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What is energy, exactly?


qijino1236
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Hi

All what is done in schools is calculating tranfering one type of enery to another. Nobody knows origin of energy.

E=mc2 is slightly wrong according to my theory. Beside, formula is correct only 1% and proven with atomic bombs. Only 1% of mass is changed to energy. Even that is not correct 100%.

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Hi

All what is done in schools is calculating tranfering one type of enery to another. Nobody knows origin of energy.

 

Science tends to be concerned with how questions not why questions. Origin to me implies why.

 

E=mc2 is slightly wrong

 

Correct, it's a simplification of E2=(mc2)2+p2c2

 

according to my theory. Beside, formula is correct only 1% and proven with atomic bombs. Only 1% of mass is changed to energy. Even that is not correct 100%.

 

I think you are missing why only 1% of the mass turns into energy it is part of the process, it's not 100% efficient. If you take matter and antimatter annihilations 100% of the mass is converted into energy.

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Correct, it's a simplification of E2=(mc2)2+p2c2

If Gravity Guy is using E as total energy and m as proper mass then the equation E = mc2 says that total inertial energy = proper mass * c2 which is wrong. If he's using m as inertial mass and E as total inertial enregy then you're wrong and Gravity Guy is right, at least regarding equation.

 

Hi

All what is done in schools is calculating tranfering one type of enery to another. Nobody knows origin of energy.

E=mc2 is slightly wrong according to my theory. Beside, formula is correct only 1% and proven with atomic bombs. Only 1% of mass is changed to energy. Even that is not correct 100%.

Please post your theory in the speculation forum. I'm curious as to what it is. More likely than not I'll find an error in it.

Edited by pmb
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If Gravity Guy is using E as total energy and m as proper mass then the equation E = mc2 says that total inertial energy = proper mass * c2 which is wrong. If he's using m as inertial mass and E as total inertial enregy then you're wrong and Gravity Guy is right, at least regarding equation.

 

As we've talked about before, we tend to make the assumption here that m is rest mass. In our experience this is the most common use in the literature and the easiest for people new to the subject to understand. I agree I was a bit lax and should have defined my terms more clearly to ensure we were all on the same page.

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That is not a definition of energy, it's an equality.

 

The OP did not ask for a definition of energy. It asked what energy is, and that sort of answer is the best you are going to do. The problem here is that ultimately it's an ontological question that science doesn't address.

 

Nobody knows origin of energy.

 

Arguably true and of little consequence. It's not a physics issue.

 

Beside, formula is correct only 1% and proven with atomic bombs. Only 1% of mass is changed to energy.

 

Non-sequitur. Who has claimed that all of the mass should convert to energy in an atomic bomb?

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As we've talked about before, we tend to make the assumption here that m is rest mass.

Yep. I'm overly aware of that. :P

 

I have to ask you, what was the purpose of you post to m? Everything in my post was created so that anybody whow knows anything about SR should be able to grasp it no matter what. That was the purpose of me stating my response for both the m = inertial mass people and the p = proper mass people.

 

Note: It's my considered opinion that the term rest energy fo a particle be tossed out the window and replaced by proper mass.

 

In any case, that's why I addressed the proper mass definition first and as such the eqution E = mc^2 is wrong. Given that it was Gravity Guy that you were responding to it seemed likely that there was no reason to assume that he wasn adhering to that rule of thumb you speak of. Hence my inclusion of the second portion. After all it is the esxception of the "tendancy" which I had in mind give my experience with Gravity Guy.

 

In our experience this is the most common use in the literature and the easiest for people new to the subject to understand. I agree I was a bit lax and should have defined my terms more clearly to ensure we were all on the same page.

That's up to you, of course. However it's very unwise to make that assumption that you just give regarding the literature. If one is working in particle physics then what you'll see in probably all instances is the mass = proper mass notion. If one is working in cosmology then one is usually working in other concepts such as active gravitational mass, proper gravitational mass and inertial mass aka relativistic mass.

 

However that may be what the author puts in writing. That doesn't mean that's what one uses in private thoughts.

 

For example: In Alan Guths journal writings I'd wager that he uses the mss = proper mass concept. However I know as fact that this is not how he thinks. Alan is an aquantance of mine. He gave me a copy of his lectue notes on his early universe course he teaches. In it he refers to light having mass and that te mass density of radiation is equal to its energy densty/c^2. I of course use it. I don't plan on having people coerce me into using otherwise. Especially when people want me to teach other than the way Guth does.

 

Here is a list of the texts I have which utilizes inertial mass (aka relativbistic mass).

 

Gravitation, Misner, Thorne and Wheeler, W.H. Freeman & Co., (1973).

Cosmological Principles, Peacock, Cambridge Univ. Press, (1999).

A First Course in General Relativity, Schutz, Cambridge Univ. Press, (1990).

A Short Course in General Relativity, Foster & Nightingale, Springer Verlag, (1994).

 

These texts use m as inertial mass

Relativity: Special, General and Cosmological, Rindler, Oxford Univ., Press, (2001).

From Introducing Einstein's Relativity, Ray D'Inverno, Oxford Univ. Press, (1992).

 

 

Here is a list from journals

 

Apparatus to measure relativistic mass increase, John W. Luetzelschwab, Am. J. Phys. 71(9), 878, Sept. (2003).

Relativistic mass increase at slow speeds, Gerald Gabrielse, Am. J. Phys. 63(6), 568 (1995).

In defense of relativistic mass, T. R. Sandin, Am. J. Phys. 59(11) 1032 (1991).

A simple relativistic paradox about electrostatic energy, Wolfgang Rindler and Jack Denur, Am. J. Phys. 56(9), Sept. (1988).

An elementary development of mass-energy equivalence, Daniel J. Steck, Frank Rioux, Am. J. Phys. 51(5), May (1983).

 

See list of online journals at

http://home.comcast....vistic_mass.htm

 

I haven't updated this in a very long time.

 

My point is this. People may use m = proper mass in print but it doesn't mean that's how they use it in there thoughts or how they teach others.

 

...we tend to make the assumption

We? I'm we too. :D

 

I consider myself to be part of the we so I believe that what I use counts. I should also use m as I see fit. Not as the majority rules. If so you'd be stiffeling thoughts. Using te symbol m as you do almost universall is taken to mean that inertial mass isn't "real" in some way.

 

I was posting here for four years my first time around and in my second round I think will be staying.. so long as I don't get banned. :blink: So I hope I don't get into this dicussion every time I speak of mass or use the symbol m to mean proper mass. It's not as if I don't know what I'm talking about.

 

We all want to prepare the reader to understand what he reads in journals, especially those who are directed towards teaching physics, like the American Journal of Physics. E.g.check your Private Messages. I sent you a link to an article I wish you to peruse and see if and how m is used as well as E and E_0.

 

The OP did not ask for a definition of energy. It asked what energy is, and that sort of answer is the best you are going to do. The problem here is that ultimately it's an ontological question that science doesn't address.

Hi Tom. Recall what I was responding to

Energy is, exactly, the conserved current related to time invariance of the Lagrangian. Google "Noether's theorem".

 

DrRocket stated Energy is, exactly .... and was thus making an assertion about what energy is and was thus making an attempt at a definition of energy. And as you know, whathe was talking about is not a definition of energy but an equality.

 

Notice the statement that followed me, i.e.

Energy, like several quantities in physics, is one of those things that goes without a definition. I did some research on energy and wrote up the result of what I thought best suited as a good response to the question What is Energy? As Richard Feynman wrote in The Feynman Lectures (see http://home.comcast.net/~peter.m.brown/mech/what_is_energy.htm)

Now I'd like to quote you.

No, it's not a physical thing. It's a useful abstraction because it is a conserved quantity owing to the time-translation symmetry of physics. It helps us keep a good set of books for problems we solve.

You're thinking of something that is derived, i.e. the properties of energy and symmetry of a time-invariant Lagrangian. By the way, to everyone - that pertains only to Lagrangians which don't have "t" in it. Some do have t. Those describe systems in which energy is not conserved.

 

Now look at the link above. There are 9 instances of the word book (or bookeeping). I was agreeing with you before I even knew you.

 

Take a look at Fig. 3. Right before the figure 3

As a general example of this type of bookkeeping is given in Fig. 2.

Figure2 outlines an EM system which should give some sort of device in which the energy moves back and forth between two types of energy. Figure 3 shows what a bookeeping tale would look like if such a thing were to be created.

 

Had you read my previous response on energy which was 6 lines below the comment you were criticizing then you'd have known all of this.

 

If I sound pissed off then yes. Saddly I am. I take a lot of time to create responses and create web pages after doing a shit load of work and people dismiss them out of hand. Why do you people think I made those things? Let me tell you. It was to help you learn. And I had plenty of help writing those pages. I have some friends at places like MIT who teach physics and wrote texts on these subjects. Maybe I just won't bother with helping any body here. Maybe I'll just sit here and get you people to help me and don't attempt to help anyone else. I know it's be easier for me that way.

Edited by pmb
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pmb

I appreciate your intention and explanation.

Can you tell me please about that "Speculation forum", is it safe? Shouldn't I file my paper and my observations somewhere more official than public forum? Can anybody give me some more directions, please?

 

If Somebody ask directly what is Energy exactly, I think nobody can give you direct answer. All answers would be connected to some specific Frame of references. All answers could be correct that way. No need to argue than as long as both parties agree with that specific frame.

 

I allways ask myself what is the origin of energy, where it come from. I think that comes from dark energy, that it is dark energy itself, something that has nobody determined jet. It's not official. This is my personal opinion and my theory and understanding base on that.

 

If somebody knows any other proces than atomic bomb case that mass change to energy with better eficiency that 1%, please let people knows about it.

 

 

 

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pmb

I appreciate your intention and explanation.

Can you tell me please about that "Speculation forum", is it safe? Shouldn't I file my paper and my observations somewhere more official than public forum? Can anybody give me some more directions, please?

 

I'm not sure what you mean by safe? You could pursue publication in a peer reviewed journal, but if you have no experience of that then you will find it difficult, not because outsiders are shunned but because the requirements are quite significant. The first thing that anyone will ask even here would be what numerical, falsifiable predictions your idea makes.

 

If Somebody ask directly what is Energy exactly, I think nobody can give you direct answer. All answers would be connected to some specific Frame of references. All answers could be correct that way. No need to argue than as long as both parties agree with that specific frame.

 

I think you are asking for something that is outside the scope of science.

 

I allways ask myself what is the origin of energy, where it come from. I think that comes from dark energy, that it is dark energy itself, something that has nobody determined jet. It's not official. This is my personal opinion and my theory and understanding base on that.

 

It's certainly an idea but not one to discuss in someone else's thread.

 

If somebody knows any other proces than atomic bomb case that mass change to energy with better eficiency that 1%, please let people knows about it.

 

Matter-antimatter annihilations as I mentioned.

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<br />I'm not sure what you mean by safe?

I wish I knew why I asked that but I can't recall.

 

You could pursue publication in a peer reviewed journal, ...

I go the speculation forum merely for entertainment. Nothing more.

 

...but if you have no experience of that then you will find it difficult, ...

I'm quite aware of the peer review process. It's a painstaking process which can take many tries in a particular journal perhaps until you realize that you tried the wrong journal. Then you have to start the whole process all over again.

 

..not because outsiders are shunned but because the requirements are quite significant.

I have the feeling that you don't consider me a physicist, or if so then perhaps a really bad one. IS th true? I find that people in this forum repeating things that even an undergrad in physics should know.

 

Let me state for you by background so we can put this to an end just in case people are making assumptions that they don't know that they're making.

 

Carrer;

 

Out of High School -> Air Force

Out of Airforce -> Electronics Technician

Out of tech field -> College - Merrimack College http://www.merrimack.edu/

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&lt;br /&gt;I'm not sure what you mean by safe?<br />
<br />I wish I knew why I asked that but I can't recall.<br /><br />
<br />You could pursue publication in a peer reviewed journal, ...<br />
<br />I go the speculation forum merely for entertainment. Nothing more.<br /><br />
<br />...but if you have no experience of that then you will find it difficult, ...<br />
<br />I'm quite aware of the peer review process. It's a painstaking process which can take many tries in a particular journal perhaps until you realize that you tried the wrong journal. Then you have to start the whole process all over again.<br /><br />
<br />..not because outsiders are shunned but because the requirements are quite significant.<br />
<br /><br /><br />I have the feeling that some people here don't consider me a physicist, or if they do then perhaps a really bad one. Is this true? I suppose I'll never really know.<br /><br />Why do I ask? Because I find that some people in this forum, and I don't keep track of who says what, I'm not that petty. Certain things keep get repeated even those points an undergrad student in physics/math should know.<br /><br />Let me state for you by background so we can put this to an end just in case people are making assumptions that they don't know that they're making.<br /><br />Carrer; <br /><br />Out of High School ----> Air Force<br />Out of Airforce  ----> Electronics Technician<br />Out of tech field  ----> College - Merrimack College ://www.merrimack.edu/<br />                               Note: Major: Physics, Mathematic (two majors)<br />After college  ----> Industry<br />                          (1) Computational Physicist for Air Force<br />                          (2) Digital Signal Processing for Air Force<br />                          (3) Systems Analyst for FAA<br />                          (4) Software Quality Assurance Engineer for FAA<br />                          (5) Lab Tech at MIT for calibrating CCDs for Chandra X-ray Observatory<br />                          (6) Software Quality Assurance Engineer for Polaroid<br />                ----> Graduate School - Northeastern University, Boston<br />                ----> Layed off and took GR at MIT. At this time I met Edwin F. Taylor <br />                         who was writing a text called Exploring Relativity. I got a chance to proof read the text and come uip with ideas for the book. Ater that I got Leukemia in <br />                         2000 and had to stop working - On disability. I spent from that time until<br />                         now studying certain things in relativity and relativistic electodynamics <br />                         I found interesting. Since I became disabled in 2000 I've been forced to<br />                         work on my own. I decide to work in relativity since I had mastered a lot<br />                         of the material. I've mastered the material to the level of someone who<br />                         did his Masters Thesis in relativity, focusing in things like the concept of mass.<br /><br />I dug into the subject since all my time was spent doing this so I came up with a truck load of ideas and learned material. So I'm no slouch in physics by any stretch of the imagination.<br /><br />Okay. Enough about me. I'l place all this in my "About Me" page and then not mention it again. Edited by pmb
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<br />Pmb, I was replying to gravity guy not you. I'd be very surprised if I had to tell you about peer review or the speculations forum.<br />
<br /><br /><br />

 

humbly appologize. I got mixed up. What a sad state I'm in tonight.

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  • 3 weeks later...

What is energy, exactly?

 

In the 19th century and before, according to Newtonian physics, energy was defined by matter whereby a force applied to it, times the distance traveled, defined the resultant energy absorbed. F x D = E. In the 20th century matter was proposed to have an energy equivalent whereby Energy accordingly is equal to mass times the speed of light squared: E = MC2 . In the 19th century EM radiation was the wave motion of the aether, in the 20th century Einstein proposed the idea of pure energy with no carrier particle since an aether was proposed to be no longer needed. In a closed system concerning calculations, energy is proposed to always be conserved converting from one type of energy/ matter into another.

 

Are the present theories of energy correct? Most aspects of energy are simply definitions and therefore cannot be wrong. Most also believe that energy conservation in a closed system must be maintained. If any part of the present theory of energy could be wrong it seemingly could only be Einstein's formulation of mass-energy conversion, or his idea of pure energy which would be invalid if EM waves were comprised of a carrier particle of some kind.

//

Edited by pantheory
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What is energy, exactly?

 

In the 19th century and before, according to Newtonian physics, energy was defined by matter whereby a force applied to it, times the distance traveled, defined the resultant energy absorbed. F x D = E.

That is the relationship for work. It is not a definition of energy. When you do work on a system it doesn't equal the energy of the system. It merely changes the energy of the system. But it can in no way be considered a form of energy.

 

In the 20th century matter was proposed to have an energy equivalent whereby Energy accordingly is equal to mass times the speed of light squared: E = MC2 .

In Einstein's derivation of E = mc2 in 1905, the mass/matter wasn't provced to have energy. The E in that expression is the amount energy emitted by a body at rest du to, say, a change in the electric structure of the body being perturbed so as t decreased the amount of EM energy in the system and thus emitting energy of equal amounts in opposite directions.

 

The m is the amount of mass that the body decreased. Einstein didn't prove that energy had mass. He started out using that as assumed. Later on the same thing held true. Never in the 20th century did this change. There was an application in elementary particle physics wherein the form of the mass changed, i.e. the creation of two photons from a matter/anti-matter annihilation with energy/inertial mass and momentum being conserved in the process

 

 

In the 19th century EM radiation was the wave motion of the aether, in the 20th century Einstein proposed the idea of pure energy with no carrier particle since an aether was proposed to be no longer needed.

Einstein never proposed that something could have pure energy. That's just a myth.

 

Are the present theories of energy correct?

There are no "theories" if energy. There is only a property of energy which din part defines energy and that's that the total energy of a closed system is a constant.

 

Most also believe that energy conservation in a closed system must be maintained.

All educated physicists know that to be true.

 

If any part of the present theory of energy could be wrong it seemingly could only be Einstein's formulation of mass-energy conversion, or his idea of pure energy which would be invalid if EM waves were comprised of a carrier particle of some kind.

Mass cannot be converted to energy and energy cannot be converted to mass. That fact was known from the start and an article to remind the scientific world to that fact was published. The article is A Relativistic Misconception, C. Roland Eddy, Science, September 1946

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That is the relationship for work. It is not a definition of energy. When you do work on a system it doesn't equal the energy of the system. It merely changes the energy of the system. But it can in no way be considered a form of energy.

 

In Einstein's derivation of E = mc2 in 1905, the mass/matter wasn't provced to have energy. The E in that expression is the amount energy emitted by a body at rest du to, say, a change in the electric structure of the body being perturbed so as t decreased the amount of EM energy in the system and thus emitting energy of equal amounts in opposite directions.

 

The m is the amount of mass that the body decreased. Einstein didn't prove that energy had mass. He started out using that as assumed. Later on the same thing held true. Never in the 20th century did this change. There was an application in elementary particle physics wherein the form of the mass changed, i.e. the creation of two photons from a matter/anti-matter annihilation with energy/inertial mass and momentum being conserved in the process

 

Einstein never proposed that something could have pure energy. That's just a myth.

 

There are no "theories" of energy. There is only a property of energy which din part defines energy and that's that the total energy of a closed system is a constant.

 

All educated physicists know that to be true.

 

Mass cannot be converted to energy and energy cannot be converted to mass. That fact was known from the start and an article to remind the scientific world to that fact was published. The article is A Relativistic Misconception, C. Roland Eddy, Science, September 1946

-- Work = Force times Distance = Energy expended -- would have been a better description :)

 

-- E = Mc2 The point was the different ways that Energy can be created.

 

Einstein never proposed that something could have pure energy. That's just a myth.

Einstein agreed with Planck's ideas concerning EM radiation being made up of quanta. "To this day, physicists describe the photon the carrier of the electromagnetic force. This verbiage of "carrier" an "radiation" imparts a dualistic nature to the subject which, curiously, rarely gets mentioned in scientific articles."

 

http://www.nobeliefs.com/photon.htm

 

The energy of EM radiation, absent the waves, has been called pure energy. "Einstein's theory is embodied in his famous equation E=mc². Although light photons don't have mass, they have energy, and "Einstein's theory says that even pure energy has to behave in some ways like mass. Therefore light could be bent by the gravitational force of the sun."

 

I'm sure you're right. Einstein may not have used the term "pure energy" but others think his theories imply it as in the quote above from the link below.

 

http://ww.oecd.org/d.../31/1946278.pdf

 

I also do not think presently that all the mass in large quantities can be converted into all energy, but the atomic bomb I think is a good example of some mass being converted into lesser mass, along with heat, light, and neutron radiation energy :)

 

In the other way two opposing gamma rays can create new electrons and positrons.

//

Edited by pantheory
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I also do not think presently that all the mass in large quantities can be converted into all energy, but the atomic bomb I think is a good example of some mass being converted into lesser mass, along with heat, light, and neutron radiation energy :)

 

In the other way two opposing gamma rays can create new electrons and positrons.

//

 

You could think of antimatter/matter annihilation as a complete transformation. Although gamma/gamma interaction is possible and it can be experimentally shown - it is extreme and rare. http://en.wikipedia.org/wiki/Two-photon_physics

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No, it's not a physical thing. It's a useful abstraction because it is a conserved quantity owing to the time-translation symmetry of physics. It helps us keep a good set of books for problems we solve.

 

 

Hmmm....

 

 

... I disagree with energy not being a physical ''thing''.... The rest I agree with. Physical is not restrained to mass.

 

 

 

 

 

Energy is, exactly, the conserved current related to time invariance of the Lagrangian. Google "Noether's theorem".

 

The conjugate of time, but even in relativity time is considered physical in that sense of the word. For instance, in General Relativity, space is not separate to time. They are the manifold we treat as being a physical sheet.

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Hmmm....

 

 

... I disagree with energy not being a physical ''thing''.... The rest I agree with. Physical is not restrained to mass.

What led you to believe that energy is a physical thing? I'm sure that you've seen all the derivations of the various forms of energy and how nothing about them was physical. E.g. what do you think is physical about, say, potential energy. There is always a constant added to the potential which is chosen for convenience. What's physical about such an arbitrary constant?

 

In case you missed my post on the definition of energy you can take a gander at it at

http://home.comcast.net/~peter.m.brown/mech/what_is_energy.htm

 

This is a page in my own website. What do you think? Do you have any comments on it? Something I might add?

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What led you to believe that energy is a physical thing? I'm sure that you've seen all the derivations of the various forms of energy and how nothing about them was physical. E.g. what do you think is physical about, say, potential energy. There is always a constant added to the potential which is chosen for convenience. What's physical about such an arbitrary constant?

 

In case you missed my post on the definition of energy you can take a gander at it at

http://home.comcast....t_is_energy.htm

 

This is a page in my own website. What do you think? Do you have any comments on it? Something I might add?

 

 

Well, it's not exactly unphysical in the eyes of General Relativity. What is unphysical about energy, which can warp the spacetime fabric? Curvature is the storage of energy in the spacetime metric, how can one really call it an unphysical manifestation?

 

Can I read your work later, btw, I need to go do something the now. Thanks.

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Hmmm....

 

 

... I disagree with energy not being a physical ''thing''.... The rest I agree with. Physical is not restrained to mass.

 

 

 

The conjugate of time, but even in relativity time is considered physical in that sense of the word. For instance, in General Relativity, space is not separate to time. They are the manifold we treat as being a physical sheet.

 

Pour me a cup of energy, then. While you're at it, I'll have a cup of length as well.

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How would you suggest that one go about pouring a cup of dark energy?

I know, I know ;) Forget the cup. Just pour and present Swansont with a glass full of his favorite drink, shaken but not stirred. After he consumes it he might relish, or not, that if dark energy is omnipresent, that it will "remain" (maybe moving in and out) in the empty glass which you presented him. If later on it is theoretically determined that dark energy probably does not exist, then (or sooner) he no longer would need to prize the empty glass as being full of dark energy and dark matter, and would then be able to use it for a better purpose, as I would if equal opportunity were involved.:D

//

Edited by pantheory
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