.

Um, it changes because the weight of the atmosphere above the point changes. Hot air is less dense than cold air, for example. That causes small changes to the overall weight of the air and thereby of the air pressure.

it is the gravitational force of the air above the manometer that matters. It the mass goes down, so does the weight.

Do you really not understand this?

 

[ratiocinator]

If I´ve not seen a circular argument before, I thank you for providing it now.

Firstly, you didn't answer my question: why do you think we have an atmosphere at all without gravity to hold it in place? Secondly, in what way do you think the argument is in any way circular?

Waht about providing the answer to why your "gravity atmospheric pressure" is constantly changing?

It doesn't change all that much but the variations are due to wind velocity and density variations due, for example, to temperature and composition, there are also tidal effects. None of this is secret, if you're interested look it up. Air pressure and gravity are school level science.

 

[Native]

The gravitational force is proportional to the masses involved. it is the air pressure that is producing a force *upwards*. That force upwards is countered by the gravitational force *downwards*. The point of balance happens when the gravitational force on the column balances the air pressure on the exposed liquid since there is no pressure at the top.

So, the weight of the column of liquid is equal to the weight of the air above the liquid.

No matter how much you´re jumping around in the scientific circus of assumptions and it´s concensus answers, you STILL have to explain logically your postulated "connection of gravity/weight of air with the frequently changes in atmospheric pressure" which is scientific defined as "weight of air!

If you stubbornly make such a connection, you also have to accept that your beloved "little-g" also is nothing more but just another assumption in the all too long row of other irrelevant assumptions in modern cosmology.

 

[Polymath257]

No matter how much you´re jumping around in the scientific circus of assumptions and it´s concensus answers, you STILL have to explain logically your postulated "connection of gravity/weight of air with the frequently changes in atmospheric pressure" which is scientific defined as "weight of air!

If you stubbornly make such a connection, you also have to accept that your beloved "little-g" also is nothing more but just another assumption in the all too long row of other irrelevant assumptions in modern cosmology.

I notice you still haven't said what would happen to an apple in a vacuum. Will it fall or not? Why?

 

[gnostic]

Did you study the posted image at all? Because galaxies are assumed to be the latest to be formed from gas and particles in 13.8 bill. year old BB Nucleosynthesis and not just about 400 mill. after a beginning.

This inconsistency in the BB Theory just accurs logically because the entire idea is nonsens in the first hand.

You do realise that the image only provide a general and therefore oversimplification of the universe timeline.

Not all the galaxies formed together after few hundreds of millions years. Some galaxies formed early, while others formed at later time lines, the same with stars forming at different times of the timeline.

Beside that, before the earliest star formation of stars, after the Big Bang Nucleosynthesis and after the Recombination Epoch, there were no atoms heavier than lithium.

Only hydrogen, deuterium, helium and lithium existed before the earliest generation of stars formed, there were only hydrogen and helium gases, no dusts.

You talk of galaxies and stars forming out of gases and dust. That’s incorrect.

Stars only produce heavier elements through mainly two general types of nucleosynthesis:

1. Stellar Nucleosynthesis: this type of nucleosynthesis generally occurred at the stars’ cores, where extreme heat and density of the core will cause hydrogen atoms to fuse and produce elements. What types of heavier elements are fused through nucleosynthesis is dependent on the total masses of stars, so there are number of different types of Stellar Nucleosynthesis. For examples:

• Stars with similar masses as our sun, will produce helium. This type is called Proton-Proton Chain Reaction nucleosynthesis.
• More massive stars could hydrogen to elements in cycle of carbon to nitrogen to oxygen, over and over again. This type is called CNO Cycle.
• There are many more, of which some I don’t really understand.

1. Supernova Nucleosynthesis: the energy produced from explosions of massive stars will produce many different heavier elements - not just helium, carbon, nitrogen and oxygen - but also nickel, iron, lead, etc.

My point, is that dust only started appearing when massive stars started dying, in supernova events, hence dust are one of the stuff produced from Supernova Nucleosynthesis.

So to summarize: The first generation of stars formed without any dust, because the Big Bang Nucleosynthesis and Recombination Epoch produce only light atoms from hydrogen to lithium, with no dust.

Only with the next generations of stars were they produced from gases and heavier elements, including dusts.

 

[ChristineM]

You do realise that the image only provide a general and therefore oversimplification of the universe timeline.

Not all the galaxies formed together after few hundreds of millions years. Some galaxies formed early, while others formed at later time lines, the same with stars forming at different times of the timeline.

Beside that, before the earliest star formation of stars, after the Big Bang Nucleosynthesis and after the Recombination Epoch, there were no atoms heavier than lithium.

Only hydrogen, deuterium, helium and lithium existed before the earliest generation of stars formed, there were only hydrogen and helium gases, no dusts.

You talk of galaxies and stars forming out of gases and dust. That’s incorrect.

Stars only produce heavier elements through mainly two general types of nucleosynthesis:

1. Stellar Nucleosynthesis: this type of nucleosynthesis generally occurred at the stars’ cores, where extreme heat and density of the core will cause hydrogen atoms to fuse and produce elements. What types of heavier elements are fused through nucleosynthesis is dependent on the total masses of stars, so there are number of different types of Stellar Nucleosynthesis. For examples:

• Stars with similar masses as our sun, will produce helium. This type is called Proton-Proton Chain Reaction nucleosynthesis.
• More massive stars could hydrogen to elements in cycle of carbon to nitrogen to oxygen, over and over again. This type is called CNO Cycle.
• There are many more, of which some I don’t really understand.

1. Supernova Nucleosynthesis: the energy produced from explosions of massive stars will produce many different heavier elements - not just helium, carbon, nitrogen and oxygen - but also nickel, iron, lead, etc.

My point, is that dust only started appearing when massive stars started dying, in supernova events, hence dust are one of the stuff produced from Supernova Nucleosynthesis.

So to summarize: The first generation of stars formed without any dust, because the Big Bang Nucleosynthesis and Recombination Epoch produce only light atoms from hydrogen to lithium, with no dust.

Only with the next generations of stars were they produced from gases and heavier elements, including dusts.

I can add a bit to that. First generation stars only fused the first few elements (up to carbon i think). During the life of second generation stars more, heavier elements are produced, up to iron. No element heavier than iron is ever formed until a star dies. Once a star begins to fuse iron it is the stars deathnell. A stars death is dependent on its size. It is during the death throws of the star that heavier elements than iron are formed. Only the heaviest elements are formed in a supernova

 

[Ben Dhyan]

Native et al, have you heard of the hypothesis wrt ZPE being the source of gravity? Here are a couple of papers that, if I understand them correctly, are suggesting something like that, can anyone comment on their credibility?

https://www.researchgate.net/public...y_and_the_Emergence_of_Gravity_Two_Hypotheses

Gravity and Zero Point Energy - ScienceDirect

 

[Native]

Native said: ↑
No matter how much you´re jumping around in the scientific circus of assumptions and it´s concensus answers, you STILL have to explain logically your postulated "connection of gravity/weight of air with the frequently changes in atmospheric pressure" which is scientific defined as "weight of air!

I notice you still haven't said what would happen to an apple in a vacuum. Will it fall or not? Why?

Why should I at all? There is no such vacuum in space.

You can take off explaining which strong dwarf is sitting in the center of the Earth pulling at everything, even far out in space.

 

[ratiocinator]

No matter how much you´re jumping around in the scientific circus of assumptions and it´s concensus answers, you STILL have to explain logically your postulated "connection of gravity/weight of air with the frequently changes in atmospheric pressure" which is scientific defined as "weight of air!

I already pointed out some of the reasons (#1033). Air pressure at a given area is the weight of the column of air above it. Air isn't static (it "sloshes around" due to all sorts of effects) and doesn't have a constant composition (most obviously, it can have more or less moisture). The pressure at sea level is actually pretty constant and the variations are relatively small.

On the other side of the coin, you have explained exactly nothing to do with air pressure without gravity. You haven't even explained why air doesn't all float off into space or anything about how it comes to have pressure at the surface at all.

If you're going to rewrite basic science like this, you've got a lot of work to do and you don't seem to have even started.