Enlighten Me wise ones

[Proton Head]

Hello, since I really know nothing of physics I would be greatfull if I could get answers for questions bugging my mind.

 

1. If from a viewpoint of an observer at rest, the mass of a moving particle approaches infinity as the speed of the particle approaches the speed of light, then why according to the observer at rest doesn't the "pull" of gravity originating from the moving object approach infinity?

 

2. What does a (matter) wave in quantum physics mean? What's so wavy about the matter? I know they call a wave on a string a wave since a point of the string oscillates between 2 fixed points. Also electromagnetic radiation is said to be a wave since its the result of an oscillating electric and magnetic field between 2 fixed values. However what is oscillating in the matter? Or is anything?

 

3. If you cannot describe the state of matter/energy with a particle model nor a wave model, alone in all situations, then why don't they construct a new model which allows a description of matter/energy in all situations?

 

4. Suppose you travelled back in time by turning the flow of time in a negative direction. Wouldn't this mean that events would happen backwards? So in others words if you travelled into a time before you were born, woudn't you be just a collection of atoms roaming the universe?

And if you travelled into a time when you were born but younger, would you even realize that you had time travelled, since memories of such events weren't on your brains at the time to where you travelld?

 

5. If it was possible to bring your present memories into the past, wouldn't it violate the uncertainty principle, since after you had seen the results of events you could in the past make accurate statements about the present state.

 

 

Thanks!

[Proton Head]

Hello, since I really know nothing of physics I would be greatfull if I could get answers for questions bugging my mind.

 

1. If from a viewpoint of an observer at rest, the mass of a moving particle approaches infinity as the speed of the particle approaches the speed of light, then why according to the observer at rest doesn't the "pull" of gravity originating from the moving object approach infinity?

 

2. What does a (matter) wave in quantum physics mean? What's so wavy about the matter? I know they call a wave on a string a wave since a point of the string oscillates between 2 fixed points. Also electromagnetic radiation is said to be a wave since its the result of an oscillating electric and magnetic field between 2 fixed values. However what is oscillating in the matter? Or is anything?

 

3. If you cannot describe the state of matter/energy with a particle model nor a wave model, alone in all situations, then why don't they construct a new model which allows a description of matter/energy in all situations?

 

4. Suppose you travelled back in time by turning the flow of time in a negative direction. Wouldn't this mean that events would happen backwards? So in others words if you travelled into a time before you were born, woudn't you be just a collection of atoms roaming the universe?

And if you travelled into a time when you were born but younger, would you even realize that you had time travelled, since memories of such events weren't on your brains at the time to where you travelld?

 

5. If it was possible to bring your present memories into the past, wouldn't it violate the uncertainty principle, since after you had seen the results of events you could in the past make accurate statements about the present state.

 

 

Thanks!

[swansont]

1. If from a viewpoint of an observer at rest' date=' the mass of a moving particle approaches infinity as the speed of the particle approaches the speed of light, then why according to the observer at rest doesn't the "pull" of gravity originating from the moving object approach infinity?

[/quote']

 

Because the rest mass doesn't change. And that's all that matters. The concept of "relativistic mass" is a misunderstanding of E = mc² and is bad physics.

 

The full, correct equation is E²=p²c² + m²c⁴

 

E = mc² only really applies to a system at rest

[swansont]

1. If from a viewpoint of an observer at rest' date=' the mass of a moving particle approaches infinity as the speed of the particle approaches the speed of light, then why according to the observer at rest doesn't the "pull" of gravity originating from the moving object approach infinity?

[/quote']

 

Because the rest mass doesn't change. And that's all that matters. The concept of "relativistic mass" is a misunderstanding of E = mc² and is bad physics.

 

The full, correct equation is E²=p²c² + m²c⁴

 

E = mc² only really applies to a system at rest

[swansont]

2. What does a (matter) wave in quantum physics mean? What's so wavy about the matter? I know they call a wave on a string a wave since a point of the string oscillates between 2 fixed points. Also electromagnetic radiation is said to be a wave since its the result of an oscillating electric and magnetic field between 2 fixed values. However what is oscillating in the matter? Or is anything?

 

What we think of as particles also exhibit wave behavior - you can get electrons' date=' protons, neutrons and even whole atoms to diffract and interfere.

 

The wavlenength is [sup'][math]\lambda=h/p[/math][/sup]

[swansont]

2. What does a (matter) wave in quantum physics mean? What's so wavy about the matter? I know they call a wave on a string a wave since a point of the string oscillates between 2 fixed points. Also electromagnetic radiation is said to be a wave since its the result of an oscillating electric and magnetic field between 2 fixed values. However what is oscillating in the matter? Or is anything?

 

What we think of as particles also exhibit wave behavior - you can get electrons' date=' protons, neutrons and even whole atoms to diffract and interfere.

 

The wavlenength is [sup'][math]\lambda=h/p[/math][/sup]

[Severian]

3. If you cannot describe the state of matter/energy with a particle model nor a wave model' date=' alone in all situations, then why don't they construct a new model which allows a description of matter/energy in all situations?

[/quote']

 

That is what quantum mechanics is! It is a model which correctly describes both the wave and particle nature of matter in one framework.

[Severian]

3. If you cannot describe the state of matter/energy with a particle model nor a wave model' date=' alone in all situations, then why don't they construct a new model which allows a description of matter/energy in all situations?

[/quote']

 

That is what quantum mechanics is! It is a model which correctly describes both the wave and particle nature of matter in one framework.

[Proton Head]

Thanks.

Just to make sure that I got things right,

 

Because the rest mass doesn't change. And that's all that matters. The concept of "relativistic mass" is a misunderstanding of E = mc² and is bad physics.

 

The full' date=' correct equation is E[sup']2[/sup]=p²c² + m²c⁴

 

E = mc² only really applies to a system at rest

 

So does this mean that by gaining velocity a particle only gains energy, not mass? Is the mass increase just some mathematical trick to handling calculations or what?

 

What we think of as particles also exhibit wave behavior - you can get electrons' date=' protons, neutrons and even whole atoms to diffract and interfere.

 

The wavlenength is [sup'][math]\lambda=h/p[/math][/sup]

 

This one I don't get. If we consider interference for example. Doesn't this happen in the case of electromagnetic radiation because different waves are at different point of electric vs. magnetic field oscillation? So they can amplify/cancel each other.

But what does the interference of particles mean? How can they amplify/cancel each other? What's the physical quantity that's being "interfered"? (as in the case of EM-radiation it's the field strenght at a given point).

 

That is what quantum mechanics is! It is a model which correctly describes both the wave and particle nature of matter in one framework.

 

Haha, I never thought it like that...

But since we have a model, why are we still talking about a dual nature of things? Why is it being pointed out that light for example can in different situations behave as waves or particles? Why don't we simply say that our universe is composed of warticles?

[Proton Head]

Thanks.

Just to make sure that I got things right,

 

Because the rest mass doesn't change. And that's all that matters. The concept of "relativistic mass" is a misunderstanding of E = mc² and is bad physics.

 

The full' date=' correct equation is E[sup']2[/sup]=p²c² + m²c⁴

 

E = mc² only really applies to a system at rest

 

So does this mean that by gaining velocity a particle only gains energy, not mass? Is the mass increase just some mathematical trick to handling calculations or what?

 

What we think of as particles also exhibit wave behavior - you can get electrons' date=' protons, neutrons and even whole atoms to diffract and interfere.

 

The wavlenength is [sup'][math]\lambda=h/p[/math][/sup]

 

This one I don't get. If we consider interference for example. Doesn't this happen in the case of electromagnetic radiation because different waves are at different point of electric vs. magnetic field oscillation? So they can amplify/cancel each other.

But what does the interference of particles mean? How can they amplify/cancel each other? What's the physical quantity that's being "interfered"? (as in the case of EM-radiation it's the field strenght at a given point).

 

That is what quantum mechanics is! It is a model which correctly describes both the wave and particle nature of matter in one framework.

 

Haha, I never thought it like that...

But since we have a model, why are we still talking about a dual nature of things? Why is it being pointed out that light for example can in different situations behave as waves or particles? Why don't we simply say that our universe is composed of warticles?

[swansont]

So does this mean that by gaining velocity a particle only gains energy, not mass? Is the mass increase just some mathematical trick to handling calculations or what?

 

The mass increase is a misapplication of the equation. You basically have to redefine what you mean by mass, which makes it difficult to make ideas mesh.

 

 

This one I don't get. If we consider interference for example. Doesn't this happen in the case of electromagnetic radiation because different waves are at different point of electric vs. magnetic field oscillation? So they can amplify/cancel each other.

But what does the interference of particles mean? How can they amplify/cancel each other? What's the physical quantity that's being "interfered"? (as in the case of EM-radiation it's the field strenght at a given point).

 

..

 

Haha' date=' I never thought it like that...

But since we have a model, why are we still talking about a dual nature of things? Why is it being pointed out that light for example can in different situations behave as waves or particles? Why don't we simply say that our universe is composed of warticles?[/quote']

 

Some people do refer to wavicles and, perhaps, warticles. That's the answer to your previous question, really - there's a limitation in understanding if you assume that particles are particles, rather than some more complex entity that has both wave and particle behavior. We are limited by our macroscopic preconceptions.

[swansont]

So does this mean that by gaining velocity a particle only gains energy, not mass? Is the mass increase just some mathematical trick to handling calculations or what?

 

The mass increase is a misapplication of the equation. You basically have to redefine what you mean by mass, which makes it difficult to make ideas mesh.

 

 

This one I don't get. If we consider interference for example. Doesn't this happen in the case of electromagnetic radiation because different waves are at different point of electric vs. magnetic field oscillation? So they can amplify/cancel each other.

But what does the interference of particles mean? How can they amplify/cancel each other? What's the physical quantity that's being "interfered"? (as in the case of EM-radiation it's the field strenght at a given point).

 

..

 

Haha' date=' I never thought it like that...

But since we have a model, why are we still talking about a dual nature of things? Why is it being pointed out that light for example can in different situations behave as waves or particles? Why don't we simply say that our universe is composed of warticles?[/quote']

 

Some people do refer to wavicles and, perhaps, warticles. That's the answer to your previous question, really - there's a limitation in understanding if you assume that particles are particles, rather than some more complex entity that has both wave and particle behavior. We are limited by our macroscopic preconceptions.

[Severian]

Haha' date=' I never thought it like that...

But since we have a model, why are we still talking about a dual nature of things? Why is it being pointed out that light for example can in different situations behave as waves or particles? Why don't we simply say that our universe is composed of warticles?[/quote']

 

I personally would call the electron a 'field' which embodies both the particle and wave properties. There is a tendancy for scientists to still call them 'particles' but they are really refering to the 'field' nature. I think people just like to cling onto things that they know and have personally experienced, so they like to say 'ooh, that behaviour was like a wave' or 'ooh, that was very particle-like'. The problem is that we really shouldn't be giving an object a name which corresponds to only one of its properties.

 

To draw an analogy, we could call a cat a 'milk-drinker' or a 'mouse-hunter' but a cat can't drink milk and hunt a mouse at the same time. It does one or the other, but the descriptions are not mutually exclusive - we don't need to introduce two different breds of cat, one which drinks milk and one which hunts mice. Similarly an electron can exhibit wave-like properties and particle-like properties depending on the situation. It can't do both at once, but that doesn't mean that we have to have two different theories to accommodate it.

[Severian]

Haha' date=' I never thought it like that...

But since we have a model, why are we still talking about a dual nature of things? Why is it being pointed out that light for example can in different situations behave as waves or particles? Why don't we simply say that our universe is composed of warticles?[/quote']

 

I personally would call the electron a 'field' which embodies both the particle and wave properties. There is a tendancy for scientists to still call them 'particles' but they are really refering to the 'field' nature. I think people just like to cling onto things that they know and have personally experienced, so they like to say 'ooh, that behaviour was like a wave' or 'ooh, that was very particle-like'. The problem is that we really shouldn't be giving an object a name which corresponds to only one of its properties.

 

To draw an analogy, we could call a cat a 'milk-drinker' or a 'mouse-hunter' but a cat can't drink milk and hunt a mouse at the same time. It does one or the other, but the descriptions are not mutually exclusive - we don't need to introduce two different breds of cat, one which drinks milk and one which hunts mice. Similarly an electron can exhibit wave-like properties and particle-like properties depending on the situation. It can't do both at once, but that doesn't mean that we have to have two different theories to accommodate it.

[Proton Head]

Some people do refer to wavicles and, perhaps, warticles. That's the answer to your previous question, really - there's a limitation in understanding if you assume that particles are particles, rather than some more complex entity that has both wave and particle behavior. We are limited by our macroscopic preconceptions.

 

Thanks,

but I'd still like to know the quantity which the physisist use when calculating particle interference.

Perhaps it would help to open my mind a bit, since well, my mind is really limited.

(Yes I know that they're not really particles, but I only mean that in some calculations people operate them that way, and then there should be some quantity they use to calculate the interference. Or maybe I'm all messed up, but even though they would use the equations of quantum mechanics to describe the state of these wave/particles, even then there should be some kind of quantity they use to calculate the interference.)

For example is the interfering quantity position? Volume? Mass? Energy? Field Strenght? Or what?

[Proton Head]

Some people do refer to wavicles and, perhaps, warticles. That's the answer to your previous question, really - there's a limitation in understanding if you assume that particles are particles, rather than some more complex entity that has both wave and particle behavior. We are limited by our macroscopic preconceptions.

 

Thanks,

but I'd still like to know the quantity which the physisist use when calculating particle interference.

Perhaps it would help to open my mind a bit, since well, my mind is really limited.

(Yes I know that they're not really particles, but I only mean that in some calculations people operate them that way, and then there should be some quantity they use to calculate the interference. Or maybe I'm all messed up, but even though they would use the equations of quantum mechanics to describe the state of these wave/particles, even then there should be some kind of quantity they use to calculate the interference.)

For example is the interfering quantity position? Volume? Mass? Energy? Field Strenght? Or what?

[swansont]

Thanks' date='

but I'd still like to know the quantity which the physisist use when calculating particle interference.

Perhaps it would help to open my mind a bit, since well, my mind is really limited.[/quote']

 

The deBroglie wavelength, ^{[math]\lambda = h/p[/math]} is a relevant quantity.

 

Notice that for macroscopic objects, the wavelength gets really small. So the wave nature of something you can see with the naked eye really doesn't impact its behavior a whole lot.

[swansont]

Thanks' date='

but I'd still like to know the quantity which the physisist use when calculating particle interference.

Perhaps it would help to open my mind a bit, since well, my mind is really limited.[/quote']

 

The deBroglie wavelength, ^{[math]\lambda = h/p[/math]} is a relevant quantity.

 

Notice that for macroscopic objects, the wavelength gets really small. So the wave nature of something you can see with the naked eye really doesn't impact its behavior a whole lot.

[Proton Head]

The deBroglie wavelength' date=' [sup'][math]\lambda = h/p[/math][/sup] is a relevant quantity.

 

Notice that for macroscopic objects, the wavelength gets really small. So the wave nature of something you can see with the naked eye really doesn't impact its behavior a whole lot.

 

Hmm...but electromagnetic radiation has a wavelength too, but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

 

 

Hmm, if for waves: wavelenght = speed/frequency,

 

then p/h = frequency/speed

m*v/h = frequency/speed

mv^2 = frequency*h

 

For light:

mc^2 = frequency*h

E = frequency*h

 

For particles:

mc^2-x = frequency*h

E = frequency*h+x

 

Hmm, so for light its internal energy is defined by its frequency, but for a particle its internal energy is only partly defined by its frequency.

This term x defines the wave character of matter. When a particle is at rest E=x, the particle has no wave nature and its internal energy is only defined by x.

 

Or maybe not.

[Proton Head]

The deBroglie wavelength' date=' [sup'][math]\lambda = h/p[/math][/sup] is a relevant quantity.

 

Notice that for macroscopic objects, the wavelength gets really small. So the wave nature of something you can see with the naked eye really doesn't impact its behavior a whole lot.

 

Hmm...but electromagnetic radiation has a wavelength too, but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

 

 

Hmm, if for waves: wavelenght = speed/frequency,

 

then p/h = frequency/speed

m*v/h = frequency/speed

mv^2 = frequency*h

 

For light:

mc^2 = frequency*h

E = frequency*h

 

For particles:

mc^2-x = frequency*h

E = frequency*h+x

 

Hmm, so for light its internal energy is defined by its frequency, but for a particle its internal energy is only partly defined by its frequency.

This term x defines the wave character of matter. When a particle is at rest E=x, the particle has no wave nature and its internal energy is only defined by x.

 

Or maybe not.

[Severian]

Hmm...but electromagnetic radiation has a wavelength too' date=' but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

[/quote']

 

Yes it does. If you start with an electron (say) at a fixed position, its momentum is uncertain, due to the uncertainty principle, so after a short time it will no longer be in the same position. But since you don't know the momentum so you don't know where the particle is after the short time. In fact, since you can't know the momentum, the position of the 'particle' is not defined - it is in reality spread over all possible places it 'could be'. When you measure the particle's momentum again, you will get a definite answer - the spread out electron will collapse into a state with definite position, and the probability of choosing a particular position is determined by the spread out electron's 'density'. It is that probability wave which is 'waving'.

[Severian]

Hmm...but electromagnetic radiation has a wavelength too' date=' but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

[/quote']

 

Yes it does. If you start with an electron (say) at a fixed position, its momentum is uncertain, due to the uncertainty principle, so after a short time it will no longer be in the same position. But since you don't know the momentum so you don't know where the particle is after the short time. In fact, since you can't know the momentum, the position of the 'particle' is not defined - it is in reality spread over all possible places it 'could be'. When you measure the particle's momentum again, you will get a definite answer - the spread out electron will collapse into a state with definite position, and the probability of choosing a particular position is determined by the spread out electron's 'density'. It is that probability wave which is 'waving'.

[swansont]

Hmm...but electromagnetic radiation has a wavelength too' date=' but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

[/quote']

 

Phase and wavelength are also used for EM radiation. The "field strength" is proportional to the number of photons, atoms or electrons of a given wavelength.

[swansont]

Hmm...but electromagnetic radiation has a wavelength too' date=' but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

[/quote']

 

Phase and wavelength are also used for EM radiation. The "field strength" is proportional to the number of photons, atoms or electrons of a given wavelength.

[cyeokpeng]

Hmm...but electromagnetic radiation has a wavelength too' date=' but the quantity used in interference is field strength.

And a wave on a string has a wavelength, but the quantity used in interference is its position (displacement from an axis).

So shouldn't there be something like that for the "particle" as well?

[/quote']

 

For particle waves like your electron waves or proton waves, the quantity used is the intensity of the electron or proton beam, which is proportional to the probability of finding the electrons or protons at at particular position of interest |wavefunction|^2. Note that the concept is quantum mechanical, it is not deterministic like your EM waves field strength and the displacement of the wave on a string.