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magnets and light


mab

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Light when falls on object ,some of it get absorbed ,and some reflected.Is there similarity between reflected light and magnet’s nature(North and south pole repelling each other .

My question is that “Is reflecting nature of light similar to repelling nature of magnets”?

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well from a long distance it may look like that photon is interacting with an AC electromagnet, in that it is "sucked" towards it and then repelled... although basically NO!, photon reflection is not related to magnetic fields.

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why doesn't light affect magnets. isn't magnetism caused by photon exchange?

um, not as far as im aware of.

 

I also want to know why some light is reflected?

i dont know, in the past ive asked ~'what is the difference between the properties of a red item and a blue item?' (just an example) and ive never really got a proper answer.

 

i think this thread should me moved to physics > classical mechanics.

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

(everyone seems to trust this site, its a good one to quote!)

A so-called permanent magnet is made of a ferromagnetic material. Such materials consist of atoms or molecules that have each a magnetic field (resulting from the spin angular momentum of electrons within them)' date=' [/b'] but objects composed of these materials have magnetic fields only to the extent that these microscopic magnetic fields are positioned to reinforce rather than cancel each other. The details of transition processes back and forth between reinforcing and cancelling orientations reflect the behavior of the material's magnetic domains, which are zones of mutually reinforcing molecules or atoms.

 

An electromagnet has a field produced by a current, typically through a loop or a coil of many turns; its field becomes insignificant when the current ceases.

 

bold underlined: what causes magnetic fields

bold: the current causes bold underlined

 

ive never heard of a relationship between magnets (and their gravitational field) and photons before

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light travels on different wavelenghts. These wavelengths are either absorded or reflected, the ones that are reflected are the colors we see. A black object absorbs all (most) light that hits it. This is why we are told not to where dark clothes on hot days, as they absorb more light, hence, more heat.

 

(not sure if wavelength is the correct term)

 

as to why light behaves like this, got me??

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im confused' date=' why is there recently so many connections between light and magnets, the two are unlrelated.

[b']how does light effect magnets?[/b]

photons are not charged, so they wont be effected by magnets.

 

Well if you would stick to one thing at a time then you may not get you self mixed up.

 

I'll find a link that show how magnets are effected by light, but I dont know about light being effected by magnets.

 

you seem to jump between the 2 like they are the same please keep it clear.

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here's how they should: A MAGNETIC FIELD IS AN EXCHANGE OF PHOTONS
really?[/sarcastic] i know that!

your body is covered in skin, if someone else touches you, it doesnt effect the state of your skin (although you may feel it). so your quote doesnt necearily mean that photons are effected by magnetic fields or vice versa.

 

I'll find a link that show how magnets are effected by light, but I dont know about light being effected by magnets.
ok. i'll wait for em.
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http://van.hep.uiuc.edu/van/qa/section/Light_and_Sound/Properties_of_Light/20020312194513.htm

the path light takes is not affected by the presence of a magnetic field. Light itself is composed of an oscillating electric and magnetic field' date=' and one very important property of electric and magnetic fields is what we call "linearity." That is, if you have two sources of electric and/or magnetic fields, you can predict what the combined field is just by adding the two source fields together. The two fields don't change each other at all.[/b'] So if you add the field of a light ray to any other field we can imagine, the light ray will continue as before and the extra field will just stay the same, adding to it in places where the extra field is strong, but having no effect beyond the reach of the extra field. So there is no way that a magnetic field can bend light.

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for instance, i have some NIB magnets (very powerful - neodymium iron boron) they are not effected by when i turn on the light, and the light just acts normal around them.... that is unless it happens on such an atomic scale that it is impossible to see by the human eye, but im sure magnets and photons dont effect each other.

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if you read this you will get the idea,

 

http://www.innovations-report.com/html/reports/information_technology/report-7770.html

 

Im still trying to find a web page i read a while back which tells you about how light shinning on a hard drive magnet disc will show it info, because as they try and get more data into a hdd they have to make the magnet bit smaller and it gets to a point where it will not get anysmaller and have enought power to read the bit, shinning the lighting on it help this to be done.

Which show that they effect each other.

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"But in these systems the laser switches the magnetic medium by warming it."

 

So it's not that the magnetism is affected by light, it's that it's affected by temperature. The laser just allows for very localized heating.

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precisely what swansont said, furthermore the link you posted:

http://www.innovations-report.com/html/reports/information_technology/report-7770.html

is a special kind of 'plasitc' magnet, NOT a normal magnet, furthermore if you read the artice it only works at -196 degrees-C. this is clearly not a normal magnet for those reasons + it is based on carbon + it is newly discovered, this is a special type of carbon which has a magnetic field, it is not a normal ferromagnetical material aka a permament magnet aka a magnet!

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