Field Question

[beecee]

9 hours ago, swansont said:

No, that's not what "a last possibility" implies (or anything else; you really should provide a link when you quote things). They  are not saying that there is any kind of solid conclusion that relativity needs to be replaced. Simply that it can't be ruled out.

Totally agreed by this lay person who has found this thread highly informative. In my language what they are simply saying, is why throw out an incredible theory [GR] that describes and predicts so much, so successfully, because of one or two problematic areas for which we can compensate for, [DE and DM] and then find evidence for and in support of that compensation. And of course while GR and other universal theories do and are getting stronger the longer they match what we see and predict successfully, they are always still open for that "last possibility" That is the strength of science, scientific theories and the scientific method.

Edited May 5, 2018 by beecee

[MikeAL]

10 hours ago, swansont said:

Because when we modify gravity to account for observations, it breaks in situations where it was working. When we add dark energy, we don't have that problem.

 

6 hours ago, Mordred said:

Everything described, defined or modelled by physics involves mathematics. It is a requirement of any model to make testable predictions of how a affects b.

 

13 hours ago, Strange said:

13 hours ago, MikeAL said:

For this to occur then we must assume one of two conditions:

1. That time and distance themselves have extra-mathematical properties attributable to them that is causing the physical effect.

2. That the interaction is occurring in a medium of some sort. Perhaps not a PB and J medium, but something.

 

I don't see why we should have to assume either of this things. Do you need to assume them if geometry is Euclidean (as we used to think)?

It turns out that the geometry of space and time measurements is non-Euclidean. I don't see why that implies a medium of some sort.

 

 

Understood, but I am not attempting to modify gravity at all. I am suggesting that the field could be weakening due to expansion, and that evidence for such a weakening could be found in the past (as was suggested it should be). The article suggests that the expansion of the universe has not been linear, that it suddenly, based on observable masses, seemed to accelerate. I linked that reference.

The idea of dark energy itself is not fully understood and is only a theory used to fill a hole in another theory. Google dictionary will tell you it is: 

a theoretical form of energy postulated to act in opposition to gravity and to occupy the entire universe, accounting for most of the energy in it and causing its expansion to accelerate.

 

My suggestion when it came to looking at gravity and matter is that we should look at matter as the manifestation of the field when a certain threshold density is crossed (the curvature of space). I have also argued previously it could account for DM and thus we don't need to invoke right hand neutrinos or anything else.

 

This led to the discussion that fields are not real in our universe but only mathematical abstractions, a fact I strongly disagree with based on the fact that they exert forces. Geometric space time  may involve the changing relationship between time and distance, but somehow that rock floating by Jupiter is acted upon. Mathematics, a pure descriptor of the universe and absolutely essential for any serious study of the universe, cannot exert a force. Something is exerting the force and thus we cannot claim the field is a mathematical abstraction, but rather it is an intangible reality.

 

That is the entirety of my argument. Can all you science guys honestly tell me that the fields that permeate our universe are simple mathematical conveniences used to answer physics questions and do not really exist?

 

 

 

 

1 hour ago, beecee said:

Totally agreed by this lay person who has found this thread highly informative. In my language what they are simply saying, is why throw out an incredible theory [GR] that describes and predicts so much, so successfully, because of one or two problematic areas for which we can compensate for, [DE and DM] and then find evidence for and in support of that compensation.

I agree that GR is an incredible theory, Einstein earned his title as genius, no doubt about it. However, there are problems with his theory at the quantum level, and when it comes to other strange areas of the universe such as DM  (which accounts for a large part of the universe). When Einstein's theory overturned Newton's the proof was the 1919 solar eclipse. Up to that point the two theories made almost the same predictions. Such a tiny thing as the degree of bending or a ray of light unhinged Newton's theory in favour of Einstein's. https://www.wired.com/2009/05/dayintech-0529/ 

Perhaps, Einstein's theory is also, like Newton's, almost there, but these areas where we have gone into gap filling mode do give me reason for pause.

[swansont]

1 hour ago, MikeAL said:

Understood, but I am not attempting to modify gravity at all. I am suggesting that the field could be weakening due to expansion, 

But you are. If you look at the model, the field doesn't weaken, as we've been pointing out. The only way for it to weaken is to modify the model.

[MikeAL]

6 minutes ago, swansont said:

If you look at the model, the field doesn't weaken, as we've been pointing out. The only way for it to weaken is to modify the model.

OK, I have no problem with that. And so my question is that if the field is not weakening and yet the universe is expanding, then something seems very wrong with that. I don't think that we can say the fields are simply imaginary mathematical abstractions and thus are not subject to the rules of increasing volume.

It is intuitive to think that if a magnet is in a magnetic field generated by W, inside of volume X, and we then keep the field generation by W the same and put it in a larger volume Y, the overall field strength should fall. If the universe is expanding, we can consider its volume expanding from X to Y. We do not however witness a fall in overall field strength. 

You might argue that the field generation is intrinsic to the fabric of the universe and therefore not subject to decay, but as such it should be subject to the fundamental rules of the universe, and because total energy cannot be created nor destroyed but can be converted, should we not ask ourselves what is being converted to sustain the field? It has a bit of a mobius strip feel to it, does it not?

 

[beecee]

2 hours ago, MikeAL said:

Understood, but I am not attempting to modify gravity at all. I am suggesting that the field could be weakening due to expansion, and that evidence for such a weakening could be found in the past (as was suggested it should be). The article suggests that the expansion of the universe has not been linear, that it suddenly, based on observable masses, seemed to accelerate. I linked that reference.

As an amateur among professionals and experts, I am open for correction...When you mention the "weakening of the field" due to expansion, Isn't that because the density of the matter/energy in the universe/spacetime, is getting less? And the way I understood it from past reputable books and such, is that after the BB and the impetus from Inflation,  the universe/spacetime has been gradually slowing down, until that is, around 5 billion years ago? [from memory] that it started the acceleration that we now observe. Why? because after the impetus from the Inflation epoch had subsided, the constant DE or this unknown constant force behind the expansion, had the effect of accelerating said expansion as matter/energy density in the universe/spacetime lessened. [hope that makes sense]

Quote

The idea of dark energy itself is not fully understood and is only a theory used to fill a hole in another theory. Google dictionary will tell you it is: 

a theoretical form of energy postulated to act in opposition to gravity and to occupy the entire universe, accounting for most of the energy in it and causing its expansion to accelerate.

Yes....as was the DM also a "fudge factor"  in the beginning, with many cosmologists doubting its existence. That of course has subsided as evidence for DM has come to light... strong evidence in fact with the bullet cluster evidence.

DE, or whatever it actually is, is something I see as imbedded in spacetime itself, and part of its nature.

 

Quote

My suggestion when it came to looking at gravity and matter is that we should look at matter as the manifestation of the field when a certain threshold density is crossed (the curvature of space). I have also argued previously it could account for DM and thus we don't need to invoke right hand neutrinos or anything else.

 

Spacetime cannot exist without the matter/energy within: So sayeth Sten Odenwald...Or he puts it far better then I do  https://einstein.stanford.edu/content/relativity/a11332.html

Quote

No. Experiments continue to show that there is no 'space' that stands apart from space-time itself...no arena in which matter, energy and gravity operate which is not affected by matter, energy and gravity. General relativity tells us that what we call space is just another feature of the gravitational field of the universe, so space and space-time can and do not exist apart from the matter and energy that creates the gravitational field. This is not speculation, but sound observation.

NB:The highlighted was a typographical error when I raised it with Sten via an E Mail: It should simply be..."DO NOT' 

 

 

Quote

This led to the discussion that fields are not real in our universe but only mathematical abstractions, a fact I strongly disagree with based on the fact that they exert forces. Geometric space time  may involve the changing relationship between time and distance, but somehow that rock floating by Jupiter is acted upon. Mathematics, a pure descriptor of the universe and absolutely essential for any serious study of the universe, cannot exert a force. Something is exerting the force and thus we cannot claim the field is a mathematical abstraction, but rather it is an intangible reality.

I see space as real, time as real, and spacetime as real. While none are physical entities, they are mathematical constructs, or backdrops against which we enact the universe and laws within. That in my opinion does not disqualify it from being real. I do admit though there appears some disagreement on whether it is real or not...more philosophical then anything else.That is the entirety of my argument.  Cosmologists also have been for years now, trying to formulate a verifiable QGT...or a quantizing gravity/spacetime. This also in my opinion supports the "real" case.

 

Quote

I agree that GR is an incredible theory, Einstein earned his title as genius, no doubt about it. However, there are problems with his theory at the quantum level, and when it comes to other strange areas of the universe such as DM  (which accounts for a large part of the universe). When Einstein's theory overturned Newton's the proof was the 1919 solar eclipse. Up to that point the two theories made almost the same predictions. Such a tiny thing as the degree of bending or a ray of light unhinged Newton's theory in favour of Einstein's. https://www.wired.com/2009/05/dayintech-0529/ 

Yet both in my opinion are still correct. GR is simply a far more precise model that reveals those very small tolerances that Newtonian misses or has no need for. I mean we certainly don't delve into the difficult mathematical structure of GR to determine events and time here on Earth, and in most cases, if not all, we use Newtonian for all space endeavours so far.

Quote

Perhaps, Einstein's theory is also, like Newton's, almost there, but these areas where we have gone into gap filling mode do give me reason for pause.

It certainly is. And I remember one astronomer on my first ever science forum, tell me that any future QGT will most likely encompass GR and the BB, while at the same time, extend the parameters of them in explaining reasonably what sort of universe we occupy.

 

 

 

Edited May 6, 2018 by beecee

[MikeAL]

58 minutes ago, beecee said:

When you mention the "weakening of the field" due to expansion, Isn't that because the density of the matter/energy in the universe/spacetime, is getting less?

Hi BeeCee, 

Yes, you could say it that way although I think it more likely to fall into a pothole and be leaped upon, which makes for very good and fun debate anyway. Volume is a simpler term. The universe is expanding, so without a compensatory increase in the field generator, the field should weaken.

It could be that the total field stays the same but aspects of the field weaken to strengthen other aspects (gravity may weaken to strengthen EM fields).

It could be that the sustenance of the field is what keeps the quantum pressure cooker bubbling over. 

It could be the universe is spinning against an external surface creating some weird friction.

Who knows? Not me. I don't know.

But, to suggest that the field does not really exist, is not being generated, should not weaken or its strength is immutable seems very strange. Afterall, imagine if we started saying that about the Earth's electromagnetic field.

[beecee]

1 hour ago, MikeAL said:

Hi BeeCee, 

Yes, you could say it that way although I think it more likely to fall into a pothole and be leaped upon, which makes for very good and fun debate anyway. Volume is a simpler term. The universe is expanding, so without a compensatory increase in the field generator, the field should weaken.

We have much to learn certainly. But while the density of the mass/energy in the universe/spacetime, gets less with expansion, the apparent constant nature of the DE imbedded in spacetime, is reflected in the observed acceleration in that expansion. That's the way I see it anyway.

Quote

It could be that the total field stays the same but aspects of the field weaken to strengthen other aspects (gravity may weaken to strengthen EM fields).

 Not sure about that. Overall and on large scales the acceleration in expansion rate is  constant, and accelerating at the same rate. No matter where you are located in the cosmos, you would see the same phenomenon happening at the same speed of around 70kms/mega parsec. The dense/er regions that exist within the universe/spacetime, represented by galaxies, groups of galaxies and walls etc, see those regions overcoming the overall expansion.

Quote

But, to suggest that the field does not really exist, is not being generated, should not weaken or its strength is immutable seems very strange. Afterall, imagine if we started saying that about the Earth's electromagnetic field.

Perhaps  people are rather concerned that this may bring to mind the old debunked ether hypothesis. at this time, I like a few answers here......

https://www.quora.com/Is-the-modern-day-space-time-fabric-the-same-as-luminiferous-aether

 

Edited May 6, 2018 by beecee

[beecee]

3 hours ago, beecee said:

 No matter where you are located in the cosmos, you would see the same phenomenon happening at the same speed of around 70kms/mega parsec.

Correction......70 kms/sec/mega parsec.

[Mordred]

Keep in mind the Hubble constant is only constant everywhere in the universe at a specific time. The value provided is T_now. However in the past it is higher. The further back in time you go the higher the Hubble value. Now this is a bit tricky with expansion.

 Although the Hubble constant is decreasing over time PER MPC. The expansion rate as per Hubbles law is accelerating. This is a consequence of the volume aspects and measuring the size of the observable universe as opposed to measuring expansion rates per Mpc.

You can see this in the H/H_0 column which compares previous Hubble values with redshift to todays Hubble value z=1090 is approximately the time of the CMB.

[latex]{\small\begin{array}{|c|c|c|c|c|c|}\hline T_{Ho} (Gy) & T_{H\infty} (Gy) & S_{eq} & H_{0} & \Omega_\Lambda & \Omega_m\\ \hline 14.4&17.3&3400&67.9&0.693&0.307\\ \hline \end{array}}[/latex] [latex]{\small\begin{array}{|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|} \hline a=1/S&S&z&T (Gy)&R (Gly)&D_{hor}(Gly)&D_{par}(Gly)&V_{gen}/c&V_{now}/c&V_{then}/c&H/Ho \\ \hline 0.001&1090.000&1089.000&0.000373&0.000628&0.056714&0.000856&21.023&3.148&66.182&22915.263\\ \hline 0.002&608.566&607.566&0.000979&0.001594&0.100794&0.002319&14.843&3.115&46.232&9032.833\\ \hline 0.003&339.773&338.773&0.002496&0.003956&0.178562&0.006124&10.712&3.068&32.869&3639.803\\ \hline 0.005&189.701&188.701&0.006228&0.009680&0.314971&0.015819&7.842&3.004&23.561&1487.678\\ \hline 0.009&105.913&104.913&0.015309&0.023478&0.552333&0.040144&5.791&2.918&16.895&613.344\\ \hline 0.017&59.133&58.133&0.037266&0.056657&0.960718&0.100464&4.298&2.800&12.036&254.163\\ \hline 0.030&33.015&32.015&0.090158&0.136321&1.651928&0.248752&3.200&2.642&8.455&105.633\\ \hline 0.054&18.433&17.433&0.217283&0.327417&2.793361&0.610939&2.386&2.431&5.800&43.981\\ \hline 0.097&10.291&9.291&0.522342&0.785104&4.606237&1.491191&1.782&2.147&3.827&18.342\\ \hline 0.174&5.746&4.746&1.252327&1.874042&7.300157&3.620922&1.337&1.768&2.364&7.684\\ \hline 0.312&3.208&2.208&2.977691&4.373615&10.827382&8.733318&1.026&1.267&1.301&3.292\\ \hline 0.558&1.791&0.791&6.817286&9.184553&14.365254&20.669840&0.875&0.642&0.562&1.568\\ \hline 1.000&1.000&0.000&13.787206&14.399932&16.472274&46.278944&1.000&0.000&0.000&1.000\\ \hline 1.791&0.558&-0.442&22.979870&16.668843&17.112278&95.281180&1.547&0.481&0.745&0.864\\ \hline 2.961&0.338&-0.662&31.510659&17.154169&17.220415&168.603314&2.486&0.741&1.842&0.839\\ \hline 4.896&0.204&-0.796&40.170941&17.267296&17.267296&290.007398&4.083&0.901&3.677&0.834\\ \hline 8.095&0.124&-0.876&48.860612&17.292739&17.292739&490.769217&6.741&0.998&6.724&0.833\\ \hline 13.383&0.075&-0.925&57.557046&17.298283&17.298283&822.704529&11.141&1.056&11.767&0.832\\ \hline 22.127&0.045&-0.955&66.254768&17.299620&17.299620&1371.505677&18.418&1.092&20.106&0.832\\ \hline 36.583&0.027&-0.973&74.952986&17.299815&17.299815&2278.857001&30.451&1.113&33.895&0.832\\ \hline 60.484&0.017&-0.983&83.651102&17.299968&17.299968&3779.010092&50.345&1.126&56.692&0.832\\ \hline 100.000&0.010&-0.990&92.349407&17.299900&17.299900&6259.261851&83.237&1.134&94.384&0.832\\ \hline \end{array}}[/latex]

 

So at z=1089 the Hubble constant was 22915.263 times greater than it is today. The particle horizon is the observable universe, Stretch 1.000 is today (Stretch is simply the inverse of the scale factor a

 

So given this data how can a weakening field be accurate if per Mpc the Hubble constant is decreasing and not increasing?

Here is a little detail a matter only universe can still expand.

Edited May 6, 2018 by Mordred

[Strange]

8 hours ago, MikeAL said:

It is intuitive to think that if a magnet is in a magnetic field generated by W, inside of volume X, and we then keep the field generation by W the same and put it in a larger volume Y, the overall field strength should fall.

I'm not sure what you man by "overall field strength".

But, obviously, the strength at any given distance falls off with the square of distance. It makes no difference whether that is because you are moving away or because space is expanding. It is purely a function of distance. 

8 hours ago, MikeAL said:

If the universe is expanding, we can consider its volume expanding from X to Y. We do not however witness a fall in overall field strength.

Again, not sure what you man by "overall field strength".

But, obviously, we do see a decrease in the gravitational force holding things together as distance increases. (Inverse square law again.) And that is why the fate of the universe is (partly) determined by the overall density. So if the density is high enough, we would expect gravity to slow expansion and then reverse it. If it is not high enough, then expansion will continue indefinitely.

The picture is complicated now by the fact that there appears to be something causing the expansion to accelerate. You seem to be suggesting that this is because we need to change the way gravity works ("weakening the overall field strength" presumably). There have been, and are, many attempts to modify the way gravity works to explain this but none, so far, work (in the sense of fitting all the evidence). 

The recent neutron star merger observation also rules out many such theories as they predict that gravitational waves and light would travel at different speeds. They don't.

[MikeAL]

32 minutes ago, Strange said:

You seem to be suggesting that this is because we need to change the way gravity works

No, this isn't a gravity discussion I'm trying to have. I would love to get into one again, but at the moment I am trying to sidestep it to focus on the field. As you might remember, Strange, we've had plenty of discussion on gravity before.

33 minutes ago, Strange said:

Again, not sure what you man by "overall field strength".

 

Let me quote from Art Hobson's book: Tales of the Quantum, Understanding Physic’s Most Fundamental Theory

An electric field at rest has the ability to exert forces on electrically charged objects and thus do work on them; such ability to do work is precisely what we mean by energy. Mass-energy equivalence then implies that EM fields at rest have mass, implying that, like Johnson’s stone, they resist acceleration and they have weight. … If you could accumulate sufficient EM field within an enclosed region, you could kick it. P88

Fields are properties of space itself. P77

Although we can’t see these fields directly, we’ll find they are physically real and not just something scientists invent to concoct theories and make calculations. P77-78

 

Contemplating this, one must wonder why with the expansion of the universe the value of the field does not change, particularly when we consider that energy is neither created nor destroyed, but simply transformed.

 

3 hours ago, Mordred said:

So given this data how can a weakening field be accurate if per Mpc the Hubble constant is decreasing and not increasing?

 

That's great. So my question is why is it not weakening?

3 hours ago, Mordred said:

Here is a little detail a matter only universe can still expand.

I'm not sure what you mean by this. Can you elaborate?

Not only energy, but also mass resides in the so-called empty space between the two separated magnets. This space isn’t really empty after all! It has weight, just like a rock. But the EM field energy does not have a significant effect on the mass of ordinary matter, because ordinary matter is made of atoms and the EMP field energy is millions of times smaller than the total energy of the atom. P89-90

The result of this theoretical calculation was that fully 95% of the mass of the protons and neutrons comes from the energy of their strong force fields! This is our best estimate of the mass of these fields! ...The mass of the universes ordinary matter comes not from so-called “solid” objects but almost entirely from force fields! P90-91

[studiot]

17 minutes ago, MikeAL said:

Fields are properties of space itself. P77

Well that's wrong.

You can have space with no field at all.

So how is this different from space where there is a field?

You might say that a field is the influence or effect of a source (or sink) on a region of space.

Edited May 6, 2018 by studiot

[MikeAL]

Interaction with the Higgs field gives quanta inertia – resistance to acceleration – and this resistance to acceleration is what we mean by mass. Hence matter differs from radiation only in that matter interacts with the Higgs field whereas radiation does not, and this confers mass on matter but not on radiation. p90

Just now, studiot said:

You can have space with no field at all.

It is the bending of the field that is noticeable. Wikipedia says: The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature (the others are gravitation, weak interaction and strong interaction). 

Granted that indefinitely may mean either unlimited or unspecified. But the upshot seems to be that the field is a property of space.

 

Edited May 6, 2018 by MikeAL

[geordief]

2 minutes ago, studiot said:

Well that's wrong.

You can have space with no field at all.

So how is this different from space where there is a field?

You might say that a field is the influence or effect of a source (or sink) on a region of space.

Have you an example of a space with no field?

(you haven't answered my 2nd  reply to your expansion question yet .....)

[studiot]

 

20 minutes ago, MikeAL said:

3 hours ago, Mordred said:

Here is a little detail a matter only universe can still expand.

I'm not sure what you mean by this. Can you elaborate?

I agree it's unfinished or something, I don't know what.

21 minutes ago, MikeAL said:

That's great. So my question is why is it not weakening?

I asked you before and you didn't answer

You need to distinguish what sort of field you are talking about please?

I would suggest that you also need to distinguish between energy and mass as they are somewhat different.

Energy is not a sort of liquid form of mass that can be transferred from one body to another.

But you can coalesce two masses to form one.

[MikeAL]

Just now, studiot said:

Energy is not a sort of liquid form of mass that can be transferred from one body to another.

No, but E = mC2

What type of field? I am talking about any of the fields that are the property of space. EM or gravitational have been the most discussed.

[Strange]

32 minutes ago, MikeAL said:

Contemplating this, one must wonder why with the expansion of the universe the value of the field does not change, particularly when we consider that energy is neither created nor destroyed, but simply transformed.

The "value of the field" depends on the charge and the distance. There is no reason expansion of the universe will change this (other than increasing the distance).

 

[MikeAL]

Just now, Strange said:

The "value of the field" depends on the charge and the distance.

This is a reflection of how well the charge is able to bend the field. The field is a property of space. If space is expanding and nothing new is entering the universe, than space must surely be diluted out, and thus the field property of space must also be diluted. If not, why not, is my question?

[studiot]

14 minutes ago, geordief said:

Have you an example of a space with no field?

(you haven't answered my 2nd  reply to your expansion question yet .....)

No, geordie, I know that.

But then nobody else has either.

Everybody glibly says words to the effect

"There is no centre of dilation" for this expansion and the balloon analogy is offered with the statement

There is no centre of expansion for the balloon.

This statement is untrue and hides the fact that

There is no centre of expansion in the manifold that forms the surface of the balloon.

However the centre of the balloon is also the centre of dilation, but it is not in the surface manifold.

In fact it is not in the same dimension as the manifold.

 

The connection between this statement and curvature and dimension is fundamental and usually glossed over.

 

I am trying to work out a way to draw this for you, but would welcome anybody else who has a good answer.

[geordief]

4 minutes ago, studiot said:

No, geordie, I know that.

But then nobody else has either.

Everybody glibly says words to the effect

"There is no centre of dilation" for this expansion and the balloon analogy is offered with the statement

There is no centre of expansion for the balloon.

This statement is untrue and hides the fact that

There is no centre of expansion in the manifold that forms the surface of the balloon.

However the centre of the balloon is also the centre of dilation, but it is not in the surface manifold.

In fact it is not in the same dimension as the manifold.

 

The connection between this statement and curvature and dimension is fundamental and usually glossed over.

 

I am trying to work out a way to draw this for you, but would welcome anybody else who has a good answer.

Is this "centre is everywhere" idea one of those** where intuition is no help?We have to understand it intellectually and not in the mind's eye?

**as perhaps,for example spacetime curvature can't be visualized at a local level (we just see its effects in the round and have to understand it at the local level as a mathematical model)

 

 

 

[studiot]

1 minute ago, geordief said:

Is this "centre is everywhere" idea one of those** where intuition is no help?We have to understand it intellectually and not in the mind's eye?

**as perhaps,for example spacetime curvature can't be visualized at a local level (we just see its effects in the round and have to understand it at the local level as a mathematical model)

 

 

 

I suppose it depends upon your background.

I have done so much surveying in my time that the idea comes naturally to me.

Do you remember I once tried to explain the surveyor's concept 'through chainage' to (I think) you.

This is an elementary example of it in everyday practice.

[geordief]

5 minutes ago, studiot said:

I suppose it depends upon your background.

I have done so much surveying in my time that the idea comes naturally to me.

Do you remember I once tried to explain the surveyor's concept 'through chainage' to (I think) you.

This is an elementary example of it in everyday practice.

This one?

 

https://www.scienceforums.net/topic/99414-alternative-analogies-for-the-curvature-of-space-time/?do=findComment&comment=949023

 

[studiot]

16 minutes ago, MikeAL said:

This is a reflection of how well the charge is able to bend the field. The field is a property of space. If space is expanding and nothing new is entering the universe, than space must surely be diluted out, and thus the field property of space must also be diluted. If not, why not, is my question?

 

But charge may 'bend' a field, but it can't bend space.

Mass, by way of gravity 'bends' space.

Do you consider space to be finite or infinite?

The answer makes a very big difference since infinity plus 20% is still just infinity.

 

As to which type of field, your answers elad me to believe that you are referring to what is known as the common background radiation along with the general distribution of light (EM radiation) we observe, which varies from direction to direction.

Such 'fields' are indeed one use of the word but they are neither the formal definition of a Field as used in Physics or in Mathematics (The one in Mathematics is different).

Just now, geordief said:

This one?

 

https://www.scienceforums.net/topic/99414-alternative-analogies-for-the-curvature-of-space-time/?do=findComment&comment=949023

 

I am just going out onto the Mendips, so you will have to educate me another time as to how you find these past trheads so readily and quickly.

 

I can never find them when I want them.

[geordief]

7 minutes ago, studiot said:

 

 

I am just going out onto the Mendips, so you will have to educate me another time as to how you find these past trheads so readily and quickly.

 

I can never find them when I want them.

https://www.google.ie/search?ei=W-vuWt21FsyegAaavaigCw&q="geordief"++studiot+surveyor&oq="geordief"++studiot+surveyor&gs_l=psy-ab.3...8224.14168.0.14644.0.0.0.0.0.0.0.0..0.0....0...1c.1.64.psy-ab..0.0.0....0.agVIrr0P618

My username is a great help  as ,in quote ,it is a great filter to start off.A few relevant search terms  narrows it down and it helps to have an idea what you are looking for and what it looks like when you get there.

Edited May 6, 2018 by geordief

[MikeAL]

Just now, studiot said:

But charge may 'bend' a field, but it can't bend space.

Mass, by way of gravity 'bends' space.

Do you consider space to be finite or infinite?

The answer makes a very big difference since infinity plus 20% is still just infinity.

If we consider it finite, we have a big bang origin. If we consider it infinite, we still have the space around us expanding. Either way we get a dilution effect. 

Interestingly, while infinity + 20% may still be infinity, infinity minus 20% may not. 

Gravity is certainly the curvature of spacetime as it relates to mass, but I'm not sure if we can say that charge doesn't bend space in some other way.

Also, if you wouldn't mind restricting your comments to the thread topic.