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What is matter? Options
RubyMoon
Posted: Saturday, April 21, 2012 10:46:18 PM
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FounDit

Talking about "decay" is in the realm of radioactivity. Maybe read up on radioactivity in general/isotopes (you know stability/non-stability, etc.). Also, check out the properties of elements 1 - 92 on the Periodic Table.

In particular, check out the isotopes of carbon.

If you then have a particular/precise question... a few of us may be able to point you in the right direction.

Keep in mind that most current theories in quantum mechanics are just that - theories
FounDit
Posted: Sunday, April 22, 2012 10:31:17 AM

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RubyMoon

I do recall a little about isotopes. If memory serves, they are atoms with neutrons in excess of the number of protons. C12, C13, C14 being a couple of the Carbon isotopes.

When they break down, they give off energy as radiation, therefore, they are radioisotopes. But that leads to asking how they got together in the first place is they are magnetically unstable (the typical asnwer is in star formation or death..ok...very well could be). Also, if matter is energy slowed down, how does energy give off energy by separating from its fellows?...Think

But if matter is energy simply combining in various forms, that still doesn't answer the question of how energy gives off energy. Also, I seem to recall that electrons are supposed to give off energy when they drop from one orbit to another. I can't recall how they were stimulated to jump to the higher orbit, only that a method is possible.

Supposedly, alpha particles (2p+2n I think), beta particles and gamma rays are 3 different types of energy supposedly given off. So there are different types of energy (different frequencies/speeds/types?)...curiouser and curiouser.

Ok. So if an atom is unstable and gives off energy to become stable, then how long can it remain stable? Forever? Nothing is supposed to be able to last forever, so they must eventually break down into.....??? Discreet parts? Then into...???

Fun.
Jean_extraterre
Posted: Sunday, April 22, 2012 4:25:30 PM
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It is nice to see the many postings in this thread and to witness the great interest that these physical issues attract. Unfortunately, there are some fancy ideas around which are rather "incompatible" with the current knowledge that physics provides. Mathematics is the language of physics and it allows the precise statements needed there. Words or pictures fail to be precise enough to furnish an adequate description. While pictorial allegories may reflect properly some aspect of a physical fact, they can become grossly misleading if taken too literally. Even if the very doubtful assertion that matter is energy slowed down is replaced by one like matter is condensed energy that comes closer to the truth, also the latter picture is still incorrect and, e.g., may lead to the confusion of "matter" with "mass"; matter and mass are not the same. As I already wrote in a previous post, matter can be characterized as a system that contains particles with non-zero rest mass. Taking the simplest atom, viz. the hydrogen atom, as an example, this consists of a proton (that itself enjoys an internal structure by being composed of quarks that are held together by the exchange of gluons) and one electron, both interacting via the exchange of virtual photons. The latter are the messenger particles that convey the electromagnetic force; photons have zero rest mass, while the electron and the proton enjoy a nonzero rest mass. The mass of the latter is about 1840 times the mass of the former, so that most of the rest mass of the atom is concentrated in its nucleus.

Let me try to provide a bit more information to some statements in postings above:

Matter can neither be created or destroyed No, that is not true. If matter and antimatter collide, e.g. hydrogen and antihydrogen (consisting of a (negatively charged) antiproton and a (positively charged) positron), then both annihilate into radiation, i.e., photons. However, the assertion above becomes correct if "matter" is replaced by "mass", so: Mass can neither be created or destroyed.

It is the motion of the electrons that creates the illusion of solid matter. Well, this "motion" must be regarded as being very different from the orbiting of, e.g., planets around a central star. If the electrons in an atom were really moving, then (since they are charged particles) this would imply that they would constantly produce electromagnetic radiation, so atoms would lose energy by radiating all the time and thus couldn't be stable. Actually, the probability distribution of electrons in an atom is static and thus does not change in time (unless perturbed by "external" effects). It is the complex phase of the electronic wavefunction that oscillates in time. On the other hand, it is true that the kinetic energy of the electrons is required to render atomic systems stable. Without this kinetic energy, the electrostatic attraction between the positive nucleus and the negatively charged electrons would make the latter to collapse into the nucleus. The structure of atoms and molecules and thus of "ordinary" matter is also significantly influenced by the fact that electrons are fermions and thus the Pauli exclusion principle holds which forbids any two electrons to occupy the same quantum state. If electrons were bosons, they could occupy the same quantum state which would result in very a different "chemistry" and very different properties of normal matter.

Electromagnetism is mostly influential at the chemical or molecular scale. At larger or smaller scales it is not all that significant, but rather follows the dominant forces. At larger scales, this is not the result of another force taking over (like it is for smaller scales), but a consequence of the neutrality of (most of) ordinary matter. If for atoms the net effect of positive nuclear and negative electronic charge wouldn't compensate "outside" of the atom to render it neutral, then the electromagnetic force would also dominate on astronomical scales and the gravitational force would play almost no role. Again, this would lead to a world rather different from that we are in now.
FounDit
Posted: Sunday, April 22, 2012 9:58:46 PM

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Thank you, Jean_extraterre.

While I didn't understand completely some of what you said, such as virtual photons, etc., I see now that the pictorial allegories of which you spoke are all I have to work with, and they are woefully insufficient to the task. Mathematics is, indeed, the language of physics, and explains why I am so ignorant on the subject. If I were twice as knowledgeable as I currently am, I would still be ignorant in physics. So I should quit while I am ahead, or behind, as the case may be. Thanks again. A very interesting read. Applause
Jean_extraterre
Posted: Monday, April 23, 2012 2:23:37 PM
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FounDit wrote:
Thank you, Jean_extraterre.

While I didn't understand completely some of what you said, such as virtual photons, etc., I see now that the pictorial allegories of which you spoke are all I have to work with, and they are woefully insufficient to the task. Mathematics is, indeed, the language of physics, and explains why I am so ignorant on the subject. If I were twice as knowledgeable as I currently am, I would still be ignorant in physics. So I should quit while I am ahead, or behind, as the case may be. Thanks again. A very interesting read.


Sorry, dear FounDit, if by pointing out the limited value of allegories I discouraged you from continuing to think about physical issues; this was definitely not my intention. Actually, pictorial allegories are quite common in physics, and scientists use and rely on them in their everyday work and thinking. A scientist familiar with the field, however, usually knows the limits of such pictures, or, if he/she employs them and builds something new upon them, then constructions based upon over-interpreted pictures will sooner or later lead to troubles with experiments or other theories, thus revealing the invalid aspects of the used allegory. This is one way how learning and research is proceeding. So, rather than to quit thinking and enquiring, it is much better to continue with allegories even if sometimes they may lead one astray.

As you have posted above an interesting question, viz. "if an atom is unstable and gives off energy to become stable, then how long can it remain stable?", let me try to comment on it.

For simplicity, consider an isolated hydrogen atom, and, for the moment, neglect the internal structure of the nucleus, i.e., of the proton. Quantum mechanically, a stable hydrogen atom (i.e., where the electron is bound to the nucleus and not ionized from it) can only exist in certain states with discrete energy levels. The state associated with the lowest possible energy is called the ground state, the other states are the excited states and have an energy that lies above the ground state energy. Suppose that initially the hydrogen atom is in one of these states. Then, without an interaction with its environment, it will remain in the same state forever. However, this is an idealized situation, as there always will be interactions of the atom with its environment, even if it is just put into the physical vacuum. The latter, in fact, is not really a void, rather, the vacuum "boils", which means that spontaneously pair creation and annihilation processes occur all the time, e.g., an electron - positron pair is created and, after its creation, almost immediately it again disappears by annihilation. Nonetheless, by interacting with these vacuum fluctuations, the electron of the hydrogen atom achieves the possibility (even if isolated from perturbations by external radiation) to change its state, where the probability to change from an excited state to the ground state is much larger than the opposite direction. Therefore, with overwhelming probability, a hydrogen atom in vacuum ends up in its ground state after a short time; although then spontaneous jumps into excited states cannot be excluded, they will be extremely rare.

Another part of the question is: "How stable are the constituents of the hydrogen atom, i.e., the electron and the proton?" For the electron, all current knowledge predicts the electron to be stable, i.e., there are no processes known by which an isolated electron can decay. The stability of the proton, on the other hand, is still an unsolved problem in physics and has attracted significant theoretical and experimental interest since many decades. GUTs (grand unified theories, i.e., theories that attempt to unify the electromagnetic, the weak, and the strong interaction into a single force) predict that a proton may decay, e.g., into a positron and a neutral pion (where the pion itself is unstable and rapidly decays into photons). Despite of many efforts, until today such decay events have not yet been observed experimentally. The lower limit of the lifetime of protons extracted from these experiments is larger than 10^30 (ten power 30) years (cf., e.g., here) and thus much much larger than the age of universe.
FounDit
Posted: Monday, April 23, 2012 10:46:52 PM

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I’m in trouble from the start with this statement:

The state associated with the lowest possible energy is called the ground state, the other states are the excited states and have an energy that lies above the ground state energy.
and
The latter, in fact, is not really a void, rather, the vacuum "boils", which means that spontaneously pair creation and annihilation processes occur all the time, e.g., an electron - positron pair is created and, after its creation, almost immediately it again disappears by annihilation.

Are you saying that energy comes into existence from nothing, then goes back out of existence? If so, it’s the first time I have heard of this. That strains my imagination to the maximum trying to comprehend how that can occur. Does anyone have any idea how this occurs?

Therefore, with overwhelming probability, a hydrogen atom in vacuum ends up in its ground state after a short time; although then spontaneous jumps into excited states cannot be excluded, they will be extremely rare.

Now I’m really baffled as to how an atom can “spontaneously” jump to an excited state. I would have thought there would have to be some kind of interaction with another force of some kind.

For the electron, all current knowledge predicts the electron to be stable, i.e., there are no processes known by which an isolated electron can decay.

Now my mind is buzzing with questions about what, exactly, a charged particle really is or even electromagnetic energy itself. But it’s too deep for me. It’s extremely interesting, but I can’t even come up with a pictorial allegory to use for it. And a pion that can change a proton into a neutron and vice-versa, ….getting way-y-y over my head there.

Jean_extraterre
Posted: Tuesday, April 24, 2012 3:45:26 PM
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Quote:

Are you saying that energy comes into existence from nothing, then goes back out of existence? If so, it’s the first time I have heard of this. That strains my imagination to the maximum trying to comprehend how that can occur. Does anyone have any idea how this occurs?


To explain these spontaneous pair creation and annihilation processes, sometimes (even in physics classes) the wrong picture is used that for a short time some energy is "borrowed" from the universe to create the pair, and then "given back" when the pair annihilates. A more correct explanation rests upon a proper use of the uncertainty relation between time and energy: the energy of the vacuum is only on the average equal to a constant (e.g., zero), and it always fluctuates around this value. For sufficiently short time intervals this fluctuation may be large enough to provide the energy required for the creation of a particle - antiparticle pair.

This picture is analogous to the uncertainty relation for canonically conjugate operators, like, e.g., position and momentum (but not quite the same, since a time operator doesn't exist in quantum mechanics). The uncertainty between position and momentum means that if one would try to localize a particle within an ever smaller region in space, this would cause ever larger fluctuations of its momentum (and thus a corresponding increase of its kinetic energy); hence, a precise localization (determination of the position) of the particle is impossible.

Quote:

Now I’m really baffled as to how an atom can “spontaneously” jump to an excited state. I would have thought there would have to be some kind of interaction with another force of some kind.


The interaction occurs between the electron and the vacuum, or, more precisely, between the electron of the atom and the electron-positron pairs that are spontaneously created in the vacuum.

Quote:

Now my mind is buzzing with questions about what, exactly, a charged particle really is or even electromagnetic energy itself. But it’s too deep for me. It’s extremely interesting, but I can’t even come up with a pictorial allegory to use for it. And a pion that can change a proton into a neutron and vice-versa, ….getting way-y-y over my head there.


No, there is no neutron involved in the hypothetical decay of protons; (one of) the proposed decay process(es) is like this:

proton --> positron + neutral pion --> positron + 2 gamma

where gamma stands for (high energy) photons.

Well, the question what is exactly an electron (or an elementary particle) isn't yet settled. From the point of view of string theory, elementary particles like electrons and quarks are quantum excitations of more fundamental objects, viz., strings and p-branes.
FounDit
Posted: Wednesday, April 25, 2012 11:03:28 AM

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Jean_extraterre wrote:
A more correct explanation rests upon a proper use of the uncertainty relation between time and energy: the energy of the vacuum is only on the average equal to a constant (e.g., zero), and it always fluctuates around this value. For sufficiently short time intervals this fluctuation may be large enough to provide the energy required for the creation of a particle - antiparticle pair.
I always heard there could not be a perfect vacuum; that there would always be something present. However, if the energy on average is around zero, then the idea is that whatever is present is sufficient to create this pair for the briefest instant? A fascinating idea.

This picture is analogous to the uncertainty relation for canonically conjugate operators, like, e.g., position and momentum (but not quite the same, since a time operator doesn't exist in quantum mechanics). The uncertainty between position and momentum means that if one would try to localize a particle within an ever smaller region in space, this would cause ever larger fluctuations of its momentum (and thus a corresponding increase of its kinetic energy); hence, a precise localization (determination of the position) of the particle is impossible.
I’m having trouble with this one. Perhaps it is the word "localizing". That conveys the idea of locating for me. First, I don't see how one could "locate" a particle as it is moving so fast to begin with, but also, why would the attempt to locate it cause it to increase its momentum? I had the impression that scientists merely observed the pathways of these particles and could not isolate them in any meaningful way. Although, I don't know how observing pathways tells them anything. But such is my ignorance on the subject.

Well, the question what is exactly an electron (or an elementary particle) isn't yet settled. From the point of view of string theory, elementary particles like electrons and quarks are quantum excitations of more fundamental objects, viz., strings and p-branes.
This one is a brain twister, also. Trying to comprehend energy itself, and its consistency. That one saps the brain cells. Its fun to attempt, but after a while, I just have to give up and deal with problems I CAN handle.
Wobbles
Posted: Thursday, April 26, 2012 7:32:42 PM
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Going back to the original question as to what is matter, I think it is safe to say that our understanding of what matters with matter has been getting more and more refined as time goes on. It is insightful to realize that mass is the measure of the amount of matter that an object has. Hence, we can say that a 2 kg mass has twice as much matter as a 1 kg mass. This matters a great deal because Science needs a way to quantify what it is talking about.

During the days of Newton, matter had two unique roles to play inside of the theories of physics. First, it was viewed as the property of matter that tended to keep it in a state of constant motion (Newton’s Law I). Physicists often say “mass is the measure of inertia”.

In order to alter a mass’s state of velocity, a force is required (Newton’s Law II). For example, to accelerate a 1 kg mass by (1 metre per second) per second a 1 Newton force is required. To accelerate a 2 kg mass by the same amount, a 2 Newton force is required. The required force for a given acceleration is proportional to the amount of mass.

This means that one can measure the amount of mass that an object possesses by applying a known force to the mass and then measuring the amount of acceleration that this produces. (The equation is that mass m is related to the size of the force F and size of acceleration by mass = F/a.)

Second, matter has the property that it is coupled to all matter through gravitation. For example, a 2 kg test mass near the surface of the earth is coupled to the mass of the earth via a gravitational interaction. The gravitational interaction produces a force of approximately (19.6 Newtons, downward) acting on the 2 kg test mass. This produces a downward acceleration of (9.8 m per second) per second. Similarly, a 1 kg mass would couple less strongly than the 2 kg mass. The gravitational interaction strength is proportional to mass according to Newton’s Law of Gravity. Since the 1 kg mass is half the mass of the 2 kg mass, the force acting on a 1 kg mass near the earth’s surface is one half the force acting on the 2 kg mass. This produces a downward acceleration of (9.8 m per second) per second, which is the same as the acceleration of the 2 kg test mass.

One of the most perplexing empirical facts in all of science is that the amount of mass of an object as determined by inertial methods is exactly the same as the amount of mass as determined through gravitational forces. Even to this day, it is not clear as to why they are the same. Mass has a duel role. Even the conjectured Higgs Boson does not explain this equivalence. The Higgs Boson is meant to explain the onset of inertial mass through interactions with the Higgs Field. (That’s another story.)

I hope this helps. I have a great interest in physics. I got my PhD in experimental high energy physics 35 years ago and did pure research for ten years and then taught undergraduate physics for 25 years. I am blessed for having had the opportunity to delve into some of the most exciting questions of our time.

Joe
Jeech
Posted: Thursday, April 26, 2012 11:48:44 PM
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Welcome to the forum, sir. It's great to be with you here and pleasing that TFD has gotten a magnifiant number of padagogical figures.

I don't have much interest in physics. That's why I never knew what I was going to poke. The subject is too vast to handle to me. THANK YOU ALL, I enjoyed almost every other line and almost all the time I realize that I know nothing.
FounDit
Posted: Friday, April 27, 2012 1:27:23 AM

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A very interesting read. Thanks for writing. A couple of questions, however.
Wobbles wrote:
Going back to the original question as to what is matter, I think it is safe to say that our understanding of what matters with matter has been getting more and more refined as time goes on. It is insightful to realize that mass is the measure of the amount of matter that an object has. Hence, we can say that a 2 kg mass has twice as much matter as a 1 kg mass. This matters a great deal because Science needs a way to quantify what it is talking about.

During the days of Newton, matter had two unique roles to play inside of the theories of physics. First, it was viewed as the property of matter that tended to keep it in a state of constant motion (Newton’s Law I). Physicists often say “mass is the measure of inertia”.

In order to alter a mass’s state of velocity, a force is required (Newton’s Law II). For example, to accelerate a 1 kg mass by (1 metre per second) per second a 1 Newton force is required. To accelerate a 2 kg mass by the same amount, a 2 Newton force is required. The required force for a given acceleration is proportional to the amount of mass.

This means that one can measure the amount of mass that an object possesses by applying a known force to the mass and then measuring the amount of acceleration that this produces. (The equation is that mass m is related to the size of the force F and size of acceleration by mass = F/a.)

Second, matter has the property that it is coupled to all matter through gravitation. For example, a 2 kg test mass near the surface of the earth is coupled to the mass of the earth via a gravitational interaction. The gravitational interaction produces a force of approximately (19.6 Newtons, downward) acting on the 2 kg test mass. This produces a downward acceleration of (9.8 m per second) per second. Similarly, a 1 kg mass would couple less strongly than the 2 kg mass. The gravitational interaction strength is proportional to mass according to Newton’s Law of Gravity. Since the 1 kg mass is half the mass of the 2 kg mass, the force acting on a 1 kg mass near the earth’s surface is one half the force acting on the 2 kg mass. This produces a downward acceleration of (9.8 m per second) per second, which is the same as the acceleration of the 2 kg test mass.
Assuming you didn't make a mistake in writing, you're saying that gravity produces the same amount of downward acceleration on different amounts of mass?
This would indicate that gravity pulls with the same amount of gravitational attraction on all objects within its field of attraction, regardless of mass, or did I miss something? I may have to re-read this tomorrow as it is late, and I'm tired. Perhaps I'm not thinking clearly.


One of the most perplexing empirical facts in all of science is that the amount of mass of an object as determined by inertial methods is exactly the same as the amount of mass as determined through gravitational forces. Even to this day, it is not clear as to why they are the same. Mass has a duel role. Even the conjectured Higgs Boson does not explain this equivalence. The Higgs Boson is meant to explain the onset of inertial mass through interactions with the Higgs Field. (That’s another story.)

I hope this helps. I have a great interest in physics. I got my PhD in experimental high energy physics 35 years ago and did pure research for ten years and then taught undergraduate physics for 25 years. I am blessed for having had the opportunity to delve into some of the most exciting questions of our time.

Joe
Jyrkkä Jätkä
Posted: Friday, April 27, 2012 3:56:22 AM

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How much does air weight?
Whistle
pedro
Posted: Friday, April 27, 2012 5:15:11 AM
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Jyrkkä Jätkä wrote:
How much does air weight?
Whistle


http://van.physics.illinois.edu/qa/listing.php?id=234

comparing the weight of the gas-filled and vacuum-filled containers should satisfy a sceptic!
FounDit
Posted: Friday, April 27, 2012 10:39:35 AM

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How much does air weigh? Is this a trick question?

As I recall, air weighs 14.7 lbs. per square inch at sea level. This is the weight of a column of air one inch square that reaches from sea level to the top of the atmosphere.

If you mean how much does ALL of the air on Earth weigh....I haven't a clue. Have to do some research on that one.


http://paul-a-heckert.suite101.com/weight-of-earths-atmosphere-a56021

According to this website the weight of the total atmosphere is 5.3 E18 kg. I'm assuming that is 5.3 x 10 to the 18th power, but I've never seen it written this way before, but then, they are always changing stuff just to screw me up, it seems. I suppose the 'E' is for exponent. I guess he can't do superscript on his website.

Jyrkkä Jätkä
Posted: Friday, April 27, 2012 4:27:06 PM

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Normally the answer is that air weights nothing.
The truth is a cubic meter of air weights approximately a kilogram.
thar
Posted: Friday, April 27, 2012 4:59:37 PM

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Jeech wrote:
almost all the time I realize that I know nothing.


congratulations, Jeech, I think you have just exhibited the trait that makes a great scientist. Applause

Not only is the universe stranger than we imagine, it is stranger than we can imagine. Sir Arthur Eddington English astronomer (1882 - 1944).

The true sign of intelligence is not knowledge but imagination.
Albert Einstein

"We live on an island surrounded by a sea of ignorance. As our island of knowledge grows, so does the shore of our ignorance." John Archibald Wheeler

Wobbles
Posted: Friday, April 27, 2012 8:55:39 PM
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FounDit wrote:
A very interesting read. Thanks for writing. A couple of questions, however.

Assuming you didn't make a mistake in writing, you're saying that gravity produces the same amount of downward acceleration on different amounts of mass?
This would indicate that gravity pulls with the same amount of gravitational attraction on all objects within its field of attraction, regardless of mass, or did I miss something? I may have to re-read this tomorrow as it is late, and I'm tired. Perhaps I'm not thinking clearly.



Yes, that is the idea. The gravitational force acting a small object is proportional to the mass of that object while the resulting acceleration produced by that force is inversely proportional to its mass. The next result is that all small objects fall with the same rate of acceleration. Of course, if other forces are acting, then forces will alter the situation. Near the earth's surface, a feather will flutter downward with hardly any acceleration as compared to a block of bricks.

The astronauts on one of the trips to the surface of the moon did the experiment of comparing the free fall acceleration of a feather to some other object. It was a dramatic confirmation of Newton's Theory of Gravity. I've done similar demonstrations for my students using an evacuated vessel. One does not need to travel to the moon to do the experiment.

Joe
FounDit
Posted: Saturday, April 28, 2012 12:25:24 PM

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FounDit wrote:
Let's go back a bit. I keep going over this, but must be missing something.
Wobbles wrote:
Going back to the original question as to what is matter, I think it is safe to say that our understanding of what matters with matter has been getting more and more refined as time goes on. It is insightful to realize that mass is the measure of the amount of matter that an object has. Hence, we can say that a 2 kg mass has twice as much matter as a 1 kg mass. This matters a great deal because Science needs a way to quantify what it is talking about.

During the days of Newton, matter had two unique roles to play inside of the theories of physics. First, it was viewed as the property of matter that tended to keep it in a state of constant motion (Newton’s Law I). Physicists often say “mass is the measure of inertia”.

In order to alter a mass’s state of velocity, a force is required (Newton’s Law II). For example, to accelerate a 1 kg mass by (1 metre per second) per second a 1 Newton force is required. To accelerate a 2 kg mass by the same amount, a 2 Newton force is required. The required force for a given acceleration is proportional to the amount of mass.
How would this be measured? Would the mass be accelerated towards the Earth, away from the Earth, or at right angles to Earth's gravitational field? Would not the direction influence the results? Since we are discussing downward acceleration produced by gravity, it only makes sense to do the experiment in the same direction. So in your example, is this the case?

This means that one can measure the amount of mass that an object possesses by applying a known force to the mass and then measuring the amount of acceleration that this produces. (The equation is that mass m is related to the size of the force F and size of acceleration by mass = F/a.)

Second, matter has the property that it is coupled to all matter through gravitation. For example, a 2 kg test mass near the surface of the earth is coupled to the mass of the earth via a gravitational interaction. The gravitational interaction produces a force of approximately (19.6 Newtons, downward) acting on the 2 kg test mass. This produces a downward acceleration of (9.8 m per second) per second. Similarly, a 1 kg mass would couple less strongly than the 2 kg mass. The gravitational interaction strength is proportional to mass according to Newton’s Law of Gravity. Since the 1 kg mass is half the mass of the 2 kg mass, the force acting on a 1 kg mass near the earth’s surface is one half the force acting on the 2 kg mass. This produces a downward acceleration of (9.8 m per second) per second, which is the same as the acceleration of the 2 kg test mass.
If a 2kg mass is gravitationally drawn in a vacuum at (9.8m per second)per second and a 2 Newton force is applied, does it eventually slow back to the original acceleration or continue at the increased acceleration? Does gravity always have a drawing effect or does it have an opposition effect as well? The gravitational field of the Earth has a positive and negative pole, so I'm just wondering. Thinking of this, would it matter if the mass is accelerated at the North Pole, the South Pole, or between the two, and to what degree?

One of the most perplexing empirical facts in all of science is that the amount of mass of an object as determined by inertial methods is exactly the same as the amount of mass as determined through gravitational forces. Even to this day, it is not clear as to why they are the same. Mass has a duel role. Even the conjectured Higgs Boson does not explain this equivalence. The Higgs Boson is meant to explain the onset of inertial mass through interactions with the Higgs Field. (That’s another story.)
Then there is this:
Yes, that is the idea. The gravitational force acting a small object is proportional to the mass of that object while the resulting acceleration produced by that force is inversely proportional to its mass.
So then, inertial measurement is: a=F/m and gravitationally a = 1/mass? Math isn't my strong suit so just checking to see if I have it right.

Jeech
Posted: Saturday, April 28, 2012 1:56:23 PM
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thar wrote:
Jeech wrote:
almost all the time I realize that I know nothing.


congratulations, Jeech, I think you have just exhibited the trait that makes a great scientist. Applause

Not only is the universe stranger than we imagine, it is stranger than we can imagine. Sir Arthur Eddington English astronomer (1882 - 1944).

The true sign of intelligence is not knowledge but imagination.
Albert Einstein

"We live on an island surrounded by a sea of ignorance. As our island of knowledge grows, so does the shore of our ignorance." John Archibald Wheeler



Thanks a lot. I admire the way you explain and your appreciation and your love for seeking and sharing knowledge.

I like the first quote from Sir Arthur Eddington English, it's quite "strange" to me.
dusty
Posted: Sunday, April 29, 2012 1:15:44 AM

Rank: Advanced Member

Joined: 4/13/2012
Posts: 1,770
Neurons: 5,765
Jeech wrote:
Hi friends, I was away from any internet approach therefore couldn't have seen your interesting, knowledgable and great heartful posts.

My ten years old son asked me that question when we were watching TV togather. He asked me how wireless devises like TV remote controle and cell phone worked...

When it came to 'waves' my answer was that they are an other category of matter. And by reading whole the thread (though felt whoosh also sometimes) I guess I hit the right answer. And by simplyfying it, I can tell him that they are extremely low maliculic densty Matter, quite opposit than solid. Gas have some higher densitiy than waves, and liquid have higher dansity than Gas...
Is it correct simplification?

However, nothing can be simplified than the way M.S Behave did it.


A lot of times words can confuse, especially if the simplification models an event in ways that are misleading. Most remotes transmit waves somewhere around infrared wavelength. If you drew you soon a line that approximated the spectrum we currently are aware of, and then to scale marked off the portion that are eyes detect as light, he might get a sense of a how the remote transmits the signal to the T.V. You could demonstrate it in progress with a flashlight and if you wanted to get more detailed, one of those old school military flashlights with the red lens (mimicking the red wavelentgh) He could then see the signal being transmitted. On the front of Televisions that can be remotely controlled, there is typically a sensor that detects the signal which is hidden behind a smoke colored lens that may look like just another piece of opaque plastic or part of an ornate design to make the outward appearance of the unit look pleasant to the eye.

The smoke colored lens is also a good analogy for the many ways that organizations attempt to WOW peoples minds, close the sale, or control through manipulation by omission of specific details in the sequence of events. It's a smoke screen that is used in almost all non-transparent interactions; the sending of a signal detected by a sensor who understands the signal to be a command. That command gets executed according to the time frame programmed.

You can demonstrate how not all signals get blocked by placing an object in between the signal transmitter and the detecting sensor. You can demonstrate how the blocking object becomes more or less effective depending on how close it is to either the source of the signal or the place of detection.
Ms. B. Have
Posted: Sunday, April 29, 2012 7:36:15 AM
Rank: Member

Joined: 4/6/2012
Posts: 355
Neurons: 686


"We are such stuff as dreams are made on;
and our little life is rounded with a sleep..."


Shakespeare, The Tempest


pedro
Posted: Wednesday, May 2, 2012 7:57:45 AM
Rank: Advanced Member

Joined: 5/21/2009
Posts: 13,057
Neurons: 63,022
I'm going to try out that Wheeler quote on a stranger at a bus stop.
Jeech
Posted: Saturday, May 5, 2012 2:15:33 AM
Rank: Advanced Member

Joined: 10/21/2009
Posts: 1,468
Neurons: 4,436
Location: Karachi West, Sindh, Pakistan
pedro wrote:
I'm going to try out that Wheeler quote on a stranger at a bus stop.


What does it mean?

Otherwise, I'm eternaly waiting for the quote.
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