The closest galaxy which can be seen by the "naked eye" (blushing) is the Andromeda Galaxy which is 2,400,000 light years from earth. We can't see other galaxies because of the extreme distance between Earth and the galaxies.
Most mass in the universe is not visible because it does not emit Electromagnetic waves. Simply put most mass in the universe does not emit visible light, X-rays, gamma rays, ultraviolet light, or infrared.
"Its presence can be inferred by observing the effect of its gravity on visible objects, such as stars, or on light."
For the same reason that you can't see a black cat in a coal mine:
Dark matter does not generate light, and unless it reflects enough light to be seen (on Earth) it remains invisible.
too bright bcs too many stars. so hard to study each star individually
Astronomers analyze the light reflected from comets with a machine, and can easily tell what major elements it is composed of.
Sonam kapoor is quite rich. Exact measure cannot be told but one can easily estimate that she is quite rich. Her father is also an actor and that makes the difference.
pretty easily because it's an active metal
"Insulator" means that electrical charge can NOT flow through it easily.
1. So that they can be seen easily/ they can be visible easily.2.To keep them cool.
If, as ancient astronomers thought, that our Earth was the center point of rotation for other planets, then it is difficult to explain why those planets would move in a direction opposite to their rotation. Ptolemy came up with a solution that worked, but it was a cumbersome one. Nicolae Copernicus was able to show that this retrograde motion could be explained easily if it were assumed that our Sun was the actual center of rotation of the planets.
The reason astronomers were able to photograph the surface of Mars is due to probes, unmanned spacecrafts used for exploration in space.
Telescopic images taken in the infrared and x-ray parts of the spectrum have been a great help in this area, to name just two. As an example: The center of our Milky Way galaxy lies in the direction of the constellation Sagittarius, but we cannot see it in normal light because of gasses and dust between our part of the galaxy and the center. But with infrared photography, the center of the galaxy is seen easily as an egg yolk-shaped "glow".
Double stars, also called binary stars, are valuable to astronomers because they are the only stars of which astronomers can easily calculate their mass. They are bound to each other by gravity and orbit about a common center. The time it takes for one star to orbit the other depends on the distance between the two stars and their masses.
Astronomers analyze the light reflected from comets with a machine, and can easily tell what major elements it is composed of.
no coal cannot break easily
The instrument is an optical microscope.
sturdy
Trick question; the center of the Milky Way galaxy cannot be observed at all. Not only are there vast clouds of interstellar gas blocking the light, but we believe that the center of the galaxy - as at the centers of MANY galaxies - is occupied by a supermassive black hole.
optical fibres work on the principle of total internal reflection.that is a long concept but easily available.because of this T.I.R the light transmitted through the wires is very small.so it can travel a longer distance(not necessarily rectilinear).so it finda application in medical surgery to get a view of the organs by inserting optical fibres through the wind pipe.it is also used to carry light to those materials that cannot be placed inside a spectroscope directly.they are also used for decoration purpose.the lamps with glowing hairs are good examples.
revesed
wood