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Author Topic: What is radiation?  (Read 10042 times)

Offline yor_on

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What is radiation?
« on: 29/01/2010 13:56:01 »
This one will take some time to explain :)

To me there can't be any radiation in a vacuum. All radiation are from a particle perspective interactions, and as I understand it the same is true from a wave perspective too. If you look at the explanations we use for the transmitting of 'energy' in those interactions (a.k.a energy carriers) we call them 'photons'.

Photons on the other hand, as far as I know, does not radiate in themselves, even though they are what we can see as f.ex. sunlight.

So how do they do it.
What is radiation?


 

Offline lightarrow

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What is radiation?
« Reply #1 on: 30/01/2010 01:42:49 »
This one will take some time to explain :)

To me there can't be any radiation in a vacuum. All radiation are from a particle perspective interactions, and as I understand it the same is true from a wave perspective too. If you look at the explanations we use for the transmitting of 'energy' in those interactions (a.k.a energy carriers) we call them 'photons'.

Photons on the other hand, as far as I know, does not radiate in themselves, even though they are what we can see as f.ex. sunlight.
??? Could you rephrase a little?
 

Offline Geezer

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What is radiation?
« Reply #2 on: 30/01/2010 02:28:37 »
I prefer to think of radiation simply as energy that propagates through space, although, I probably should not really say "propagates" because that suggests that "space" is an "aether" which seems to be a very unpopular concept, despite the fact that "space" has some very distinct properties. While "vacuum" suggests nothingness, I think it is misleading. Space is "somethingness". If it's "nothingness", how could it ever expand to create our Universe?

Photons seem to be the minimum quanta of energy that can be transmitted through space. Thinking of photons as particles, or waves, is likely to lead to confusion (as I have discovered.)

IMHO, Startrek was 100% right. "Space is the final frontier."  We continue to examine the consequences of energy in space (particles etc.) but we are finding it difficult to discern the nature of space itself. Once we figure that out, I am sure a lot more will be revealed.
 

Offline JP

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What is radiation?
« Reply #3 on: 30/01/2010 02:33:30 »
Exactly, Geezer.  "Vacuum" does not mean "nothing."  Vacuum means volumes of space with a minimal amount of stuff in it.  But that minimal amount allows radiation (and particles) to exist there.
 

Offline yor_on

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What is radiation?
« Reply #4 on: 30/01/2010 12:21:54 »
JP?

Does that mean that without that 'minimal amount' there wouldn't be any radiation?
Or do you see it differently?
===

And Geezer, if you see a vacuum as 'something', what do you see it as?
===

Lightarrow, you could say it's a discussion of EM in a vacuum if you like.
 

Offline JP

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What is radiation?
« Reply #5 on: 30/01/2010 13:05:55 »
Well, we first need to agree on what we mean by vacuum and what we mean by radiation.  By vacuum, what I mean is empty space, far from all matter.  By radiation, I'm assuming you mean particles (photons) emitted by something and absorbed by something else. 

Even there, because there is the potential for radiation to exist, the electromagnetic field exists there, and at its lowest energy it is non-zero energy, as I mentioned.  There entire universe is permeated by this field, so there is nowhere that doesn't have this tiny bit of vacuum energy.  I suppose if you wanted to think of a universe without any electromagnetism, you wouldn't have this field everywhere and you also wouldn't have the ability to have radiation anywhere.

So this energy is kind of a signature of the electromagnetic existing throughout the universe, even if there isn't radiation there yet.
 

Offline yor_on

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What is radiation?
« Reply #6 on: 30/01/2010 14:11:32 »
Yeah, the idea of the potential vacuum energy, but as I understand it it's only potential? How do you see that supporting a particle emitted from the sun f.ex.

Like it's coming to existence at it's path?
a trail of virtual particles supporting it.

Or no particles at all?
 

Offline lightarrow

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What is radiation?
« Reply #7 on: 30/01/2010 14:22:10 »
The other posters must be smarter than me because I still don't understand what all this discussion is about. Could you please ask a precise question?
 

Offline yor_on

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What is radiation?
« Reply #8 on: 30/01/2010 15:13:25 »
Well lightarrow, if you don't like the questions or find them too vague, that's cool with me.

EM in space (perfect vacuum), and me saying that you need an interaction for proving EM, is that too vague?


« Last Edit: 30/01/2010 15:40:58 by yor_on »
 

Offline litespeed

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What is radiation?
« Reply #9 on: 30/01/2010 16:51:48 »
The Fifth Dimension?

Plank units lead this novice to suspect a fifth dimension. Particles are forever jumping from place to place without existing in between those places, after all. If the fifth dimension has no time, then the particle just sort of gets temporarily parked there as the fourth dimension chugs away, plank unit by plank unit; particles hoping in and out of both it as time and 'distance' click past in our four dimensional world.

Sort of like a motion picture. Intuitively, this seems a reasonable way to approach relativity, and perhaps black holes. Black hole 'singularities' are not infinitely small and infinitely dense. Their centers might, however, crack the time barrier, or come very close. Time coming to a near complete stop in our fourth dimension.

Perhaps photons are nothing more then a ripple effect from this other dimension. Again, after all, they can be converted into particles that suddenly go slower then the speed of light, but these then begin popping in and out of existence according to QM.

Just me babbling.....



« Last Edit: 30/01/2010 16:58:13 by litespeed »
 

Offline yor_on

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What is radiation?
« Reply #10 on: 30/01/2010 18:14:46 »
As for black holes and time I'm leaning toward your idea Litespeed, assuming that time stops at a singularity it seems very reasonable to assume a BH to be 'out'a this world:)'.

As for dimensions?

That's a possibility. Time is after all defined as a 'dimension' of its own, and don't we say that 'virtual particles' exist outside Planck time?

But can you call that a fifth?
I don't know.

But it's an idea.
==



 

Offline lightarrow

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What is radiation?
« Reply #11 on: 30/01/2010 20:28:10 »
Well lightarrow, if you don't like the questions or find them too vague, that's cool with me.

EM in space (perfect vacuum), and me saying that you need an interaction for proving EM, is that too vague?
Ok, now I have understood the question, thank you.
I would say that it's correct, you need an interaction.
 

Offline yor_on

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What is radiation?
« Reply #12 on: 30/01/2010 21:31:21 »
Yes, and without that interaction does it exist, and if it exist, would it be a wave undefined in distance or a particle. Can it travel or does it just exist in its interaction.

Photon's doesn't 'radiate' which seems to make them the 'smallest' 'energy carriers' we know. And then the question might be if I should see them as geometric shapes 'traveling' in a universe defined by it's plastic abilities when it comes to mass, acceleration and 'times arrow?

And if light doesn't travel at all then its interactions as particles and the waves we describe becomes something else.

And what is then this radiation?

Anyone read this one?

How does it do it?
And yeah, I'm vague now :)
 

Offline Geezer

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What is radiation?
« Reply #13 on: 01/02/2010 18:56:21 »
"And Geezer, if you see a vacuum as 'something', what do you see it as?"

Well, going way out on a limb :D, I think we all see it all the time. I think "matter" is simply a manifestation of space. Energy is encapsulated within space to produce the stuff we call matter. So, in a sense, there is nothing but space and energy. Matter is just a combination of the two.

And don't ask me to prove it, although I think this is the general concept behind String Theory, so I may not be alone.
 

Offline syhprum

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What is radiation?
« Reply #14 on: 02/02/2010 21:06:58 »
Radiation is a term that is used rather loosly, it is often wrongly in my mind used to refer to particles emitted by radioactive substances I would like it to be used only to refer to electromagnetic radiation.
 

Offline yor_on

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What is radiation?
« Reply #15 on: 09/02/2010 22:58:46 »
"And Geezer, if you see a vacuum as 'something', what do you see it as?"

Well, going way out on a limb :D, I think we all see it all the time. I think "matter" is simply a manifestation of space. Energy is encapsulated within space to produce the stuff we call matter. So, in a sense, there is nothing but space and energy. Matter is just a combination of the two.

And don't ask me to prove it, although I think this is the general concept behind String Theory, so I may not be alone.

Looking at what you wrote Geezer. If I assume our universe to be a 'closed bubble' then there should be a limited amount of energy to it. That energy may then be placed in two categories loosely speaking. Energy that can transform and 'do work' and energy that already have been 'used up' and therefore can't do any more work. We then have times arrow that points us in one direction macroscopically but seems to allow for more directions quantum mechanically.

If we look at it from a macroscopic point of view the idea of 'work done', as far as I understand, is a direct result of entropy, and in that motto our flow point to a position where no energy will be able to be transformed. When you introduce your idea you lift up the quantum mechanical aspects of SpaceTime and seem to place it at the same level as our macroscopic interactions?

If that is correct why do we see this arrow only as pointing one way?
And what does it do the concept of entropy as QM can describe events as going both backward and forward in 'time'?

To clarify :)
What I'm asking is, if there is no 'boundary' between QM and Macroscopic events (arrow of time) why doesn't we notice it?
 

Offline Geezer

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What is radiation?
« Reply #16 on: 10/02/2010 21:15:17 »
Looking at what you wrote Geezer. If I assume our universe to be a 'closed bubble' then there should be a limited amount of energy to it. That energy may then be placed in two categories loosely speaking. Energy that can transform and 'do work' and energy that already have been 'used up' and therefore can't do any more work. We then have times arrow that points us in one direction macroscopically but seems to allow for more directions quantum mechanically.

If we look at it from a macroscopic point of view the idea of 'work done', as far as I understand, is a direct result of entropy, and in that motto our flow point to a position where no energy will be able to be transformed. When you introduce your idea you lift up the quantum mechanical aspects of SpaceTime and seem to place it at the same level as our macroscopic interactions?

If that is correct why do we see this arrow only as pointing one way?
And what does it do the concept of entropy as QM can describe events as going both backward and forward in 'time'?

To clarify :)
What I'm asking is, if there is no 'boundary' between QM and Macroscopic events (arrow of time) why doesn't we notice it?

I dunno! Maybe it's simply a question of "resolution". As we go down to smaller scales, things might get a bit "jittery", including time maybe?

There is no denying quantum effects. It certainly seems as if electromagnetic radiation (I'd rather not use the P word) has a minimum quantum of energy (for a particular frequency).

As I am unencumbered with much training in this field, my observations are probably much more philosophical that scientific. It just seems to me that there are many "coincidences" that might be pointing us to a solution. Personally, I think the idea of trying to explain everything in terms of particles is a forced fit. Somewhere along the line, it became rather "untrendy" to describe space as "something", despite the fact that space has some very distinct properties.

Here are some of the things that may be leading me down the garden path:
Matter can be converted into energy, and energy can be converted into matter.
Matter distorts space (and space distorts matter).
Electromagnetic phenomena have very clear wavelike properties. Therefore, electromagnetic energy is propagating through something.
If space can transmit energy by means that we don't seem to understand, why can't it also encapsulate energy to form "particles" by means that we don't seem to understand?

Only sayin'
 
 

Offline yor_on

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What is radiation?
« Reply #17 on: 11/02/2010 10:25:19 »
Yeah it's weird. Thinking of 'free space' you either define it, as I do, as having no pressure at all, which to me seems logical :) or you can define it as having a pressure. It depends on how you look at space. I look at it as a 'emergence' without a pressure. But you can also look on it form of 'forces' (negative and positive energy) equalizing each other, a little like Lagrangian points 'equalize' gravitational 'forces'.

What you are doing here is to decide that light do travel in space, and from there try to reason out the properties needed for your definition to work, right?

To do that, the question seems to become under what circumstances can we say that light propagate. And the bottom line seems to me to become. Does it need a 'medium'?
« Last Edit: 11/02/2010 10:29:26 by yor_on »
 

Offline JP

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What is radiation?
« Reply #18 on: 11/02/2010 10:34:58 »
Here are some of the things that may be leading me down the garden path:
Matter can be converted into energy, and energy can be converted into matter.
Matter distorts space (and space distorts matter).
Electromagnetic phenomena have very clear wavelike properties. Therefore, electromagnetic energy is propagating through something.
If space can transmit energy by means that we don't seem to understand, why can't it also encapsulate energy to form "particles" by means that we don't seem to understand?

Only sayin'
 

We have very good mathematical models of particles being created from energy (the standard model), but I don't think people would claim to fundamentally understand "why."  That's the realm of a "theory of everything."
 

Offline lightarrow

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What is radiation?
« Reply #19 on: 11/02/2010 13:15:05 »
Electromagnetic phenomena have very clear wavelike properties. Therefore, electromagnetic energy is propagating through something.
False. Electromagnetic field can propagate in the void and the ether doesn't exist.
 

Offline Geezer

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What is radiation?
« Reply #20 on: 11/02/2010 18:01:11 »
Electromagnetic phenomena have very clear wavelike properties. Therefore, electromagnetic energy is propagating through something.
False. Electromagnetic field can propagate in the void and the ether doesn't exist.

A bold statement Lightarrow. I prefer to keep an open mind.
 

Offline Geezer

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What is radiation?
« Reply #21 on: 11/02/2010 18:29:52 »
To do that, the question seems to become under what circumstances can we say that light propagate. And the bottom line seems to me to become. Does it need a 'medium'?

I think we are a bit too focused on light (pretty good, eh  ;)) perhaps because we have senses to detect it. We have to consider the entire EM spectrum. The further you move from the visible spectrum towards lower frequency "radio" spectrum, the more improbable the particulate nature of EM becomes and the more probable the wave nature of EM becomes, but it's all EM energy transmission nonetheless. To me, it seems far more likely that EM radiation is simply a wave.

We know about lots of other waves that can transmit energy through all sorts of mediums. Why not EM too? I find it interesting that, despite the fact that no one has ever observed a photon, a great many people have an unshakable belief that they have a discrete nature. In fact, the quantization of EM radiation seems (to me) to be a property of the underlying "transmission fabric" more than anything else.
 
 

Offline Ron Hughes

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What is radiation?
« Reply #22 on: 11/02/2010 19:26:58 »
 

Offline Geezer

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What is radiation?
« Reply #23 on: 12/02/2010 00:10:27 »
What can I say.  See,   http://www.thenakedscientists.com/forum/index.php?topic=28667.msg299038#msg299038

Hi Ron: I noticed you used the term "propagates". Would that not suggest some sort of wave action?
 

Offline Ron Hughes

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What is radiation?
« Reply #24 on: 12/02/2010 01:37:01 »

 

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