Hello all,
If anyone knows. I'd like some idea of how scientists know for a fact that cosmic rays are a completely separate source of rays from the rest of the earth's sun's rays?

On the surface it seems to me almost impossible to separately measure and identify the suns rays, from rays coming from elsewhere in the cosmos. I think this because the sun's rays are sent out in all directions, and would obviously mingle with any supposedly external cosmic rays.

I'm curious because scientists use these measures to assess global warming.

I'd appreciate any laymans explanations that make sense.

cheers. :)

I think this because the sun's rays are sent out in all directions, and would obviously mingle with any supposedly external cosmic rays.
So how do the sun's rays get to the surface of the Earth at night time?
They bend round and sneak up?

So how do the sun's rays get to the surface of the Earth at night time?
They bend round and sneak up?

The light is bounced off the moon.

Cosmic rays come from all directions, not just from the sun or moon. More important, the rays from the sun and moon are photons, while cosmic rays are generally high energy charged particles, usually protons.

Hopefully Klippymitch was kidding...

More to the point, we understand the stellar dynamics very well, and (just as mathman said), we would have to be wrong in a BIG way if the cosmic rays were coming from the sun.

The other thing to think about is that it is only by accident that we get hit by as few cosmic rays as we do. This is a major problem for space flight between the planets, and eventually the stars. Sure we could GET to alpha centauri, but what difference does it make if we have lukemia?

The light is bounced off the moon.

And on "moonless" nights?

Cosmic Ray Muon Detector

"The University of Adelaide operates a one square metre muon detector which records the number of detected cosmic ray muons every 15 minutes. The detector was designed to provide data for undergraduate teaching purposes including student project work.

Cosmic ray muons make up something like half of the natural sea-level radiation background. They are produced high in our atmosphere from the interactions of primary cosmic ray particles with atmospheric gas nuclei. The muons then lose energy as they pass through the atmosphere to reach us. Some will lose so much energy that they fail to reach us and, as a result, there is a dependence of the muon rate on the atmospheric pressure.

The primary cosmic rays reach the Earth after travelling through the solar wind. Not all of them are able to make that journey, especially when there are strong solar outbursts. As a result, the rate of detection of muons depends on the "solar weather" and, at times of solar flare activity, there may be significant changes to the muon rate known as "Forbush decreases". These are naturally more common at times of maximum solar activity which follow an eleven year cycle. Solar activity is currently building towards the next maximum, expected in the year 2000.

The muon detector is located in the Physics Department of the University of Adelaide with about 300 g cm-2 of building material above it. Our atmosphere has a depth of about 1000 g cm-2 so, assuming that muons lose energy by ionisation at a rate of about 2 MeV(g cm-2)-1, the threshold energy (at production) for the muons we detect is a rather high 2.6 GeV. To get lower energies, neutron monitors are used since neutrons do not suffer ionisation energy loss in passing through our atmosphere. The Earth's magnetic field prevents low energy charged cosmic rays from reaching the atmosphere. There is a rigidity threshold for all place on the Earth due to this. For Adelaide it is about 3 GV. By coincidence then, for protons, this is about the same value as the threshold for muons to reach the detector. A map of rigidities over the Earth can be found through the Chicago link.

The data show a strong pressure dependence but deviations from that relate to solar effects."

http://www.physics.adelaide.edu.au/astrophysics/muon/

Thankyou for your responses.

Ok, I’m assuming now that star radiation affecting the earth is most accurately measured whilst the sun is not directed, or reflected, onto the measuring device.
And I think the assumption from scientists is that ‘high energy charged particles’ are not known to come from the sun, because cosmic ray detectors pointed at the sun show no evidence of ‘high energy charged particles’. Correct?

Is it plausible that ‘high energy charged particles’ (and other non sun cosmic rays) are the result of being initially sent from our sun, in a known cosmic ray form, bounce off some galactic body whilst collecting other matter, or, being transformed by other matter, and bounce back onto the earth, thus producing the theory that cosmic rays are not coming from our sun, when they actually are, only indirectly like light bouncing off a mirror?

Also, can ‘extremely heavy Iron nuclei’ (or any non sun cosmic rays for that matter), possibly penetrate through our sun, at any concentration?

Please let me know if I’m not being clear enough.

Thanks, Cosmic traveler for the details on the ‘Cosmic Ray Muon Detector’.

Cheers.:)

By far the most advanced and world's biggest (30 times larger than Paris!) detector of very high energy cosmic rays is now being built* in dark expanse of the Argintine pampas. For details (and about anything you want to know related to cosmic rays) see;

WWW.auger.org (and the subpage links)

I also recomend reading:

http://cerncourier.com/cws/article/cern/29661

-------------------------------------
*About 80% done now and has been operational for a couple of years.

One aspect I think very clever is the use of GPS. First used to know exactly where each of the 1600 large high-purity water Cherenkof detectors are and then, once that is known, to invert GPS to know exactly the time of each Cherenkof flash detected. I.e. In operation mode, GPS distributes very precise event timing. (Event time is known to an accuracy of about that in which GPS signal (or light) can travel a small fraction of a meter (10 cm?). This permits "high-multiplicy triangulation" back to the primary event, I think, and aids the processing of the faint air glow by the four main telescopes (each actually six).

I do not know much high energy physics, but it seems possible to me that this Auger detector may indirectly discover the Higgs boson (if it exist) before the LHC does as the details of what happened in the primary collision are worked out. The cost of the LHC is now 5.4 billion dollars - many times more than four telescopes and 1600 water tanks.

By far the most advanced and world's biggest (30 times larger than Paris!) detector of very high energy cosmic rays is now being built* in dark expanse of the Argintine pampas. For details (and about anything you want to know related to cosmic rays) see;



I also recomend reading:



-------------------------------------
*About 80% done now and has been operational for a couple of years.

One aspect I think very clever is the use of GPS. First used to know exactly where each of the 1600 large high-purity water Cherenkof detectors are and then, once that is known, to invert GPS to know exactly the time of each Cherenkof flash detected. I.e. In operation mode, GPS distributes very precise event timing.

Cheers,
I'll take a look.


What? I can't relpy with links on my reply because I have only 2 posts :confused: Tough regulations here. :bugeye::)

Cheers,
I'll take a look.:)


What? I can't relpy with links on my reply because I have only 2 posts :confused:

Just do a copy of the shortcut then paste it after you comment here.

Cheers, I'll take a look. ...I added a final comment to post 10 after you quoted to effect that:

this Auger detector may indirectly discover the Higgs boson (if it exist) before the LHC does at much less cost (>1%).

If anyone has any questions about AUGER, there are several experimenters on the collaboration here at Ohio State. If you want, I can try to find a fellow grad student and ask them any questions, but no promises:)

this Auger detector may indirectly discover the Higgs boson (if it exist) before the LHC does at much less cost (>1%).

I don't think that this is likely, because I don't think that they're going to have enough events to do statistics on. In physics, we are very careful about ``evidence'' versus ``discovery''. So,in this respect, we already have ``evidence'' for the higgs---the electroweak force is spontaneously broken, and the gauge bosons have mass.

arent the cosmic rays the microwave backgroung radiation?

if we're talking about the same thing, then the MBR do not come from the sun, they are a reminent from the Big Bang explosion, sort of like the echo but in microwaves instead of sound waves. And yes they are everywhere, one needs nothing but a sensitive geiger counter to confirm this.

Camilus:

You need to do some more basic reading.

The CMB is electromagnetic [photons] only, and is the visible-light emitted by a white-hot Hydrogen/Helium plasma that is highly redshifted [redshift of 1,000] into the microwave frequencies due to the high recessional velocity of the receding plasma [receding at about 0.9999991 c], in earth's reference frame. See my post on your 'theory' of the mapping of the universe.

Cosmic rays are the nuclei of atoms. While most are simply protons, the ones of interest to cosmic ray researchers have been the higher-Z atoms, i.e. Iron to Uranium, etc. These nuclei travel at such high speed, that their electrons are stripped from their orbitals [it only takes about 100 KeV to strip the innermost electron orbitals of high-Z elements; just ask an X-ray tech how many KeV they generate, and what their target is that is used for generating an X-ray beam].

Thus, the cosmic rays are essentially the bare nuclei of atoms traveling at high speed.

There are, however, a few interesting cosmic rays that do not fit that broad definition. For example, see: "Evidence for Detection of a Moving Magnetic Monopole", Price et al., Physical Review Letters, August 25, 1975, Volume 35, Number 8. A magnetic monopole was first theorized in 1931 by Paul A.M. Dirac, Proceedings of the Royal Society (London), Series A 133, 60 (1931), and again in Physics Review 74, 817 (1948).

Good luck with your reading.

....I don't think that this is likely, because I don't think that they're going to have enough events to do statistics on. In physics, we are very careful about ``evidence'' versus ``discovery''. So,in this respect, we already have ``evidence'' for the higgs---the electroweak force is spontaneously broken, and the gauge bosons have mass.I know so little in the high energy particle physics field that I am only guessing, but I too think it not likely, but more because it may not be possible to nearly definitely back out that the Higgs is the only reasonable explaination. (Those clever, mathematically-gifted, HE theorists can explain anything and usually in at least 6 different ways! :D) but as far as "too little data" limiting, that may be (I think is) just be a question of time; however, LHC may win the race if it comes down to that. Note I said "possibly" in my original post suggesting this "posibility."

Also as I recall, several "proven to exist" particles initially had only two or three events as the proof. (Sort of if you see and capture a unicorn, you only need to see and have one to show others.)

Thus, while we agree, we do so for different reasons.

P.S. A geiger counter will not detect the CMB. It only detects ionizing radiations able to penetrate its window, which the CMB cannot do, and cannot ionize [needs to be closer to UV frequencies].

Billy T

We need much more information from Pierre Auger regarding the cosmic rays before we fire up the LHC. If it's possible that the very high energy showers are actually the breakup of the rest-mass of rare particles [such as magnetic monopoles], showering down on earth and being detected by Pierre Auger and elsewhere, then the highest verifiable energy cosmic rays that are actually detected in space [satellite detectors] would be closer to 1E15 eV, and the COM energy of such struck-particle in our atmosphere would be some 1E12 to 1E13 eV, well below the LHC's 1E15 eV potential COM energies for Lead-Lead collisions. In other words, that particular safety net would be completely evaporated if it turns out that those very rare showers are not cosmic ray kinetic energies, but rest-mass energies of exotic particles.

P.S. A geiger counter will not detect the CMB....Are your trying for the "Understatement of the Year" award? I am too lazy to compute it but I guess the typical CMB photon carries all of 0.0001ev - i.e. too little to pass thru a flea's wing if it were a particle.

PS glad to see you bring up one of my favorates (magnetic monopoles) I was considering doing so as Auger make have a peak or some structure in the distribution curve at their rest mass energy, if they are part of the or mystery as to where all that energy comes from. Here Ben TM's point is 100,000% correct - Even if this is the case, to show it will be a race between the collection of events and the death of the sun. :eek:

later by edit: I had read only your post 16 when I wrote the above. In post 19, I get most of your drift (without full understanding) but this anything you are saying must depend on what mass the monopole is assumed to have. - I have seen estimates that differ by about a factor of 10^10 ! At the high end, some are even suggesting the reason we do not find any is that they became micro black holes and evaporated. - Just now, this provoked a thought (built on 99% ignorance, of course): I seem to have the impression that the monopoles were formed prior to the baryons and if this is true (and they evaporated) is it possible it was when the univese was so small that subsequent expansion has them as part of the CBR?

P.S. A geiger counter will not detect the CMB. It only detects ionizing radiations able to penetrate its window, which the CMB cannot do, and cannot ionize [needs to be closer to UV frequencies].

I'm sorry you are correct. I remember now that's why they built all those satelite receivers, to be able to detect the CMB. That wouldn't have made sense if you could detect it with a simple geiger counter...

I'm sorry you are correct. I remember now that's why they built all those satelite receivers, to be able to detect the CMB. That wouldn't have made sense if you could detect it with a simple geiger counter...Actually, detection of CBM on Earth's surface is easy. (that is where they were accidently first discovered) All you really need is a very cold , low noise reciever front end (and a dish antenna).

By far the most advanced and world's biggest (30 times larger than Paris!) detector of very high energy cosmic rays is now being built* in dark expanse of the Argintine pampas. For details (and about anything you want to know related to cosmic rays) see;

I also recomend reading:



-------------------------------------
*About 80% done now and has been operational for a couple of years.

One aspect I think very clever is the use of GPS. First used to know exactly where each of the 1600 large high-purity water Cherenkof detectors are and then, once that is known, to invert GPS to know exactly the time of each Cherenkof flash detected. I.e. In operation mode, GPS distributes very precise event timing. (Event time is known to an accuracy of about that in which GPS signal (or light) can travel a small fraction of a meter (10 cm?). This permits "high-multiplicy triangulation" back to the primary event, I think, and aids the processing of the faint air glow by the four main telescopes (each actually six).

I do not know much high energy physics, but it seems possible to me that this Auger detector may indirectly discover the Higgs boson (if it exist) before the LHC does as the details of what happened in the primary collision are worked out. The cost of the LHC is now 5.4 billion dollars - many times more than four telescopes and 1600 water tanks.

Thanks again Bill T,
this from the Auger website clears up alot for me.

"How and when were cosmic rays discovered?

In 1912 a scientist named Viktor Hess carried an instrument called an ionization chamber in a balloon to high altitudes. An ionization chamber is a device that records the passage of charged particles. As Hess made his ascent in the balloon, the ionization chamber recorded fewer particles, up to an altitude of 2,000 meters. The interpretation is that some of this ionization is due to the natural radioactivity of the earth, and its influence decreases with altitude. Above 2,000 meters, however, he recorded more particles, and the increase in particles became even more rapid as his balloon reached its maximum altitude of 5,350 meters. Hess correctly guessed that this increase was due to radiation entering the atmosphere from space. On one occasion he rode the balloon during a solar eclipse, and found no decrease in ionization. From this he concluded that the radiation was coming from somewhere other than the sun. We now know that much of this cosmic radiation originates far outside the solar system."

Cheers.

And on "moonless" nights?

How about the light is bounced off every single planet and asteroid in the asteroid belt. Better? Also dont forget about the light from the stars. A small percentage will also be reflected by space dust.