Is dimensionless singularity truly dimensionless?

[No-where-man]

Hi, everybody.
I have the question about initial, gravitational big bang singularity.
My first question is if the universe was created from dimensionless singularity, is singularity truly dimensionless?
Can extreme gravity truly destroy all that is (space, time, matter, energy, just about everything you can or you can't think of at an given moment) and come back to dimensionless singularity.

I wonder if physicists consider that singularity truly exists, since all the equations break down in it?
I read Marcus posts on these subjects, but I'm still not sure what to think?

Should I, and do you actually think that singularity is something real, I mean how can it be real if it literally destroy physics and space-time.
I had a chat with someone who actually says that as a proven fact, so I came here without knowing what to think?

Should I consider singularity as a fact?
Should I consider that dimensionless-ness/sizelessness does exist?
Is dimensionless-ness/sizelessness a proven fact, I'm not talking about just singularity, I'm also talking about dimensionless/size-less particles?

I mean, is there any way to experimentally prove dimensionless singularity and dimensionless particles?
How do you do it, what are the methods?

There is also one more thing that tortures me:
If universe does not expand into anything/nothing at all, I have a hypothetical question:

Let's suppose you have to separate universes, both they have been created from dimensionless singularity, so let's suppose scientists want to get into another universe, how exactly can they do it, since there is absolutely nothing outside of any of those 2 universes?

I heard this from any documentary if human civilization could reach such level of science and technology with so much energy in which you can open portal to another universe?
But my question here is: how can you open portal at all to anything at all if there is absolutely nothing (no space, no time not anything, complete non-existence) between these 2 universes?

Basically, what this is implying is that both universe and dimensionless singularity were created from absolutely nothing/non-existence, so non-existence creates existence?
Of course that science cannot tell what was before the big bang and before singularity, but we have to think for just one minute, where did singularity came from as well.

Also, dimensionless particles like let's say photon, how can they exist if they are truly dimensionless, how can they have effects on sorrounding environment and just about everything?

But do physicists truly take singularity as literally dimensionless and literally the end of space-time, or do physicists take singularity and its dimensionlessness only as figurative speech, and yet the are aware that dimensionlessness does not exist-can anyone give me more detailed explanation here, because I truly don't know should I understand singularity and particles literally dimensionless or not, do the physicists understand singularity literally dimensionless of not?

Does dimensionlessness of singularity and do dimensionless particles truly exist or not?

How can the existence any of these non-existence and dimensionless singularity be experimentally and practically proven at all?
That's all, I truly hope you can shed some light in this darkness.

That' all.
I also need to mention something, I owe apology to Drakkith for my pm-s to him regarding these subjects, regarding these questions.
That was a bad and arrogant behaviour from me, I was lucky not to get banned permanently.
Drakkith was ok to me all the time, and I truly don't know how did he have nerves at all, because I'd lose patience with myself too as well.

Thank you for your time and patience.

 

[craigi]

Some things that might help:

Think about what causality actually is. Is there really any meaning to asking what caused the first event? By definition, nothing caused it. Our brains are prediction machines highly specialised to analyse cause and effect, so it's no surprise that they should get frustrated when they're asked to contemplate the one thing that doesn't fit what they were designed to do.

Not all cosmologists believe that there is nothing outside our universe and not all believe that time and space originated at a singularity at the beginning of it.

Hawking changes his mind quite a lot, but talks of the singularity occurring in imaginary time. I doubt that many cosmolgists really know what he's talking about.

We have data for measurements incredibly close to what we call the start of our universe but no way of seeing before that.

I'm not sure that it helps with your frustration with the subject but there are different ways of looking at the problem and some things that you can look into.

 

[Chronos]

Many physicists, and laymen, struggle with the concept of a universe from 'nothing' - which probably accounts for the popularity of multiverse and religious ideologies. I fail to see how either alternative is satisfactory.

 

[Drakkith]

I wonder if physicists consider that singularity truly exists, since all the equations break down in it?
I read Marcus posts on these subjects, but I'm still not sure what to think?

To my understanding, no, most scientists who actually work on this issue don't believe the singularity is real.

Should I consider singularity as a fact?

I wouldn't. I'd consider it to be the point where our theories and models break down and stop giving reliable predictions.

Should I consider that dimensionless-ness/sizelessness does exist?
Is dimensionless-ness/sizelessness a proven fact, I'm not talking about just singularity, I'm also talking about dimensionless/size-less particles?

This is a complicated issue that cannot be answered in just a few sentences. Elementary particles are considered to be "point-like", but this does not mean that they are truly dimensionless objects. The reality is that the concept of size isn't very meaningful at the quantum level for fundamental particles.

Let's suppose you have to separate universes, both they have been created from dimensionless singularity, so let's suppose scientists want to get into another universe, how exactly can they do it, since there is absolutely nothing outside of any of those 2 universes?

We can't start with the premise that there are two universes but nothing "outside" either of them. Furthermore, there is no known way to get from any universe to another in most of the various multiverse theories.

I heard this from any documentary if human civilization could reach such level of science and technology with so much energy in which you can open portal to another universe?
But my question here is: how can you open portal at all to anything at all if there is absolutely nothing (no space, no time not anything, complete non-existence) between these 2 universes?

Whatever you heard it from most certainly wasn't using mainstream science to come up with these conclusions, so we can't answer this. Portals allowing travel to places either inside or outside our universe don't exist as far as we know.

Basically, what this is implying is that both universe and dimensionless singularity were created from absolutely nothing/non-existence, so non-existence creates existence?
Of course that science cannot tell what was before the big bang and before singularity, but we have to think for just one minute, where did singularity came from as well.

Real science does not imply that. It makes certain predictions using theories and models that have very real limitations. Attempting to extrapolate beyond these models is almost guaranteed to either be wrong or not make any sense. So while the Big Bang Theory and the Standard Model of Cosmology allow us to make predictions very far back in time, they are ultimately limited in their scope to after the universe already existed.

Unfortunately, most of your questions are on topics that science simply doesn't have a good answer for yet. Where did the universe come from? How small can things ultimately get? What is the size of the universe? None of these have satisfactory answers yet (And they may never have satisfactory answers).

 

[No-where-man]

Some things that might help:

Think about what causality actually is. Is there really any meaning to asking what caused the first event? By definition, nothing caused it. Our brains are prediction machines highly specialised to analyse cause and effect, so it's no surprise that they should get frustrated when they're asked to contemplate the one thing that doesn't fit what they were designed to do.

Not all cosmologists believe that there is nothing outside our universe and not all believe that time and space originated at a singularity at the beginning of it.

Hawking changes his mind quite a lot, but talks of the singularity occurring in imaginary time. I doubt that many cosmolgists really know what he's talking about.

We have data for measurements incredibly close to what we call the start of our universe but no way of seeing before that.

I'm not sure that it helps with your frustration with the subject but there are different ways of looking at the problem and some things that you can look into.

To be honest, that kind of surprised me, because I thought all cosmologists think there is absolutely nothing outside the universe and that space and time originated in singularity.

 

[No-where-man]

Many physicists, and laymen, struggle with the concept of a universe from 'nothing' - which probably accounts for the popularity of multiverse and religious ideologies. I fail to see how either alternative is satisfactory.

Could you be more specific?
What do you mean by probably accounts for the popularity of the universe?
I guess, you mean multiverse theories are fairy tales or something like that?

 

[No-where-man]

To my understanding, no, most scientists who actually work on this issue don't believe the singularity is real.
I wouldn't. I'd consider it to be the point where our theories and models break down and stop giving reliable predictions.

OK, this changes everything what I thought about singularity.

This is a complicated issue that cannot be answered in just a few sentences. Elementary particles are considered to be "point-like", but this does not mean that they are truly dimensionless objects. The reality is that the concept of size isn't very meaningful at the quantum level for fundamental particles.

OK, what do you mean by "the reality is that the concept of size isn't very meaningful at the quantum level for fundamental particles"? Does it have to do with Heisenberg's uncertainty principle or something else?

What about dimensionless particles should we consider these particles (like photon and electron) truly dimensionless or they are just very, very small?
If you look at this list of dimensionless quantities-should we consider this as fact as well?
http://en.wikipedia.org/wiki/Dimensionless_quantity

We can't start with the premise that there are two universes but nothing "outside" either of them. Furthermore, there is no known way to get from any universe to another in most of the various multiverse theories.

Just for the record, it was Michio Kaku who was saying this as an possibility if we could somehow achieve that kind of scientific and technological level to achieve what I wrote above.

]Whatever you heard it from most certainly wasn't using mainstream science to come up with these conclusions, so we can't answer this. Portals allowing travel to places either inside or outside our universe don't exist as far as we know.

True.

Real science does not imply that. It makes certain predictions using theories and models that have very real limitations. Attempting to extrapolate beyond these models is almost guaranteed to either be wrong or not make any sense. So while the Big Bang Theory and the Standard Model of Cosmology allow us to make predictions very far back in time, they are ultimately limited in their scope to after the universe already existed.

Sadly, but true.

Unfortunately, most of your questions are on topics that science simply doesn't have a good answer for yet. Where did the universe come from? How small can things ultimately get? What is the size of the universe? None of these have satisfactory answers yet (And they may never have satisfactory answers).

True, sadly, but true, my only hope science and technology will one day achieve level where we could actually detect beyond from what we can see now with telescopes, microscopes and that we can see further and that we can see smaller than today.

 

[craigi]

Just for the record, it was Michio Kaku who was saying this as an possibility if we could somehow achieve that kind of scientific and technological level to achieve what I wrote above.

Kaku will be referring to the open questions of whether such a thing can exist as a traversable wormhole formed by an Einstein Rosen bridge at the centre of a rotating black hole and if they can exist, where (and when) they lead. He tries very hard to engage non-physicists in physics and picks the most fantastical things to talk about.

I can't vouch for the book, but if you want to find out more you could try this:

The Physics of Stargates: Parallel Universes, Time Travel, and the Enigma of Wormhole Physics by Enrico Rodrigo

The author has researched the subject professionally and published papers on it.

 

[No-where-man]

Kaku will be referring to the open questions of whether such a thing can exist as a traversable wormhole formed by an Einstein Rosen bridge at the centre of a rotating black hole and if they can exist, where (and when) they lead. He tries very hard to engage non-physicists in physics and picks the most fantastical things to talk about.

I can't vouch for the book, but if you want to find out more you could try this:

The Physics of Stargates: Parallel Universes, Time Travel, and the Enigma of Wormhole Physics by Enrico Rodrigo

The author has researched the subject professionally and published papers on it.

OK, and could you also give (as well as others, too) opinion on question I asked Drakkith:
OK, what do you mean by "the reality is that the concept of size isn't very meaningful at the quantum level for fundamental particles"? Does it have to do with Heisenberg's uncertainty principle or something else?

What about dimensionless particles should we consider these particles (like photon and electron) truly dimensionless or they are just very, very small?
Big thanks.

 

[craigi]

OK, and could you also give (as well as others, too) opinion on question I asked Drakkith:
OK, what do you mean by "the reality is that the concept of size isn't very meaningful at the quantum level for fundamental particles"? Does it have to do with Heisenberg's uncertainty principle or something else?

What about dimensionless particles should we consider these particles (like photon and electron) truly dimensionless or they are just very, very small?
Big thanks.

I know Drakkith's answer seems vague, but I'm not sure that we have a better one at the moment. An elementary particle is only ever measured at an exact position and the concept of the existence of a particle beyond a measurement event is a complex one. When we do consider a particle to exist beyond a measurement event, its position isn't considered perfectly localised, which is related to the HUP. In the newer theories, which remain unproven, there's growing interest in the concept of the Planck length, which again is related to the HUP. For instance, in superstring theory, a string is of the Planck length, but I'm not sure that we could unambiguously say the size of a particle is the length of its string.

 

[Chronos]

You need quantum corrections to properly define the charge and mass density of a point particle. Filip Tenado provides a good explanation here http://www.quantumdiaries.org/2009/...ms-and-why-electrons-dont-have-infinite-mass/.

 

[No-where-man]

I actually though that is scientifically proven that dimensionless particles do exist-but like I asked before how do you prove that something is dimensionless with scientific experiments?

 

[craigi]

I actually though that is scientifically proven that dimensionless particles do exist-but like I asked before how do you prove that something is dimensionless with scientific experiments?

That's certainly not true. String theory requires that particles exist in 10 dimensions. Other theories use the concept of a point particle, but that can be a misleading term for the reasons already given in this thread.

 

[No-where-man]

That's certainly not true. String theory requires that particles exist in 10 dimensions.

So photon, quark, electron, boson and etc. are not dimensionless particles?
Because when you google it, you'll find that these particles are actually dimensionless.

 

[craigi]

So photon, quark, electron, boson and etc. are not dimensionless particles?
Because when you google it, you'll find that these particles are actually dimensionless.

You'll have to provide a more specific reference than google.

 

[No-where-man]

You'll have to provide a more specific reference than google.

Well, I don't know how good or bad is wikipedia, but I also have been reading in so many books, TV documentaries, Scientific American that photon, electron (which are elementary particles) are both dimensionless, I truly don't know if it has ever been posted from arxiv.org or anything like it.

Unfortunately I don't have any kind of link, but try to google it and you'll find that particles like electrons and photons are considered dimensionless.

 

[craigi]

Well, I don't know how good or bad is wikipedia, but I also have been reading in so many books, TV documentaries, Scientific American that photon, electron (which are elementary particles) are both dimensionless, I truly don't know if it has ever been posted from arxiv.org or anything like it.

Unfortunately I don't have any kind of link, but try to google it and you'll find that particles like electrons and photons are considered dimensionless.

Wikipedia's usually very good. Search for "point particle" there. That should explain what we're trying to get across very well.

Let me offer a comparison based upon scale:

When we measure the position of an electron we get a single location
The position of an electron gets 'spread' across an entire atom at the scale of ~ 10^-10 m
In superstring theory an electron has a string of length ~ 10^-35 m
The entire observable universe is ~ 10^26 m
(You might want to check these numbers).

To give an idea of scale, if a string were the size of an atom, then a human would be the size of the universe.

Which would you say is an electron size? The spread around an atom? The size of a string? The point that it's measured at? I'd say all three are valid and that's why we say that the concept of size of an elementary particle doesn't have much meaning.

 

[Drakkith]

So photon, quark, electron, boson and etc. are not dimensionless particles?
Because when you google it, you'll find that these particles are actually dimensionless.

We don't have a good answer for you. We can only say that they are point-like as far as we know, depending on how you define size for an elementary particle.

 

[Mordred]

We don't have a good answer for you. We can only say that they are point-like as far as we know, depending on how you define size for an elementary particle.

To add a side note, particle physics can determine a particles mass, spin and momentum. However much of the information we get on a particle is usually measured by its deflections and impacts.
Much of the particles were discovered by shooting particles at a small region and watching for path interference patterns. Most detection mechanisms rely on the fact that when high-energy charged particles pass through matter they ionize atoms along their path.

The "Wilson cloud chamber" is an early example of a particle detector.

 

[No-where-man]

When we talk about dimensionlessnes of particles; is the following true?
According to one professor of physics:
Yes, experiments with these particles have not shown any internal structure, deserving the name elementary particle. Why does that mean they are point particles? Relativity forbids faster than light propagation of signals. So pushing on one side of an extended electron would instantaneously move the other side (any elasticity would mean internal structure). That cannot be the case unless the size is zero.

But how does this exactly prove that electron is dimensionless?

 

[No-where-man]

To add a side note, particle physics can determine a particles mass, spin and momentum. However much of the information we get on a particle is usually measured by its deflections and impacts.
Much of the particles were discovered by shooting particles at a small region and watching for path interference patterns. Most detection mechanisms rely on the fact that when high-energy charged particles pass through matter they ionize atoms along their path.

The "Wilson cloud chamber" is an early example of a particle detector.

But how does this prove that electron, quark, or photon and etc. are all dimensionless particles?
They even say that composite particles are also dimensionless?

 

[No-where-man]

Wikipedia's usually very good. Search for "point particle" there. That should explain what we're trying to get across very well.

Let me offer a comparison based upon scale:

When we measure the position of an electron we get a single location
The position of an electron gets 'spread' across an entire atom at the scale of ~ 10^-10 m
In superstring theory an electron has a string of length ~ 10^-35 m
The entire observable universe is ~ 10^26 m
(You might want to check these numbers).

To give an idea of scale, if a string were the size of an atom, then a human would be the size of the universe.

Which would you say is an electron size? The spread around an atom? The size of a string? The point that it's measured at? I'd say all three are valid and that's why we say that the concept of size of an elementary particle doesn't have much meaning.

Ok, understood, but if that's the case why is everyone talking about electron as purely dimensionless particle, when based on your post it is not dimensionless at all, after all?

 

[julcab12]

Ok, understood, but if that's the case why is everyone talking about electron as purely dimensionless particle, when based on your post it is not dimensionless at all, after all?

... In QM. As far as they know. We can't be sure or able to tell the internal structure of a particle-absolute size. In a sense that we can deduce any inferences from the supposition that it is localized, at the cost of momentum uncertainty. Meaning particle is a wave packet - in principle have any given size and shape(above).

 

[craigi]

According to one professor of physics:
Yes, experiments with these particles have not shown any internal structure, deserving the name elementary particle. Why does that mean they are point particles? Relativity forbids faster than light propagation of signals. So pushing on one side of an extended electron would instantaneously move the other side (any elasticity would mean internal structure). That cannot be the case unless the size is zero.

That really needs a reference. If I search the internet for that quote, I find one result and it's on a Croation religion forum.

Is that where you got it from?

 

[Drakkith]

Ok, understood, but if that's the case why is everyone talking about electron as purely dimensionless particle, when based on your post it is not dimensionless at all, after all?

I don't think you understood his post at all. Look again.

Which would you say is an electron size? The spread around an atom? The size of a string? The point that it's measured at? I'd say all three are valid and that's why we say that the concept of size of an elementary particle doesn't have much meaning.

He's saying that the size of an elementary particle such as an electron will be different depending on what you accept as size.

To quote a paper on arxiv: http://arxiv.org/abs/quant-ph/0702112

Simple arguments based on uncertainty principle and Dirac's equation are examined which show that electron behaves either as a point-like charge or as an extended distribution according as high- or low-energy experiments are considered.

In other words, the electron behaves either as a point-like charge or as an extended distribution depending on how you ask the question. (Much like how a particle can be viewed as either a particle or a wave depending on how you set up the experiment)

You keep wanting "proof" that an elementary particle is zero-dimensional. Perhaps it is best to say that an elementary particle can be either non-dimensional or 3-dimensional depending on how you look at it. There are times when the point particle concept is very useful and times when the "smeared out" 3-d view is useful.

If you take anything away from this thread I think the above description would be most useful.

 

[julcab12]

When we talk about dimensionlessnes of particles; is the following true?
According to one professor of physics:
Yes, experiments with these particles have not shown any internal structure, deserving the name elementary particle. Why does that mean they are point particles? Relativity forbids faster than light propagation of signals. So pushing on one side of an extended electron would instantaneously move the other side (any elasticity would mean internal structure). That cannot be the case unless the size is zero.

But how does this exactly prove that electron is dimensionless?

... http://arnold-neumaier.at/physfaq/physics-faq.html#pointlike-- Find chapter B3

 

[Mordred]

But how does this prove that electron, quark, or photon and etc. are all dimensionless particles?
They even say that composite particles are also dimensionless?

the answers are already provided, I particularly like Drakkith's post with the arxiv link. Good read I enjoyed it. julcab12's link is also a decent read, very straightforward layman's style of writing.

 

[No-where-man]

the answers are already provided, I particularly like Drakkith's post with the arxiv link. Good read I enjoyed it. julcab12's link is also a decent read, very straightforward layman's style of writing.

Thanks to Drakkith and Julcab12 for links, I read in pdf arxiv link that Drakkith provided says this:
Nowadays many physicists agree that elementary particles are point-like objects.
This opinion is based mostly on results of late experiments on high-energy electron-positron collisions.
These experiments show that the electron size is less than 10^−16cm, that is, more than three orders of magnitude smaller than the classical electron radius.

But 10^−16cm does actually mean that electron does have a size.

 

[No-where-man]

the answers are already provided, I particularly like Drakkith's post with the arxiv link. Good read I enjoyed it. julcab12's link is also a decent read, very straightforward layman's style of writing.

I don't think you understood his post at all. Look again.
He's saying that the size of an elementary particle such as an electron will be different depending on what you accept as size.

To quote a paper on arxiv: http://arxiv.org/abs/quant-ph/0702112
In other words, the electron behaves either as a point-like charge or as an extended distribution depending on how you ask the question. (Much like how a particle can be viewed as either a particle or a wave depending on how you set up the experiment)

You keep wanting "proof" that an elementary particle is zero-dimensional. Perhaps it is best to say that an elementary particle can be either non-dimensional or 3-dimensional depending on how you look at it. There are times when the point particle concept is very useful and times when the "smeared out" 3-d view is useful.

If you take anything away from this thread I think the above description would be most useful.

Thanks to Drakkith and Julcab12 for links, I read in pdf arxiv link that Drakkith provided says this:
"Nowadays many physicists agree that elementary particles are point-like objects.
This opinion is based mostly on results of late experiments on high-energy electron-positron collisions.
These experiments show that the electron size is less than 10^−16cm, that is, more than three orders of magnitude smaller than the classical electron radius."

But 10^−16cm does actually mean that electron does have a size.

Similar, basically the same answers are provided by links that Julcab12 gave.

 

[TumblingDice]

I read in pdf arxiv link that Drakkith provided says this:
Nowadays many physicists agree that elementary particles are point-like objects.
This opinion is based mostly on results of late experiments on high-energy electron-positron collisions.
These experiments show that the electron size is less than 10^−16cm, ...

But 10^−16cm does actually mean that electron does have a size.

I think the words "less than" are of significance here. This is how physicists tighten the noose on values to the best of their measurement capabilities. A similar example you'll come across is that the mass of a (massless) photon is "less than" some value. Many times information like this is misinterpreted. These statements aren't meant to suggest that an electron has a size or that a photon has mass, but rather to aggressively test these values to the limits that current technologies allow.

 

[Drakkith]

To bounce off of TumblingDice, note that this is commonplace is physics. For example, the mass and electric charge of a photon are taken to be zero, but real measurements can only measure to a finite degree of accuracy.

The very first section of the following paper shows that the mass of the photon has been measured to be less than 1 x 10^-18 eV and the electric charge has been measured to be less than 1x10^-35 e.

http://pdg.lbl.gov/2009/tables/rpp2009-sum-gauge-higgs-bosons.pdf

 

[No-where-man]

I think the words "less than" are of significance here. This is how physicists tighten the noose on values to the best of their measurement capabilities. A similar example you'll come across is that the mass of a (massless) photon is "less than" some value. Many times information like this is misinterpreted. These statements aren't meant to suggest that an electron has a size or that a photon has mass, but rather to aggressively test these values to the limits that current technologies allow.

To bounce off of TumblingDice, note that this is commonplace is physics. For example, the mass and electric charge of a photon are taken to be zero, but real measurements can only measure to a finite degree of accuracy.

The very first section of the following paper shows that the mass of the photon has been measured to be less than 1 x 10^-18 eV and the electric charge has been measured to be less than 1x10^-35 e.

http://pdg.lbl.gov/2009/tables/rpp2009-sum-gauge-higgs-bosons.pdf

But if that's all correct, than it's not fair to say that electron/quark/photon or whatever particle has no size or mass if technologies are unable to prove or disprove this hypothesis?
Believe it or not, there are phsicists who actually think that these particles do have size, for example.
I guess, unless you can truly prove something 100%, than there will never be possible to say ok, these particles are dimensionless, and none is questioning this anymore, because it's 100% irrefutably, 100% proven scientific fact.
Like you said the problem is with detection and measurement abilities that our technologies can provide-and they are very limited.
Unless we have a technology that can directly both detect and measure infinitely small sizes, there is absolutely no way to know what exactly is true: particles do have size, or particles do not have size?
It's a zillion dollar question.
To be honest, I'd like that science can 100% prove that these particles are truly dimensionless, but that is only my wishful thinking, since it's impossible to prove or disprove if all particles are truly dimensionless or all particles actually do have a size.

 

[Chronos]

A little logic never hurts. Is it reasonable to assume an electron has infinite charge or mass density? I doubt you will find any credible scientist who would agree.

 

[No-where-man]

I need advice from all of the members-physicists here:
I'm right in the situation that I'm in a debate with someone who is studying physics and who is far more knowledgeable than me when it comes to physics.

But the problem is that he says that dimensionless particles are 100% irrefutably, 100% proven scientific facts as well as the mathematics which enabled us to come to these conclusions, unlike people here this is why I asked you all here on the forum for your professional opinions about this subject.
Unlike him, neither of you is coming to fast conclusions and neither is saying that is 100% proven that particles are truly dimensionless and neither is really claiming that it is 100% proven they have size-basically, from what I can see you are always neutral and objective (which is the best position you can take).

Since he knows physics much better than I do, the only thing I'm saying is that it is unprovable that particles are truly dimensionless or that they do have a size-mostly because of technologies available which are very limited when it comes measurement and detection of infinitely small things/particles/fields and etc., and you would need technology that would be able to directly detect and measure infinitely small things, particles, singularities, whatever.

So, I'm asking you all what do you recommend what should I answer to him?
Is he right or wrong, of being so sure that particles are truly dimensionless?

Am I right when I say that is impossible to prove or disprove that particles are truly dimensionless because of the measurements and detections that technologies can provide which are all very limited?
I don't understand why is he such an absolutist?
If he is so sure about this than I guess for him there is no rule: in science there is nothing that can be proven or disproven, and that's golden rule for any scientist, or at least should be, if you're truly an objective scientist.

In the end what do you recommend me?

 

[Chronos]

It might be worth exploring a parallel question - why is an electron not infinitely dense [i.e., a black hole]? For discussion, see http://cow.physics.wisc.edu/~ogelman/guide/e/ . This is a ridiculous proposition that entirely lacks observational support.

 

[No-where-man]

I also have one quick question:
How can electron, quark, photon be dimensionless if the smallest quantum size limit-the Planck's length is below their size, since all of the particles are bigger in size than Planck's length?
Most likely, I'm misunderstanding something, but I don't know what exactly.

http://blogs.discovermagazine.com/b...you-dont-know-about-black-holes/#.UzphiVT_RXo

 

[No-where-man]

A little logic never hurts. Is it reasonable to assume an electron has infinite charge or mass density? I doubt you will find any credible scientist who would agree.

It might be worth exploring a parallel question - why is an electron not infinitely dense [i.e., a black hole]? For discussion, see http://cow.physics.wisc.edu/~ogelman/guide/e/ . This is a ridiculous proposition that entirely lacks observational support.

This is a good thing to know; that all credible physicists know that an electron does not really have infinite charge or infinite mass density after all.

 

[Drakkith]

I also have one quick question:
How can electron, quark, photon be dimensionless if the smallest quantum size limit-the Planck's length is below their size, since all of the particles are bigger in size than Planck's length?
Most likely, I'm misunderstanding something, but I don't know what exactly.

http://blogs.discovermagazine.com/b...you-dont-know-about-black-holes/#.UzphiVT_RXo

To quote the article (underlining mine):

At some point, the collapsing core will be smaller than an atom, smaller than a nucleus, smaller than an electron. It’ll eventually reach a size called the Planck Length, a unit so small that quantum mechanics rules it with an iron fist. A Planck Length is a kind of quantum size limit: if an object gets smaller than this, we literally cannot know much about it with any certainty.

All this says is that IF something is smaller than the Planck length, we simply cannot know anything about it. It's not saying that an object cannot be smaller than this length. Besides, I don't know where you're getting the idea that all particles are larger than this size. It's that the upper limit to their sizes are larger than this, which is a result of our measurement methods having finite accuracy and precision.

So, I'm asking you all what do you recommend what should I answer to him?
Is he right or wrong, of being so sure that particles are truly dimensionless?

Am I right when I say that is impossible to prove or disprove that particles are truly dimensionless because of the measurements and detections that technologies can provide which are all very limited?
I don't understand why is he such an absolutist?
If he is so sure about this than I guess for him there is no rule: in science there is nothing that can be proven or disproven, and that's golden rule for any scientist, or at least should be, if you're truly an objective scientist.

I don't know how to answer this since I don't know his rationale for claiming that particles have been proven to be point particles. I'd recommend asking him why he believes this.

 

[julcab12]

I also have one quick question:
How can electron, quark, photon be dimensionless if the smallest quantum size limit-the Planck's length is below their size, since all of the particles are bigger in size than Planck's length?
Most likely, I'm misunderstanding something, but I don't know what exactly.

http://blogs.discovermagazine.com/b...you-dont-know-about-black-holes/#.UzphiVT_RXo

...Maybe he is referring to the 18+ or so dimensionless parameter of Standard model. Anyways, QFT doesn't have a fundamental measurement since it is always has some adjustable parameters. It is subject to rescaled unless we have a Quantum theory that reduces energies less than some large energy to confine particle to a degree.. This is actually how they determine the mass of proton. They can only measure to a certain constraint and it can't be absolute. Those measurements has value but has unpredictable real quantities. (The link i provided has a good straight forward bird droppings/sublinks. Chapter b3-4 should give you a rundown).



...Instead of debating with your friend. Try to get as much info. Ask questions, investigate and re-evaluate. (He's more knowledgeable on the subject). BTW. Learn more on his/her language..^^

 

[craigi]

I also have one quick question:
How can electron, quark, photon be dimensionless if the smallest quantum size limit-the Planck's length is below their size, since all of the particles are bigger in size than Planck's length?

We've already discussed this. There is no proven significance of the Planck length, though modern theories of quantum physics take the Planck length as a minimum size of an object very seriously. They remain unproven. It's also worth reminding yourself of the scale comparision that I gave to see how small the Planck length really is.

...
So, I'm asking you all what do you recommend what should I answer to him?
Is he right or wrong, of being so sure that particles are truly dimensionless?
...
In the end what do you recommend me?

In all seriousness, my recommendation is that you politely excuse yourself from the argument. I don't see what either of you can gain by trying to defeat the other. Which of you is right comes down to subtleties of definitions, so if one of you does walk away the victor, it will be a very hollow victory.

 

[Chronos]

In the real world, you apply logic and causality - neither of which explains an infinitely dense charge or mass density.

 

[No-where-man]

In the real world, you apply logic and causality - neither of which explains an infinitely dense charge or mass density.

Sure, he will say than, that human logic has made mistakes through history-which is true, so, he will say, that if math says that dimensionless singularity, dimensionless particles, an infinitely dense charge and infinite mass density all do exist, becuase they are 100% proven to exist, and that all of this is 100% experimentally proven.

We've already discussed this. There is no proven significance of the Planck length, though modern theories of quantum physics take the Planck length as a minimum size of an object very seriously. They remain unproven. It's also worth reminding yourself of the scale comparision that I gave to see how small the Planck length really is.

What do you exactly mean? You mean that is particles are dimensionless despite the Planck's length-which is the quantum size limit, or that is uncertain (and it will always be uncertain) that particles are truly dimensionless?

In all seriousness, my recommendation is that you politely excuse yourself from the argument. I don't see what either of you can gain by trying to defeat the other. Which of you is right comes down to subtleties of definitions, so if one of you does walk away the victor, it will be a very hollow victory.

Trust me, I did not argue with this guy who knows physics very good, this is not a fight like you thought it is, the only thing I was asking him, why is so sure about what he is saying about dimensionless objects; sure we have mathematics and experimantal evidences, but it's far from being 100% proven as he claims it is.
What I can see in the forums that none here is absolutist when it comes dimensionlessness, dimensionless particles, singularity and etc. none of you ever said or even thought that all of this in physics is 100% proven, you simply use words; it is uncertain-which is the only true thing (as you all specifically confirmed), because nothing in science can ever be 100% proven or disproven.

 

[No-where-man]

...Maybe he is referring to the 18+ or so dimensionless parameter of Standard model. Anyways, QFT doesn't have a fundamental measurement since it is always has some adjustable parameters. It is subject to rescaled unless we have a Quantum theory that reduces energies less than some large energy to confine particle to a degree.. This is actually how they determine the mass of proton. They can only measure to a certain constraint and it can't be absolute. Those measurements has value but has unpredictable real quantities. (The link i provided has a good straight forward bird droppings/sublinks. Chapter b3-4 should give you a rundown).



...Instead of debating with your friend. Try to get as much info. Ask questions, investigate and re-evaluate. (He's more knowledgeable on the subject). BTW. Learn more on his/her language..^^

Thanks for the support, as I said above to Chronos and Craigi in post #42, I did not try to debate him at all because he knows physics so much more than I do, basically what I was saying all the time to him, that nothing in science can be 100% proven or disproven, as well as the problems with measurements, and detection, there are always shreds of doubt that are present, and there is truly nothing 100% provable/proven/disproven-I think these statements are accurate, and yes I will look up to this link that you gave me, and I will listen to your advices.
Big thanks to all for help and advices.

 

[craigi]

Thanks for the support, as I said above to Chronos and Craigi in post #42, I did not try to debate him at all because he knows physics so much more than I do, basically what I was saying all the time to him, that nothing in science can be 100% proven or disproven, as well as the problems with measurements, and detection, there are always shreds of doubt that are present, and there is truly nothing 100% provable/proven/disproven-I think these statements are accurate, and yes I will look up to this link that you gave me, and I will listen to your advices.
Big thanks to all for help and advices.

The problem that I have with this thread is that you're clearly using it to generate ammunition for an argument that you're having on a Croation religion forum, here: http://www.forum.hr/showthread.php?p=49381433

You're not following what we're telling you, rather you cherry-pick the parts that suit your purpose then throw them at someone else without context, in the other thread. It doesn't matter which side of the religious debate that you're on, this isn't how science works and it isn't how this forum works either. It doesn't form a reasonable basis for debate in theology or philosophy either, for that matter. Contrary, to what we've suggested previously, if you take anything away from this thread it should be that.

I don't speak Crotatian and machine translations aren't particularly reliable, but it doesn't seem that the guy in the other thread is telling you anything different to what we're telling you here. It seems like you're arguing with different physicists who agree on the same concepts, but filtering them through a one-man Chinese whisper machine.

 

[No-where-man]

The problem that I have with this thread is that you're clearly using it to generate ammunition for an argument that you're having on a Croation religion forum, here: http://www.forum.hr/showthread.php?p=49381433

You're not following what we're telling you, rather you cherry-pick the parts that suit your purpose then throw them at some one else without context, in the other thread. It doesn't matter which side of the relgious debate that you're on, this isn't how science works and it isn't how this forum works either. It doesn't form a reasonable basis for debate in theology or philosophy either, for that matter. Contrary, to what we've suggested previously, if you take anything away from this thread it should be this.

Trust me, I pick no side at all, if there is a side I pick, its the side of pure science. We were simply discussing about if it's 100% proven that particles are dimensionless and about singularity, so although the thread is from religion forum, the theme that NOD and I were discussing were based purely on science and what is 100% proven and what is 100% disproven; plus the poster is an obviously a physicist who knows what he is talking about and who is using science/physics for arguments, but he is absolutely sure that what he says about the existence of dimensionlessnes, dimensionless particles and dimensionless singularity are 100% mathematically and 100% experimentally proven and that the existence of dimensionlessnes, dimensionless particles and dimensionless singularity all are 100% irrefutably, 100% proven scientific facts.

But in this thread on physics forums, I see that it's obvious that story with is far from over, since nothing in science can be 100% proven or disproven.
I will listen to all of your advices, what you, Craigi, and the rest of people/physicists here on this forum suggested me to do.
Big thanks to all.

 

[craigi]

Trust me, I pick no side at all, if there is a side I pick, its the side of pure science. We were simply discussing about if it's 100% proven that particles are dimensionless and about singularity, so although the thread is from religion forum, the theme that NOD and I were discussing were based purely on science and what is 100% proven and what is 100% disproven; plus the poster is an obviously a physicist who knows what he is talking about and who is using science/physics for arguments, but he is absolutely sure that what he says about dimensionlessnes, dimensionless particles and dimensionless singularity is 100% mathematically and 100% experimentally proven, as in this thread it's obvious that story is far from over, since nothing in science can be 100% proven or disproven.
I will listen to advices, what you, Craigi, and the rest of people/physicists here on this forum suggested me to do.
Big thanks to all.

If you want to discuss science on a science forum, it doesn't make a lot of sense to cast doubt on the scientific method when you're presented with a conclusion that you don't like. Scientists are, of course, aware that to prove anything we need to make a philosophical assumption about the validity of the method, but it should be no surprise to you that we don't debate this assumption within the field of science.

You can see an detailed description here: http://en.wikipedia.org/wiki/Scientific_method, but for obvious reasons this isn't up for discussion on this forum.

 

[No-where-man]

If you want to discuss science on a science forum, it doesn't make a lot of sense to cast doubt on the scientific method when you're presented with a conclusion that you don't like. Scientists are, of course, aware that to prove anything we need to make a philosophical assumption about the validity of the method, but it should be no surprise to you that we don't debate this assumption within the field of science.

You can see an detailed description here: http://en.wikipedia.org/wiki/Scientific_method, but for obvious reasons this isn't up for discussion on this forum.

Actually this was indeed discussed in science sub-forum in the same forum as well, I will give you a link if you don't believe me:
http://www.forum.hr/showthread.php?t=818634

I posted the same thing that you were answering me as well as the fact there are posters who know physics in this thread in science sub-forum and they agreed with me.
This NOD for some reason kept continuing to be absolutist on Religion sub-forum, claiming that when it comes to dimensionless particles, singularity and etc, is all 100% proven.
Sure NOD does know physics but there other people on the forum who know more physics than he does, but unlike NOD, some other posters who truly know physics are not absolutists like NOD is, because they know, unlike NOD, that there is always that degree of uncertainty.

 

[craigi]

Actually this was indeed discussed in science sub-forum in the same forum as well, I will give you a link if you don't believe me:
http://www.forum.hr/showthread.php?t=818634

I posted the same thing that you were answering me as well as the fact there are posters who know physics in this thread in science sub-forum and they agreed with me.
This NOD for some reason kept continuing to be absolutist on Religion sub-forum, claiming that when it comes to dimensionless particles, singularity and etc, is all 100% proven.
Sure NOD does know physics but there other people on the forum who know more physics than he does, but unlike NOD, some other posters who truly know physics are not absolutists like NOD is, because they know, unlike NOD, that there is always that degree of uncertainty.

Case closed.

This thread should be too.

 

[No-where-man]

Here is a weird question: Does gravity has a size at all?
Yes, gravity is a force, but does it have a size, or it is completely dimensionless?
I'm asking this because everything that has to do with gravity is/are basically effects of gravity and not the gravity itself.
For that matter, does a force/any force have a size, and does energy have a size at all, or what we can see everywhere in the universe, are simply effects of forces and energy?
I'm not sure if I asked this question right or wrong.
I'm not sure how to ask this question.

I'm opened to other posters' suggestions, opinions and whatever.
Big thanks in advance to all.

 

[Drakkith]

Here is a weird question: Does gravity has a size at all?
Yes, gravity is a force, but does it have a size, or it is completely dimensionless?
I'm asking this because everything that has to do with gravity is/are basically effects of gravity and not the gravity itself.
For that matter, does a force/any force have a size, and does energy have a size at all, or what we can see everywhere in the universe, are simply effects of forces and energy?
I'm not sure if I asked this question right or wrong.
I'm not sure how to ask this question.

That really depends on what you mean by "size". By the way you've worded your question I assume you're asking if it has physical dimensions like a physical object would. In that case, no, gravity does not have a size because it is not an object. Gravity takes up no space. It has no volume.

Of course, I'm sure someone will point out the event horizon of a black hole, but that is also not a physical object. An infalling observer would never know they crossed the event horizon. It is merely the radius where the strength of gravity won't let even light escape.

Also, by "dimensionless", are you asking about dimensionless quantities?