Could someone please explain to me how Hertz demonstrated the existence of EMR? (1 Viewer)

[Momentazeus]

Please

 

[bruhwth]

Essentially he used an initial spark to induce another spark in another metal loop with a gap in its circumference placed a distance away with a mirror behind it (the mirror enabled hertz to form standing waves). He then moved the other loop (called the receiver loop) closer to the initial spark and noticed periodically the spark would get brighter and dimmer. Hertz calculated the distance between two successive bright spark and noted that was the distance between two antinodes (could say the same for the distance between two dim sparks). Distance between 2 antinodes is wavelength/2, thus hertz could calculate the wavelength of the wave he had created from the initial spark. Furthermore knowing the frequency of the spark (which he set himself) he could calculate the velocity of the waves he formed (which was c = 3x10^8 m/s)

This was the first experimental evidence supporting Maxwell's prediction of EMR. Hertz showed the waves he created (radiowaves to be specific) could propagate through the air without the need of a medium (self-propagating), travelled at c= 3x10^8 m/s (which was hypothesised by Maxwell) and through altering the frequency of the initial spark oscillation he demonstrated a range of EMR existed as hypothesised by Maxwell earlier.

Pretty much it. To anyone reading this, if i have missed anything crucial, or have said something incorrect please correct me without hesitation. The more accurate, the better!

 

[Run hard@thehsc]

Essentially he used an initial spark to induce another spark in another metal loop with a gap in its circumference placed a distance away with a mirror behind it (the mirror enabled hertz to form standing waves). He then moved the other loop (called the receiver loop) closer to the initial spark and noticed periodically the spark would get brighter and dimmer. Hertz calculated the distance between two successive bright spark and noted that was the distance between two antinodes (could say the same for the distance between two dim sparks). Distance between 2 antinodes is wavelength/2, thus hertz could calculate the wavelength of the wave he had created from the initial spark. Furthermore knowing the frequency of the spark (which he set himself) he could calculate the velocity of the waves he formed (which was c = 3x10^8 m/s)

This was the first experimental evidence supporting Maxwell's prediction of EMR. Hertz showed the waves he created (radiowaves to be specific) could propagate through the air without the need of a medium (self-propagating), travelled at c= 3x10^8 m/s (which was hypothesised by Maxwell) and through altering the frequency of the initial spark oscillation he demonstrated a range of EMR existed as hypothesised by Maxwell earlier.

Pretty much it. To anyone reading this, if i have missed anything crucial, or have said something incorrect please correct me without hesitation. The more accurate, the better!

Yes, this is right - one thing to add, he did not notice a spark when the metal loop was turned 90 degrees, which showcased the presence of plane polarisation - thing is polarisation only occurs with transverse waves. Thus, Hertz was able to be conclusive that EMR and light waves are transverse waves in nature with oscillating perpendicular electric and magnetic fields

 

[bruhwth]

Yes, this is right - one thing to add, he did not notice a spark when the metal loop was turned 90 degrees, which showcased the presence of plane polarisation - thing is polarisation only occurs with transverse waves. Thus, Hertz was able to be conclusive that EMR and light waves are transverse waves in nature with oscillating perpendicular electric and magnetic fields

ohh shoot yeah. sike forgot about that one. Thank you!

 

[wizzkids]

Hertz was a skilled builder of his own experimental apparatus, and a perfectionist. At the age of just 31, and armed with the theory of Maxwell, Hertz set out to be the first person to prove if electromagnetic energy could be generated by accelerating electric charges [yes]. The energy could propagate through space in three dimensions [yes]. The energy would obey the laws of reflection (using a zinc parabolic mirror), refraction (using solid wax prism) and interference (using multiple wave paths) [yes]. He showed the EM waves also displayed polarisation. He knew approximately the frequency "f" of the electric oscillations in his spark-gap apparatus. Experimentally he was able to determine the wavelength "lambda" of his EM waves. By multiplying f x lambda he obtained a speed of 3 x 10^8 metres per second for the waves. Hertz died just before his 37th birthday from chronic blood poisoning.