Is this possible?
When an electro-magnetic wave passes from one medium to other, part of the wave gets relected at the boundary and part transmitted. The reflecting surface electro-magnetic property determines the amount of reflection.
For a Z-directed wave with Electric intensity E in x direction and magnetic intensity in Y direction, the phasor fields are given by
Ex = E0e-jkz + E0’ejkz
Hy = (h)-1[E0e-jkz - E0’ejkz] -> (1)
After applying the boundary conditions, we obtain the reflection and transmission coefficients (i.e the ratio of reflected wave or transmitted wave to the incident wave]
E0’/ E0 = h” – h/h”+h
E0”/ E0 = 2h”/ h”+ h -> (2)
where h is the reflectivity of medium
My question is, if we send a EM wave and measure the amount of reflected wave, we can definitely tell that which medium refected it by having a simple database of medium and its reflectivity. And if this em wave is coherent, we can decide at what point on earths surface what element is present and what is present inside the earth too. Thus exploration of new planets can be done by transmitting and recieving coherent EM beam. Is this possible?
Thanks
Rajesh
posted by Rajesh @ 4:55 PM
4 comments
4 Comments:
rajesh,
finding of materials inside earth could be found using this methof.
if we do not find any hit in the database, then we have to consider
that as new element and update the database.
but, not sure how it will help in finding a new planet..
by sending the wave and observing the reflect wave, we will know whether it is a new material or not.
the new material could be from the existing planets... am i missing anything here?
krish,
Im first of all not sure if this will work.
Even if it works I agree with your concern that we wont hit the database in new planet.
Regards,
Rajesh
rajesh,
is this all about refractive index?
when light (electro magnetic wav) travels from one medium to
another, there will be reflection
and refraction, and refractive
index is based on that. and it is unique for a given element.
-Krishna Ram
Look at this for light reflected and transmitted by a medium- http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/reflco.html . Also look at http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/freseq.html#c1 . Looks like this idea will work. I saw the equation I mentioned about relection and transmission coefficients as Fresnel formaula in http://staff.chess.cornell.edu/~smilgies/refl/Reflectivity.htm#Fresnel_formulae . Just now knew about this.
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