Long wavelength photon, how lonnnng is it?

[AlienUFO]

I can't imagine a very long photon travelling like, is it it just a particle that campletes its cycle (like spin or frequency) at longer distant or a really lonnng discrete string that vibrating, or, otherwise?

 

So, in consider of photoelectric, diffraction, interference, resonance heating... what is that length of wave is mean?

[[Tycho?]]

Uh, do you know what a photon is? Your post seems... confused.

 

I'm also not sure what you're asking, but here is wikipedia

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

[AlienUFO]

Well, I do know some formula and calculation related to photon, but that's only maths.

 

Such as wave-length, I don't understand that weither the wave-length calculated is the actual length of the photon, I mean, how could I imagne that kind of half-wave half-particle thing? Having a very lonnnnng photon but than it's a particle, no way seems logic.

 

So, I want to know that.

[Severian]

The photon wavelength can be as long as you like.

 

I think you are being confused by the particle/wave duality thing. I have always thought that 'particle' was a bad choice of word because it implies something has no spatial extent. They only have no spacial extent immediately when their position is measured.

 

The effect of the measurement itself it to focus the photon down to a point. At this time, the photon no longer has a definite wavelength - it is in fact composed of all possible wavelengths added up together. Only when you measure the wavelength will it take on a definite value, but then it will not have a definite position.....

[AlienUFO]

There is a kind of photon model appeared in my mind. Imagine I spin-throw a ball on space, at first the hole of the ball (where we pump air in) is in front, as the ball spinning, until we see the hole in front again, the distant the ball travelled is what we call 'wavelength', but actually it just a ball, depent on how fast I spin when spin-throw the ball.

 

But if what Severian said is the best answer, is it possible that there was a photon very long that passing through our body long ago but haven finish penetrating yet? And there is no way to measure its existant...

[5614]

I'm not quite sure what you're trying to get at here but see this for wavelength:

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

 

Low frequency radio waves have a wavelength of about 10km if that helps.

[YT2095]

quick question, IS there a theoretical Max wavelength?

say 300,000 kms.

the lowest possible frequency a photon can exist at.

[5614]

As, for a photon, [math]c = f \lambda [/math]

c = speed of light

f = frequency

[math]\lambda[/math] = wavelength

 

Remembering that c is constant, so [math]f \times \lambda[/math] always equals the same thing, if there is a minimum frequency then there must be a maximum wavelength.

[YT2095]

I agree, but what is the min freq? and what happens below this?

[Severian]

Well, there is no minimum frquency in principle (ie. in the physical laws), but I suppose in practical terms it would be difficult to have a photon with a period longer than the lifetime of the universe.

[YT2095]

forgive my transposition of terms here; a Photon is "AC" (like the current), can it exist at "DC"?

or does it become like a plain North/South magnet sitting still on a table?

 

since we Are talking about the EM spectrum, would the Lowest freq (longest wavelength) be like that emited from a stationary magnet?

[5614]

Well, there is no minimum frquency in principle (ie. in the physical laws), but I suppose in practical terms it would be difficult to have a photon with a period longer than the lifetime of the universe.

Yeah, I thought so, hence I said "if there is a minimum frequency", emphasis on the if. YT where did you get the idea there was a minimum frequency?

 

forgive my transposition of terms here; a Photon is "AC" (like the current), can it exist at "DC"?

If I understand the analogy then I don't think so. It's AC as in it is oscillating.

[YT2095]

YT where did you get the idea there was a minimum frequency?

 

If I understand the analogy then I don't think so. It's AC as in it is oscillating.

 

well both of these are related, and yes AC because it oscillates

I`ve no idea where this idea came from either, it`s just something I considered.

the possiblity of a photon so low in frequency that it approached "DC" levels, and what would the nature of such a "thing" be.

 

think, a wire is put across a battery, this is done 1 million times per second, Photons are emited and broadcast a signal at 1mHz.

now just put that wire across and leave it there, you have basicly a Magnetic Field not doing anything particularly fantastic, is it giving off "DC" photons at this point?

 

is a "flatlined photon" simply just a stationary magnetic field?

[5614]

Imagine a simple circuit with a power supply and a bulb. If it is turned on then the light will emit at a certain frequency. Now if you turn it on and off 1 million times per second then the bulb will still emit light at the same frequency.

 

In your example the 1MHz comes from when the field is there or not. It is not the actual frequency of the field itself. Do you see what I mean? The field comes and goes at 1MHz, but that doesn't mean the photons in the field have that frequency.

 

Remember a DC signal could still be a wave shape, it just can never be negative. So this graph shows a DC signal, yet it is osciallating:

http://img.photobucket.com/albums/v601/5614/graph.jpg

so when we talk about photons what does the x axis really mean? For current being below the x axis means a negative current, but to me it seems meaningless for a photon?

 

What do you mean by a "flatlined photon"? Do you mean a photon which isn't oscillating at all? Then it isn't a wave and so it isn't really EM radiation at all.

[YT2095]

so since there`s No lower frequency limit (beyond that of the universes` life), it would be possible to "see"/Demonstrate the effects of Negative Photons?

a photon who maybe heading upwards in Oscillation towards the Positive of the X-axis, but may take a year or 2 to get there?

 

this is getting quite Bizare but interesting!

[5614]

so since there`s No lower frequency limit (beyond that of the universes` life), it would be possible to "see"/Demonstrate the effects of Negative Photons?

What?!?? What I meant (and what I said) was that the whole negative or positive thing for current is meaningless for photons.

 

Like I showed on that graph a photon could be oscillating above the x axis so be all positive. In fact you could put an oscillating wave wherever the hell you want! Because that x axis is meaningless.

 

In the AC or DC current graphs position on the y-axis is a specific value, right. So if the AC curve goes between 1 and -1 on the y-axis then, well, that's the min and max current values. But for a photon it is nothing. The axis are irrelevant and/or meaningless, you don't even need them to show an oscillating wave, which a photon is.

 

I think the whole AC/DC thing is confusing the matter.

[YT2095]

ok, simple terms, a Photon Oscillates, Yes?

 

right, now then, What is lowest Frequency this Oscillation can be?

we Ignore the Y-Axis (amplitude) and focus Soley upon the distance on the X-Axis from peak to peak (one cycle).

that`s going to have to be enough as I have no other way to explain this in terms more simple.

[swansont]

You can have static electric and magnetic fields, though I wouldn't call them "flatlined photons." But they are DC, i.e. they are constant in time. EM radiation (photons) have them oscillating at some frequency. So if you wiggle an electron, it radiates photons (as I'm sure you already know, YT, because that's what happens in an antenna)

[YT2095]

Hmmm... now that`s put alot of my thoughts in perspective! Thanks

 

although I AM curious about the Transition of the 2 types, namely VLF and ELF e.m radiation, 50Hz for instance is quite receivable as a distinct Radio wave, so is this really "slow" oscillating photons?

and just How Low can this go in frequency before it`s no longer a Photon but a magnetic field or a static electrical charge?

[AlienUFO]

But I still don't get my answer, is the wavelength of photon is a part of photon itself, like a string, or just the distant where photon completes its cycle but not a part of photon?

[5614]

YT: As Severian said, there is no theoretical limit to how small the frequency can go.

 

AlienUFO: Wavelength is the distant where photon completes its cycle. Didn't you look on the picture on the link I gave you?

[YT2095]

YT: As Severian said' date=' there is no theoretical limit to how small the frequency can go.

[/quote']

 

you really don`t get the question do you?

 

for instance can you give me an example of where a Photon(s) have a frequency from peak to peak once every 50 years?

[5614]

Yeah, there's one by that tree on the right!

 

I get what you're asking and no I can't give you an example, but that doesn't mean it can't exist.

 

Or look at it this way, it could exist, it just would not occur naturally. You could however, in theory, artificially create a wave with that frequency though, there's no law stopping you.

[YT2095]

Or look at it this way, it could exist, it just would not occur naturally. You could however, in theory, artificially create a wave with that frequency though, there's no law stopping you.

 

this is NOW at least Getting somewhere!

how would you create this artificialy and what would the properties of such wave be in real observable terms?

[5614]

You're the electronics guy. You can vary the frequencies of a radio wave you produce, well vary it so that it is low... very low.

 

Something like this would have such little energy and such a large wavelength I doubt you'd pick it up with anything, but in all other respects it is like all other parts of the EM spectrum.