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Author Topic:   The resilience of matter's fundamental components
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 16 of 46 (210047)
05-20-2005 3:54 PM
Reply to: Message 14 by Tony650
05-20-2005 2:12 AM


Re: Bump?
Tony650
I don't recall the details so I may have this wrong, but the upshot of it (I think) was that an overall body can have mass even if its fundamental components have no mass of their own.
As the formula E=MC^2 is an equivalency formula the energy possesed by these components can be regarded as their "mass".

This message is a reply to:
 Message 14 by Tony650, posted 05-20-2005 2:12 AM Tony650 has replied

Replies to this message:
 Message 19 by Tony650, posted 05-21-2005 10:23 AM sidelined has replied

  
Tony650
Member (Idle past 4032 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 17 of 46 (210178)
05-21-2005 10:12 AM
Reply to: Message 15 by SirL
05-20-2005 1:34 PM


Point-like particles
SirL writes:
Elemental particles, including quarks, are considered point objects: that is, they have neither volume nor any internal structure as far as anyone can tell.
Ah, point-like particles. This is another thing I've always had trouble wrapping my head around. I find the concept fascinating but I've never been able to really understand it.
How, for example, can a point-like particle be said to "exist" if it has a total lack of dimension? In what sense is anything really "there" if it has no size? Are these things which we call "particles" actually nothing more than locations in spacetime?
To clarify my meaning, when I think of a "point" I don't imagine it to be an actual, corporeal entity denoting a location in spacetime; I imagine it to be the location itself. Or to put it another way, I am of the understanding that "points" in spacetime do not actually exist in any tangible way; they are essentially an abstraction that we use to represent locations. Does this mean that, in some sense, matter is ultimately composed of nothing more than locations in spacetime?
My other dilemma is how any quantity of zero-sized particles can comprise anything with non-zero size. No matter how many times you add zero to itself it will only ever be zero. How, then, can a body with a positive volume be composed of nothing but empty space and particles with no size?
I knew that the vast majority of matter was empty space, but if its most basic components have no size at all then does it not follow that matter is actually 100% empty space? What, then, gives a material body its "substance"? Is it ultimately nothing but a web of forces spanning points (locations?) in spacetime?

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Replies to this message:
 Message 18 by Brad McFall, posted 05-21-2005 10:17 AM Tony650 has replied

  
Brad McFall
Member (Idle past 5032 days)
Posts: 3428
From: Ithaca,NY, USA
Joined: 12-20-2001


Message 18 of 46 (210180)
05-21-2005 10:17 AM
Reply to: Message 17 by Tony650
05-21-2005 10:12 AM


Re: Point-like particles
Not that this is going to help you get back up on this road, but Euclid says
http://aleph0.clarku.edu/...e/java/elements/bookI/defI1.html
a point is that which has no part.
I often think/thought that a whole that has the parts equal to the whole is still a point.
This was too philosophical for a person at Cornell.

This message is a reply to:
 Message 17 by Tony650, posted 05-21-2005 10:12 AM Tony650 has replied

Replies to this message:
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Tony650
Member (Idle past 4032 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 19 of 46 (210182)
05-21-2005 10:23 AM
Reply to: Message 16 by sidelined
05-20-2005 3:54 PM


What is energy?
sidelined writes:
As the formula E=MC^2 is an equivalency formula the energy possesed by these components can be regarded as their "mass".
Ah, yes! Energy is mass is energy.
Something I've never been completely clear about, though, is what energy actually is in this context. Why, for example, does a photon have no mass? Does it not have energy? What exactly do "massive" particles have that it doesn't? This is one of the things that confuses me; particles that would seem to have energy yet no mass. Of course, I'm not sure how "energy" is defined at this level, so this is likely part of my problem.

This message is a reply to:
 Message 16 by sidelined, posted 05-20-2005 3:54 PM sidelined has replied

Replies to this message:
 Message 21 by sidelined, posted 05-21-2005 11:31 AM Tony650 has replied

  
Tony650
Member (Idle past 4032 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 20 of 46 (210189)
05-21-2005 10:54 AM
Reply to: Message 18 by Brad McFall
05-21-2005 10:17 AM


Re: Point-like particles
Hi Brad. Thanks for the link.
Yes, well this is something that kind of jolts my mind a bit. Of course, mind jolts are a pretty common occurrence when dealing with these subjects.
The difficulty I have, in this case, is understanding how anything with a material substance can be composed of particles with no size. To my intuitive senses, "no size" equates to "non-existent." However, having said that, I then wonder about those locations themselves. Do they exist? As concepts, certainly. But pick any arbitrary location in spacetime and what is it that is being said to "exist"?
I expect that the problem is that we think of locations in relative terms. If we were to find ourselves floating in a black, empty void with no contrasting "landmarks," however, I imagine the concept of "location" would become somewhat meaningless. In such a scenario, the only sense of location you could speak of would be relative to you.
Ah, but relativity's off-topic here. We're talking about quantum theory, relativity's mortal enemy.

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 Message 18 by Brad McFall, posted 05-21-2005 10:17 AM Brad McFall has not replied

  
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 21 of 46 (210199)
05-21-2005 11:31 AM
Reply to: Message 19 by Tony650
05-21-2005 10:23 AM


Re: What is energy?
Tony650
Why, for example, does a photon have no mass? Does it not have energy? What exactly do "massive" particles have that it doesn't?
This is the great mystery.We do not know what energy is.Unlike the colloquial terms used in phrases such as chemical energy wind energy,these are actually the fundemental forces and energy in this instance should properly be called work, since it is the work done by the fundemental forces as energy moves through potential states.
Energy in science is simply a quantity that is conserved in all interactions of the fundemental forces.A photon has no mass and as such cannot be at rest and as a consequence must always move at the speed of light.Massive particles,by virtue of their movement at less than the speed of light,possess rest mass,or energy that is localized with the framework of matter.
So massive particles have the property of moving at speeds short that of light while massless particles can only move at that speed.
I am not sure that answers your questions though.

In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.
Douglas Adams

This message is a reply to:
 Message 19 by Tony650, posted 05-21-2005 10:23 AM Tony650 has replied

Replies to this message:
 Message 22 by GDR, posted 05-25-2005 1:06 AM sidelined has not replied
 Message 28 by Tony650, posted 05-26-2005 9:16 PM sidelined has replied

  
GDR
Member
Posts: 6202
From: Sidney, BC, Canada
Joined: 05-22-2005
Member Rating: 1.9


Message 22 of 46 (211023)
05-25-2005 1:06 AM
Reply to: Message 21 by sidelined
05-21-2005 11:31 AM


Re: What is energy?
If you guys don't mind I'd like to have a brief go at this so that my thinking can be critiqued. The basis of my knowledge is reading a few Brian Greene, Stephen Hawking, and similar books over the last couple of months and becoming enthralled with the subject. I had no idea of any of this. I have no scientific education and I took high school physics back when the Earth was still flat.
I gather that the majority of scientists would agree that the particle is the basic building block. By combining what I have read about particles, string theory etc I understand the theory is that particles are all essentially the same except that they behave differently. If string theory is to be believed it is based on the vibration of each individual string or particle. The greater the vibration, the greater the mass. If there is little enough vibration there can be zero mass, and if I recall correctly, it is even possible to have negative mass, whatever that would mean.
As I understand part of Tony's question, he is asking if all space between particles is gone in a singularity. I got the impression from Brian Greene's book that wouldn't be the case as you would reach maximum entropy before that would occur, although maybe that is the point of maximum entropy. As I understand it, that means a black hole has maximum mass for a given size and that if you try to increase the entropy by introducing more mass you can't because the size will increase.
I got somewhat lost in this because it seemed to me that a Black Hole is pretty much all energy and virtually zero mass, it must mean that it is composed almost exclusively of energy particles. Does this mean that particles of mass such as quarks have their characteristics changed so that instead of being a particle with mass they become a particle of energy such as a photon? What is it that changes in the particles in a black hole that causes mass to become energy?
Please be gentle. This is my first time.
This message has been edited by GDR, 05-24-2005 10:42 PM

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Replies to this message:
 Message 23 by 1.61803, posted 05-25-2005 4:29 PM GDR has replied
 Message 29 by Tony650, posted 05-26-2005 9:26 PM GDR has not replied

  
1.61803
Member (Idle past 1504 days)
Posts: 2928
From: Lone Star State USA
Joined: 02-19-2004


Message 23 of 46 (211227)
05-25-2005 4:29 PM
Reply to: Message 22 by GDR
05-25-2005 1:06 AM


Re: What is energy?
Within a black hole's singularity there is, in theory, zero volume and infinite density. The gravity of something that dense becomes like a particle roach motel. particles check in but they dont check out. Light (photons) do not even exit. Hence the name Black hole.
Black holes do have mass though but they have zero volume at the singularity. Do not worry if that makes no sense to you or if you can not wrap your mind around it. You are in good company.
At a quantum level of such extremes things cease to be things and human understanding of physics breaks down. Energy is the currency of the universe IMO.

This message is a reply to:
 Message 22 by GDR, posted 05-25-2005 1:06 AM GDR has replied

Replies to this message:
 Message 24 by GDR, posted 05-25-2005 6:03 PM 1.61803 has replied
 Message 30 by Tony650, posted 05-26-2005 9:38 PM 1.61803 has not replied

  
GDR
Member
Posts: 6202
From: Sidney, BC, Canada
Joined: 05-22-2005
Member Rating: 1.9


Message 24 of 46 (211261)
05-25-2005 6:03 PM
Reply to: Message 23 by 1.61803
05-25-2005 4:29 PM


Re: What is energy?
Thanks for the reply
Does mass always have volume?
I found this definition of mass on the web: >>The modern definition assigns every object just one mass, an invariant quantity that does not depend on velocity. this is given by m = E0 / c2, where E0 is the total energy of that object at rest.<<
Hawking's definition in "The Universe in a Nutshell" is "The quantity of matter in a body; its inertia or resistance to acceleration in free space".
It helps to remember that mass is interchangeable with energy, but when Hawking talks about the quantity in matter I'm back to thinking volume. Does mass by definition always have volume so that although the black hole has mass and volume the singularity itself does not?
I'd like to describe how I picture a black hole and I'd appreciate it if you could let me know how accurate the picture is.
A star burns out and collapses in on itself. After this event and at the center of what was previously the star is the singularity with its properties of infinite energy but zero volume. I assume this would come about because the particles whose properties caused them to have energy but not mass would be drawn into the singluarity.
Encasing the singularity would be a spherical volume with maximum entropy and a volume determined by the amount of mass, and bounded by its event horizon.
Inside the event horizon nothing including light escapes. (Although it seems to me that they recently determined that some information escapes whatever that means.)
Thanks again for the help.

This message is a reply to:
 Message 23 by 1.61803, posted 05-25-2005 4:29 PM 1.61803 has replied

Replies to this message:
 Message 25 by sidelined, posted 05-25-2005 9:43 PM GDR has replied
 Message 27 by 1.61803, posted 05-26-2005 4:18 PM GDR has not replied

  
sidelined
Member (Idle past 5908 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 25 of 46 (211323)
05-25-2005 9:43 PM
Reply to: Message 24 by GDR
05-25-2005 6:03 PM


Re: What is energy?
GDR
I am in a bit of a rush here so I will just drop a website to check out. http://explorepdx.com/feynman.html If you scroll down the page and follow the hyperlinks on energy there will be much to clarify things such as mass and energy.Bye for now.

In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.
Douglas Adams

This message is a reply to:
 Message 24 by GDR, posted 05-25-2005 6:03 PM GDR has replied

Replies to this message:
 Message 26 by GDR, posted 05-26-2005 1:45 AM sidelined has not replied
 Message 32 by Tony650, posted 05-26-2005 9:48 PM sidelined has not replied

  
GDR
Member
Posts: 6202
From: Sidney, BC, Canada
Joined: 05-22-2005
Member Rating: 1.9


Message 26 of 46 (211361)
05-26-2005 1:45 AM
Reply to: Message 25 by sidelined
05-25-2005 9:43 PM


Re: What is energy?
Thanks sidelined

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1.61803
Member (Idle past 1504 days)
Posts: 2928
From: Lone Star State USA
Joined: 02-19-2004


Message 27 of 46 (211545)
05-26-2005 4:18 PM
Reply to: Message 24 by GDR
05-25-2005 6:03 PM


Re: What is energy?
GDR writes:
Does mass by definition always have volume so that although the black hole has mass and volume the singularity itself does not?
an objects mass divided by its volume will give you its density. In the case of a black hole that density will always be an infinite value. Do not think of the Black hole and the singularity as separate. A blackhole terminates at a singularity. (in theory)
Energy is what causes. The causes are what we observe. ***edit to add: I read a cute bumper sticker that said: "Black holes are where God divides by zero."
This message has been edited by 1.61803, 05-26-2005 04:21 PM
This message has been edited by 1.61803, 05-26-2005 04:35 PM

This message is a reply to:
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Tony650
Member (Idle past 4032 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 28 of 46 (211609)
05-26-2005 9:16 PM
Reply to: Message 21 by sidelined
05-21-2005 11:31 AM


Re: What is energy?
Hi sidelined.
Sorry for taking so long to get back to this but I've been reading around a bit to see what I could find.
sidelined writes:
I am not sure that answers your questions though.
Mmm...kind of.
I understand that massive particles must travel slower than light and massless particles at the speed of light, but I'm not sure how that relates to their energy. If mass and energy are equivalent then is it possible for a particle to have one but not the other? Could it be that a photon, for example, possesses energy despite being massless?
Hmm...I'm going to do a little amateur hypothesising here so pull me up if I go wrong anywhere.
Massive particles have variable velocities, but it affects their mass with it approaching infinity as their velocity approaches the speed of light, correct? Massless particles, though, have a constant velocity and a constant mass (zero). So, if mass and energy are equivalent, is a particle's velocity itself an expression of its energy?
Also, a couple of statements that leapt out at me...
sidelined writes:
Energy in science is simply a quantity that is conserved in all interactions of the fundemental forces.
I'm still not sure what this means physically, though. I am very much a layman and not familiar with the underlying mathematical theory, so I really need some kind of physical model/approximation that I can visualize. If it's possible, could you (or anyone else reading) perhaps give me an example of this. It doesn't have to be anything complex. In fact, the more basic the better. Something illustrating a single particle's energy, for example, would be perfect.
I believe I am still thinking, as you said, too much in terms of the common usage. When I hear the word "energy" I think of electrical energy, kinetic energy, etc. But this still isn't the essence of energy, any more than concepts like solid matter or liquid matter are the essence of matter, is it? To understand what matter is you need to get down to its fundamentals, so that's kind of what I'm trying to do with energy. Of course, this may be the wrong approach when it comes to energy, but I don't know how else to go about it.
sidelined writes:
Massive particles,by virtue of their movement at less than the speed of light,possess rest mass,or energy that is localized with the framework of matter.
I'm not sure what you mean by "...energy that is localized with the framework of matter." Could you elaborate on this a little? You mention its rest mass so I am guessing that your statement refers strictly to only the energy that is inherent in matter. That is, to the exclusion of any effect the matter's velocity may have on its overall mass/energy. Is this correct?
Sorry to hit you with all these questions. I'm just trying to get a handle on some things.

This message is a reply to:
 Message 21 by sidelined, posted 05-21-2005 11:31 AM sidelined has replied

Replies to this message:
 Message 46 by sidelined, posted 06-01-2005 8:16 AM Tony650 has not replied

  
Tony650
Member (Idle past 4032 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 29 of 46 (211611)
05-26-2005 9:26 PM
Reply to: Message 22 by GDR
05-25-2005 1:06 AM


Re: What is energy?
GDR writes:
If you guys don't mind...
Not me. My threads aren't exactly renowned for their overwhelming popularity, so the more the merrier.
GDR writes:
As I understand part of Tony's question, he is asking if all space between particles is gone in a singularity.
Not quite. I'm not particularly concerned with whether or not this actually does happen, just whether or not it theoretically can happen. And if so, would it prevent any further collapse or would it continue unabated?
I'm also curious about its general properties. Would a substance in this state be, in some sense, an "absolute" mass/density? If this is the greatest possible density then would it differ in any significant way from neutronic matter, which I believe is currently the densest substance known to exist?
These aren't specifically for you to answer, GDR (though feel free, if you wish). I'm just throwing some thoughts around. Ultimately, there may turn out to be no answers anyway. It's quite possible that such a state simply can't be achieved by matter, and if so, it would render many of my questions effectively meaningless. Although, I suppose it would still leave open the question of why such a state is impossible.

This message is a reply to:
 Message 22 by GDR, posted 05-25-2005 1:06 AM GDR has not replied

  
Tony650
Member (Idle past 4032 days)
Posts: 450
From: Australia
Joined: 01-30-2004


Message 30 of 46 (211614)
05-26-2005 9:38 PM
Reply to: Message 23 by 1.61803
05-25-2005 4:29 PM


Re: What is energy?
1.61803 writes:
Within a black hole's singularity there is, in theory, zero volume and infinite density.
I must admit, I've always had a really hard time with this. I don't understand in what sense a body with no volume can be said to "exist."
Just to be sure of what you're saying, does the math actually show a singularity to be of zero size, or just something vanishingly small? That is, does it actually work out to zero and no more? Not a micron, not a nanometer, not even the size of Planck length itself...but zero? Absolutely and totally zero? From what I understand of this, I imagine that you really are saying zero, but I'm just making sure.
In any case, an unimaginably small volume I have no problem with, but no volume at all ties my brain in knots. I've never been able to grasp the reality of it, as "no size" would seem, for all intents and purposes, to mean "not there." If you are indeed saying absolutely zero, and I suspect that you are, is there any way to grasp this beyond showing it mathematically (which I am not familiar with anyway)?

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 Message 23 by 1.61803, posted 05-25-2005 4:29 PM 1.61803 has not replied

Replies to this message:
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