Lesson 2: Muggle-made Tools for Astronomy
Chapter 2
(Sorry if it's too long, everything is important for the quiz)
~Most of the advances in the non-magical area of astronomy were made by Muggles.
~We witches and wizards learned about their findings second-hand.
~A telescope is an optical instrument that magnifies a distant object and makes it appear brighter.
~They are astronomy’s most important tool and were used to discover Uranus, Neptune, and Pluto.
~The earliest telescopes had two lenses at opposite ends of a tube.
~ At the far end of the tube is the light-gathering lens, called the objective lens. This lens is convex – that is, thicker in the middle than at the edges – like a magnifying glass and is called a positive lens.
~Distant objects seen through a magnifying glass on its own appear blurry. To make them appear sharp, you need another lens at the near end of the tube, called the eyepiece.
~In the earliest telescopes (Hans Lippershey, a Dutch eyeglass maker, in 1608), the eyepiece was concave – that is, thinner in the middle than at the edges – and was called a negative lens.
~It made distant objects look three times as big as with the naked eye.
~Two years later, the design was improved (Galileo Galilei). By making the objective lens less curved, the magnifying power was improved from 3 to 20.
~One problem is that it has a very narrow field of view, so you can only see a very small part of the sky with it.
~Johannes Kepler found that if the eyepiece is also a positive lens, you can see much more of the sky.
~In that sort of telescope, the eyepiece has two positive lenses; the one nearest your eye turns what you see right side up again.
~Since their invention, all three types of telescopes have been altered and improved in order to enable the user to adjust the focus.
~In the newer models there are two tubes instead of one, a wider tube containing the objective lens, and a narrower tube, which can be slid in or out, containing the eyepiece.
~In the terrestrial telescope, the magnifying power can be adjusted too - the farther apart the two lenses of the eyepiece are, the greater the magnifying power.
~Telescopes that use only lenses are called refracting telescopes, as lenses refract light.
~The amount by which a telescope magnifies distant objects is called the telescope’s power. Basically, the weaker the objective lens or mirror is and the stronger the eyepiece is, the more powerful the telescope will be.
~The ancient Greeks divided the circle into 360 degrees. If one star is on the eastern horizon and another one is on the western horizon, they are half a circle – 180 degrees – apart.
~If you double the diameter of the objective lens or mirror, you double the resolution – that is, you can resolve two stars that appear twice as close together.
~A satellite of a planet is an object that is in orbit around the planet.
~Moons are natural satellites, whereas an artificial satellite is a man-made object launched into orbit by means of a rocket.
~Satellites are also used for many purposes, mainly to put telescopes above the atmosphere, which is one contribution that they make to astronomy.
~The Hubble telescope,named after Edwin Hubble, is one such telescope orbiting Earth. It is about 2.5 meters wide, so it should be able to resolve two stars that are 0.05 arcseconds apart.
~Satellites have other uses besides carrying telescopes: they house other tools like cameras, radars, and remote sensors, tools to collect and analyze space particles, and more that give us other important information.
~The first satellite, called Sputnik - a Russian word meaning “fellow traveler” - was launched in 1957 by the Soviet Union.
~Four months later, United States had successfully launched its first satellite and the Soviet Union had launched their second satellite
~Shortly thereafter, they launched their third satellite, which carried the first man into outer space – Yuri Gagarin.
~US sent two men (1969), Neil Armstrong and Buzz Aldrin, on the Moon and brought them safely back to Earth.
~The Soviet Union sent the first women (Valentina Tereshkova) into space in 1963.
~Twenty years later, US sent a women (Sally Ride) into space.
~Since then, NASA no longer takes gender into consideration in evaluating candidates for space travel.
~There are space agencies in numerous countries such as:
-US
-Russia
-Europe
-Canada
-India
-Japan
-China
~China National Space Administration first landed a rocket on the far side of the Moon on January 3, 2019.
~Some wizards have actually worked under cover with those other space agencies, but not in NASA, because in 1790 MACUSA, the American equivalent of the British Ministry of Magic, passed Rappaport’s Law, an edict enforcing total segregation between magical people and No-Majs.
~In the early 1980s, NASA began a program called the Space Transportation System, using artificial satellites, called space shuttles.
~There were two accidents on space shuttles, which killed a total of 14 astronauts.
~ The program was terminated in 2011.
~United States has been relying on the Russian spacecraft Soyuz to transport astronauts and supplies to and from the International Space Station.
~Radar as a device used by the military to detect enemy planes and missiles.
~Radar is a detection system that uses radio waves or microwaves to determine the range, angle, or velocity of objects.
~A radar bounces waves off an object and studies those that are reflected by the object.
~USES:
-air and ground traffic control
-locating landmarks and ships at sea
-ocean surveillance
-monitoring the weather
-geological observations
-radar astronomy.
~Many astronomical objects have been studied by radar: the Moon, Venus, Mars, Mercury, the four biggest moons of Jupiter, Saturn’s rings and its largest moon, Titan, and a few nearby asteroids and comets.
~A rover is a vehicle designed to move across the surface of a planet or a moon.
~Rovers are used to study the planet or moon they land on by taking pictures, readings of the atmosphere, or samples of dust and rock.
~United States, is currently searching for evidence of past or present life.
~If a rover can be driven from the Earth, the driver can decide at any moment what is the most interesting place for it to visit.
~A signal does not arrive at its destination the instant it is sent; it travels at the speed of light, which is very fast, but if the distance between the source and the destination is too great, the delay makes driving a rover from the Earth impractical.
~A rover on the Moon can be driven from the Earth because it takes only one and a quarter seconds for a signal to travel.
~But a rover on Mars has to be self-driving because it takes at least four minutes, and sometimes as long as 24 minutes.
~Most of the advances in the non-magical area of astronomy were made by Muggles.
~We witches and wizards learned about their findings second-hand.
Telescopes
~A telescope is an optical instrument that magnifies a distant object and makes it appear brighter.
~They are astronomy’s most important tool and were used to discover Uranus, Neptune, and Pluto.
~The earliest telescopes had two lenses at opposite ends of a tube.
~ At the far end of the tube is the light-gathering lens, called the objective lens. This lens is convex – that is, thicker in the middle than at the edges – like a magnifying glass and is called a positive lens.
~Distant objects seen through a magnifying glass on its own appear blurry. To make them appear sharp, you need another lens at the near end of the tube, called the eyepiece.
~In the earliest telescopes (Hans Lippershey, a Dutch eyeglass maker, in 1608), the eyepiece was concave – that is, thinner in the middle than at the edges – and was called a negative lens.
~It made distant objects look three times as big as with the naked eye.
~Two years later, the design was improved (Galileo Galilei). By making the objective lens less curved, the magnifying power was improved from 3 to 20.
~One problem is that it has a very narrow field of view, so you can only see a very small part of the sky with it.
~Johannes Kepler found that if the eyepiece is also a positive lens, you can see much more of the sky.
~In that sort of telescope, the eyepiece has two positive lenses; the one nearest your eye turns what you see right side up again.
~Since their invention, all three types of telescopes have been altered and improved in order to enable the user to adjust the focus.
~In the newer models there are two tubes instead of one, a wider tube containing the objective lens, and a narrower tube, which can be slid in or out, containing the eyepiece.
~In the terrestrial telescope, the magnifying power can be adjusted too - the farther apart the two lenses of the eyepiece are, the greater the magnifying power.
~Telescopes that use only lenses are called refracting telescopes, as lenses refract light.
~The amount by which a telescope magnifies distant objects is called the telescope’s power. Basically, the weaker the objective lens or mirror is and the stronger the eyepiece is, the more powerful the telescope will be.
~The ancient Greeks divided the circle into 360 degrees. If one star is on the eastern horizon and another one is on the western horizon, they are half a circle – 180 degrees – apart.
~If you double the diameter of the objective lens or mirror, you double the resolution – that is, you can resolve two stars that appear twice as close together.
Satellites
~A satellite of a planet is an object that is in orbit around the planet.
~Moons are natural satellites, whereas an artificial satellite is a man-made object launched into orbit by means of a rocket.
~Satellites are also used for many purposes, mainly to put telescopes above the atmosphere, which is one contribution that they make to astronomy.
~The Hubble telescope,named after Edwin Hubble, is one such telescope orbiting Earth. It is about 2.5 meters wide, so it should be able to resolve two stars that are 0.05 arcseconds apart.
~Satellites have other uses besides carrying telescopes: they house other tools like cameras, radars, and remote sensors, tools to collect and analyze space particles, and more that give us other important information.
~The first satellite, called Sputnik - a Russian word meaning “fellow traveler” - was launched in 1957 by the Soviet Union.
~Four months later, United States had successfully launched its first satellite and the Soviet Union had launched their second satellite
~Shortly thereafter, they launched their third satellite, which carried the first man into outer space – Yuri Gagarin.
~US sent two men (1969), Neil Armstrong and Buzz Aldrin, on the Moon and brought them safely back to Earth.
~The Soviet Union sent the first women (Valentina Tereshkova) into space in 1963.
~Twenty years later, US sent a women (Sally Ride) into space.
~Since then, NASA no longer takes gender into consideration in evaluating candidates for space travel.
Space Agencies in Other Countries
~There are space agencies in numerous countries such as:
-US
-Russia
-Europe
-Canada
-India
-Japan
-China
~China National Space Administration first landed a rocket on the far side of the Moon on January 3, 2019.
~Some wizards have actually worked under cover with those other space agencies, but not in NASA, because in 1790 MACUSA, the American equivalent of the British Ministry of Magic, passed Rappaport’s Law, an edict enforcing total segregation between magical people and No-Majs.
Space Shuttles
~In the early 1980s, NASA began a program called the Space Transportation System, using artificial satellites, called space shuttles.
~There were two accidents on space shuttles, which killed a total of 14 astronauts.
~ The program was terminated in 2011.
~United States has been relying on the Russian spacecraft Soyuz to transport astronauts and supplies to and from the International Space Station.
Radar
~Radar as a device used by the military to detect enemy planes and missiles.
~Radar is a detection system that uses radio waves or microwaves to determine the range, angle, or velocity of objects.
~A radar bounces waves off an object and studies those that are reflected by the object.
~USES:
-air and ground traffic control
-locating landmarks and ships at sea
-ocean surveillance
-monitoring the weather
-geological observations
-radar astronomy.
~Many astronomical objects have been studied by radar: the Moon, Venus, Mars, Mercury, the four biggest moons of Jupiter, Saturn’s rings and its largest moon, Titan, and a few nearby asteroids and comets.
Rovers
~A rover is a vehicle designed to move across the surface of a planet or a moon.
~Rovers are used to study the planet or moon they land on by taking pictures, readings of the atmosphere, or samples of dust and rock.
~United States, is currently searching for evidence of past or present life.
~If a rover can be driven from the Earth, the driver can decide at any moment what is the most interesting place for it to visit.
~A signal does not arrive at its destination the instant it is sent; it travels at the speed of light, which is very fast, but if the distance between the source and the destination is too great, the delay makes driving a rover from the Earth impractical.
~A rover on the Moon can be driven from the Earth because it takes only one and a quarter seconds for a signal to travel.
~But a rover on Mars has to be self-driving because it takes at least four minutes, and sometimes as long as 24 minutes.
