How did herschel and ritter contribute to the discovery of waves outside the limits of the visible spectrum?

Answer 1

On 11 February 1800, (William) Herschel ... discovered infrared radiation in sunlight by passing it through a prism and holding a thermometer just beyond the red end of the visible spectrum... He was shocked when it showed a higher temperature than the visible spectrum. Further experimentation led to Herschel's conclusion that there must be an invisibleform of lLIGHT beyond the VISIBLE SPECTRUM.

source:Wikipedia

White light is actually not a single colour. It is made up of lots of colours. The colours that you can convince yourself of seeing are red, orange, yellow, green, indigo, blue and violet. Each of these colours is actually a transverse wave. Becasue we can see them, we call this 'mini collection' of waves the 'visible spectrum'. Here's the note sheet on these 'visible' waves:

The Waves of the Visible Spectrum

So, this is what Herschel did:

Then, we tried it in the lab and here's the photo. The stick thing is a thermometer probe. We checked out the temperatures in the spectrum made by splitting white light with a 60° prism. Then we looked at the temperatures outside what we can see (to the left of the red in the photo).

Repeating Herschel's experiment in the lab

And, much to our surprise, more than half of the class reported a higher temperature outside of the red part of the spectrum. If this is correct, we repeated Herschel's experiment in our lab. This 'unsee-able' colour is in fact a wave that we call today 'infra red'.

The Electromagnetic Spectrum2.2 Demonstrate an understanding that all electromagnetic waves are transverse and that they travel at the same speed in a vacuum

2.3 Describe the continuous electromagnetic spectrum including (in order) radio waves, microwaves, infrared, visible (including the colours of the visible spectrum), ultraviolet, X-rays and gamma rays

2.4 Demonstrate an understanding that the electromagnetic spectrum is continuous from radio waves to gamma rays, but the radiations within it can be grouped in order of decreasing wavelength and increasing frequency

Electromagnetic dangers2.5 Demonstrate an understanding that the potential danger associated with an electromagnetic wave increases with increasing frequency

2.6 Relate the harmful effects, to life, of excessive exposure to the frequency of the electromagnetic radiation, including:

• microwaves: internal heating of body cells
• infrared: skin burns
• ultraviolet: damage to surface cells and eyes, leading to skin cancer and eye conditions
• X-rays and gamma rays: mutation or damage to cells in the body

Using the Electromagnetic Spectrum2.7 Describe some uses of electromagnetic radiation

• radio waves: including broadcasting, communications and satellite transmissions
• microwaves: including cooking, communications and satellite transmissions
• infrared: including cooking, thermal imaging, short range communications, optical fibres, television remote controls and security systems
• visible light: including vision, Photography and illumination
• ultraviolet: including security marking, fluorescent lamps, detecting forged bank notes and sterilising water
• X-rays: including observing the internal structure of objects, airport security scanners and medical X-rays
• gamma rays: including sterilising food and medical equipment, and the detection of cancer and its treatment

Ionising radiation2.8 Recall that ionising radiations are emitted all the time by radioactive sources

2.9 Describe that ionising radiation includes alpha and beta particles and gamma rays and that they transfer energy