Easy Cash Home About Contact Privacy Policy
Get A FREE e-Book on HOW TO MAKE EASY CASH !

33 Pages -
Absolutely FREE!

We have a No Spam Policy - Read More

Stargazer, Astronomy Be a Stargazer

All sciences are making an advance, but Astronomy is moving at high speed. Since the principles of this science were settled by Copernicus,four hundred years ago, it has never had to beat a retreat. It is rewritten not to correct material errors, but to incorporate new discoveries. At one time, Astronomy studied mostly tides,

 

seasons, and telescopic aspects of the planets; now these are only primary matters. Once it considered stars as mere fixed points of light; now it studies them as suns, determines their age, size, color, movements, chemical constitution, and the revolution of their planets. Once it considered space as empty; now it knows that every cubic inch of it quivers with greater intensity of force than that which is visible in Niagara. Every inch of surface that can be conceived of between suns is more wave-tossed than the ocean in a storm.


The invention of the telescope constituted one era in Astronomy; its
perfection in our day, another; and the discoveries of the spectroscope
a third--no less important than either of the others. New discoveries
are made every day with the advancement of telescopes. The Hubble
space telescope has let man see further into the universe then ever
before. Astronomy and space science is an ever changing study, and
possibly the most exciting of the sciences. It is for one reason that this
book was written, to hopefully interest more people in the exciting
study of the universe around us.


Why Study Light?
For most of history, humans have used visible light to explore the
skies. With basic tools and the human eye, we developed sophisticated
methods of time keeping and calendars. Telescopes were invented in
the 17th century. Astronomers then mapped the sky in greater
detail­­still with visible light. They learned about the temperature,
constituents, distribution, and the motions of stars.


There are two main techniques for analyzing starlight. One is called
spectroscopy and the other photometry. Spectroscopy spreads out the
different wavelengths of light into a spectrum for study. Photometry
measures the quantity of light in specific wavelengths or by combining
all wavelengths. Astronomers use many filters in their work. Filters
help astronomers analyze particular components of the spectrum. For
example, a red filter blocks out all visible light wavelengths except
those that fall around 600 nanometers (it lets through red light).


Introduction to Light
Light is a form of radiant energy or energy that travels in waves. Since
Greek times, scientists have debated the nature of light. Physicists now
recognize that light sometimes behaves like waves and, at other times,
like particles. When moving from place to place, light acts like a
system of waves. In empty space, light has a fixed speed and the
wavelength can be measured. In the past 300 years, scientists have
improved the way they measure the speed of light, and they have
determined that it travels at nearly 299,792 kilometers, or 186,281
miles, per second.


When we talk about light, we usually mean any radiation that we can
see. These wavelengths range from about 16/1,000,000 of an inch
to 32/1,000,000 of an inch. There are other kinds of radiation such as
ultraviolet light and infrared light, but their wavelengths are shorter
or longer than the visible light wavelengths. When light hits some form
of matter, it behaves in different ways. When it strikes an opaque
object, it makes a shadow, but light does bend around obstacles. The
bending of light around edges or around small slits is called diffraction
and makes patterns of bands or fringes.


All light can be traced to certain energy sources, like the Sun, an
electric bulb, or a match, but most of what hits the eye is reflected
light. When light strikes some materials, it is bounced off or reflected.
If the material is not opaque, the light goes through it at a slower
speed, and it is bent or refracted. Some light is absorbed into the
material and changed into other forms of energy, usually heat energy.
The light waves make the electrons in the materials vibrate and this
kinetic energy or movement energy makes heat. Friction of the moving
electrons makes heat.


Experiments With Light
A light set in a room is seen from every place; hence light streams in
every possible direction. If put in the centre of a hollow sphere, every
point of the surface will be equally illumined. If put in a sphere of twice
the diameter, the same light will fall on all the larger surface. The
surfaces of spheres are as the squares of their diameters; hence, in
the larger sphere the surface is illumined only one-quarter as much as
the smaller. The same is true of large and small rooms. In Fig. 7 it is
apparent that the light that falls on the first square is spread, at twice
the distance, over the second square, which is four times as large, and
at three times the distance over nine times the surface. The varying amount of light received by each planet is also shown in fractions
above each world, the amount received by the earth being 1.

Fig. 7.


Fig. 8.--Measuring Intensities of Light.
The intensity of light is easily measured. Let two lights of different
brightness, as in Fig. 8, cast shadows on the same screen. Arrange
them as to distance so that both shadows shall be equally dark. Let
them fall side by side, and study them carefully.

Measure the respective distances. Suppose one is twenty inches, the other forty. Light varies as the square of the distance: the square of 20 is 400, of
40 is 1600. Divide 1600 by 400, and the result is that one light is four
times as bright as the other.


Fig. 9.--Reflection and Diffusion of Light.
Light can be handled, directed, and bent, as well as iron bars. Darken
a room and admit a beam of sunlight through a shutter, or a ray of
lamp-light through the key-hole. If there is dust in the room it will be
observed that light goes in straight lines. Because of this men are able
to arrange houses and trees in rows, the hunter aims his rifle
correctly, and the astronomer projects straight lines to infinity. Take a
hand-mirror, or better, a piece of glass coated on one side with black
varnish, and you can send your ray anywhere. By using two mirrors,
or having an assistant and using several, you can cause a ray of light
to turn as many corners as you please.


Set a small light near one edge of a mirror; then, by putting the eye
near the opposite edge, you see almost as many flames as you please
from the multiplied reflections. How can this be accounted for?
Into your beam of sunlight, admitted through a half-inch hole, put the
mirror at an oblique angle; you can arrange it so as to throw half a
dozen bright spots on the opposite wall.


$
Easy Cash $ 10 Tips For Losing Weight $ A Beginners Guide To Outsourcing $ Adsense $ Affiliate Marketing $ Affiliates $ Appetizers $ Bargain Hunter $
Astrology - Be A Stargazer $ Bird Treats $ Blog Content $ Body Language $ Can't Get Pregnant $ Childrens Party Games $ Cash Advance $ Competitions $ Copy The Super Affiliates $ Craft Wholesale Lists $ Dating Ideas $ Astrology Myths $ Dog Health $ Cajun Recipes $ Toolbars $ Domains Yahoo $ eBooks $ Make Your Own Perfume $ How To Create A Garden Pond $ How To Do A WheelStand On Your Motorbike $ How To Save Energy And Money $ Moon Signs $ Link To Weekendeasycash $ Math $ Millionaires Resources $ Metabolism $ Mobile Phones and Popcorn $ Moon Signs $ Online Dating $ Online Games $ Photography $ Podcasting $ Procastination $ Remote Control Car Guide $ Register A Domain $ Sell Your House $ Sell Your House $ Stacks Of Money $ Stop $ Tips On Buying A Second hand boat $ Tips On Buying A Second hand Car $ Traffic $ Wedding Video Business $ Woodfinishing $ Wrecked Plane $ XBox Repair Guide $ Xyberblocks $ User Manual Template



All information on this website is subject to Copyright.

Copyright www.weekendeasycash.com
© 2007 - 2009

easycashfast