How higher frequency EM waves become more dangerous

In summary: View MoreIn summary, high frequency EM waves can be dangerous for us because their energy is proportional to their frequency and can cause damage through ionization. In vacuum, all EM waves have the same speed, which is equivalent to the speed of light. However, when not in vacuum, the speed of EM waves can be slowed down due to their interaction with charged particles in the medium, such as electrons. This delay in propagation can also result in the absorption of energy by the medium. The amount of slowing down depends on the density of the medium.
  • #1
Raghav Gupta
1,011
76
How high frequency makes waves dangerous for us.also does all em waves have same speed of light?
 
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  • #2
Energy of the wave is proportional to its' frequency. Higher the energy, more damage possible. In vacuum all EM waves have same speed (speed of light).
 
  • #3
Once the energy of the (individual) photons becomes high enough to cause ionisation, they become much more damaging to living cells (and electronics, too). The problem starts with UV and extends right up into gamma radiation.
 
  • #4
To bounce off of what Sophie said, EM waves have their energy divided into "quanta", little packets of energy that they interact with matter through. The higher the frequency, the larger this packet of energy is. Once the frequency of the wave becomes high enough, about the UV range and higher, each packet contains enough energy to knock electrons completely out of their atom and molecules. Removing an electron is called ionization and leaves behind two highly reactive particles, the electron and the atom/molecule, which can then react with other atoms/molecules in your body to cause damage.
 
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  • #5
Drakkith said:
To bounce off of what Sophie said, EM waves have their energy divided into "quanta", little packets of energy that they interact with matter through. The higher the frequency, the larger this packet of energy is. Once the frequency of the wave becomes high enough, about the UV range and higher, eat packet contains enough energy to knock electrons completely out of their atom and molecules. Removing an electron is called ionization and leaves behind two highly reactive particles, the electron and the atom/molecule, which can then react with other atoms/molecules in your body to cause damage.
100% approval, there.
Notice that he never, once, mentioned the word Particle. Something we could all make sure to include in our New Year's Resolutions.:)
 
  • #6
Sophie Sir 99.9% approval must be there to what Drakkith Sir has said.As you will carefully notice post there is "eat packet".Well I have read in books that E=hv but can anyone explain proof or give experiment link for formula verification.Also how does speed of em waves change when not in vacuum?
 
  • #7
Raghav Gupta said:
Well I have read in books that E=hv but can anyone explain proof or give experiment link for formula verification.

http://en.wikipedia.org/wiki/Planck–Einstein_relation
http://www.franklychemistry.co.uk/20to9/snap_tuition/y13/Energy_of_photon.pdf
http://hyperphysics.phy-astr.gsu.edu/hbase/mod6.html#c3
http://disciplinas.stoa.usp.br/pluginfile.php/48089/course/section/16461/qsp_chapter10-plank.pdf

Experimental verification:
http://en.wikipedia.org/wiki/Photoelectric_effect
Every CCD and CMOS camera sensor ever made depends on the energy of an EM wave being quantized.
 
  • #8
The Einstein work was the early stuff that clinched a lot of the Quantum ideas. It seemed to appeal to everyone who I taught it too - even when they didn't see how simple and elegant it is.
 
  • #9
Raghav Gupta said:
Sophie Sir 99.9% approval must be there to what Drakkith Sir has said.As you will carefully notice post there is "eat packet".Well I have read in books that E=hv but can anyone explain proof or give experiment link for formula verification.Also how does speed of em waves change when not in vacuum?
@Drakkith Bad boy, naughty boy. Your spelling is all to hell! :-p
 
  • #10
Thanks Drakkith sir for providing me with proof and experiment link although I am not so acquainted with all those partial derivatives and proof stuff and it all looks hi-fi at the moment.Will look in future to all these by gathering enough basic information.
Can anyone answer my second question that how EM waves speed changes when not in vacuum,that is not speed of light?
 
  • #11
Raghav Gupta said:
Thanks Drakkith sir for providing me with proof and experiment link although I am not so acquainted with all those partial derivatives and proof stuff and it all looks hi-fi at the moment.Will look in future to all these by gathering enough basic information.
Can anyone answer my second question that how EM waves speed changes when not in vacuum,that is not speed of light?
As you don't want a Maths based answer, ( and I can't blame you at this stage!) I could suggest that you look at it this way. As an EM wave propagates through a substance that is an insulator (metals are not included in this simple example), the Fields in the EM wave will have an effect on the charged particles in the material. This will be the electrons for all but the highest frequency waves. You could imagine the electrons moving slightly, 'in synchronism with the fields in the wave. As they move, they will re radiate a wave at the same frequency as the incident wave but there will be a delay. So that will have the effect of increasing the time taken for the energy to get through the substance i.e. the speed of the wave.
The amount that the wave is slowed down will depend upon the number of electrons it encounters on the way through so you would expect the more dense substances to slow the waves more than the less dense. Air makes very little difference at all but water and glass will have a very significant effect on the speed.
Many (most) dense substances will tend to absorb the energy as it passes through so they tend not to be 'transparent'.
 
  • #12
sophiecentaur said:
@Drakkith Bad boy, naughty boy. Your spelling is all to hell! :-p

Fixed!
 
  • #13
sophiecentaur said:
As an EM wave propagates through a substance that is an insulator (metals are not included in this simple example), the Fields in the EM wave will have an effect on the charged particles in the material. This will be the electrons for all but the highest frequency waves. You could imagine the electrons moving slightly, 'in synchronism with the fields in the wave. As they move, they will re radiate a wave at the same frequency as the incident wave but there will be a delay. So that will have the effect of increasing the time taken for the energy to get through the substance i.e. the speed of the wave.
The amount that the wave is slowed down will depend upon the number of electrons it encounters on the way through so you would expect the more dense substances to slow the waves more than the less dense. Air makes very little difference at all but water and glass will have a very significant effect on the speed.
Many (most) dense substances will tend to absorb the energy as it passes through so they tend not to be 'transparent'.
It looks like both you Sophie Sir(though your boat name is Sophie) and Drakkith Sir have deep knowledge in this subject.I got it all by explaining in simple manner.
 

1. How do higher frequency EM waves become more dangerous?

Higher frequency EM waves have more energy than lower frequency waves. This means that they can cause more damage to living tissue when absorbed. The higher the frequency, the more energy an EM wave has, and thus the more potential for harm.

2. What are the potential health risks associated with exposure to higher frequency EM waves?

Exposure to higher frequency EM waves can potentially lead to tissue damage and heating of the body's cells. This can cause a variety of health issues, including skin burns, eye damage, and even DNA damage. Additionally, prolonged exposure to high frequency EM waves has been linked to an increased risk of cancer.

3. How do different sources of high frequency EM waves affect the level of danger?

The level of danger associated with high frequency EM waves can vary depending on the source. For example, exposure to high frequency EM waves from natural sources, such as the sun, is generally less harmful than exposure to man-made sources, such as cell phones and Wi-Fi routers. However, the amount of exposure and the distance from the source also play a significant role in determining the level of danger.

4. Are there any safety measures that can be taken to reduce the potential harm from high frequency EM waves?

Yes, there are several safety measures that can be taken to reduce the potential harm from high frequency EM waves. These include limiting the amount of time spent near high frequency sources, using protective barriers or clothing, and using devices with lower frequencies when possible. It is also important to follow safety guidelines and regulations set by organizations such as the FCC.

5. How can the general public protect themselves from the potential dangers of high frequency EM waves?

The general public can protect themselves from potential dangers of high frequency EM waves by staying informed about the sources of these waves and taking necessary precautions. This includes limiting exposure, using protective measures, and following safety guidelines. It is also important to educate oneself on the potential risks and make informed decisions about the use of devices that emit high frequency EM waves.

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