Science report
Today’s topic is: Light which we can not see?
Introduction
You must be wondering what are the light which we can’t see, we can see many colours, isn’t that supposed to constitute the light?
Are there more things to see from our eyes which we are not able to see?
Are we able to unlock our supernatural power?
Ok so without sounding like Morgan Freeman. Let’s start.
Electromagnetic spectrum
There are many parts of the electromagnetic spectrum(for simplicity let’s use the light of the ES)
There are parts of light that we cannot see. Because our eyes are not capable of producing an image with that spectrum of light. (duh..)
So what constitutes light?
Gamma radiation
Gamma rays are an electromagnetic spectrum. It is emitted by decaying radioactive waste. Therefore it is quite harmful and hazardous to organic matter and living compounds.
Its wavelength is 10^(-12), which is even smaller than a water molecule.
Natural sources of gamma rays originating on Earth are mostly a result of radioactive decay and secondary radiation from atmospheric interactions with cosmic ray particles. However, there are other rare natural sources, such as terrestrial gamma-ray flashes, which produce gamma rays from electron action upon the nucleus. Notable artificial sources of gamma rays include fission, such as that which occurs in nuclear reactors, and high energy physics experiments, such as neutral pion decay and nuclear fusion.
X-rays
As the name suggests, it was not identified in the early 90s therefore it was named “X rays”
Its wavelength is 10^(-11) and it passes through soft objects but reflects upon striking hard objects. Therefore it is used to look at the joints and bones of the body as it is harder and less penetrable than muscles. It is used to see whether you have cracked(fractured) your knee while recklessly playing or had an unfortunate accident. (sad)
Ultraviolet rays
Ultraviolet (UV) is a form of electromagnetic radiation with wavelengths from 10 nm to 400 nm shorter than that of visible light, but longer than X-rays. UV radiation is present in the sunlight and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapour lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet light is not considered ionizing radiation because its photons lack the energy to ionize atoms, it can cause chemical reactions and cause many substances to glow or fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules.
Visible light
Ahh…it is the light which we can see. It involves colours like Red, Orange, Yellow, Green, Blue, Indigo and Violet.
It is a small spectrum of 400nm-700nm. Red has the biggest wavelength, therefore, we can see it quickly and it is also the reason why the traffic light has the colour red so people can see it from afar.
Infrared rays
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from the nominal red edge of the visible spectrum around 700 nanometers to 1 millimetre. Black-body radiation from objects near room temperature is almost all at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, with properties corresponding to both those of a wave and a particle, the photon. Infrared radiation is used in industrial, scientific, military, commercial, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected. Military and civilian applications include target acquisition, surveillance, night vision, homing, and tracking.
Microwaves
A microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimetre.
The prefix micro- in the microwave is not meant to suggest a wavelength in the micrometre range. Rather, it indicates that microwaves are “small” (having shorter wavelengths). High-power microwave sources use specialized vacuum tubes to generate microwaves. These devices operate on different principles from low-frequency vacuum tubes, using the ballistic motion of electrons in a vacuum under the influence of controlling electric or magnetic fields, and include the magnetron (used in microwave ovens).
Radio waves
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 10,000 km (longer than the radius of the Earth).to as low as 1 mm (shorter than a grain of rice). Like all electromagnetic waves, radio waves in vacuum travel at the speed of light, and in the Earth’s atmosphere at a close, but slightly lower speed. Radio waves are generated by charged particles undergoing acceleration, such as time-varying electric currents. Naturally occurring radio waves are emitted by lightning and astronomical objects and are part of the blackbody radiation emitted by all warm objects.
Effect of the Light spectrum on animals
Many species can see light within frequencies outside the human “visible spectrum”. Bees and many other insects can detect ultraviolet light, which helps them find nectar in flowers. Plant subspecies sensitive colour, insect pollination may owe reproductive success to their appearance in ultraviolet light rather than how colourful they appear to humans. Birds, too, can see into the ultraviolet (300–400 nm), and some have sex-dependent markings on their plumage that are visible only in the ultraviolet range. Many animals that can see into the ultraviolet range cannot see a red light or any other reddish wavelengths. Bees’ visible spectrum ends at about 590 nm, just before the orange wavelengths start. Birds can see some red wavelengths, although not as far into the light spectrum as humans. The popular belief that the common goldfish is the only animal that can see both infrared and ultraviolet light is incorrect because goldfish cannot see infrared light.
Most mammals are dichromatic, and dogs and horses are often thought to be colour blind. They are sensitive colours, sensiticolours ray as humans. Some snakes can “see” radiant heat at wavelengths between 5 and 30 μm to a degree of accuracy such that a blind rattlesnake can target vulnerable body parts of the prey at which it strikes, and other snakes with the organ may detect warm bodies from a meter away. It may also be used in thermoregulation and predator detection.
Bye! Have a great time.
Science Maniac 