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Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: guest39538 on 15/04/2016 09:00:16

Title: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 15/04/2016 09:00:16
I keep hearing the Universe is expanding in comparison to like a balloon inflating, the evidence an apparent red shift observed of matter. We do not observe space red shifting we only observe light/matter interaction red shift, so how from that do you conclude the Universe is expanding when that makes no logical sense or is a any sort of rational thought?
I read this morning that it is now expanding faster than we first thought and soon and the Universe will become cold and the Universe will end, how on Earth doe's any one derive that ?



Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: puppypower on 15/04/2016 12:46:17
In the lab, we can start with a block of mass, divide it into two, separate the two pieces, we can alter the local space-time near the mass. This is an example of lowering mass density leading local space-time to expand using the math of GR. This is mass leading space-time.

I have never heard of any demonstrated lab experiment where we start by expanding space-time first, then the mass follows, without using bigger mass, to move the smaller mass. This is supposed to happen, in the universe, via dark energy. However, we haven't shown dark energy in the lab either, so we can use this dark energy to do the first experiment.

It is not clear to me why we explain the expanding universe, with a space-time first approach, if we can't demonstrate this in the lab. I am not saying it can't be true. However, this is in violation of the scientific method. It is not like those in charge of the task are poor humble scientists, who don't have access to resources.

One way to maintain a version of the current theory; apparent space-time first, while having mass leading; paradox, is to use one new assumption. The forces of nature, such as EM and the strong and weak nuclear forces, give off energy when they lower potential. If gravity is a force, like the other three forces, then the lowering of gravitational potential; compaction, should give off some type of energy.

When an electron lowers potential via the EM force and gives off energy, this energy can be used to excite an electron in another atom. Relative to gravity, if the lowering of gravitational potential gives off energy, this energy output should be able to increase the gravitational potential elsewhere; expansion. Such an exothermic output from gravity, may be the source of dark energy.

One observation that strongly suggests there is an exothermic output from gravity, is connected to rotation. When a cloud of space gas and debris collapses to form a star or even a galaxy, there is rotation. It does not typically collapse only to center. Rotation creates centrifugal force, which causes the matter to want to fly outward, away from the center of gravity. This is not anti-gravity, per se, but it creates a force vector opposite the direction gravity, in the proper direction for the action-reaction one would expect from of an exothermic output based on gravity lowering potential.

The expansion of the universe, relative to the galaxies, would imply that galaxies are the most potent central centers for the exothermic output from gravity lowering potential.

This is my experimental prediction. Since we are in an accelerated expansion phase, then I predict that there are more stars and other gravity bound objects forming today, than in the past. This will accelerate the exothermic output. Someone else can do the compiling of data. I don't have the access.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 15/04/2016 13:36:42
In the lab, we can start with a block of mass, divide it into two, separate the two pieces, we can alter the local space-time near the mass. This is an example of lowering mass density leading local space-time to expand using the math of GR. This is mass leading space-time.

I have never heard of any demonstrated lab experiment where we start by expanding space-time first, then the mass follows, without using bigger mass, to move the smaller mass. This is supposed to happen, in the universe, via dark energy. However, we haven't shown dark energy in the lab either, so we can use this dark energy to do the first experiment.

It is not clear to me why we explain the expanding universe, with a space-time first approach, if we can't demonstrate this in the lab. I am not saying it can't be true. However, this is in violation of the scientific method. It is not like those in charge of the task are poor humble scientists, who don't have access to resources.

One way to maintain a version of the current theory; apparent space-time first, while having mass leading; paradox, is to use one new assumption. The forces of nature, such as EM and the strong and weak nuclear forces, give off energy when they lower potential. If gravity is a force, like the other three forces, then the lowering of gravitational potential; compaction, should give off some type of energy.

When an electron lowers potential via the EM force and gives off energy, this energy can be used to excite an electron in another atom. Relative to gravity, if the lowering of gravitational potential gives off energy, this energy output should be able to increase the gravitational potential elsewhere; expansion. Such an exothermic output from gravity, may be the source of dark energy.

One observation that strongly suggests there is an exothermic output from gravity, is connected to rotation. When a cloud of space gas and debris collapses to form a star or even a galaxy, there is rotation. It does not typically collapse only to center. Rotation creates centrifugal force, which causes the matter to want to fly outward, away from the center of gravity. This is not anti-gravity, per se, but it creates a force vector opposite the direction gravity, in the proper direction for the action-reaction one would expect from of an exothermic output based on gravity lowering potential.

The expansion of the universe, relative to the galaxies, would imply that galaxies are the most potent central centers for the exothermic output from gravity lowering potential.

This is my experimental prediction. Since we are in an accelerated expansion phase, then I predict that there are more stars and other gravity bound objects forming today, than in the past. This will accelerate the exothermic output. Someone else can do the compiling of data. I don't have the access.

Well my issues with it are a lot less complex, my issue is that space itself is not made of anything, I can't see how nothing can expand and expanding into what exactly, oblivion?


We also do not actually observe space red shifting and we do not observe dark energy.


Are we sure that it is not the radius of light that is expanding between two point sources?

Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: RobC on 16/04/2016 11:31:23
Perhaps a silly question but as space expands does this mean that the distance between the earth and the sun is increasing?
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 16/04/2016 11:58:44
Perhaps a silly question but as space expands does this mean that the distance between the earth and the sun is increasing?


The length of space between the Earth and the Sun is a variant because of orbital path, only if the orbit was a perfect circle would the length remain the same.

Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: puppypower on 16/04/2016 13:27:13

Well my issues with it are a lot less complex, my issue is that space itself is not made of anything, I can't see how nothing can expand and expanding into what exactly, oblivion?

We also do not actually observe space red shifting and we do not observe dark energy.

Are we sure that it is not the radius of light that is expanding between two point sources?

Let me explain this with an analogy. Say you are on a rocket, ready to launch. After launch, you keep accelerating until finally you  approach the speed of light. According to special relativity, if you look out your window, you will see universal space-time appear to contract more and more. At the speed of light, the universe will appear to be contracted to a point.

Say you have finally reached your destination and you apply the breaks and begin to decelerate. If you look out your window, now it will appear like the universe is expanding. The bulk universe is not expanding. Rather the universe appears to be expanding relative to your rocket reference. The same universal space and time is there from launch, during acceleration toward C, and then also during deceleration. What changed was connected to another layer of superimposed space-time connected to special relativity, associated with only your rocket reference.

The following was my first original theory in cosmology back in 1987.

Say we start with the singularity of the BB. If this singularity began as pure energy, its reference would exist at the speed of light. This is because energy moves at C. Therefore the universe, no matter big or small, would appear like a point-instant, if we sat on any photon of energy; rocket reference. If we began to slow reference to below C; energy condenses into mass which cannot move at C, the universe would now appear to expand, from the POV of all the mass reference points. Mass cannot move at the speed of light so it can't see a point universe perception.

The net affect is a reference in reference affect. The current model assumes a single universal reference created by the BB, which leads to the question, how can space, which by definition is nothing, increase? With a reference in reference model nothing new ever has to be created.  It is all about the reveal of the primary, from the slow down reference of the secondary. 

This is much easier to prove in the lab because it is consistent with special relativity and the experiment used to prove SR; reference in reference; particle collider reference and particle reference.

I also had a second related theory;

Reference in reference has another application, at the micro-level. The second question I asked myself was, why do the sub particles of protons last so long, whereas if we collide protons and release these same sub particles, the life expectancy of the sub particles fall drastically? Both scenarios are made of the same sub-particles, yet the sub-particles last orders of magnitude longer, if they remain contained in the proton; billions of years if contained versus fraction of a second if released.

One simple answer was the sub particles in the proton have built in time dilation; reference in reference. They still last a fraction of a second in their reference, but due to reference in reference they will last billions of years in our reference. The bulk proton is in our reference and forms atoms and molecules, but inside the proton is a time dilated reference. In the inside reference, time and space are extremely contracted, as inferred by the life expectancy, allowing protons to interact all the way to infinity like this is nearby; gravity and EM. 

Say the inner reference of the proton was to slow, ever so slightly. Since the innards are no longer seeing the universe appear with the same amount of contraction. The means their distant impact via EM and gravity, will get weaker, due to the increase in perceived distances in their  reference. This fall off of force allows matter to clump; galaxies, in a more independent way throughout the universe. This also makes the universe appear to expand from the POV of the innards.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 17/04/2016 11:47:25

Well my issues with it are a lot less complex, my issue is that space itself is not made of anything, I can't see how nothing can expand and expanding into what exactly, oblivion?

We also do not actually observe space red shifting and we do not observe dark energy.

Are we sure that it is not the radius of light that is expanding between two point sources?

Let me explain this with an analogy. Say you are on a rocket, ready to launch. After launch, you keep accelerating until finally you  approach the speed of light. According to special relativity, if you look out your window, you will see universal space-time appear to contract more and more. At the speed of light, the universe will appear to be contracted to a point.

Say you have finally reached your destination and you apply the breaks and begin to decelerate. If you look out your window, now it will appear like the universe is expanding. The bulk universe is not expanding. Rather the universe appears to be expanding relative to your rocket reference. The same universal space and time is there from launch, during acceleration toward C, and then also during deceleration. What changed was connected to another layer of superimposed space-time connected to special relativity, associated with only your rocket reference.

The following was my first original theory in cosmology back in 1987.

Say we start with the singularity of the BB. If this singularity began as pure energy, its reference would exist at the speed of light. This is because energy moves at C. Therefore the universe, no matter big or small, would appear like a point-instant, if we sat on any photon of energy; rocket reference. If we began to slow reference to below C; energy condenses into mass which cannot move at C, the universe would now appear to expand, from the POV of all the mass reference points. Mass cannot move at the speed of light so it can't see a point universe perception.

The net affect is a reference in reference affect. The current model assumes a single universal reference created by the BB, which leads to the question, how can space, which by definition is nothing, increase? With a reference in reference model nothing new ever has to be created.  It is all about the reveal of the primary, from the slow down reference of the secondary. 

This is much easier to prove in the lab because it is consistent with special relativity and the experiment used to prove SR; reference in reference; particle collider reference and particle reference.

I also had a second related theory;

Reference in reference has another application, at the micro-level. The second question I asked myself was, why do the sub particles of protons last so long, whereas if we collide protons and release these same sub particles, the life expectancy of the sub particles fall drastically? Both scenarios are made of the same sub-particles, yet the sub-particles last orders of magnitude longer, if they remain contained in the proton; billions of years if contained versus fraction of a second if released.

One simple answer was the sub particles in the proton have built in time dilation; reference in reference. They still last a fraction of a second in their reference, but due to reference in reference they will last billions of years in our reference. The bulk proton is in our reference and forms atoms and molecules, but inside the proton is a time dilated reference. In the inside reference, time and space are extremely contracted, as inferred by the life expectancy, allowing protons to interact all the way to infinity like this is nearby; gravity and EM. 

Say the inner reference of the proton was to slow, ever so slightly. Since the innards are no longer seeing the universe appear with the same amount of contraction. The means their distant impact via EM and gravity, will get weaker, due to the increase in perceived distances in their  reference. This fall off of force allows matter to clump; galaxies, in a more independent way throughout the universe. This also makes the universe appear to expand from the POV of the innards.

Thank you Puppy for your conversation, it is hard to relate anything you said with the real world and universe.  For example looking out  of a rocket ship window that was travelling at the speed of light, you would see nothing unless you passed parallel a point source. This point source however will relatively pass you faster than you can see it, so it will look visual contracted to a 0 point source.  You would ''see'' it but not really  observe it has a register in your mind.
I also do not understand how you would see space to have contracted, with no points sources we can not observe space and the length we would observe is L0  and blackness.


added - this is the view you see from the rocket ship window at any speed.


* rship.jpg (5.25 kB . 572x522 - viewed 14427 times)

where 0, and n apply?

and L applies if there is a visual point source.




Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: RobC on 17/04/2016 13:16:19
Quote
The length of space between the Earth and the Sun is a variant because of orbital path, only if the orbit was a perfect circle would the length remain the same.

I was asking if the distance between the earth and the sun was changing due to space expanding rather than the shape of the orbit.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 17/04/2016 14:20:10
Quote
The length of space between the Earth and the Sun is a variant because of orbital path, only if the orbit was a perfect circle would the length remain the same.

I was asking if the distance between the earth and the sun was changing due to space expanding rather than the shape of the orbit.


Then it would have to expand and contract because of the length of distance being a variant.  Also space would have be made of something such as an aether.  However we do not really observe space expanding or contracting and I am sure it something to do with the ambiguity of the statements that leaves confusion .   There is a certainty that light expands or contracts, I personally consider space-time must mean light?



Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: JoeBrown on 17/04/2016 14:59:35
Cosmologists like the idea of expansion, kinda hard to get around that fact.  Lambda-CDM is the most accepted theory for the start of the universe.  It requires expansion at the beginning and every bit of observable evidenced goes to support that thesis.

Unfortunately, they use General Relativity to make sense of it all.  GR is incomplete.  It's author died before resolving differences between GR & QM.  He started to make strides in the right direction, but never had the luxury of technology we take for granted.  Nor did he have belief of validity for black holes...

Most ppl don't understand GR well enough to grasp what all it says.  More importantly they don't realize what it doesn't say.

GR states time is variable and speed is constant.  Via experiments, we know light doesn't travel at a fixed speed...  That's a serious flaw in GR, IMO.  We don't know what medium radio/light travels through in space.  We assume it's empty yet these "fields" exist in nothingness...  GR doesn't address that at all. 

GR only describes the path of COM (center of mass) points in space-time through fields of gravity, with gravity and time as variables and speed of light constant.  If photon speed is variable depending on it's medium of traverse and we cannot define the medium of space, we have incomplete understanding of the universe.

So when you hear Pop-Sy say the Universe is expanding...  Don't worry, they don't truly understand everything.  Dark Energy isn't explainable via GR, because GR is incomplete.

Personally I believe Dark Energy is pressure waves...  But that's my belief.  I term it Lambda shift.  Because it can probably go both ways, but we'll never live long enough to see it change much.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 17/04/2016 15:29:02
Cosmologists like the idea of expansion, kinda hard to get around that fact.  Lambda-CDM is the most accepted theory for the start of the universe.  It requires expansion at the beginning and every bit of observable evidenced goes to support that thesis.

Unfortunately, they use General Relativity to make sense of it all.  GR is incomplete.  It's author died before resolving differences between GR & QM.  He started to make strides in the right direction, but never had the luxury of technology we take for granted.  Nor did he have belief of validity for black holes...

Most ppl don't understand GR well enough to grasp what all it says.  More importantly they don't realize what it doesn't say.

GR states time is variable and speed is constant.  Via experiments, we know light doesn't travel at a fixed speed...  That's a serious flaw in GR, IMO.  We don't know what medium radio/light travels through in space.  We assume it's empty yet these "fields" exist in nothingness...  GR doesn't address that at all. 

GR only describes the path of COM (center of mass) points in space-time through fields of gravity, with gravity and time as variables and speed of light constant.  If photon speed is variable depending on it's medium of traverse and we cannot define the medium of space, we have incomplete understanding of the universe.

So when you hear Pop-Sy say the Universe is expanding...  Don't worry, they don't truly understand everything.  Dark Energy isn't explainable via GR, because GR is incomplete.

Personally I believe Dark Energy is pressure waves...  But that's my belief.  I term it Lambda shift.  Because it can probably go both ways, but we'll never live long enough to see it change much.

Thank you Joe, I have looked up the theory, I had not heard of the  -

 https://en.wikipedia.org/wiki/Lambda-CDM_model


Cold is rather contradictory to expansion in my opinion and cold being a direct and equal opposite to expansion, things that are hot expand, shouldn't the correct definition be
the lambda- HDM?

Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: JoeBrown on 17/04/2016 20:01:58
CDM is all about how matter forms.  The CMBR (Cosmic Microwave Background Radiation) is supposed to be evidence of CDM forming massive atoms.  I've come to believe it does require cold to form atoms.  But I believe pressure is required.

Lambda-CDM doesn't say where pressure comes from, can't find an edge to the universe, so there's no exterior walls that we know of...  I've argued expansion requires existence of universe of multiverse qualities then been kicked off scienceforums . net for it...  LOL. 

Those folks there, like throwing Lambda-CDM foobaz in yo face when you say anything against expansion.  Then ask you to show an equation...  Grrr...  I'm working on an equation.  Think I know all that's needed, but my postulation goes against a lot of accepted belief...  So I'm probably not going to prove a thing.

Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 18/04/2016 08:40:06
CDM is all about how matter forms.  The CMBR (Cosmic Microwave Background Radiation) is supposed to be evidence of CDM forming massive atoms.  I've come to believe it does require cold to form atoms.  But I believe pressure is required.

Lambda-CDM doesn't say where pressure comes from, can't find an edge to the universe, so there's no exterior walls that we know of...  I've argued expansion requires existence of universe of multiverse qualities then been kicked off scienceforums . net for it...  LOL. 

Those folks there, like throwing Lambda-CDM foobaz in yo face when you say anything against expansion.  Then ask you to show an equation...  Grrr...  I'm working on an equation.  Think I know all that's needed, but my postulation goes against a lot of accepted belief...  So I'm probably not going to prove a thing.

I also have been on scienceforums.net several times where I got banned several times .   They indeed are some sort of ''religion'' over on that site.  However this site let's us discus things to a degree.  I have had one post I posted twice over a period of time on this site, both times removed , the reasons to me are quite clear but let's not get into that. 
I personally do not agree with a multi-verse quality although I do agree that the single entity Universe beyond our visual scope extends to n and contains other galaxies. 
I also believe relative to any individual observer, even so much as  the smallest particle, the visual universe depends on light and visual area contraction over distance, however this gets chucked in new theories every time I try to discuss it.
I now see an din compliance with my own theory from your explanation that lambda-CDM is negative?, I think Jeff has it nailed over in New theories,

positive suggests expansion always in my mind?


Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 18/04/2016 23:35:20
Sorry it just came to me, the red shift is evidence that the visual universe is expanding ?
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: RobC on 23/04/2016 12:29:36
We are told that the universe is not a collection of galaxies sitting in space, all moving away from a central point. Instead, a more appropriate analogy is to think of the universe as a giant blob of dough with raisins spread throughout it (the raisins represent galaxies; the dough represents space). When the dough is placed in an oven, it begins to expand, or, more accurately, to stretch, keeping the same proportions as it had before but with all the distances between galaxies getting bigger as time goes on.

My query is, if this is the case, why are certain galaxies colliding?
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: JoeBrown on 23/04/2016 13:54:02
Sorry it just came to me, the red shift is evidence that the visual universe is expanding ?

That was the first thought Sir Edwin Hubble put forth.  He knew about doppler shift and calculated that most galaxies are headed away from us, like we got the plague or something else...  Cosmologists and Lambda-CDM models have taken into account for Einstein shift with more accurate measurements for distances. 

Hubble didn't know about Einstein shift, AFAIK.  Einstein had predicted (einstein/)gravity-shift but it was verified during his lifetime.  He may have told Hubble about it, but there's no record indicating such conversation had occurred.  Seems Einstein didn't think about gravity shift either, because he choose to add the Lambda constant (his termed blunder) to General Relativity to account for the doppler effect they perceived at the time.

After taking into account doppler effects to plot comoving galaxies and einstein shift for differing weight of galaxies & stars, there's still a little shift that's unaccounted for, which is termed Dark Energy.

So yeah, it's like redshift, because that's the direction the shift is headed.  Doppler & Gravity shift are essentially the same, only difference is observers relative perspective.

So there's a third or more shift, Einstein didn't predict, based on cosmological measurements.  Dark Energy is the term used because we don't know what's causing it.  It appears stronger closer to home than in the distant past.  Which makes it even more perplexing.  Its like the Universe is gaining momentum of some sort.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: JoeBrown on 23/04/2016 14:11:29
My query is if this is the case why are certain galaxies colliding?

It does seem odd that it would be possible if everything is expanding, how do some collide.  Cosmologists have picked Dark Matter (unseen mass) as the culprit for pulling galaxies together.  If you see the superstructure of the universe, its like filaments of galaxies being drawn together in a web like structure.

They theorize that there's enough dark mass left over from the big bang in regions where galaxies collect &/or collide that it keeps pulling more in.

Personally, I find it a bit frustrating.  There's a lot we don't know about space and gravity in specific.  While those theories are reasonable, based on what we do understand...  They use General Relativity as a basis for understanding the Universe.  General Relativity isn't complete.  It's the best standing description of gravity, to date, but Einstein knew it wasn't complete and unfortunately he passed before completing a grand unified theory.

A truly unified theory would help explain a lot of what we don't understand, unfortunately, not too many ppl grasp GR and what it actually describes.   Quantum Mechanics describes a lot of stuff that GR doesn't address.  A unified theory of everything would make a lot of things easier to understand.  But...  Such a theory isn't easy to develop.

I think I have a clue, but...  There's a lot of stuff I've theorized that goes against a lot of presently accepted science...  My not being a "physicist" really doesn't qualify me for asserting things are different than others believe. 

I cannot back up my assertion that Black Hole formation causes pressure change in the Universe, with math...  This pressure change is the likely cause of unpredicted shift.  That's frustrating to me.  If found some math that would lead toward evidence, but its not my own.  A grand unified theory will likely be necessary for me to complete my assertion.  Argh...  Don't know if I'm up for the task.

If you're familiar with Mandelbrot fractals...  A unified theory should produce the superstructure of galaxies like Mandelbrot's  a fractal universe (https://www.google.com/search?q=mandelbrot+set+coloring&tbm=isch&imgil=KqUk_4NL50xrXM%253A%253BmA71WmDY10bbyM%253Bhttp%25253A%25252F%25252Fwww.hiddendimension.com%25252Ffractalmath%25252Fdivergent_fractals_main.html&source=iu&pf=m&fir=KqUk_4NL50xrXM%253A%252CmA71WmDY10bbyM%252C_&usg=__3D-PPntmcm7WccoL9f6tik4UB5E%3D&biw=1320&bih=753&ved=0ahUKEwjv74u-66TMAhXCez4KHUy0AQEQyjcIPg&ei=HXUbV6_tBML3-QHM6IYI#imgrc=KqUk_4NL50xrXM%3A).
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: evan_au on 24/04/2016 14:22:26
Quote from: RobC
Perhaps a silly question but as space expands does this mean that the distance between the earth and the sun is increasing?
No.

The expansion attributed to Dark Energy is visible on very large scales, such as for galaxies at least 10 billion light-years away.
At this point in the history of the universe, it does not affect the size of individual galaxies (or the spacing of stars and planets within the galaxy). It would have minimal impact on our local cluster of galaxies, which are bound together gravitationally.
See: https://en.wikipedia.org/wiki/Lambda-CDM_model#Overview

There are a number of values in this Lambda-CDM model which are currently set to some default values; one of them is "w=-1".
Current best estimates are that w=-0.96; however, if it were more negative (like w=-1.5), the universe would eventually experience a "Big Rip", which would eventually tear apart galaxies, solar systems, planets and atoms (in about 22 billion years, by which time the Sun and Earth will be long gone). 

It is thought that the Sun will puff off some of its mass as solar wind over the next 5 billion years, meaning that Earth's orbit will expand outwards, perhaps to where Mars is now. But this is not enough to prevent Earth from being baked to a crisp as the Sun burns all its hydrogen fuel, and expands into a red giant star.

Quote
why are certain galaxies colliding?
Each galaxy has its own random motion within our local cluster of galaxies. In a cluster of galaxies, if some galaxies are moving apart, that means some are likely to be moving towards each other.

It is thought that some globular clusters and stellar streams (https://en.wikipedia.org/wiki/List_of_stellar_streams) may be the remains of dwarf galaxies which have been previously swallowed and disrupted by our galaxy.

The gravity of galaxies means that as they approach more closely, they are attracted more strongly towards each other.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: PmbPhy on 24/04/2016 15:06:55
The universe is not expanding into nothing. You appear to keep thinking something similar to the idea that the big bang is like a nuclear or chemical atomic explosion occurring in empty space. It's nothing of the sort. In fact that's a common misconception. The big bang is nothing like any explosion that you're aware of. It's an explosion of space itself.

See Misconceptions About The Big Bang, Scientific American, March 2005
www.mso.anu.edu.au/~charley/papers/LineweaverDavisSciAm.pdf
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 24/04/2016 16:09:06
The universe is not expanding into nothing. You appear to keep thinking something similar to the idea that the big bang is like a nuclear or chemical atomic explosion occurring in empty space. It's nothing of the sort. In fact that's a common misconception. The big bang is nothing like any explosion that you're aware of. It's an explosion of space itself.

See Misconceptions About The Big Bang, Scientific American, March 2005
www.mso.anu.edu.au/~charley/papers/LineweaverDavisSciAm.pdf


Clearly contradictory dogma, space itself is made of nothing, nothing can not expand, you are clearly stuck in your strict ways and naive to what you have learnt over time. You accept contradiction and Dogma, I do not accept contradiction and dogma.   Space itself is not expanding, there was no explosion of space of the whole of space .  Objects pass through space and space passes through objects, the balloon analogy is terrible, even outside of the balloon is space. 

What do you suggest the balloons surface is expanding into?  It not a solid for sure, it is more space, your ideas are contradictory and border line insane, I suggest you all go see a doctor, this is absurd, the big bang is hypothetical absurd dogma.   Theories are not fact, fact is fact and the truth is you have no facts other than your dogma.


P.s Before the big  nothing existed is complete Dogma.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: evan_au on 25/04/2016 12:01:24
Recent attempts to measure the rate of expansion (the Hubble "constant") appear to give slightly different results.
http://www.scientificamerican.com/article/cosmic-speed-measurement-suggests-dark-energy-mystery/
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: McQueen on 25/04/2016 13:56:40
The most fascinating aspect of this subject  is that the Universe is actually expanding faster than the speed of light. Impossible right ? That is what the astronomers who first made the discovery thought. For this reason for a long time this evidence was ignored. However, the rate of expansion at 13.6 billion years was measure at five times the speed of light ! Think about it, it shouldn't happen. Yet under the special conditions prevailing in the early Universe it might have been possible. This is exactly my point, if the Universe was expanding at FTL speeds, it can no longer be doing so, because in our own local space FTL speeds are just not possible and we have physical evidence to this effect. Therefore what we are seeing is evidence form 13.6 billion years ago , when the Universe was young and the acceleration due to the inflationary process was still very apparent.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: PmbPhy on 25/04/2016 15:42:33
Quote from: Thebox
Clearly contradictory dogma, ...
Not only a rude response but an ignorant one as well. I refuse to respond to each of those totally rude and ignorant responses. You don't have the knowledge nor intelligence to properly understand the answer.

If you actually chose to study physics in my forum like you agreed to rather than squander that opportunity then you might one day have learned what it means for space to expand. That has a precise meaning which you've never taken the time to learn. That space itself can be altered has been demonstrated to be true in experiments. But you're too ignorant to understand its meaning and you'll remain so until you make the effort to learn. However that requires having an open mind which is something you don't have.

Note: Chances are that you'll mistake my use of the term "ignorant" to mean "stupid". That is not what it means. The term ignorant is defined as lacking knowledge or information. However your constant ignorant responses and rude attacks do demonstrate to me a person of lesser intelligence than normally displayed by the members of this forum. Most people here are rather intelligent and wouldn't post such rude comments. Most of them would ask what physicists mean whey the speak of space expanding or changing.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: PmbPhy on 25/04/2016 15:55:05
Quote from: McQueen
The most fascinating aspect of this subject  is that the Universe is actually expanding faster than the speed of light. Impossible right ?
Not at all. It doesn't even violate special relativity which implies that nothing can travel faster than light since its speaking only of objects traveling in space. It doesn't have anything to do with how fast space itself is expanding or how fast two objects which are at rest in an expanding space can move apart.

Quote from: McQueen
That is what the astronomers who first made the discovery thought. For this reason for a long time this evidence was ignored.
That's news to me. Where did you get such an idea from? General Relativity (GR) has been around since before that discovery was made and its GR that can explain it.

Quote from: McQueen
However, the rate of expansion at 13.6 billion years was measure at five times the speed of light !
Where did you get such a figure from? It makes no sense to speak of space expanding at a particular speed since the speed at which two objects recede from each other depends on the distance between them.

Quote from: McQueen
Think about it, it shouldn't happen.
I disagree and so do all the cosmologists in the world who understand general relativity.

Quote from: McQueen
  This is exactly my point, if the Universe was expanding at FTL speeds, it can no longer be doing so, because in our own local space FTL speeds are just not possible and we have physical evidence to this effect.
You're confusing the speed of an object moving in space with the speed of an object due to the expansion of space.

Quote from: McQueen
Therefore what we are seeing is evidence form 13.6 billion years ago , when the Universe was young and the acceleration due to the inflationary process was still very apparent.
And yet space is still expanding and objects are still moving FTL because of it.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: McQueen on 26/04/2016 10:10:44
Not at all. It doesn't even violate special relativity which implies that nothing can travel faster than light since its speaking only of objects traveling in space. It doesn't have anything to do with how fast space itself is expanding or how fast two objects which are at rest in an expanding space can move apart.
Maybe this is too nonchalant a dismissal of what after all is an unusual event.  In fact while doing a ( admittedly cursory search of the forum) I couldn't find a single reference to faster than light expansion of the Universe ! In fact the only reference to this subject appears to be from threads that I have posted.  That having been said the implications remain, so space expanding doesn't come under special relativity ?  When you use the term fast you are implying objects moving with velocity so how actually doesn't this count. ?
That's news to me. Where did you get such an idea from? General Relativity (GR) has been around since before that discovery was made and its GR that can explain it.
Once again I see the same dogged pedagogy, where only one explanation exists and nothing else can be right. For your information there are several reasons put forward for faster than light expansion of the Universe and the theory I have outlined here happens to be one oof the major ones:
Perhaps it's dark energy acceleration, or the earliest inflationary period of the universe when EVERYTHING expanded faster than the speed of light.    Read more at:  (http://phys.org/news/2015-10-galaxies-faster.html#jCp)

I disagree and so do all the cosmologists in the world who understand general relativity.
See answer above.
I disagree and so do all the cosmologists in the world who understand general relativity.
Again just one viewpoint and a highly disputable one at that

Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: stacyjones on 26/04/2016 17:00:20
Our visible Universe is a larger version of what is represented by the blue lines in the following.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fastronomynow.com%2Fwp-content%2Fuploads%2F2015%2F08%2Fblack_hole_gas_jet_circulation_940x940.jpg&hash=e7b43f1e683766342fb8f7a9150355a6)

'Supermassive Black Holes Transport Matter into Cosmic Voids, Astronomers Say'
sci-news.com/astronomy/supermassive-black-holes-matter-cosmic-voids-03658.html

Quote
“Some of the matter falling towards the holes is converted into energy. This energy is delivered to the surrounding gas, and leads to large outflows of matter, which stretch for hundreds of thousands of light years from the black holes, reaching far beyond the extent of their host galaxies,” the astronomers explained.

At the scale of our Universe the energy referred to above is dark energy. A Universal black hole is powering our visible Universe causing the galaxy clusters to accelerate away from us.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 28/04/2016 19:59:21


At the scale of our Universe the energy referred to above is dark energy. A Universal black hole is powering our visible Universe causing the galaxy clusters to accelerate away from us.


That is interesting, how would that compare to a stationary universe that gained motion because at a relative central point a single planet changed in entropy causing the universe to inflate away from this point?

Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: stacyjones on 28/04/2016 20:17:31


At the scale of our Universe the energy referred to above is dark energy. A Universal black hole is powering our visible Universe causing the galaxy clusters to accelerate away from us.


That is interesting, how would that compare to a stationary universe that gained motion because at a relative central point a single planet changed in entropy causing the universe to inflate away from this point?

A Universal black hole powering our visible Universe explains why most everything appears to be accelerating away from us. The stuff that has been getting pushed for longer than we have is accelerating away from us. We are accelerating away from the newer stuff that has been getting pushed for less time than we have been. From our perspective, most of the matter is accelerating away from us.

A Universal black hole powering our visible Universe also explains the directionality of the matter associated with the dark flow (https://en.wikipedia.org/wiki/Dark_flow). The energy associated with the Universal black hole is pushing the matter associated with the dark flow, causing it to move directionally through our visible Universe.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: guest39538 on 29/04/2016 06:17:49


At the scale of our Universe the energy referred to above is dark energy. A Universal black hole is powering our visible Universe causing the galaxy clusters to accelerate away from us.


That is interesting, how would that compare to a stationary universe that gained motion because at a relative central point a single planet changed in entropy causing the universe to inflate away from this point?

A Universal black hole powering our visible Universe explains why most everything appears to be accelerating away from us. The stuff that has been getting pushed for longer than we have is accelerating away from us. We are accelerating away from the newer stuff that has been getting pushed for less time than we have been. From our perspective, most of the matter is accelerating away from us.

A Universal black hole powering our visible Universe also explains the directionality of the matter associated with the dark flow (https://en.wikipedia.org/wiki/Dark_flow). The energy associated with the Universal black hole is pushing the matter associated with the dark flow, causing it to move directionally through our visible Universe.

Dark flow?  do you simply mean beyond the visible spectrum and Fr=0?


The same ''dark'' flow that makes this work

https://en.wikipedia.org/wiki/Crookes_radiometer


In the universe only exist two directions, - or + relative to the observer.   


Up down left right are not real, neither is north or south, in the universe our own evidence suggests that when things gain entropy they move + from a central point and vice versus when they lose entropy gain they - in direction and contract.








Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: stacyjones on 29/04/2016 11:56:14
Dark flow? 

https://en.m.wikipedia.org/wiki/Dark_flow
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: RobC on 05/05/2016 10:45:31
You will probably realise from my posts that my knowledge of cosmology is rudimentary to say the least.

What I find fascinating is that the rate of expansion is accelerating.

Speculation for the cause?
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: McQueen on 05/05/2016 12:24:27
You will probably realise from my posts that my knowledge of cosmology is rudimentary to say the least.

What I find fascinating is that the rate of expansion is accelerating.

Speculation for the cause?

Firstly the Universe is everything, so there is nothing outside the Universe, If there was anything outside the Universe  it would also be part of the Universe.  So from our view-point the Universe is infinite.

Secondly a good analogy of the expanding Universe would be as follows:  Instead of an explosion, imagine the expanding Universe is like a loaf of raisin bread rising in the oven. From the perspective of any raisin, all the other raisins are moving away in all directions. This is all very well , the problem here is that it is possible to measure the rate at which the raisins are moving away from each other. So when speaking of either cosmological red-shift or a normal red-shift, the same principles of objects moving away from a location are involved. The fact that many of these cosmological red-shifts, seem to indicate near to light speeds or FTL  speeds is disturbing.  The only reasonable explanation would seem to be that when we see red-shifts that are close to C  or to FTL speeds, what we are seeing is the remnant of acceleration that took place at a time close to the Big Bang event. This is in fact one of the possibilities, that cosmologists agree exists.  So the Universe might not in fact be expanding and there is considerable proof that the Universe is instead slowing down.

To state that light can move faster than light because space itself is expanding allowing light to move FTL, even using GR sounds suspect, after all light within space and light within expanding space is still light or we wouldn't be able to record the red-shift in the first place.  How could we even record this light if space expansion gives it the ability to move at any FTL velocity ?

Here is a brief summary of why astrophysicists believe that FTL speeds are possible:

" Astrophysicist Edward Robert Harrison said, "Light leaves a galaxy, which is stationary in its local region of space, and is eventually received by observers who are stationary in their own local region of space. Between the galaxy and the observer, light travels through vast regions of expanding space. As a result, all wavelengths of the light are stretched by the expansion of space. It is as simple as that..."] Steven Weinberg clarified, "The increase of wavelength from emission to absorption of light does not depend on the rate of change of a(t) [here a(t) is the Robertson-Walker scale factor] at the times of emission or absorption, but on the increase of a(t) in the whole period from emission to absorption." "

As can be seen this theory seems to depend on some quite out f the way theories.

Quote
Between the galaxy and the observer, light travels through vast regions of expanding space. As a result, all wavelengths of the light are stretched by the expansion of space. It is as simple as that..."

The fact remains that light is travelling through vast regions of space, that would not result in red-shift, a red-shift would only occur IF an object were moving away, it has nothing to do with distance.

Quote
The increase of wavelength from emission to absorption of light does not depend on the rate of change of a(t) [here a(t) is the Robertson-Walker scale factor] at the times of emission or absorption, but on the increase of a(t) in the whole period from emission to absorption."

How  does time taken for absorption  produce red-shift effects ?
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: savemars on 11/07/2020 22:57:48
I keep hearing the Universe is expanding in comparison to like a balloon inflating, the evidence an apparent red shift observed of matter. We do not observe space red shifting we only observe light/matter interaction red shift, so how from that do you conclude the Universe is expanding when that makes no logical sense or is a any sort of rational thought?
I read this morning that it is now expanding faster than we first thought and soon and the Universe will become cold and the Universe will end, how on Earth doe's any one derive that ?
I believe I can explain it in a simple way. the universe is expanding (the distance between two objects) this can be shown with the classroom experiment showing gravity. if you have a sheet pulled then place a ball on it. this will create an example of a gravity well, but at the same time it will show the expansion of spacetime. while the ball pulls on the fabric it will cause the rest of the fabric to slightly expand. for every force there is an equal and opposite  force.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: evan_au on 12/07/2020 08:32:30
Quote from: Staceyjones
The energy associated with the Universal black hole is pushing the matter associated with the dark flow, causing it to move directionally through our visible Universe.
From the link, Dark Flow is a trend of galaxies moving towards a certain patch of the sky
- Different physicists argue about whether Dark Flow is real or imagined, so it's not obvious that it exists
- If Dark Flowdoes exist, it is a small perturbation on the overall expansion of the universe
- So Dark Flow cannot explain the overall expansion of the universe, even if it is confirmed
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: evan_au on 12/07/2020 08:42:28
Quote from: savemars
if you have a sheet pulled then place a ball on it. this will create an example of a gravity well, but at the same time it will show the expansion of spacetime. while the ball pulls on the fabric it will cause the rest of the fabric to slightly expand.
This analogy of spacetime is useful for showing the local distortion of spacetime caused by the presence of matter.
- That includes bending the path of light traveling near the Sun

However, if you wanted to show the expansion of the universe, you would need to then make the frame holding the sheet to expand, causing all objects on the sheet to move away from each other, at a speed proportional to their separation.

Like all analogies, you need to be careful of taking it too far. And sometimes it is better to focus one analogy on one effect (distortion of spacetime), and use a different analogy for a different effect (expansion of the universe).

I think some of the other analogies above are clearer for explaining the expansion of the universe:
- Blowing up a balloon: dots move away from each other
- Baking raisin bread (I liked that one... it works in 3 dimensions!)
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: hamdani yusuf on 13/07/2020 12:19:43
- Baking raisin bread (I liked that one... it works in 3 dimensions!)
It's also delicious, hence we can avoid leaving trash when the experiment is finished.
But still, it expands to space around it which was previously empty.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: Bill S on 13/07/2020 15:56:55
Quote
But still, it expands to space around it which was previously empty.

Only if you accept that empty space really exists.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: hamdani yusuf on 14/07/2020 05:29:41
Quote
But still, it expands to space around it which was previously empty.

Only if you accept that empty space really exists.
There was space which doesn't contain bread before the experiment, but does contain bread afterward.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: Bill S on 14/07/2020 16:08:01
Quote
There was space which doesn't contain bread before the experiment, but does contain bread afterward.

True; but the space was not empty before the bread arrived.  What did the bread displace?
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: Halc on 15/07/2020 02:22:37
Quote
There was space which doesn't contain bread before the experiment, but does contain bread afterward.
True; but the space was not empty before the bread arrived.  What did the bread displace?
There is no known viable model of a bang happening at a location in otherwise empty space.  So the bread expanding into not-bread space analogy just doesn't work.  The bread is the space, and it having an edge would violate the cosmological principle on which all the theories rest.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: Bill S on 15/07/2020 11:47:29
Exactly! 

The analogy works only if you don’t try to look as far as the crust.  Interesting to compare this with Hilbert’s Hotel and all the examples of infinite sequences.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: Petrochemicals on 15/07/2020 18:30:34
I keep hearing the Universe is expanding in comparison to like a balloon inflating, the evidence an apparent red shift observed of matter. We do not observe space red shifting we only observe light/matter interaction red shift, so how from that do you conclude the Universe is expanding when that makes no logical sense or is a any sort of rational thought?
I read this morning that it is now expanding faster than we first thought and soon and the Universe will become cold and the Universe will end, how on Earth doe's any one derive that ?




Its expanding into god of course. And the reason for the anomolies is god.

Seriously though a conventional pressure expantion starts off slow, accelerates eases off and then halts. Like a big crunch when all of the debris falls to the floor.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: Bill S on 21/07/2020 14:59:42
Quote
……expanding into nothing.

If nothing doesn’t exist, how can anything expand into it?  Nit-pickers could have a great time finding a different way to express that idea, though.
Title: Re: How do we know the Universe is expanding, and expanding into nothing?
Post by: CPT ArkAngel on 22/07/2020 05:10:15
It is not expanding into nothing. It may just expand because it is emergent from matter and energy. It is not expanding into but from... Or space could be finite and static and we just shrink  ;D. Or a combination of both processes.