Mola, that's the way it should be constructed, since one should set up a coordinate system for one's own convenience.
Does dark matter actually exist?
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Originally Posted By: MolaKule
First of all Al, I was merely dissecting and criticizing the article, not you. No need to personalize this.
Understand..I sometimes get carried away
And really, like I said, at the deepest level we may be so far away from the real answer that it may never be possible to unravel it. I am betting that Occam's Razor may not be applicable. And folks that immediately rule out things like we/universe are a Holograph and or more than 4 dimensions are impossible do so be it doesn't "make sense".
Exciting times.
First of all Al, I was merely dissecting and criticizing the article, not you. No need to personalize this.
Understand..I sometimes get carried away
And really, like I said, at the deepest level we may be so far away from the real answer that it may never be possible to unravel it. I am betting that Occam's Razor may not be applicable. And folks that immediately rule out things like we/universe are a Holograph and or more than 4 dimensions are impossible do so be it doesn't "make sense".
Exciting times.
Originally Posted By: Al
And really, like I said, at the deepest level we may be so far away from the real answer that it may never be possible to unravel it. I am betting that Occam's Razor may not be applicable. And folks that immediately rule out things like we/universe are a Holograph and or more than 4 dimensions are impossible do so be it doesn't "make sense".
It feels like the Universe is there to never give us the answer.
We look further out than we ever could before and see more new stuff. We look further in (and colliders are that), and we see more new stuff.
And really, like I said, at the deepest level we may be so far away from the real answer that it may never be possible to unravel it. I am betting that Occam's Razor may not be applicable. And folks that immediately rule out things like we/universe are a Holograph and or more than 4 dimensions are impossible do so be it doesn't "make sense".
It feels like the Universe is there to never give us the answer.
We look further out than we ever could before and see more new stuff. We look further in (and colliders are that), and we see more new stuff.
Since I was a kid, I've struggled with the idea of "What's outside the universe?"
When I'd ask my parents, not wanting to get into a long discussion about it, they'd reply simply, "It's infinite". It goes on forever. Well, for all intents and purposes, it is pretty infinite...to a human being with a lifespan of 100 years. But really...it's not. There has to be something outside of the realm we and all the galaxies occupy. I've heard the analogy of a bathtub full of bubbles with our universe being one of the bubbles. For all I know, that crude analogy could be fairly accurate.
When I'd ask my parents, not wanting to get into a long discussion about it, they'd reply simply, "It's infinite". It goes on forever. Well, for all intents and purposes, it is pretty infinite...to a human being with a lifespan of 100 years. But really...it's not. There has to be something outside of the realm we and all the galaxies occupy. I've heard the analogy of a bathtub full of bubbles with our universe being one of the bubbles. For all I know, that crude analogy could be fairly accurate.
Originally Posted By: Triple_Se7en
Originally Posted By: Nick1994
Originally Posted By: Merkava_4
It's a bunch of hokus pokus [censored]. Don't buy into it.
Yeah, and the world is 6,000 years old right?
Whoever said the world is 6K years-old? Where did you get that from?
My next door neighbor relating to me what his pastor told him. He also sold all his investments in 1999 expecting that the world economy would collapse when 1/1/2000 rolled around due to computers no being programmed for the change. Nothing happened. According to him, the universe is still 6000 years old.
Originally Posted By: Nick1994
Originally Posted By: Merkava_4
It's a bunch of hokus pokus [censored]. Don't buy into it.
Yeah, and the world is 6,000 years old right?
Whoever said the world is 6K years-old? Where did you get that from?
My next door neighbor relating to me what his pastor told him. He also sold all his investments in 1999 expecting that the world economy would collapse when 1/1/2000 rolled around due to computers no being programmed for the change. Nothing happened. According to him, the universe is still 6000 years old.
Originally Posted By: john_pifer
Since I was a kid, I've struggled with the idea of "What's outside the universe?"
. But really...it's not. There has to be something outside of the realm we and all the galaxies occupy.
Great minds think alike. I wondered that when I was a kid. There is no "outside" our universe bc there is no space "beyond" it.
The truly great question is how many "universes" exist. And "infinite" really doesn't work for me. There "must" be a number... then again.............
Since I was a kid, I've struggled with the idea of "What's outside the universe?"
. But really...it's not. There has to be something outside of the realm we and all the galaxies occupy.
Great minds think alike. I wondered that when I was a kid. There is no "outside" our universe bc there is no space "beyond" it.
The truly great question is how many "universes" exist. And "infinite" really doesn't work for me. There "must" be a number... then again.............
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Originally Posted By: Al
Originally Posted By: john_pifer
Since I was a kid, I've struggled with the idea of "What's outside the universe?"
. But really...it's not. There has to be something outside of the realm we and all the galaxies occupy.
Great minds think alike. I wondered that when I was a kid. There is no "outside" our universe bc there is no space "beyond" it.
The truly great question is how many "universes" exist. And "infinite" really doesn't work for me. There "must" be a number... then again.............
Just no real basis for all that, just speculation. Sorta like Occam's Razor on how many angels can dance on the head of a pin.
What's really amazing about the current universe is that it's expanding so fast that there are galaxies moving away from us at such speeds that even if you had light speed, you'd never be able to reach them. Eventually you won't even be able to see the light from them and the local universe gets darker in a few billion years. There are probably galaxies further away than we can actually see.
And let's not even talk about the pending collision of our galaxy with the Andromeda galaxy in about 4 billion years.
Originally Posted By: john_pifer
Since I was a kid, I've struggled with the idea of "What's outside the universe?"
. But really...it's not. There has to be something outside of the realm we and all the galaxies occupy.
Great minds think alike. I wondered that when I was a kid. There is no "outside" our universe bc there is no space "beyond" it.
The truly great question is how many "universes" exist. And "infinite" really doesn't work for me. There "must" be a number... then again.............
Just no real basis for all that, just speculation. Sorta like Occam's Razor on how many angels can dance on the head of a pin.
What's really amazing about the current universe is that it's expanding so fast that there are galaxies moving away from us at such speeds that even if you had light speed, you'd never be able to reach them. Eventually you won't even be able to see the light from them and the local universe gets darker in a few billion years. There are probably galaxies further away than we can actually see.
And let's not even talk about the pending collision of our galaxy with the Andromeda galaxy in about 4 billion years.
Originally Posted By: Wolf359
Al said:
Beings with brains three times bigger than optimal will always come up with questions they may never be able to answer.An encephalisation quotient of three is sometimes dowwnright maddening when you don't have all the tools needed to come up with an answer.
Originally Posted By: fdcg27
Originally Posted By: KrisZ
Dark matter is measurable? That's news to me. I thought that it was the measurements of things we can measure, like rotational speed of galaxies, did not makes sense and it led to the concept of dark matter.
Inventing things to make the existing concepts work smacks of R.
Dark matter is of course not measurable.
The mass required to make our existing models of the mechanics work is calculable, though.
It's a plug number, as my wife had it.
Yes, but like a plug number it's not pulled out of thin air. The plug number in accounting totals the missing or excess money (invoices lost, or stuff that got stolen etc). You don't know where it went or came from but it's real enough.
Originally Posted By: KrisZ
Dark matter is measurable? That's news to me. I thought that it was the measurements of things we can measure, like rotational speed of galaxies, did not makes sense and it led to the concept of dark matter.
Inventing things to make the existing concepts work smacks of R.
Dark matter is of course not measurable.
The mass required to make our existing models of the mechanics work is calculable, though.
It's a plug number, as my wife had it.
Yes, but like a plug number it's not pulled out of thin air. The plug number in accounting totals the missing or excess money (invoices lost, or stuff that got stolen etc). You don't know where it went or came from but it's real enough.
Originally Posted By: MolaKule
There have been many fudge factors introduced in Astronomy to keep the status quo and to make the equations appear valid.
Dark Matter and Dark Energy are not new fudge factor concepts.
Around 1890, it was observed that Mercury’s orbit was being perturbed and some unknown agency was involved.
Specifically, Mercury’s perihelion ( https://en.wikipedia.org/wiki/Perihelion_and_aphelion ) was advancing 43 seconds of arc per century and could not be explained by Newtonian orbital mechanics.
The solution was to propose some form of “dark” matter which could not be seen, such as the planet “Vulcan” or an asteroid belt. Astronomers ignored the fact that a mass associated with Mercury would have a shorter orbital period than Earth.
In 1915 Einstein’s General Theory of Relativity solved the problem and was able to calculate precisely the anomalous 43 arc-seconds perturbation. Thus, Dark Matter was no longer needed.
Newton’s equation for mass, M = v^2*R/G, is still used by astronomers today to determine masses outside our solar system, where M = mass, v is the velocity of the orbital body, and R is the distance between the star and the orbiting body.
Masses can also be inferred from the amount of visible luminous material seen and measured from telescopes.
The problem is, Newton’s M and the mass inferred from visible luminous material doesn’t agree.
From Newton’s M (dynamical considerations) there appears to be more mass than from the “inferred” method, and this is called the M/L ratio. The problem with this ratio is that the calculated Mass/Luminosity ratio can vary between 2 and 600.
Since there is such a wide variation in this ratio, something was needed to make this wildly varying ratio fit the cosmological theories. So Dark Matter was re-introduced.
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density? No wonder this relationship varies so much. Even the density of the planets in our own solar system vary wildly. Earth is the most dense at ~5.51 g/cc with Saturn having the lowest density of ~0.687 g/cc...and that much variation is just in our own solar system. It doesn't seem like a wise idea to estimate the mass in this manner.
There have been many fudge factors introduced in Astronomy to keep the status quo and to make the equations appear valid.
Dark Matter and Dark Energy are not new fudge factor concepts.
Around 1890, it was observed that Mercury’s orbit was being perturbed and some unknown agency was involved.
Specifically, Mercury’s perihelion ( https://en.wikipedia.org/wiki/Perihelion_and_aphelion ) was advancing 43 seconds of arc per century and could not be explained by Newtonian orbital mechanics.
The solution was to propose some form of “dark” matter which could not be seen, such as the planet “Vulcan” or an asteroid belt. Astronomers ignored the fact that a mass associated with Mercury would have a shorter orbital period than Earth.
In 1915 Einstein’s General Theory of Relativity solved the problem and was able to calculate precisely the anomalous 43 arc-seconds perturbation. Thus, Dark Matter was no longer needed.
Newton’s equation for mass, M = v^2*R/G, is still used by astronomers today to determine masses outside our solar system, where M = mass, v is the velocity of the orbital body, and R is the distance between the star and the orbiting body.
Masses can also be inferred from the amount of visible luminous material seen and measured from telescopes.
The problem is, Newton’s M and the mass inferred from visible luminous material doesn’t agree.
From Newton’s M (dynamical considerations) there appears to be more mass than from the “inferred” method, and this is called the M/L ratio. The problem with this ratio is that the calculated Mass/Luminosity ratio can vary between 2 and 600.
Since there is such a wide variation in this ratio, something was needed to make this wildly varying ratio fit the cosmological theories. So Dark Matter was re-introduced.
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density? No wonder this relationship varies so much. Even the density of the planets in our own solar system vary wildly. Earth is the most dense at ~5.51 g/cc with Saturn having the lowest density of ~0.687 g/cc...and that much variation is just in our own solar system. It doesn't seem like a wise idea to estimate the mass in this manner.
People who say things like dark matter, nasa, and science in general aren't worthy of funding or investigating and bring us no real advantages are just unfathomably ignorant...
Originally Posted By: DriveHard
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density?
Mass is based on star structure..pretty well known bc of Quantum Mechanics.
Originally Posted By: FordCapriDriver
People who say things like dark matter, nasa, and science in general aren't worthy of funding or investigating and bring us no real advantages are just unfathomably ignorant...
Stick to just driving Vehicles..Science ain't your strength. Leave that thinking to others.
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density?
Mass is based on star structure..pretty well known bc of Quantum Mechanics.
Originally Posted By: FordCapriDriver
People who say things like dark matter, nasa, and science in general aren't worthy of funding or investigating and bring us no real advantages are just unfathomably ignorant...
Stick to just driving Vehicles..Science ain't your strength. Leave that thinking to others.
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Triple_Se7en
$50 Site Donor 2024
Originally Posted By: FordCapriDriver
People who say things like dark matter, nasa, and science in general aren't worthy of funding or investigating and bring us no real advantages are just unfathomably ignorant...
I agree!
''Learning Something New Everyday'' is more than just a saying!
We shouldn't worry about dark matter ever reaching as far as the Golden Gates either. That place at least 125 Million light years away.
People who say things like dark matter, nasa, and science in general aren't worthy of funding or investigating and bring us no real advantages are just unfathomably ignorant...
I agree!
''Learning Something New Everyday'' is more than just a saying!
We shouldn't worry about dark matter ever reaching as far as the Golden Gates either. That place at least 125 Million light years away.
MolaKule
Staff member
Quote:
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density? No wonder this relationship varies so much.
First an "OMEGAm" factor is determined (from the Schwarzchild Radius of the present universe) in which OMEGAm = 0.0401. Then the universe rest mass Mo is calculated from
Mo = OMEGAm*(c^3*tau/2G) = 1.74x10^21 Solar Masses. Multiply that by 2X10^30 kg and you get the total average rest mass of the Universe.
The average matter density is then calculated to be 3.92^-31 grams/cubic centimeter.
Here are some excerpts from an Astrophysical Article:
Quote:
MASS-TO-LIGHT RATIOS OF E AND S0 GALAXIES
Three basic methods can be used to determine the mass and mass-to-light ratio of a spheroidal stellar system. The first of these utilizes the global virial theorem, extensively discussed by Poveda in 1958:
Equations for calculation involve theoretical parameters which are far removed from observed quantities. for example is usually estimated from the observed line-of-sight velocity dispersion (sigma) in the nucleus by assuming that sigma2 is constant throughout the galaxy, an assumption usually not supported by any observational data. The estimate of the total potential energy Omega is likewise subject to great uncertainty. It is generally assumed that the light distribution is an adequate tracer of the mass and that the luminosity profiles of most ellipticals are similar
The virial theorem thus leads to uncertain results basically because it treats the whole galaxy, including the poorly understood outer regions. To circumvent this difficulty, King has devised a second method to determine M / L; this method is based on stellar hydrodynamical equations applied to the core only. The observational data required include the central surface brightness, core radius (the point where surface brightness drops to 1/2 of central value), and core line-of-sight velocity dispersion. From these one determines the core density and core mass-to-light ratio. Total mass is not derived. The method assumes only that the nuclear velocity distribution is Gaussian and isotropic with constant sigma over the core region, in agreement with the properties of model star clusters whose cores closely resemble the nuclear regions of elliptical galaxies (King 1966). Young et al. (1978) and Sargent et al. (1978) have developed a similar formalism which is applicable to regions outside the core.
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density? No wonder this relationship varies so much.
First an "OMEGAm" factor is determined (from the Schwarzchild Radius of the present universe) in which OMEGAm = 0.0401. Then the universe rest mass Mo is calculated from
Mo = OMEGAm*(c^3*tau/2G) = 1.74x10^21 Solar Masses. Multiply that by 2X10^30 kg and you get the total average rest mass of the Universe.
The average matter density is then calculated to be 3.92^-31 grams/cubic centimeter.
Here are some excerpts from an Astrophysical Article:
Quote:
MASS-TO-LIGHT RATIOS OF E AND S0 GALAXIES
Three basic methods can be used to determine the mass and mass-to-light ratio of a spheroidal stellar system. The first of these utilizes the global virial theorem, extensively discussed by Poveda in 1958:
Equations for calculation involve theoretical parameters which are far removed from observed quantities. for example is usually estimated from the observed line-of-sight velocity dispersion (sigma) in the nucleus by assuming that sigma2 is constant throughout the galaxy, an assumption usually not supported by any observational data. The estimate of the total potential energy Omega is likewise subject to great uncertainty. It is generally assumed that the light distribution is an adequate tracer of the mass and that the luminosity profiles of most ellipticals are similar
The virial theorem thus leads to uncertain results basically because it treats the whole galaxy, including the poorly understood outer regions. To circumvent this difficulty, King has devised a second method to determine M / L; this method is based on stellar hydrodynamical equations applied to the core only. The observational data required include the central surface brightness, core radius (the point where surface brightness drops to 1/2 of central value), and core line-of-sight velocity dispersion. From these one determines the core density and core mass-to-light ratio. Total mass is not derived. The method assumes only that the nuclear velocity distribution is Gaussian and isotropic with constant sigma over the core region, in agreement with the properties of model star clusters whose cores closely resemble the nuclear regions of elliptical galaxies (King 1966). Young et al. (1978) and Sargent et al. (1978) have developed a similar formalism which is applicable to regions outside the core.
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MolaKule
Staff member
OMEGAm is the present-epoch, Matter-Density factor = 0.0401.
MolaKule
Staff member
Originally Posted By: Al
Originally Posted By: DriveHard
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density?
Mass is based on star structure..pretty well known bc of Quantum Mechanics.
Physicists Robert Oppenheimer, Subrahmanyan Chandrasekhar, and Friedrich Hund developed some of the early conceptual theories of Quantum Mechanics as they related to star physics, but mass was not part of their core studies; their core studies involved the structure of stars and dense matter under extreme conditions.
Originally Posted By: DriveHard
Mola, who came up with the idea to estimate mass based on luminous material visible? Isn't this just estimating the volume based on a diameter, then estimating the mass given some arbitrary density?
Mass is based on star structure..pretty well known bc of Quantum Mechanics.
Physicists Robert Oppenheimer, Subrahmanyan Chandrasekhar, and Friedrich Hund developed some of the early conceptual theories of Quantum Mechanics as they related to star physics, but mass was not part of their core studies; their core studies involved the structure of stars and dense matter under extreme conditions.
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