Is the wave a particle?

[benhur]

It's said waves and particles are different. I am finding it hard to see how.

If we consider slinky, which is the usual example given, the coils are the particles, and the disturbance is the wave. Now without the coil, no disturbance is carried from one end to the other in the form of waves. In fact, the coil is the wave, transferring energy from one place to another.

So why do we distinguish between wave and particle (coil, in this case), when it appears as if wave is simply a particle (coil) in vibration, and has no existence apart from the particle?:(

[ÑóẊîöʼn]

If I may...


It's said waves and particles are different. I am finding it hard to see how.

They're actually the same thing. Or a rather wierd entity that is both a wave and a particle, and which has no counterpart in the macro-world familiar to us hairless apes.


If we consider slinky, which is the usual example given, the coils are the particles, and the disturbance is the wave. Now without the coil, no disturbance is carried from one end to the other in the form of waves. In fact, the coil is the wave, transferring energy from one place to another.

So why do we distinguish between wave and particle (coil, in this case), when it appears as if wave is simply a particle (coil) in vibration, and has no existence apart from the particle?:(It looks like you've been given a misleading analogy. Wave-particles are quite unlike anything experienced by human beings, so anything besides mathematical descriptions are inadequate.

However, an interactive computer program that simulates the behaviour of a wave-particle on the macroscale might help. Also look at the Double-slit Experiment. (http://en.wikipedia.org/wiki/Double-slit_experiment)

[Dr Mindbender]

light, which is a form of wave, is accredited with consisting of 'packets of energy' or particles of zero mass called 'photons'. It's never been proven one way or the other what they really are, but i like to think of light as 'waves of massless particles'.

[Rosa Lichtenstein]

In fact, we still do not know the answer to this one, something that convinces many physicists that current theory is seriously incomplete.

[black magick hustla]

In fact, we still do not know the answer to this one, something that convinces many physicists that current theory is seriously incomplete.

I think the confusion between laymen arises from the fact that thanks to platonic physicists they think of quantum mechanics as nature, rather than a tool. "matter waves" are "information waves" i.e. they are not really physical entities, but mathematical constructs that tell us about the probability of finding a particle in a certain place. they are "waves" because they can mathematically experience things like destructive interference. From what I gather, most physcists do not understand the reasons behind this mathematical results. They just think of it as just a rule of thumb.

[Rosa Lichtenstein]

Marmot:


I think the confusion between laymen arises from the fact that thanks to platonic physicists they think of quantum mechanics as nature, rather than a tool. "matter waves" are "information waves" i.e. they are not really physical entities, but mathematical constructs that tell us about the probability of finding a particle in a certain place. they are "waves" because they can mathematically experience things like destructive interference. From what I gather, most physcists do not understand the reasons behind this mathematical results. They just think of it as just a rule of thumb.

To some extent I agree -- but then, you have the problem of trying to explain why our rules of probability work.

They either map out Platonistically the actual world, or nature 'obeys' these rules. If the latter, then nature must be mind (for only minds can 'obey'). If the former, nature was made by mind.

[piet11111]

i find it odd that light can be curved/trapped by gravity from a black hole.
would it not need some mass to be affected ?

(my "science" classes consisted of messing with wires and resistances until a led light came on so forgive my ignorance)

[Mecha_Shiva]

i find it odd that light can be curved/trapped by gravity from a black hole.
would it not need some mass to be affected ?

(my "science" classes consisted of messing with wires and resistances until a led light came on so forgive my ignorance)

I remember hearing in my physics class that the photons that make up light have momentum. And to have a momentum, they would have to have some sort of mass?

[Rosa Lichtenstein]

Apparently they are massless but have momentum -- figure that one out.

http://physics.about.com/od/lightoptics/f/photon.htm

Wikipedia says they are 'virtually massless':

http://physics.about.com/od/lightoptics/f/photon.htm

[black magick hustla]

Well, electromagnetic waves can exert pressure and do exert pressure, and pressure is F/A and Force is the change of momentum. I dont really think its that difficult to understand, honestly. Why do you think you can cut stuff with lasers?


To some extent I agree -- but then, you have the problem of trying to explain why our rules of probability work.

They either map out Platonistically the actual world, or nature 'obeys' these rules. If the latter, then nature must be mind (for only minds can 'obey'). If the former, nature was made by mind.

You dont really have to explain anything. You do experiments, and this equations work. You cant explain something that you do not have any idea why it is like that.

[Rosa Lichtenstein]

Marmot:


You do experiments, and this equations work. You cant explain something that you do not have any idea why it is like that.

Maybe so, but then few scientists are going to be satisfied with that.

[KC]

i find it odd that light can be curved/trapped by gravity from a black hole.
would it not need some mass to be affected ?

(my "science" classes consisted of messing with wires and resistances until a led light came on so forgive my ignorance)Light is not curved or trapped by gravity from a black hole. Space-time is.


Apparently they are massless but have momentum -- figure that one out.It is because E=Mc^2 is the simplified version of Einstein's theory (when a particle is at rest, p=0, so then we are left with Einstein's famous equation E=mc^2). In order to discuss the momentum of the photon the full equation must be taken into consideration.

E^2 = (m^2)(c^4) + (p^2)(c^2)

Because the mass of a photon is 0, m=0, so our equation can be simplified as:

E = pc (p = momentum, c = speed of light)

Momentum then is p = E/c, so the momentum is related linearly to just the energy it contains.


Well, electromagnetic waves can exert pressure and do exert pressureCheck this (http://emdrive.com/) out.

[ÑóẊîöʼn]

Check this (http://emdrive.com/) out.

Doesn't that violate conservation of momentum?

[KC]

Doesn't that violate conservation of momentum?From the FAQ:

Q. Does the theory of the EmDrive contravene the accepted laws of physics or electromagnetic theory?

A. The EmDrive does not violate any known law of physics. The basic laws that are applied in the theory of the EmDrive operation are as follows:


Newton’s laws are applied in the derivation of the basic static thrust equation (Equation 11 in the theory paper) and have also been demonstrated to apply to the EmDrive experimentally.

The law of conservation of momentum is the basis of Newtons laws and therefore applies to the EmDrive. It is satisfied both theoretically and experimentally.

The law of conservation of energy is the basis of the dynamic thrust equation which applies to the EmDrive under acceleration,(see Equation 16 in the theory paper).

The principles of electromagnetic theory are used to derive the basic design equations.



Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?

A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.


Basically, when you approach the speed of light you can treat the drive as an open system, due to relativity somehow. I don't remember how it works, but I did look into it a while ago and the math seemed valid.

EDIT: Here's a better explanation


The inevitable objection raised, is that the apparently closed system produced by this arrangement cannot result in an output force, but will merely produce strain within the waveguide walls. However, this ignores Einstein’s Special Law of Relativity in which separate frames of reference have to be applied at velocities approaching the speed of light. Thus the system of EM wave and waveguide can be regarded as an open system, with the EM wave and the waveguide having separate frames of reference.




A similar approach is necessary to explain the principle of the laser gyroscope, where open system attitude information is obtained from an apparently closed system device.
Source (http://emdrive.com/principle.html)


Also, the theoretical/mathematical proof can be found here (http://www.emdrive.com/theorypaper9-4.pdf) (PDF).

[ÑóẊîöʼn]

This PDF file (http://www.assassinationscience.com/johncostella/shawyerfraud.pdf) debunks it pretty well. Basically, momentum is unchanged in a closed system, and relativity doesn't change that fact one wit.

[KC]

This PDF file (http://www.anonym.to/?http://www.assassinationscience.com/johncostella/shawyerfraud.pdf) debunks it pretty well. Basically, momentum is unchanged in a closed system, and relativity doesn't change that fact one wit.

Wow, thanks for that.

[Dystisis]

I am no expert but it seems to me light is perhaps one of the areas where scientists are still somewhat left in the dark.

By that I mean sure, we have theories that some may be completely sure of, but in 10 years we could still have a completely different understanding of it than today.

[Rosa Lichtenstein]

^^^Perhaps too this explains why Lee Smolin is right when he says that there have been no fundamental advances in Physics now for over 25 years:

http://en.wikipedia.org/wiki/Lee_Smolin

http://www.thetroublewithphysics.com/