Several hundred years ago Copernicus was able to determine approximate distances between the planets through trigonometry. The distances were all found relative to the distance between the Earth and the Sun, the astronomical unit. Kepler refined these measurements to take into account the elliptical orbits. However, they did not know how large an astronomical unit was.
To establish an absolute distance scale, the actual distance to one of the planets had to be measured. Distances to Venus and Mars were measured from the parallax effect by observers at different parts of the Earth when the planets were closest to the Earth.
Knowing how far apart the observers were from each other and coordinating the observation times, astronomers could determine the ...
... middle of paper ...
Angular velocity = 36 degrees / 4 hours = 9 degree/hour
Full time rotation = 360 degrees / 9 degree/hour = 40 hours
With the invention of radar, the distance to Venus could be determined very precisely. By timing how long it takes the radar beam travelling at the speed of light to travel the distance to an object and back, the distance to the object can be found from distance = (speed of light) × (total time)/2. The total time is halved to get just the distance from the Earth to the object. Using trigonometry, astronomers now know that the astronomical unit =149,597,892 kilometers. This incredible degree of accuracy is possible because the speed of light is known very precisely and very accurate clocks are used. You cannot use radar to determine the distance to the Sun directly because the Sun has no solid surface to reflect the radar efficiently.
Need Writing Help?
Get feedback on grammar, clarity, concision and logic instantly.Check your paper »
- World is moving fast towards rapid use of renewable energy source that will generate scarcity one day. On the other hand, solar energy is considered to be highly dependent renewable energy source which is not yet tapped very effectively. Solar energy can be utilized in multiple ways through either creating thermal energy or converting it into electrical energy. The solar power growth has witnessed significant presence since 2007 while moved from 3.1 (gigawatts PV manufacturing) in 2007 to 50 (gigawatts PV manufacturing) in 2014 (Chu, 2011).... [tags: Photovoltaics, Solar cell, Solar power]
1788 words (5.1 pages)
- Nuclear and Solar Energy What would the nation do if every gas station was shut down. With a daily consumption of over nineteen million barrels per day, fossil fue won’t always be an option. An alternative source needs to be taken into consideration. Two of the best possible uses for the future are solar and nuclear energy. Both produce less emissions than fossil fuels and can be much more efficient. There are many dangers with nuclear energy and sometimes hazardous by-products are produced. Advances in technology are a likely result of the use of these resources.... [tags: Nuclear power, Nuclear fission, Nuclear physics]
1032 words (2.9 pages)
- INTRODUCTION Physics attempts to describe the fundamental nature of the universe and how it works, always striving for the simplest explanations common to the most diverse behaviour. For example, physics explains why rainbows have colours, what keeps a satellite in orbit, and what atoms and nuclei are made of. The goal of physics is to explain as many things as possible using as few laws as possible, revealing nature's underlying simplicity and beauty. Physics has been applied in many industrial fields, which include the air industry, construction industry, automobile industry, manufacturing industry and many others.... [tags: Physics]
1954 words (5.6 pages)
- Solar ability to power our future Abstract Solar Energy is the process of using the rays from the sun and transferring the energy into thermal or electric energy. A main contribution to solar energy is PV panels. The Solar panels are found in a variety of locations, but mostly found on roofs of buildings or other large surfaces. The panels are devices used to capture the solar energy transferring it into electric or heat energy. Solar energy is beneficial in numerous ways, including helping the environment.... [tags: Energy Solar PV Panel Electricity]
815 words (2.3 pages)
- With the call for an ecological conversion imminent, the need to adopt new techniques for power usage is more urgent than ever. As global warming as a result of Carbon Dioxide emissions becomes at the forefront of all environmental issues, the need for a global metanoia is encouraged. The breakdown of coal to create electricity becomes more and more frowned upon each day by environmental activists, the call for a greater proportion of alternative power such as wind and solar is recommended. The question is often posed as to which alternative energy source is leading the market in terms of efficiency, effectiveness and economy.... [tags: renewable sources of energy]
1162 words (3.3 pages)
- Our Place in the Universe Our fascination with the Solar System has preceded astronomical antiquity, in a process of conceptualising the cosmos. Fundamental theories of Ptolemy, Copernicus, Brahé, Kepler, Galileo and Newton, have dominated history, stimulating a constant re-evaluation of the nature of the Solar System. In particular, the theories postulated by Copernicus and Kepler had a fundamental influence on the interpretation of the Solar System through challenging the prevailing orthodoxy of Aristotelian physics; thus paving the way for revolutionary challenges to the medieval worldview to prevail.... [tags: astronomy, history]
1029 words (2.9 pages)
- History of Physics Physics began when man first started to study his surroundings. Early applications of physics include the invention of the wheel and of primitive weapons. The people who built Stone Henge had knowledge of physical mechanics in order to move the rocks and place them on top of each other. It was not until during the period of Greek culture that the first systematic treatment of physics started with the use of mechanics. Thales is often said to have been the first scientist, and the first Greek philosopher.... [tags: Science Scientific Physics Essays]
1319 words (3.8 pages)
- Science fiction will often have fantastic stories about humans traversing stars at great speeds, faster than light. Vast interstellar civilizations are maintained by fleets of starships that fly from world to world in a matter of days or weeks. The truth, sadly, is far less fantastic. The universal speed limit is the speed of light, or approximately 2.998x108 m/sec. Nothing can move faster than that constant. Even at that extreme speed, it would take approximately 4 years for any spaceship to reach the closest of other stars.... [tags: physics science wormhole wormholes]
926 words (2.6 pages)
- Stars are phenomenal glowing spheres that everyone has noticed in the night sky. Long ago they were poorly understood. Today, with the help from astronomers, physicists, and other space scientists, we have discovered a large amount of information about stars. These huge balls of flaming gas have many different ranges of characteristics. We can observe the many fascinating colors that may be displayed from stars. Some of them are not stars themselves, but the trillions of fragments left behind after they explode into supernova (Moreau, 2000).... [tags: physics science space star]
1037 words (3 pages)
- Sea ice is frozen sea water. Salt ions in the water complicate the growth of ice crystals, and makes sea ice much more dynamic than freshwater ice. Sea ice covers nearly 7% of the Earth's surface, has a huge effect on global climate, and is one of the largest, single biomes on Earth. Ice is the solid, crystalline form of water, which solidifies at 0ºC. Roughly 9 polymorphs of ice are defined, only one, however, occurs naturally on Earth. This common form of ice is known as ice 1h, and its lattice displays six-fold rotational symmetry.... [tags: physice ice sea]
872 words (2.5 pages)