What is above gamma and what is less than radio waves

[Lekgolo555]

What frequencies are above gamma rays and what are they called? Also what is below radio waves on the spectrum, and what is it called?

 

Does the photon move in straight lines or the wavey pattern going up and down?

 

When you shut off a light's power source, do the photons keep moving or do they stop immediately? For example you have a real big intergalactic flashlight that is projecting light for well over a year. Then all of a sudden you turn it off. Will the photons that have traveled a light-year stop instantly or will they keep going?

[Royston]

What frequencies are above gamma rays and what are they called? Also what is below radio waves on the spectrum, and what is it called?

 

Well you can get high frequency gamma rays, and low frequency radio waves, but they are the two extremes of the electromagnetic spectrum.

 

Does the photon move in straight lines or the wavey pattern going up and down?

 

In short, light gets refracted and also follows the curvature of space. Light propogates as waves, basically a photon is the point of the wave that's been isolated mathematically. I'm at work so I can't provide a full explanation.

 

When you shut off a light's power source, do the photons keep moving or do they stop immediately? For example you have a real big intergalactic flashlight that is projecting light for well over a year. Then all of a sudden you turn it off. Will the photons that have traveled a light-year stop instantly or will they keep going?

 

They certainly wouldn't stop, they'll carry on their merry way until absorbed by matter et.c I'm sure somebody will be able to provide a more detailed explanation...sorry, very busy at the moment.

[insane_alien]

alrighty, i'll have a go at explaining it.

 

Above gamma is kind of iffy, after a certain frequency there are some quantum mechanical effects that come into play that reduce the frequency back to a high energy gamma ray. This is where the photon forms a particle-antiparticle pair (usually electrons) which then annihilate and you end up with two other photons. if those photons are high enough in energy the same thing will happen so you'll end up with lots of lower frequency gamma photons instead of one big one.

 

light travels in a straight line but it can be refracted when it passes through materials and gravity (which bends space) can bend light.

 

when you turned off the torch the photons would still keep going. lets take a star as an example. its a pretty big light source. if the nearest star (other than the sun) disappeared right this instant it would take 4 years for us to see it. The light would have stopped emmitting but the light already on its way would stop because of that.

 

you could think of a water pistol, you fire it and the stream of water is photons. when you let go of the trigger and it stops spraying the stream of water doesn't just disappear it carries on. same thing with light.

[swansont]

The EM spectrum has some fuzzy definition. Most of the low-frequency stuff has general guidelines based on frequency or wavelength, though where e.g. RF stops and microwave starts depends on whether you talk to an engineer or a physicist and what their specific area is.

 

But in physics, X-rays come from atomic interactions and gammas come from nuclear interactions. So it's possible to have X-rays higher in energy than some gammas. (In astronomy, AFAIK, they use an arbitrary energy division. IIRC it's 1 MeV) In general, gammas are considered to be high-energy, and there's no other name — nothing higher than gamma. Radio waves get subdivided, like high frequency, low frequency, very low frequency and extremely low frequency. But nothing lower.

 

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

[Norman Albers]

I have read contradictory things: that above several GEV there are not photons because the energy probabilities are manifesting whatever all they do there. On the other hand, I read that there is no theoretic limit to k. This seems crazy if I think in terms on photons whose equilibirum state, if that exists as I am presenting it, is conformal to a Gaussian packet. Here, if the three spatial dimentions shrink with k, and also the energy density iincreases by k, then total density goes up by the fourth power of k . Things are getting awfully dense and you'd think it must yield. What can folks tell me here?

[Rocket Man]

if you approach a visible light source very close to c, the photon you see will be doppler shifted up, but also increased in frequency due to your time dialation.

the closer you get to c, the higher the frequency gets. basically, there's no limit to how high you can shift a photon so there's no limit to how high energy a photon is. it's all determined by your inertial frame.

 

a high energy gamma ray requires a particle to interact with before it can under go pair production. it needs to interact with something locked to an inertial frame

[YT2095]

in Laymans terms, aren`t Cosmic Rays higher than Gamma in frequency?

 

lower than radio would be a perfectly stationary magnet.

[Rocket Man]

are cosmic rays photons? i thought they were all manner of particles at really high energy.

[YT2095]

No idea. it`s just listed in my book here as after Gamma.

the highest it says is Antiproton annihilation at 938Mev and the wavelength is 10^-15 metres.

it`s just after the last entry of 10^23 Hz.

[Klaynos]

in Laymans terms, aren`t Cosmic Rays higher than Gamma in frequency?

 

lower than radio would be a perfectly stationary magnet.

 

This is a normal thing to believe. But normally they are just lumped in with gamma.

 

But they are indeed photons.

 

As swansont said, it's a bit fuzzy/

[YT2095]

yeah it says that in here (or similar)

 

" Secondary Cosmic Rays (Gamma rays produced by Cosmic rays)"

[swansont]

yeah it says that in here (or similar)

 

" Secondary Cosmic Rays (Gamma rays produced by Cosmic rays)"

 

I think what might be meant there is the gammas from the particle annihilation. Those are gammas, by the definition of gamma, and are from a cosmic-ray origin. More confusion from the different definitions (energy band vs source of the radiation)

[Norman Albers]

I thought cosmic "rays" are alpha particles and such. They come into the upper atmosphere, some at VERY high energies, like 10^20 ev. Thus they produce a shower miles deep as they repeatedly scatter, producing gammas and particle pairs.

[Klaynos]

I thought cosmic "rays" are alpha particles and such. They come into the upper atmosphere, some at VERY high energies, like 10^20 ev. Thus they produce a shower miles deep as they repeatedly scatter, producing gammas and particle pairs.

 

I think the term is used to cover lots of things. We where taught in school that they where the next on from gamma. But school teaches alot of stuff, and what I've heard it used for mostly since is a very wide range of stuff that is very very high energy that comes from outside the earth.

[Norman Albers]

Wikipedia says they are 90% protons, 9% alphas, and 1% electrons. Think about the magnitudes of energy here. Can we even detect a photon at 10^18 ev? When these energetic particles crash through atmosphere it's one hell of a pinball game.. . . . . . . . . . time passes. . . . . . . . I am reading on the HiRes program, and they mention that if a highly energetic proton or other nucleus interacts with gas molecules near the production site, then neutral products such as gammas and neutrinos may be produced, and might be of detectable strength. Am I reading this correctly?

[YT2095]

although Wiki is good, it`s not really a Scientific Resource.

and I get the feeling most of the time it only tells Half the story, so although it May be partly correct, the Group term; "Cosmic Rays", may encompass many other things too

[Norman Albers]

I could not get back on the site yesterday. Go to HiRes and click on the site map. On slide #3 there is a statement about tera-and peta-volt "rays".

[YT2095]

it`s interesting really, as the book I used to ref is a 1971 Data book (Like a CRC handbook), and there`s things in there out of date or at least not Complete to Todays standards and Knowledge, it`s still a great little book though

 

I dare say in another 30+ years peta volt stuff and beyond will be almost Common Knowledge, Quite Exciting when you think about it

 

and yes, the site was Borked yesterday, no-one could get on

[[Tycho?]]

Yeah I've always read that cosmic rays included gamma rays, as well as the massive particles.

[YT2095]

come to think of it, it would make perfect sense that a proportion of "Cosmic Rays" have Mass, I`ve seen Electron Microscope pictures of Chips that have been hit with a Cosmic "ray" and the silicon substrate looks like a Land Mine went off on it, quite Spectacular!

[Norman Albers]

On that third slide/page, it says in the range of 10^12 to 10^15 ev, there are about 50% proton events, 25% alphas, 13% combined nuclei C/N/O, 1% electrons, and 0.1% gammas.

[Norman Albers]

Fresh news on the wires: a set of 1600 detector tanks in Argentina is showing that ultra-high-energy cosmic particles (rays) around 10^19ev are sourced by nearby active galactic nuceii. This is good news because we think they interact with the CMB sufficiently that their energy is scattered down over distances larger than 300 million LY.

[Martin]

Fresh news on the wires: a set of 1600 detector tanks in Argentina is showing that ultra-high-energy cosmic particles (rays) around 10^19ev are sourced by nearby active galactic nuceii. This is good news because we think they interact with the CMB sufficiently that their energy is scattered down over distances larger than 300 million LY.

 

You reported this before i did, I see.

I started a thread on it here

http://www.scienceforums.net/forum/showthread.php?p=370324#post370324

 

Good news item to pick up on.

[Farsight]

I've been wondering about this issue of late. My model is telling me that there is something very unusual about high-energy gamma waves with a wavelength less than 10ˉ¹³ metres. This might sound odd, but they appear to be exhibiting the strong force rather than the electromagnetic force. I'd like to look at this some more. Can anybody advise re any measured photons with very high energies? The cosmic "rays" as per Martin's link are relativistic protons.

[Norman Albers]

Good one, Farsight. I recently ran this through with BenTheMan who said, yes, at energies of around 100 GEV (roughly 10^-17 m, I guess) what's manifested are the higher energy bosons instead of photons. Then too I read the opposite opinion. You speak of 10^-13 m which corresponds to maybe 10 MEV.