What is an EM Wave? Exploring the Nature of Radiation

In summary, the conversation discusses the nature of electromagnetic (EM) waves and how they are produced. The participants also explore the possibility of detecting individual photons in the radio frequency range using a photodetector, but conclude that it would be difficult due to the small energy of each photon in this range.
  • #1
iScience
466
5
i think I've asked this a number of times on different posts stemming from various discussions but i don't think this question was in the wrong thread. so I've decided to make a new thread for this.

so what 'IS' an EM wave? i understand that the acceleration of charges could produce a wave (disturbance) in the E-field, and hence a sinusoidal oscillation of the charge would produce an EM wave; if all EM radiation are the same, except for their wavelengths, then this implies that EM radiation is just a transverse wave in the electric field right? ie, it is a transverse wave of the electric field?

the process i gave describes the production of RF, which is radiated radially (in 2-D) from the antenna. but if you put a photodetector around the antenna, would it detect individual photons?
 
Physics news on Phys.org
  • #2
iScience said:
so what 'IS' an EM wave? i understand that the acceleration of charges could produce a wave (disturbance) in the E-field, and hence a sinusoidal oscillation of the charge would produce an EM wave; if all EM radiation are the same, except for their wavelengths, then this implies that EM radiation is just a transverse wave in the electric field right? ie, it is a transverse wave of the electric field?
It is a transverse wave in the electroMAGNETIC field. In an EM wave the magnetic field is perpendicular to the electric field and they are of equal magnitude (in units where c=1).

iScience said:
the process i gave describes the production of RF, which is radiated radially (in 2-D) from the antenna. but if you put a photodetector around the antenna, would it detect individual photons?
It would be very hard to detect individual photons in the RF range, their energy is extremely small. In principle, it could be done, but in practice I think it would be undetectable.
 
  • #3
iScience said:
the process i gave describes the production of RF, which is radiated radially (in 2-D) from the antenna. but if you put a photodetector around the antenna, would it detect individual photons?

No, as a photodetector doesn't work in the microwave/radio frequency regions. The energy of each photon is simply too small to cause the photodetector to detect them.
 

1. What is an EM Wave?

An EM wave, short for electromagnetic wave, is a type of energy wave that is created by the movement of electrically charged particles. It consists of both an electric field and a magnetic field that oscillate perpendicular to each other and travel through space at the speed of light.

2. How is an EM Wave created?

An EM wave is created when an electric charge accelerates or changes direction. This can happen naturally, such as with lightning, or be man-made, such as with radio transmitters. The changing electric field creates a magnetic field, which then creates a changing electric field, and the cycle repeats, resulting in the propagation of an EM wave.

3. What is the nature of radiation in an EM Wave?

Radiation in an EM wave refers to the transfer of energy from the electric and magnetic fields as the wave travels through space. This energy can be in the form of light, radio waves, microwaves, x-rays, and more. The nature of radiation in an EM wave is that it is able to travel through a vacuum, unlike mechanical waves, which require a medium.

4. How do different frequencies of EM Waves affect their properties?

Different frequencies of EM waves can affect their properties in several ways. Higher frequencies have shorter wavelengths and more energy, which can make them more dangerous, such as with gamma rays. Lower frequencies have longer wavelengths and less energy, which makes them less harmful, such as with radio waves. Additionally, different frequencies can be used for specific purposes, such as infrared waves for thermal imaging and ultraviolet waves for sterilization.

5. What are some common uses of EM Waves?

EM waves have a wide range of applications in various fields, including communication, medicine, and technology. Some common uses include radio waves for broadcasting and communication, microwaves for cooking and wireless technology, infrared waves for thermal imaging and remote controls, visible light for illumination and vision, ultraviolet waves for sterilization and tanning, and x-rays for medical imaging.

Similar threads

EM waves, longitudinal EM propagation?
    • Electromagnetism
Replies
15
Views
1K
I Check out this YouTube video on EM waves in free space
    • Electromagnetism
Replies
7
Views
901
Frequency of EM waves produced by linearly accelerating charges
    • Electromagnetism
Replies
20
Views
1K
From Maxwell's equations to EM waves
    • Electromagnetism
Replies
9
Views
7K
A Voltage and current waves in a transmission line
    • Electromagnetism
Replies
4
Views
964
EM Wave - basic question on energy conservation in a wave
    • Electromagnetism
Replies
4
Views
824
Want accurate cartoons of EM Waves
    • Electromagnetism
Replies
5
Views
3K
EM wave generation using a single charge in a vaccum?
    • Electromagnetism
Replies
4
Views
3K
What are the most intense electromagnetic waves in nature?
    • Electromagnetism
Replies
18
Views
3K
How EM Waves Move: Exploring Electric & Magnetic Fields
    • Electromagnetism
Replies
16
Views
2K

Hot Threads

Recent Insights

Back
Top