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giza


Registered: 08/25/09
Posts: 2,089
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Re: Energy question. [Re: johnm214]
#14752724 - 07/11/11 05:58 PM (12 years, 10 months ago) |
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@johnm214
Ah I see, so wouldn't a certain sound frequency cause enough vibration for the bomb to explode? Is that how they trigger some bombs by sending a sound frequency?
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ChuangTzu
starvingphysicist



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Re: Energy question. [Re: giza]
#14752767 - 07/11/11 06:06 PM (12 years, 10 months ago) |
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Quote:
giza said: Ah I see, so wouldn't a certain sound frequency cause enough vibration for the bomb to explode?
Yeah it would, like when another bomb blows up on top of it.
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giza


Registered: 08/25/09
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Re: Energy question. [Re: ChuangTzu]
#14752827 - 07/11/11 06:16 PM (12 years, 10 months ago) |
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Very interesting, So is the breakdown of a bomb the following? Fragments at high speed Loud sound?? That does what? Fire
So to create protection from a bomb one would have to create material that can stop a high speed fragment of the most dense metals, fire proof, sound proof material(?)
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teknix
πβπ
’ππ
π°π‘ πΌπ⨻


Registered: 09/16/08
Posts: 11,953
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Re: Energy question. [Re: giza]
#14753535 - 07/11/11 08:46 PM (12 years, 10 months ago) |
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Depends on the bomb, if there is fallout it's a whole nother story.
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giza


Registered: 08/25/09
Posts: 2,089
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Re: Energy question. [Re: teknix]
#14757209 - 07/12/11 01:56 PM (12 years, 10 months ago) |
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I have another question if you don't mind.
Isn't dance proof of sound being a source of energy?
Say a person goes to a club, as they start listening to the music for some reason this causes the person to move, where are they getting that energy from? Is it the tones of the music that cause them to start using energy? Or are they getting the energy from the music?
Are we feeling a lower form of electricity through sound? Since power can run out of a battery where does the energy go? Or is sound the electricity scattering?
Edited by giza (07/12/11 02:53 PM)
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ChuangTzu
starvingphysicist



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Re: Energy question. [Re: giza]
#14757553 - 07/12/11 03:02 PM (12 years, 10 months ago) |
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Quote:
giza said: Very interesting, So is the breakdown of a bomb the following? Fragments at high speed Loud sound?? That does what? Fire
So to create protection from a bomb one would have to create material that can stop a high speed fragment of the most dense metals, fire proof, sound proof material(?)
The explosion and the loud sound are one and the same.
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ChuangTzu
starvingphysicist



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Re: Energy question. [Re: giza]
#14757575 - 07/12/11 03:06 PM (12 years, 10 months ago) |
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Quote:
giza said: I have another question if you don't mind.
Isn't dance proof of sound being a source of energy?
Say a person goes to a club, as they start listening to the music for some reason this causes the person to move, where are they getting that energy from? Is it the tones of the music that cause them to start using energy? Or are they getting the energy from the music?
They're just using their internal carbohydrates for that energy. The music gives them nothing other than perhaps more motivation to tap those stores of energy.
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Are we feeling a lower form of electricity through sound?
Nope.
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Since power can run out of a battery where does the energy go?
Internal chemical reactions in the battery, small surface current leaks across the battery, and possibly ionization of nearby air.
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Or is sound the electricity scattering?
Sound is just a pressure difference. It can be generated with or without electricity.
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giza


Registered: 08/25/09
Posts: 2,089
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Re: Energy question. [Re: ChuangTzu]
#14757582 - 07/12/11 03:08 PM (12 years, 10 months ago) |
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Okay, thanks for your time.
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Diploid
Cuban



Registered: 01/09/03
Posts: 19,274
Loc: Rabbit Hole
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That process just exploits the energy available in chemical bonds, not the conversion of matter into energy.
Just to be picky, chemical bonds are equivalent to matter (and energy).
If you burn a log of wood then weigh the resulting ash and combustion gasses, there will be a tiny bit of mass missing. This is the energy released by the burning.
In fact, if you take a spring out of a click-pen and compress it, it will gain a tiny bit of mass (it gets heavier) as a function of the energy you put into it.
-------------------- Republican Values: 1) You can't get married to your spouse who is the same sex as you. 2) You can't have an abortion no matter how much you don't want a child. 3) You can't have a certain plant in your possession or you'll get locked up with a rapist and a murderer. 4) We need a smaller, less-intrusive government.
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zappaisgod
horrid asshole


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Re: Energy question. [Re: johnm214]
#14803341 - 07/21/11 01:31 PM (12 years, 9 months ago) |
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johnm214 said:
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zappaisgod said:
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johnm214 said:
The fact that we use carbohydrates as a fuel means they have energy.
I don't know what you mean by "make into energy" as energy is an intangible property and you cannot make some matter into it any more than you can make matter into happy.
Matter is energy, John. That's what E=Mc2 means. But that has nothing to do with energy extraction from carbohydrates. That process just exploits the energy available in chemical bonds, not the conversion of matter into energy.
Matter is not energy. As I said, energy is an intangible property of a system, including matter: the amount of work it can do. The equivalence principle you refer to merely relates the mass and energy of an item, rather than defining one as the other.
False, as any physicist will tell youQuote:
Incidentally, the chemical reactions which liberate energy from carbohydrates do indeed decrease the total mass of the chemicals, as per the equivalence principle: the mass of the chemical species decreases proportionate to the root of the energy liberated. This is true in chemical as well as nuclear reactions, the former just yields much, much, less of a mass disparity.
I don't think this is correct either but even if it was don't you think it contradicts your earlier assertion that mass isn't energy? I think it is just a conversion of energy from one form to another with no concomitant transmutation.
Dude, what do you think E=Mc2 means? Energy equals mass. Don't let the c2 distract you.
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johnm214


Registered: 05/31/07
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Loc: Americas
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Quote:
False, as any physicist will tell you
Well, we've got some folks with physics bachelor's degrees on here, maybe they'll opine on the matter, but this seems fundamentally wrong.
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Incidentally, the chemical reactions which liberate energy from carbohydrates do indeed decrease the total mass of the chemicals, as per the equivalence principle: the mass of the chemical species decreases proportionate to the root of the energy liberated. This is true in chemical as well as nuclear reactions, the former just yields much, much, less of a mass disparity.
I don't think this is correct either but even if it was don't you think it contradicts your earlier assertion that mass isn't energy? I think it is just a conversion of energy from one form to another with no concomitant transmutation.
My statement is correct, the energy change between the product chemicals and reactant chemicals will correspond to a loss of mass equal to the change in energy divided by the square of c. If you measure the mass of the products in the same state (same temp, charge, et cet) as the reactants you will find the products weigh less than the reactants if the chemical reaction had a negative change in energy.
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Dude, what do you think E=Mc2 means? Energy equals mass. Don't let the c2 distract you.
I think that equation means the energy of a system is equal to the mass of the system times the speed of light squared. The energy of the system and the mass of the system are different properties that are related by the equation.
Energy is the capacity to do work, mass is the amount of matter something has (something like that), different things with different units.
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DieCommie

Registered: 12/11/03
Posts: 29,258
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Re: Energy question. [Re: johnm214]
#14803675 - 07/21/11 02:39 PM (12 years, 9 months ago) |
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Its customary to give them the same units. You will often set c=1 (thats a pure number, with no units). Then its simply E=M and they are each expressed in eV's. Momentum gets expressed in the same unit as well, because the full equation is E2=(mc2)2+(pc)2.
Beyond that, Im not sure what the confusion is. It is true that if you take a spring, and compress it it will weigh more on a scale from the energy of compression. Similarly, a rock on a hill has more mass than the same rock at the bottom of a hill - or an electron and a proton have more mass than a hydrogen atom.
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johnm214


Registered: 05/31/07
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Re: Energy question. [Re: DieCommie]
#14804014 - 07/21/11 04:01 PM (12 years, 9 months ago) |
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The confusion is whether mass and energy are equivalent, whether mass is energy.
The other point disputed was whether a chemical reaction with a change in energy will have a change in mass due to the equivalence principle. I say it will, zappa says he doesn't think so. The mass of the product chemicals will weigh less than the mass of the reactant chemicals in an exothermic reaction (negative delta energy)
Zappa also suggests my answer to the second point contradicts my assertion that mass is not energy. I say it does not: mass and energy are both properties of an item, that they are related does not mean they are the same thing.
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ChuangTzu
starvingphysicist



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Re: Energy question. [Re: johnm214]
#14804398 - 07/21/11 05:22 PM (12 years, 9 months ago) |
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Quote:
johnm214 said:mass and energy are both properties of an item, that they are related does not mean they are the same thing.
This argument is kind of splitting hairs.
For example, a photon has energy hΞ½ (Planck constant times frequency), but a mass of 0, regardless of how high Ξ½ is. Once the energy of that photon gets absorbed by some physical system which has mass, the energy of said system increases by hΞ½ and the mass increases by hΞ½/c2. However, all of the matter (which has mass) in any physical object can theoretically be converted into energy. All of this energy can once again be theoretically converted back to matter. So there is basically a complete equivalent and to say whether they are "the same thing" or not really just depends on how deep of a level you're willing to dig down to and ultimately is just a philosophical argument.
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johnm214


Registered: 05/31/07
Posts: 17,582
Loc: Americas
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Re: Energy question. [Re: ChuangTzu]
#14807344 - 07/22/11 08:00 AM (12 years, 9 months ago) |
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Quote:
ChuangTzu said:
Quote:
johnm214 said:mass and energy are both properties of an item, that they are related does not mean they are the same thing.
This argument is kind of splitting hairs.
I agree, but I think it is quite true despite being semantic nonsense.
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For example, a photon has energy hΞ½ (Planck constant times frequency), but a mass of 0, regardless of how high Ξ½ is.
But it only has a rest mass of 0, which doesn't make much sense to speak about with photons because they don't spend any time at rest. The more reasonable measure of mass (rest and relativistic) that is actually observed, shows that the photon does have mass, always.
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However, all of the matter (which has mass) in any physical object can theoretically be converted into energy. All of this energy can once again be theoretically converted back to matter. So there is basically a complete equivalent and to say whether they are "the same thing" or not really just depends on how deep of a level you're willing to dig down to and ultimately is just a philosophical argument.
I would imagine the relevance of the argument is a philosophical question, but the truth of it is pretty simple: what is mass? What is energy? Are they equivalent?
Clearly they are not. That the mass of a system is related to its energy is besides the point.
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Seuss
Error: divide byzero



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Re: Energy question. [Re: johnm214]
#14807425 - 07/22/11 08:33 AM (12 years, 9 months ago) |
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But it only has a rest mass of 0, which doesn't make much sense to speak about with photons because they don't spend any time at rest.
Rest mass isn't the best term. The concept of a "rest mass" is important, even though a particle might never be at rest. The rest mass is simply the invariant magnitude (length) of the particles four-momentum.
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The more reasonable measure of mass (rest and relativistic) that is actually observed, shows that the photon does have mass, always.
I've never liked to use the word mass to describe a photon's relativistic mass because it leads people to think in terms of the invariant mass of traditional Newtonian physics. Instead, when working with photons, I prefer to think in terms of energy (rather than "relativistic mass" or in terms of frequency (which again leads back to energy).
-------------------- Just another spore in the wind.
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Visionary Tools



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Re: Energy question. [Re: giza]
#14807465 - 07/22/11 08:51 AM (12 years, 9 months ago) |
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sure you can. Get some peanuts, set fire to them. Fats as well as carbs burn good.
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johnm214


Registered: 05/31/07
Posts: 17,582
Loc: Americas
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Re: Energy question. [Re: Seuss]
#14807741 - 07/22/11 09:59 AM (12 years, 9 months ago) |
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Quote:
Seuss said:
Quote:
But it only has a rest mass of 0, which doesn't make much sense to speak about with photons because they don't spend any time at rest.
Rest mass isn't the best term. The concept of a "rest mass" is important, even though a particle might never be at rest. The rest mass is simply the invariant magnitude (length) of the particles four-momentum.
I don't mean to suggest I think the rest mass is not an important concept, but to speak of the mass of a photon in such terms is a bit misleading since by definition the photon has a large velocity and hence has a large relativistic mass. This, of course, is what will be observed when we measure the photon's energy, momentum, whatever, the 'rest mass' and 'relativistic mass'
What do you suggest calling the rest mass, the 'invarient magnitude of the particles four-momentum'?
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The more reasonable measure of mass (rest and relativistic) that is actually observed, shows that the photon does have mass, always.
I've never liked to use the word mass to describe a photon's relativistic mass because it leads people to think in terms of the invariant mass of traditional Newtonian physics. Instead, when working with photons, I prefer to think in terms of energy (rather than "relativistic mass" or in terms of frequency (which again leads back to energy).
eV or any other metric may indeed be more convieniant, but my point was simply that ChuangTzu's statement that a photon has a mass of 0 despite having a non-zero energy is not really very descriptive in my opinion, as by all observations the photon will not have a mass of 0, and hence its non-zero energy/momentum is not surprising nor contradictory.
Maybe I'm misusing terms here, and I'm certainly the least informed amongst those I'm speaking with, but I always thought of mass as unambiguously the total mass of the object: the invarient mass and the relativistic mass. That's clearly the mass figure you obtain by any measurement of the photon or any object, right?
Anyways, my replies kind of miss the point of the original discussion which is the question of whether:
a) mass and energy are equivalent properties b) whether a chemical reaction with a change in energy will likewise have a change in mass of the chemicals, specifically a change equal to the change in energy divided by the square of c
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DieCommie

Registered: 12/11/03
Posts: 29,258
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Re: Energy question. [Re: johnm214]
#14807818 - 07/22/11 10:19 AM (12 years, 9 months ago) |
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Relativistic mass is a term that has fallen out of favor because it's misleading. Photon's dont have mass, they have energy and momentum.
Here is a quote from wikipedia,
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Many contemporary authors such as Taylor and Wheeler avoid using the concept of relativistic mass altogether: "The concept of "relativistic mass" is subject to misunderstanding. That's why we don't use it. First, it applies the name mass - belonging to the magnitude of a 4-vector - to a very different concept, the time component of a 4-vector. Second, it makes increase of energy of an object with velocity or momentum appear to be connected with some change in internal structure of the object. In reality, the increase of energy with velocity originates not in the object but in the geometric properties of spacetime itself."[17]
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Seuss
Error: divide byzero



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Re: Energy question. [Re: johnm214]
#14807853 - 07/22/11 10:28 AM (12 years, 9 months ago) |
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> What do you suggest calling the rest mass, the 'invarient magnitude of the particles four-momentum'?
That would be more appropriate and much less misleading.
-------------------- Just another spore in the wind.
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