Refraction of light results from the phase shift of wavefront points, as their velocity changes within media of different optical properties. Snell’s law (the law of refraction) is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water, glass, or air. Reflection occurs when a surface exposed to light immediately emits back a portion of the energy received. The law of reflection states that the incident ray, the reflected ray, and the normal to the surface of the mirror all lie in the same plane.
The law of reflection explains how the the reflected ray and the normal rays to the surface on the mirror lie in the same plane and reflect. The laws of reflection enabled the understanding of how to visualise the object under the microscope through understanding how to reflect the light and images. Microscopes are tubes packed with lenses, curved pieces of glass that bend (or refract) light rays passing through them. The simplest microscope of all is a magnifying glass made from a single convex lens, which typically magnifies by about 5–10 times. Light traveling up from the mirror passes through the glass slide, specimen, and cover slip to the objective lens. To make the image appear bigger the microscope spreads out light rays from the specimen so they appear to come from a bigger object. The laws of reflection and refraction enabled the understanding of how to visualise the object under the microscope through understanding how to reflect the light and image throughout the telescope as well as make the image smaller. Refraction of light also results from the phase shift of wavefront points, as their velocity changes within media of different optical properties. Reflecting telescopes, on the other hand, don’t use lenses at all. Instead, they use mirrors to focus the light together. In this case, the type of mirror that they use is a concave mirror, allowing the image to be visualised. Evidently showing how the laws of reflection and refraction lead to the development of the microscope and telescope.
Radioactivity and radioactive decay on the development of radiotherapy and nuclear bombs.
Radioactivity, property exhibited by certain types of matter of emitting energy and subatomic particles spontaneously. Atomic nuclei consist of protons and neutrons, which attract each other through the nuclear force, while protons repel each other via the electromagnetic force due to their positive charge. These two forces compete, leading to various stability of nuclei. Neutrons stabilise the nucleus, because they attract each other and protons , which helps offset the electrical repulsion between protons. As a result, as the number of protons increases, an increasing ratio of neutrons to protons is needed to form a stable nucleus. If there are too many (neutrons also obey the Pauli exclusion principle) or too few neutrons for a given number of protons, the resulting nucleus is not stable and it undergoes radioactive decay.
Nuclear decay (Radioactive decay) occurs when an unstable atom loses energy by emitting ionising radiation. Radioactive decay is a random process at the level of single atoms A nucleus does not “age” with the passage of time. Thus, the probability of its breaking down does not increase with time, but stays constant no matter how long the nucleus has existed. During its unpredictable decay this unstable nucleus spontaneously and randomly decomposes to form a different nucleus (or a different energy state – gamma decay), giving off radiation in the form of atomic particles or high energy rays. Radiotherapy can be traced back to experiments made soon after the discovery of x-rays (1895), when it was shown that exposure to radiation produced cutaneous burns. It was Influenced by electrotherapy and escharotics (the medical application of caustic substances), doctors began using radiation to treat growths and lesions produced by diseases such as lupus, basal cell carcinoma, and epithelioma. The understanding of radioactive decay and radioactivity allowed society to understand what they both were, how they worked and how they could be applied to modern medicine.
Through discovering what radiation was and how it worked, they discovered nuclear radiation. Nuclear radiation is in the form of elementary particles emitted by an atomic nucleus, as alpha rays or gamma rays and is produced by decay of radioactive substances or by nuclear fission. During World War II America had a project known as the, “The Manhattan Project” , there it was discovered an atom of radioactive material splits into lighter atoms, there’s a sudden, powerful release of energy. This lead to the discovery of Nuclear fusion, which is another type of reaction in which two lighter atoms combine to release energy. The discovery of nuclear fission opened up the possibility of nuclear technologies, including weapons such asNuclear bombs. Nuclear bombs, are powerful weapons that use nuclear reactions as their source of explosive energy.
The discovery of the structure of DNA and the development of biotechnologies to genetically modify organisms.
Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known organisms and many viruses. DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). In medicine genetically modifying an organism can be used to eliminate genetic disease, to allow an organism to have a desirable trait, . It can also be used in agriculture to improve foods and crops by using. Both can be done through the use of biotechnologies such as: selective breeding, gene engineering and gene editing.
The start of farming thousands of years ago started using modern biotechnologies such as selective breeding, this lead the discovery of how genetically modify living organisms in order for the offspring to posses desirable characteristics that could be passed onto future generations. Understanding the structure of DNA and biotechnologies allowed scientists to understand how to manipulate DNA to create products for humans (gene technology). Biotechnology allowed scientists to understand how using tools of genetic engineering can not only make specific proteins but also regulate cell processes so that specific outcomes can be achieved and precise needs can be met. This enabled the creation of genetically modified organisms.
Newton’s laws and the technology required to build buildings capable of withstanding earthquakes.
An earthquake causes shaking of ground. So a building resting on it will experience motion at its base. From Newton’s first law of motion which states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Even though the base of the building moves with the ground, the roof has a tendency to stay in its original position. But since
An earthquake causes shaking of ground. So a building resting on it will experience motion at its base. From Newton’s first law of motion which states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Even though the base of the building moves with the ground, the roof has a tendency to stay in its original position. But since the walls and columns are connected to it, they drag the roof along with them. Newtons second law of motion states that the acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. Newton’s third law: All forces in the universe occur in equal but oppositely directed pairs. There are no isolated forces; for every external force that acts on an object there is a force of equal magnitude but opposite direction which acts back on the object which exerted that external force.
Newton’s first law of motion states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. In this case, that “outside force” would be an earthquake. By understanding Newtons first law of motion it has allowed future generations to make a buildings resistant to earthquakes: where one must either increase the building’s resistance of a change in motion, or engineer to allow the building to move slightly with the earthquake. Through understanding Newtons laws of motion scientists were able to uncover how an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Even though the base of the building moves with the ground, the roof has a tendency to stay in its original position. But since the walls and columns are connected to it, they drag the roof along with them. This evidently lead to the construction skyscrapers that float on systems of ball bearings, springs and padded cylinders. Acting like shock absorbers in a car, these systems allow the building to be decoupled from the shaking of the ground, making them earth quake resistant buildings.
2019-3-20-1553120356