Mass= energy,how we know this.

[Strange]

Strange; This is not some new radical perspective I am illustrating with the Calder scenerio. It is compelling thoughts like it that lead physicists to mass- energy equvalence. At least give Calder's thoughts some reflection. Notice when Einstein or any noted physicist states mass-energy equivalence they don mince words such as "somewhat equivalent" or "analogous to" etc. Or "equivalent to in some ways.". Equivalent. Yes. Period.

 

I don't disagree with any of that.

[swansont]

Strange; This is not some new radical perspective I am illustrating with the Calder scenerio. It is compelling thoughts like it that lead physicists to mass- energy equvalence. At least give Calder's thoughts some reflection. Notice when Einstein or any noted physicist states mass-energy equivalence they don mince words such as "somewhat equivalent" or "analogous to" etc. Or "equivalent to in some ways.". Equivalent. Yes. Period. In the words of Bob Dylan, dont critisize what you cant understand. I dont and do appreciate all input. This beats drinking beer at the beach doesnt it?

 

I believe the issue is with conflating "equivalent" with "equal". There is a mass-energy equivalence. But "energy is mass" (and E=M) is not saying that, and is wrong.

 

Mass is a form of energy. Not all energy is mass.

 

E=mc² but E≠m

[michel123456]

 

I believe the issue is with conflating "equivalent" with "equal". There is a mass-energy equivalence. But "energy is mass" (and E=M) is not saying that, and is wrong.

 

Mass is a form of energy. Not all energy is mass.

 

E=mc² but E≠m

Right

 

 

E is something

m is something different

But you can transform m into E by making the following:

_multiply m with square meters

_multiply m with a number (a constant)

_divide m by square seconds

 

After executing those 3 operations, m can be transformed into E. So clearly, m is different from E.

 

The "equivalence" simply means that if you are given E, you can easily calculate m.

As if you were given apples and the constant weight of an apple then you can calculate the weight of a million apples. But apple and weight are different concepts. And of course if all apples have a weight, not all weights are made of apples.

[swansont]

Right

 

 

E is something

m is something different

But you can transform m into E by making the following:

_multiply m with square meters

_multiply m with a number (a constant)

_divide m by square seconds

 

After executing those 3 operations, m can be transformed into E. So clearly, m is different from E.

 

The "equivalence" simply means that if you are given E, you can easily calculate m.

As if you were given apples and the constant weight of an apple then you can calculate the weight of a million apples. But apple and weight are different concepts. And of course if all apples have a weight, not all weights are made of apples.

 

I think there's more to it than that — there is an underlying concept that this "recipe" does not address. Just like with a cookbook — you may know that it says to mix ingredients, and take certain steps in cooking, but it says nothing of why you do it that way. And science is more than following a recipe.

 

What's missing is the basic concept that in figuring out the total energy of an object, one must include the mass. An object at rest has energy, even though it has no CoM kinetic energy, and that was a huge paradigm shift from the physics people knew up to that point.

[jajrussel]

Asimov: Are you saying that E=M is a dimensionless expression of E=MC^2, where E is said to equal 1, and M is said to equal 1? If this is what you are saying could you explain? I have read that there are reasons for using dimensionless expressions in order to reduce the need for keeping track of different units.

 

Where C=1, G=1. What was the other? I am not sure I remember correctly, hbar=1?

 

I being a newbie, wouldn't these types of expressions normally be used in an equation that expresses at least one type of unit? Truthfully I thought that mass was a unit of energy. So from that view I am not sure at the moment what to think.

Edited September 14, 2015 by jajrussel

[Strange]

Truthfully I thought that mass was a unit of energy.

 

They are equivalent (in many ways) and one can be converted to the other. But they are not the same. That is why we use different units to measure each of them: joules and kilograms, usually. Even in units where C=1 (etc) you still use different units for mass and energy.

[Asimov]

jujrussel: M=E. You are most correct. dont let units confuse you. 10 Kg mass-energy is also 2.14663986514E+17 Calories of mass- energy. There is a reason for that dash you know. Calories from the sun make it to your table to the glucose in muscles you use to lift that 16oz. beverage against gravity.. Note the different units. Mass- energy is conserved.. You could also use pounds, ounces, joules or any number of appropriate units. The fact that different units are used for mass than energy is not relevant to M=E. Kg for mass is just more convenient in describing mass as its conglomeration of fields manifests as mass or a mass. Mass-energy that is. Calories are more convenient for the energy manifestation of mass-energy. Joules can work too.Conservation of energy verifies this. Nothing that isnt energy can be converted to energy and visa versa.So much for "converting" one to the other. Not in this universe. See my earlier offer of Caldwells experiment and even a newbie can appreciate this very basic concept. Some have trouble with this because mass of mass-energy and energy of mass-energy.manifest in such different behaving ways. This is really basic relativity.IMO you are on the right track

 

Note, there are many opinions on forums. Some seem less kind than others and can seem a little personal when you dissagree with them. Read , Study them all and decide for yourself.. The best scientists in all fields dissagree. So can forum members.

[Strange]

jujrussel: M=E.

 

You are wrong. Please stop repeating this.

Note, there are many opinions on forums.

 

It isn't a matter of opinion. You are just wrong - as many people have pointed out.

[swansont]

Mass- energy is conserved..

It most decidedly is not. A nucleus undergoing e.g. alpha decay sees a reduction in its mass energy, which is converted to kinetic energy of the daughter and the alpha.

[Asimov]

Strange: Thanx for your patience and candor. Candor sounds nice.. I wont repeat that famous equation in this thread. I am not interestred in some popularity contest among forum members though. IMO Your opinions are wrong but I appreciate them and respect them as an honest opinion by you and others. Whether right or wrong. Give me the same courtesy. I will leave you and the others with this most informative link and some quotes from Stanford Encyclopedia. Ive presented my best case and rest my case. If you provide me with some links that support you view it is appreciated.

 

Your views and apparently that of other forum members arent as clear cut as you may think regarding the "same-property" interpretation of that famous equation..

 

Both the Einstein-Infeld and Zahar{1989} interpretations adopted the "same- property" interpretation of that notorious equation. "Thus, according to both interpretations,mass and energy are the same properties."

 

In relativistic physics as well as in classical physics mass and energy are both regarded as properties of the constiuents of physical systems." Matter is nothing more than a conglomeration of fields manifesting itself as matter.

 

Check the link, it covers the topic well. http:\\plato.stanford.edu/entries/equivME/

 

Swansont: Sorry, energy is always conserved. Conservation of energy applies at all times.In your example the mass- energy lost by the nucleus was conserved as the kinetic energy.of the sister and alpha particle. Advise me if I am wrong here. . I never intended this thread to be controversial. It certainly introduced me to this good forum. A simple thought experiment like others that led to an appreciation of mass-energy equivalence.. among leading physicists. Wham! I will try to stick more to medical and biological topics where my word has authority and might be respected.. I am really trying to understand QM and will have many questions. Unlike relativity I have no opinions there. Thank you for your patience with me.

[Mordred]

Here maybe this will help on GR and conservation of energy.

 

. "When the space through which particles move is changing, the total energy of those particles is not conserved."

 

http://www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/

 

One way to look at this. You have a light Ray or any multi particle/single particle system. Fall into or climb a gravity well. The total energy of said particles will undergo gravitational redshift. They gain or lose energy respectively. The energy lost or gain doesn't add or subtract from the gravity well. So it isn't conserved within the system being described.

[Asimov]

Modred: Thank you for your input but the article is quirky. Your statement if accurate would destroy the law of conservation of energy Conservation of energy has been proven many times and is essential in this universe. It always applies.. Google it for confirmation The article stated that as the universe expands so does the amount of energy. .The universe has all the energy it has ever had or will have. Old stuff.Their radical idea smacks of the old steady state universe where as the universe expands matter is produced maintaining a steady state., largely discarded in the 60s after cosmic background radiation was accidently discovered. I dont consider conservation of energy a viable topic for debate .You cant create or destroy energy.

 

http://www.newworldencyclopedia.org Steady state theory

[Mordred]

Actually it doesn't affect the law of conservation of energy. A thermal dynamic state depends on the system being described.

 

For example the above described what occurs due to space time curvature. However it does not describe total energy of the universe.

 

The total energy of the universe remains roughly the same. Approx equivalent to 10^90 particles.

 

However within the mathematics of GR total energy isn't conserved.

Think of it this way how one measures mass or energy is observer dependant.

 

If two observers in different frames of reference measures two different values. Both are correct from their frame of reference.

[Strange]

Check the link, it covers the topic well. http:\\plato.stanford.edu/entries/equivME/

 

Maybe you should get your physics from physics sites, rather than philosophy ones? There are a number of basic errors in that page, which you are repeating.

 

Energy is measured in joules, or an equivalent unit: https://en.wikipedia.org/wiki/Units_of_energy. This has units of length ² x mass / time².

Mass is measured in kilograms, or equivalent: https://en.wikipedia.org/wiki/Mass#Units_of_mass. This has units of mass (surprise!)

 

If you don't think that difference is important, then you need to read this: https://en.wikipedia.org/wiki/Dimensional_analysis

[ajb]

Your statement if accurate would destroy the law of conservation of energy Conservation of energy has been proven many times and is essential in this universe. It always applies..

Locally this is true. We have conservation of energy.

 

Now you have to think about what energy 'is', what is it related to? Well energy is the 'charge' that is related to physics not changing with time. You can make this much more precise using Noether's theorem.

 

For example, linear momentum in classical mechanics is conserved because you can translate you experiment in space and get the same results. You see that energy is conserved in your experiment if it does not matter when you make your measurements.

 

The problem is that our Universe is not static (we can make this a precise mathematical statement). The Universe is expanding, it is changing with time, and so on large enough scales it does matter when we do an experiment.

 

Like I said you can make this much more mathematical and concrete using killing vectors and the various definitions of energy/mass in general relativity. But in short as the physics does depend on time, we cannot expect energy to be conserved.

[michel123456]

Actually it doesn't affect the law of conservation of energy. A thermal dynamic state depends on the system being described.

 

For example the above described what occurs due to space time curvature. However it does not describe total energy of the universe.

 

The total energy of the universe remains roughly the same. Approx equivalent to 10^90 particles.

 

However within the mathematics of GR total energy isn't conserved.

Think of it this way how one measures mass or energy is observer dependant.

 

If two observers in different frames of reference measures two different values. Both are correct from their frame of reference.

 

 

Locally this is true. We have conservation of energy.

 

Now you have to think about what energy 'is', what is it related to? Well energy is the 'charge' that is related to physics not changing with time. You can make this much more precise using Noether's theorem.

 

For example, linear momentum in classical mechanics is conserved because you can translate you experiment in space and get the same results. You see that energy is conserved in your experiment if it does not matter when you make your measurements.

 

The problem is that our Universe is not static (we can make this a precise mathematical statement). The Universe is expanding, it is changing with time, and so on large enough scales it does matter when we do an experiment.

 

Like I said you can make this much more mathematical and concrete using killing vectors and the various definitions of energy/mass in general relativity. But in short as the physics does depend on time, we cannot expect energy to be conserved.

 

But then what are these theories about the total energy of the Universe being null? (Universe from nothing theories)

[Mordred]

No.. One of the biggest misconceptions sources is the believe all metrics are generic. The truth is any metric is designed for the system/ system state its developed to handle. GR for example has numerous different coordinate systems based on very specific observer and emitter observation influences. (Rightly so)

 

In the " Universe from nothing theories ie Lawrence Krauss. This model is based on zero point energy universe.

 

 

http://arxiv.org/pdf/gr-qc/0605063

This model suffers a few problems. It doesn't explain that virtual particle creation. requires energy.

2) the model requires pseudo polar coordinates

It's not the most highly professional viewed models, from my external study... Though at one time I advocate this model. Lol

Edited September 16, 2015 by Mordred

[ajb]

But then what are these theories about the total energy of the Universe being null? (Universe from nothing theories)

Such as getting a zero or small energy density after inflation?

 

One usually talks of densities rather than total, I think.

[Mordred]

 

 

 

But then what are these theories about the total energy of the Universe being null? (Universe from nothing theories)

After thinking about it further your descriptive rings a bell in the zero point energy universe.

 

http://arxiv.org/pdf/gr-qc/0605063

 

" as an accelerated expansion of the Universe, immediately after the creation instant,while the Universe, as it expands,borrows energy from the gravitational field to create more matter. According to his description, the positive matter energy is exactly

balanced by the negative gravitational energy, so that the total energy is zero,and that when the size of the Universe doubles, both the matter and gravitational energies also double, keeping the total energy zero (twice zero). ur task will be to show why the

Universe is a zero-total-energy entity, by means of pseudo-tensors."

 

The problem is this model works via the Heisenberg uncertainty principle.

 

120 orders of magnitude of energy too much , derived from this model.

 

(I once saw, but will provide never relocate an article discussing a suppression mechanism.)

[imatfaal]

!

Moderator Note

 

This thread has crossed the line from enquiries about mainstream physics to postulations of new ideas. Moved to Speculations

 

[swansont]

 

Swansont: Sorry, energy is always conserved.

Yes, it is. But you had said that mass-energy is conserved, and that's not true. The two statements are not the same.

[jajrussel]

 

They are equivalent (in many ways) and one can be converted to the other. But they are not the same. That is why we use different units to measure each of them: joules and kilograms, usually. Even in units where C=1 (etc) you still use different units for mass and energy.

Thank you I see my mistake in what I thought. To be specific about my wrong thinking. I was thinking of mass as being a unit of energy. I can picture,and practically feel Gibbs giving me a wake up call. Edited September 16, 2015 by jajrussel

[Strange]

Thank you I see my mistake in what I thought. To be specific about my wrong thinking. I was thinking of mass as being a unit of energy. I can picture,and practically feel Gibbs giving me a wake up call.

 

Now if you could only explain that to Asimov ...

[jajrussel]

If you want to learn you have to accept the chance that you might be wrong. I have been in situations where I was certain that I was right only to eventually hear someone say just the right thing that made me go duh! Okay I was wrong. Fortunately, I am not a rocket scientist, and other than being a little embarrassed no harm done. It has happened to me enough times now that that I don't even let it slow the conversation down. Okay you are right, I am wrong, do some cart wheels while I fix it.

 

I thought at first he was referring to dimensionless quantities, and remember reading somewhere that using that concept E=MC^2 reduced to E=M. I will eventually remember where I read it. As an expression it seemed to make sense, but this is a science forum, and as an equation the dimensions are still implied. E is energy, which is measured in joules, and M is mass which is measured in kilograms. As an equation the left side has to equal the right side. Like it or not, one side has to be converted so that both sides are the same dimensionally.

 

If it turns out I am wrong, I still like the direction this thread has taken. I have to go back and reread the last few post. What was it? The universe is accelerating therefore the amount of energy in the universe is increasing, and something else about energy not being conserved? I paraphrase terribly when I can't exactly remember what I've read. I was wondering though, if you guys did this just to get this thread transferred to speculations.

 

I hope you don't plan to just let it die.

[jajrussel]

Okay, I am wrong again. Energy is not a dimension. ?