https://en.wikipedia.org/wiki/Energy

Found this article which is semi-protected in the Wikipedia.

I guess the physicists know these things quite well, but particles are having weight most of the time, but could be massless a few times as well.

Energy could be thought of as radiation, because heat coming from the sun is by means of infrared waves, but rather are photons.

Or am I perhaps getting this wrong?

https://en.wikipedia.org/wiki/Photon

A featured article in the Wikipedia. Need to get back reading these articles.

We are having the Law of Electromagnetism which might be explaining such things like lightning and magnetism.

https://en.wikipedia.org/wiki/Electromagnetism

This article apparently needs some more work before being accepted.

You are supposed to be including both photons as well as other particles into the subject of Quantum Mechanics and Quantum Law.

But even though three of these laws have now been merged into one by means of the discovery of two elementary particles, the properties of photons could well be explained by means of not only the Law of Electromagnetism, but most likely by means of the Weak Nuclear Force as well.

Therefore I assume that Quantum Mechanics is just another way of trying to explain the same principles being related to the other three nuclear forces.

Are you supposed to be including gravity into Quantum Mechanics and Quantum Law, or is this force better being explained by means of something else, like General Relativity.

Hopefully tullio should be able to give an answer to these questions.

That part of the day. I know what this thread is all about, but do you know the answers?

Read "Seven short physics lessons" by Carlo Rovelli. He can explain things better than myself. He is also a leader in quantum loop gravity, which attempts to include both relativity and quantum mechanics.
Tullio

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Read "Seven short physics lessons" by Carlo Rovelli. He can explain things better than myself. He is also a leader in quantum loop gravity, which attempts to include both relativity and quantum mechanics.
Tullio

Here is his website.
http://www.cpt.univ-mrs.fr/~rovelli/

Quantum Gravity is the problem of combining Einstein's general relativity with quantum mechanics. This is one of the major open problems in fundamental physics. The main activity of the Quantum Gravity group of the CPT is the development of the loop approach to quantum gravity, both in its canonical form and in the spinfoam formalism. A review article on loop quantum gravity has appeared on the electronic journal Living Reviews in Relativity. A review of the spinfoam formalism is here. http://fr.arxiv.org/abs/gr-qc/0409061 Other activities of the group include quantum cosmology and foundations of quantum mechanics.

Spinfoam? Makes me think of beer:)

Cheers.

Thanks, janneseti.

I appreciated the picture.

I was ill in bed yesterday and was not able to do anything.

https://en.wikipedia.org/wiki/Energy

Found this article which is semi-protected in the Wikipedia.

I guess the physicists know these things quite well, but particles are having weight most of the time, but could be massless a few times as well.

Energy could be thought of as radiation, because heat coming from the sun is by means of infrared waves, but rather are photons.

Or am I perhaps getting this wrong?

https://en.wikipedia.org/wiki/Photon

A featured article in the Wikipedia. Need to get back reading these articles.

We are having the Law of Electromagnetism which might be explaining such things like lightning and magnetism.

https://en.wikipedia.org/wiki/Electromagnetism

This article apparently needs some more work before being accepted.

You are supposed to be including both photons as well as other particles into the subject of Quantum Mechanics and Quantum Law.

But even though three of these laws have now been merged into one by means of the discovery of two elementary particles, the properties of photons could well be explained by means of not only the Law of Electromagnetism, but most likely by means of the Weak Nuclear Force as well.

Therefore I assume that Quantum Mechanics is just another way of trying to explain the same principles being related to the other three nuclear forces.

Are you supposed to be including gravity into Quantum Mechanics and Quantum Law, or is this force better being explained by means of something else, like General Relativity.

Hopefully tullio should be able to give an answer to these questions.

That part of the day. I know what this thread is all about, but do you know the answers?

Hmm
In physics, energy is a property of objects which can be transferred to other objects or converted into different forms, but cannot be created or destroyed.[citation needed] The "ability of a system to perform work" is a common description, but it is difficult to give one single comprehensive definition of energy because of its many forms.[1] For instance, in SI units, energy is measured in joules, and one joule is defined "mechanically", being the energy transferred to an object by the mechanical work of moving it a distance of 1 metre against a force of 1 newton.[note 1] However, there are many other definitions of energy, depending on the context, such as thermal energy, radiant energy, electromagnetic, nuclear, etc., where definitions are derived that are the most convenient.

Which means that we don't know what energy really is...
E=mc2...

So we do know what energy is, as it has the dimension set
Mass x (Distance / time)^2

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

So we do know what energy is, as it has the dimension set
Mass x (Distance / time)^2

No. Energy can be calculated as Mass * (Speed of light)^2.
Speed of light is a constant.
Constants are dimension less.
Distance / time however have the dimension meters per seconds.
Or perhaps Space per Time are more correct.

Energy is both elusive and real...

Yes, the c^2 part of the famous equation E=mc2.

Which in fact should be written as m*c^2 for clarity.

Or possibly it should in fact be read as m * (c^2) here.

c again is the speed of light, which is a constant.

And of course we assume light to be energy, even though it may be particles, including photons as well.

For now I am not able to see how this equation relates to the three laws of gravity formulated by Isaac Newton.

Please explain this to me.

Yes, the c^2 part of the famous equation E=mc2.
Which in fact should be written as m*c^2 for clarity.
Or possibly it should in fact be read as m * (c^2) here.
c again is the speed of light, which is a constant.
And of course we assume light to be energy, even though it may be particles, including photons as well.
For now I am not able to see how this equation relates to the three laws of gravity formulated by Isaac Newton.
Please explain this to me.

Hang on. Photons don't have mass when not travelling.
Photons have mass when they are travelling at the speed of light.
Thats rather strange.

AFAIK Isaac Newton stipulated only one gravitional law.

c has dimension meter/s. Only e^2/hc is dimensionless and amounts to 1/137 * 2Pi.
Tullio

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c has dimension meter/s. Only e^2/hc is dimensionless and amounts to 1/137 * 2Pi.
Tullio

How can it be? c is a constant.
In my world all costants are dimensionless.
G (gravitional constant) for instance that only is a factor to scale the force.
e^2/hc is also a scaling factor with no dimensions.

Constants are NOT dimensionless. Each has its own dimension, either in the CGS or SI units system.Numerical values are different in the two systems but dimensions are identical. Only the combination of the three constants, electric charge, Planck constant and c is dimensionless. The numeical value I gave I cannot remember if it is CGS or SI.
Tullio

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Constants are NOT dimensionless. Each has its own dimension, either in the CGS or SI units system.Numerical values are different in the two systems but dimensions are identical. Only the combination of the three constants, electric charge, Planck constant and c is dimensionless. The numeical value I gave I cannot remember if it is CGS or SI.
Tullio

Constants are dimensionless per definition.
They are scale factors and do not change in dimensions.
Perhaps you could give me an example of a constant that is not.
Whatever it's CGS or SI it's only about units.

See the American Handook of Physics. I am reading a page of "Statistical Mechanics" by Joseph Edward Mayer and Maria Goeppert Mayer, pag. 482. Their numerical values are in the CGS system. I cannot copy all the page and give a few examples.
Velocity of light c=2.9979250+/-10 * 10exp10 cm/s
Planck constant h=6.626196+/-50*10exp-27 erg s
Electron charge e=1.6021917+/-70 * 10exp-19 Coulomb
Now, an exercise, you can calcolate the numerical value of e^2 divided by hc. this h is really h/2Pi and its numerical value is
1.0545919+/-80*10exp-27 erg s

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See the American Handook of Physics. I am reading a page of "Statistical Mechanics" by Joseph Edward Mayer and Maria Goeppert Mayer, pag. 482. Their numerical values are in the CGS system. I cannot copy all the page and give a few examples.
Velocity of light c=2.9979250+/-10 * 10exp10 cm/s
Planck constant h=6.626196+/-50*10exp-27 erg s
Electron charge e=1.6021917+/-70 * 10exp-19 Coulomb
Now, an exercise, you can calcolate the numerical value of e^2 divided by hc. this h is really h/2Pi and its numerical value is
1.0545919+/-80*10exp-27 erg s

With SI units.
The speed of light in vacuum c, is a physical constant and is 299 792 458 m/s (exact value).
Planck constant = 6,6261·10exp−34 Js.
Electron charge = 1,602 177·10exp-19 coulomb.
This charge was long considered to be the minimum charge a particle can have. The quark model however says that any quark have a charge that is either 1/3 or 2/3 of the electron charge.
But where are the dimensions?

Those small letters after the numerical values are the dimensions.You have four fundamental dimensions, like space, time,mass, electric charge and from those you build all other dimensions.

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Those small letters after the numerical values are the dimensions.You have four fundamental dimensions, like space, time,mass, electric charge and from those you build all other dimensions.

So you mean units and dimensions are the same?

I find it's very hard to say that constants have dimensions.
They are only scale factors.
G for instance
G is a universal constant whose numerical value is approximately (6.6743 ± 0.0007) · 10exp-11 N · m² / kg².

No. Dimensions are dimensions and units are units. But consult any physics textbook, I am tired of repeating myself.
Tullio
Units have dimensions. The kilogram has dimension mass and so the others.

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No. Dimensions are dimensions and units are units. But consult any physics textbook, I am tired of repeating myself.
Tullio
Units have dimensions. The kilogram has dimension mass and so the others.

Does the numbers 1, 2 or PI have dimensions?
Of course not.
They are all scale numbers.
You could say that PI has the dimension meter but thats wrong:)
You cannot derive constants and say they have dimension or units.
Whatever.

Physical constant e has dimensioni [electrical charge]
Planck constant h has dimension [energy x time]
joule, erg,energy has dimensiom [mass x velocity squared]
c,velocity has dimension [space/time]
electron mass has dimension [mass]
and so on and so forth
All physical constants have dimensions that can be solved in terms of space,mass, time,electric charge, and Kelvin (temperature), to include thermodynamics
Tullio

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