Currently there are different types of radiometers, each with its own way of detecting and measuring electromagnetic wavelength, but the most popular model still remains to be the Crookes radiometer. Made in 1873 by a physicist named Edward Crooks, this model is one of the earliest to have been used. It is made of a spindle fitted with a rotor and a set of vanes inside a partial vacuum. The vanes, which are painted silver on one side and black on the other, rotate upon exposure to light. This motion is commonly explained by physicists as the result of the heat generated upon absorption of the blackened side of the vanes of the photons from the light. The Crookes radiometer is used to provide a quantitative measurement of electromagnetic radiation. In principle, the more intense the light is that hits the vanes, the faster the rotation will be.

But as popular as the Crookes radiometer is, its use has been usurped by newer models such as the MEMS and Nichols radiometer which tend to be more diverse and sensitive in measuring electromagnetic radiation.

Crookes Radiometer

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This pertains to a device for detecting and analyzing radio waves emitted from astronomical objects. You commonly see the radio telescope as a large dish. The first of the long line of radio telescopes was built by the engineer Karl Guthe Jansky who was able to capture static radio signals from the galaxy’s core. Today, the largest radio telescope the Arecibo Observatory, which is 305 meters in diameter, is found in Puerto Rico. Radio telescopes are large in order to capture sharp radio images from radio wavelengths extending from one millimeter to as long as one kilometer.

A radio telescope is basically composed of an antenna (the large dish you usually see), a detector, and amplifier. Incoming radio waves are captured and focused by the antenna toward a supersensitive receiver capable of detecting signals as weak as 10-17. Some of the parts of the telescope are kept at an absolute zero temperature for sustained maximum performance. Because of the range of frequencies of radio waves, radio telescopes specifically the antenna can differ in terms of configuration, size, and design. Unlike optical telescopes, which are almost always in mountains, radio telescopes are built in valleys to be screened from electromagnetic interference.

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Depending on the application, the exact angles between each surface differs. Traditionally, a prism is that of a triangular prism, with a triangle shaped base and rectangular sides. Most prisms are made of glass, though it can also be made of other transparent material, equal to the wavelength to which they are meant to be used.

It can be used to break up light to its equivalent spectral colors, which include the colors red, orange, yellow, green, blue, indigo and violet. It can also reflect light or even split light into various wavelength.

Prisms work in dependence to light. As the speed light changes from one medium to another (e.g. light from air and into the section of the prism), it then causes light to be refracted and then enter the new medium, this time at a different angle or view. This is the basic principle of using a prism. Aside from this, the angle or the bending level of the light is hugely dependent on the angle where the light hit the object, and also varies in terms of wavelength due to the refractive ratio of the two light gathering objects.

There are also other types of prism: namely, the dispersing, grating, reflecting and polarizing types. The dispersing prism is the common type, where it breaks light into spectral colors. Grating prisms are used for light diffraction or splitting. Reflecting prisms are used in binoculars to reflect light. And polarizing on the other hand is used for splitting light into different spectrums.

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The constant movement of the earth causes the appearance of the sky to vary based on the time of the day, at certain times of the year and your specific location on earth. In order to pinpoint the exact location of a star or constellation, you will need to put all these components in consideration. The planisphere will help you do just that.

A planisphere is a circular star chart with an adjustable circular overlay on top of it that has a clear elliptical hole showing the portion of the sky that is visible in a particular location at a given time. With just a simple twist, this device will show you the astronomical sights you can possibly see on your night sky at a particular hour of the day.

There are, however, some complications to the use of a planisphere. Northern and southern hemispheres have different designs of planispheres so if one that has been made for use in the northern hemisphere is used in the southern hemisphere, it may not give you an accurate data. Some models also only work efficiently for a particular range of latitudes, so you have to make sure you get the one is appropriate for your location.

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A photometer is the primary tool used in the field of photometry – a field that focuses on the study of the emitted intensity of the electromagnetic radiation of an astronomical body. Photometers typically measure the flux coming from these celestial objects. Photometers can measure luminance, irradiance, light absorption, scattering of light, reflection of light, fluorescence, phosphorescence and luminescence. The detection of light by this device usually occurs after the light passes through a filter or a monochromatic that distinguishes the wavelengths of the emitted electromagnetic radiation. Photon counting is also employed in other photometers that do not make use of the value of flux.

A photometer is often used in conjunction with telescopes. Some amateur astronomers create custom-built photometers to perfectly fit their telescopes and conduct photometry while observing the brilliant night sky. Even the world’s most popular telescope, the Hubble Space Telescope, housed a High Speed Photometer before the failure of the primary mirror.

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After all, this telescope is known to provide an immense view of the sky itself. What is a Rich Field Telescope (RFT)? They are actually low power telescopes with immense field of view. They offer some of the advantages of the binoculars where large areas of the sky may be scanned through them.

There are viewing techniques that will take in a large area of the heavens. These are very useful because some celestial objects will not fit into a narrow field. Also, many large galaxies have a very low surface brightness. It means the area is large and dim, therefore they can only be seen when surrounded by dark sky. Large deep objects are easily observed when there is some contrast between them and their surroundings. Only a wide field of view will provide that contrast.

To take advantage of a true rich field telescope you must have a small compact scope. These can be hand held or mounted. They are very portable and easy to use. This should provide you with views of the Milky Way that are truly breathtaking. This is something that you and your family would certainly enjoy doing.

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A spectrometer is an instrument that is used in analyzing a specific portion of light. This instrument is commonly used in to provide spectral analysis in identifying materials. If you are highly observant, you would have noticed that these instruments have found their way into pop TV culture.

Spectrometers are commonly featured in popular TV crime-solving series where unknown materials are subject to spectral analysis so that their chemical makeup and composition can be determined. The fun part about spectrometers is that they cannot only be used for things found on the ground; they can also be used for things in the sky. Aside from determining the composition of materials found on earth, spectrometers are also utilized in determining the composition of stars.

Early spectrometers used prisms in order to break down light into its components. This was then viewed at different angles on a rotating platform. Modern spectrometers now work by diffracting a light source which involves passing a ray of light through a diffraction grating.

The resulting spectrum is then scanned by a detector in order to measure the different wavelengths and the intensities found in the sample. All of these are controlled by a computer. Nowadays, spectrometers have a wider range of operation and not only scan the visible area of the spectrum but also the highly energetic gamma rays, x-rays and infrared regions that are not visible to the eye.

If the instrument used measures the light in absolute units rather that in relative intensities, the instrument is called a spectrophotometer.

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The concept of a space mirror works very much like the mechanism of the moon. With the presence of a space mirror, possibility of light in any surface comes to fruition. For example, a mirror in orbit around a planet like Mars could duplicate Earths conditions.

Terra-forming, or providing warmth to a patch of another planet’s surface for the possibility of habitation is at present still fiction. However, the scheme is not entirely impossible, as sunlight can be reflected through the use of orbiting mirrors.

Another use of such space mirrors is to reflect images back to telescopes, so that not only a single view can be used as resource. A mirror the size of a football field when launched into the Earth’s orbit just like a satellite could provide high-resolution images from space, and better aid telescopes limited with views only from the Earth.

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A magnetometer is the instrument that scientists use in order to measure the direction and/or strength of the magnetic field within the scope of the instrument. Magnetism differs from one place to another so it is important to measure how strong the magnetic field is in a specific location in the Earth’s magnetic field or the Earth’s magnetosphere. Magnetosphere is created when the planet’s natural magnetic field deflects the Sun’s charged particles such as the solar wind. Different interaction may occur in specific areas within the Earth’s magnetosphere resulting to different degrees of magnetism. In addition, different nature of rocks may also after the strength of the magnetism in an area.

Magnetometers are important instruments used by those love to explore planets. On Earth, it is used to conduct electromagnetic geophysical surveys like magnetotellurics and magnetic surveys which are done to identify the mineralization and geological structures. Magnetometers are also used in airborne geophysical surveys to detect variations on magnetic field due to mineralization. It is also useful in detecting archaeological sites and other objects buried on the ground or submerged in water. It can be used to detect magnetic anomalies, too. It is important in the military in order to spot submarines.

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