Cosmic rays and measuring them

[dichotomy]

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'd appreciate any laymans explanations that make sense.

 

cheers.

[insane_alien]

well, radiation from the sun tends to come from, well, the sun. cosmic radiation comes from everywhere else.

 

also, you get particles and photons that couldn't possibly have come from the sun as they are extremely heavy(iron nuclei) and have higher energy than the sun is known to produce.

 

to filter out the suns influence(particularly in space) all you have to do is put some kind of block or directional filter on to your detector.

 

a little experiment you can do to see what i mean(its basic but it works) go out in your back garden with a torch at night. the torch is going to take the place of the sun. if you look up at the stars(assuming your not in a big city) if you can only see one or two thats fine. the star light is going to be the cosmic radiation.

 

now shine the torch across your face, you can see the stars anymore because of the glare. you need a filter so you can see the cosmic radiation, so hold up your other hand to shield your eyes. you'll be able to see thee starlight again. this is pretty much how it works. we block out or ignore signals coming from the sun so other things can be seen.

[dichotomy]

Thanks for the quick reply.

 

I'm not convinced that you can actually block out all of the our sun's rays whilst measuring external cosmic rays. Although, I am sure that cosmic rays are emmited from other stars and do reach us. The astronomer, Stuart Clark, has said that some of our sun's rays actually penetrate through the earth, and take a long time to get through. So, if the earth itself can't screen out all rays, I can't imagine anything made on earth can? Can you see what I'm getting at?

 

cheers.

[insane_alien]

the earth will screen out everything but neutrinos and particles that got pulled round by the magnetic field although, they get blocked by the atmosphere.

 

everything else is completely blocked.

 

with manmade blocks, there will be some slight interference from solar radiation but this can be accounted for sort of like how noise cancelling ear protectors work.

[swansont]

You don't have to filter them all out. Depending on what you are actually measuring, you might just have to measure how much of a contribution they make, and subtract that from your signal.

[MangoChutney]

I read that cosmic rays are deflected by the earths electromagnetism, but electromagnetism has decreased over the last 100 years by around 6%, which means more cosmic rays are reaching the earths surface.

 

Is this true?

[insane_alien]

certain cosmic rays have always been able to get to the earths surface because they are not affected by magnetic fields.

 

the decrease in field strength is because we are coming up to a pole reversal(magnetic poles, not geographic poles) which happen every 10,000 years or so. this does not mean that the cosmic rays will affect us any more as the atmosphere provides a good bit of shielding.

 

you'd still be getting 100 times more radiation from your own body than cosmic radiation then.

[dichotomy]

Ok, I’m assuming now that star radiation affecting 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 ‘extremely heavy Iron nuclei’ are not known to come from the sun because cosmic ray detectors pointed at the sun show no evidence of ‘EHIN’? Correct?

 

Can ‘extremely heavy Iron nuclei’ (and other non sun rays) be the result of being initially sent from our sun, in a known cosmic ray form, bounce off some galactic body whilst collecting other matter, and bounce back onto the earth, thus producing a 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 cosmic rays for that matter), penetrate through our sun, at any concentration?

 

You can tell me if I'm not being clear enough.

 

Cheers.

[insane_alien]

umm, its not an extremely heavy iron nuclei. its just an iron nuclei.

 

and they definitely come from elsewhere as they come from everywhere but the sun and planets a those shield against them.

 

these o not bahave like light. the only cosmic radiation particles that can go through the sun are neutrinos. but neutrinos are produced in the sun anyway so the background signal gets lost.

[dichotomy]

umm, its not an extremely heavy iron nuclei. its just an iron nuclei.

 

Thanks for the clarification.

 

and they definitely come from elsewhere as they come from everywhere but the sun and planets a those shield against them.

 

So my comment on the sun rays being changed in transit to another form of ray, and returned to earth by some mechanism, isn't being explored by anyone? Or, has been explored and found to be highly unlikely?

 

these o not bahave like light. the only cosmic radiation particles that can go through the sun are neutrinos. but neutrinos are produced in the sun anyway so the background signal gets lost.

 

This gets me. How would anyone know if neutrinos pass through the sun if they are at the same time being produced by the sun? Again, two identicle properties, one from the sun and one from a star, being measured, when they are capable of passing through everything else. I can't see this as an accurate measure at all. Particularly since we have nothing (assuming except neutrinos) that can move through a star and come out 'alive' to give accurate measures.

 

Thanks for the Neutrino info. An amazing element if it does what scientist say it does.

 

cheers.

[Klaynos]

So my comment on the sun rays being changed in transit to another form of ray, and returned to earth by some mechanism, isn't being explored by anyone? Or, has been explored and found to be highly unlikely?

 

What physical mechanism could cause this? I'm pretty sure that even if we could think of one, conservation of energy and momentum would get in our way

 

This gets me. How would anyone know if neutrinos pass through the sun if they are at the same time being produced by the sun? Again, two identicle properties, one from the sun and one from a star, being measured, when they are capable of passing through everything else. I can't see this as an accurate measure at all. Particularly since we have nothing (assuming except neutrinos) that can move through a star and come out 'alive' to give accurate measures.

 

Thanks for the Neutrino info. An amazing element if it does what scientist say it does.

 

cheers.

 

Because we know how well neutrinos interact with matter. Neutrinos are not elements.

[insane_alien]

to screen out half of the neutrinos in a beam you would need something on the order of a lightyear thickness of lead. the sun poses no obstacle.

[Severian]

Cosmic rays are incredibly interesting because they are such extreme high energies. Some cosmic rays have 10¹⁰GeV energy, which is 6 orders of magnitude more than the highest energy colliders on Earth.

[dichotomy]

to screen out half of the neutrinos in a beam you would need something on the order of a lightyear thickness of lead. the sun poses no obstacle.

 

 

So, taking this neutrinos that are detected on earth could feasibly come from anywhere, other stars, or they could come solely from the sun.

 

We are unable to identify what star exactly, that a particular neutrino originates from. Due to the fact that they are able to pass through virtually everything. Correct?

 

cheers

[insane_alien]

but we CAN detect the direction they can from due to the way we detect them.

 

basically, we dig into a mountain, put a great big tank of heavy water. and surround it by a network of light sensors. when a neutrino interacts with a deuterium nuclei you get a cone of light in the direction the neutrino was travelling in. the detectors pick this up and can give direction as well.

 

of course we only pick up on in every trillion or so(though thats probably optimistic.)

[dichotomy]

but we CAN detect the direction they can from due to the way we detect them.

 

basically, we dig into a mountain, put a great big tank of heavy water. and surround it by a network of light sensors. when a neutrino interacts with a deuterium nuclei you get a cone of light in the direction the neutrino was travelling in. the detectors pick this up and can give direction as well.

 

of course we only pick up on in every trillion or so(though thats probably optimistic.)

 

So, I'm assuming its proven that neutrinos travel only in straight lines from the star they originate from then? Thus making it easy to identify which star they are actually coming from.

[insane_alien]

well, they interact through gravity as they have mass so the direction can be slightly distorted but in general, yes. as easily as we can tell which star light is coming from.

[Klaynos]

tiny tiny tiny mass!

[foodchain]

the decrease in field strength is because we are coming up to a pole reversal(magnetic poles, not geographic poles) which happen every 10,000 years or so. this does not mean that the cosmic rays will affect us any more as the atmosphere provides a good bit of shielding.

 

Actually the study of paleomagnitism does not put a particular standard of time to a reversal per say, as in other variables I guess could apply to the flips. Someone made what basically looks like a serial code you might find on a item for purchase. The code when finished was somewhat easier to describe by simply looking at it with the word chaos then anything else, as in there could be many flips in a time equal to the lasting of one, as it sometimes you would find long stretches of time without a flip, and in other areas the flips came in minor fractions of the time that others had lasted.

[insane_alien]

yes, so its a tiny tiny tiny force. which causes a reasonable acceleration since the 'tiny's cancel out.

 

foodchain, oh right. i'm not well read on the phenomenon. sorry for the error.

[dichotomy]

well, they interact through gravity as they have mass so the direction can be slightly distorted but in general, yes. as easily as we can tell which star light is coming from.

 

Thanks IA,

I've a clearer basic understanding of cosmic rays now, and particularly how and why they are bulit into the climate debate.

 

cheers and thank you very much.

[insane_alien]

how are they built into the climate debate? they don't dump anywhere near enough energy into the atmosphere to make a blind bit of difference.

[dichotomy]

how are they built into the climate debate? they don't dump anywhere near enough energy into the atmosphere to make a blind bit of difference.

 

http://www.spacecenter.dk/research/sun-climate/climate-debate-and-faq

“How can cosmic rays influence cloud formation?

Cosmic rays ionize the atmosphere and an experiment performed at the Danish National Space Center has found that the production of aerosols in a sample atmosphere with condensable gases (such as sulphuric acid and water vapor) depends on the amount of ionization. Since aerosols work as precursors for formation of cloud droplets, this is an indication that cosmic rays affect climate.

Climate models only include the effects of the small variations in the direct solar radiation (infrared, visible and UV). The effects of cosmic rays on clouds are not included in models and the models do a rather poor job of simulating clouds in the present climate. Since cloud feedbacks are a large source of uncertainty, this is a reason for concern when viewing climate model predictions. “

 

And here -

 

http://www.sciencebits.com/ClimateDebate

 

I'm certain there is a ton more info on this out there.

 

Cheers.

 

Here’s some interesting updated info on the cosmic ray search.

 

http://www.physorg.com/news106837906.html

 

“Current theory is that the suprathermal cosmic rays are found inside the solar system because they sneak across the heliopause into the heliosphere as electrically neutral atoms, which are not deflected by magnetic force. Once inside the solar system, they become electrically charged as the sun's radiation strips electrons off of them. Once charged, they feel magnetic force and are carried out of the solar system by the magnetic field embedded in the solar wind. When they reach the termination shock, they are accelerated by the clashing magnetic fields there and shot back into the solar system, where we detect them as suprathermal cosmic rays.

 

However, since Voyager 1 has not yet found fully definitive evidence that the termination shock accelerates cosmic rays, Cooper thinks that instead they come from interstellar space. "The magnetic 'shield' formed by the solar wind is probably not smooth. Instead, as the solar wind crashes into the plasma found in interstellar space, it may roll and billow like a cloud, distorting the magnetic field carried with it. I believe interstellar suprathermal cosmic rays can slip between these folds to enter our solar system."

 

Another possibility is that the dragon lies somewhere between the termination shock and interstellar space, in the vast, teardrop-shaped region around the solar system called the heliosheath. This is where the low-speed solar wind piles up against the interstellar plasma. It forms a teardrop shape as our solar system moves through the galaxy. "However, Voyager 1 has sailed through the heliosheath for two and a half years since crossing the termination shock, and no other local acceleration source has been detected," said Cooper.

 

Cooper's theory will be tested again soon as the second Voyager spacecraft crosses the termination shock. "If Voyager 2 also finds no evidence of local cosmic ray acceleration as it crosses the termination shock, it will strengthen the case for more remote dragons in interstellar space, perhaps very far beyond in the galaxy, as the source of suprathermal cosmic rays," said Cooper. The first direct traces of these fiercer dragons may be found when the two Voyager spacecraft eventually cross the heliopause into local interstellar space. “

 

 

Cheers.