NEBULA

                                           

                                        NEBULA

        

                                                 If we translate the Latin word ‘nebula’, it would simply mean ‘cloud’.A nebula is an interstellar cloud of dust,ionized gasses.The main gases are hydrogen and helium gas, and plasma.It is form when portion of interstellar medium collapse due to gravitational force(attraction) by the particle in that medium.Many of  you think that outer space is vacuum but it aint true it is fill with medium called ether which may contain many gasses and other dust particles,and this all known as ISM(interstellar medium

                        There are many nebula till found and some of most prominent are Eagle Nebula,Horse head Nebula,Red Rectangle Nebula,Crab Nebula and many more.

                        As the material collapses under its own weight, massive stars may form in the center, and their ultraviolet radiation ionizes the surrounding gas, making it visible at optical wavelengths.The more masses clump together, the greater their gravitational attraction will be to other bodies and particles in their vicinity. As the particles clump further to form larger and more massive structures, they attract more dust and gas. The pressure inside then gets so high that nuclear fusion ensues. This results in the emission of high-energy electromagnetic radiation, which in turn ionizes the outer layers of gas.Ionized gas is plasma, and so plasma and electromagnetic radiation are now added to the mix. This now becomes the earliest stages of star formation.
                                   Some nebulae are formed as the result of supernova explosions, the death throes of massive, short-lived stars. The materials thrown off from the supernova explosion are ionized by the energy and the compact object that it can produce,other nebulae may form as planetary nebulae. This is the final stage of a low-mass star's life, like Earth's Sun.

                                                                           (HELIX NEBULA)

                                                  Planetary Nebula.

                               Planetary nebulae form from the gaseous shells that are ejected from low-mass asymptotic giant branch stars when they transform into white dwarfs.Nebula is just not the starting point of the formation of heavy masses,ironically it may be end point.Stars that evolve into red giants can lose their outer layers during pulsations in their outer layers, known as their atmospheres releasing hydrogen and helium into 9.7:0.3 ratio.It is this released matter that forms what is known as a planetary nebula.

       

                                                                     (CAT EYE NEBULA)

THEORY OF RELATIVITY.

RELATIVITY

 

RELATIVITY IS THE WORD WHICH CAN MAKE US TO BLAME SOMEONE WRONG OR TO APPRECIATE FOR SOMEONE'S GOOD.BUT HOW?

DO YOU REALLY THINK THAT DR.ALBERT EINSTEIN WHEN GAVE THE PAPERS ON THE THEORY OF RELATIVITY WAS THINKING OF THIS PAPERS ON THE VERY STARTING OF HIS LIFE,NO THE ANSWER IS NO(in my opinion). AT THE EARLY STAGE OF HIS LIFE HE WAS SO MUCH DISTRESSED BECAUSE OF THE INCOMPLETE EDUCATION,NO JOB,NO MONEY,HIS PARENTS THOUGHT THAT HE WAS A TOTAL WASTE. THIS ALL THING MADE HIM FEEL VERY SORRY FOR HIMSELF . HE STARTED THINKING WHY THEY ALL CALL ME BAD? 

ONE DAY, TRAVELING ON THE BUS HE LOOKS AT VERY FAMOUS WATCH TOWER AND HE STARES AT THE WATCH AND NOTICED THAT IF BUS CAN REACH THE SPEED OF THE LIGHT THEN HE WOULD NOT BE ABLE TO SEE THE HANDS OF THE WATCH MOVING. THIS GIVE HIM THE IDEA OF RELATIVITY BUT AS WE KNOW  THAT IDEA CAN NOT MAKE A DIFFERENCE ALONE,THERE MUST BE SOMETHING ELSE AND EINSTEIN HAD THAT THING AND WE CALL IT SADNESS. THE FAILURE OF HIS MAKE OTHERS TO POINT FINGER ON HIM AND THAT POINTY FINGER MAKE HIM TO THINK WHY HE IS SO WORTHLESS. THEN ONCE FROM THE IDEA OF RELATIVITY HE STARTED BELIEVING THAT I AM BAD BECAUSE THERE ARE SOME GOOD PEOPLE ALSO,THIS ALL THING ARE IN RELATIVE WITH EACH OTHER.

HE MIGHT BE WRONG BUT I DO ALSO HAVE SAME BELIEVE THAT IF THERE ARE BAD PEOPLE THAT ONLY BECAUSE  THAT THERE SOME GOOD PEOPLE ALSO.THIS UNIVERSE MUST BE BALANCED TO RUN SMOOTHLY.IF AN ATOM ALSO NEED EQUAL NUMBER OF ELECTRON PROTON TO BE BALANCE AND STABLE AND WE ARE HERE TALKING ABOUT THE WHOLE UNIVERSE.

THEORY OF RELATIVITY

THEORY OF RELATIUVITY IS FIRST PAPER PROPES BY ONE OF THE GREATEST MIND OF ALL TIME,DR.ALBERT EINSTEIN.

ACCORDING TO HIS THEORY,MOTION AND REST ARE DEPENDED TO EACH OTHER OR WE CAN SAY RELATED TO EACH OTHER.IF A BODY IS MOVING THEN ITS NOT SEEN TO BE MOVING UNTIL THERE IS NO  OTHER BODY ON REST POSITION AND  VICE-VERSE IS ALSO TRUE. 

THE THEORY OF RELATYIVITY GENERALLY ENCOMPASSES TWO THEORIS NAMELY GANEREAL THEORY OF RELATIVITY AND SPECIAL THEORY OF RELATIVITY.

Einstein sought to explain situations in which Newtonian physics might fail to deal successfully with phenomena, and in so doing proposed revolutionary changes in human concepts of time, space, and gravity.

The special theory of relativity was based on two main postulates: first, that the Speed of light is constant for all observers; and second, that observers moving at constant speeds should be subject to the same physical laws. Following this logic, Einstein theorized that time must change according to the speed of a moving object relative to the frame of reference of an observer. Scientists have tested this theory through experimentation - proving, for example, that an atomic clock ticks more slowly when traveling at a high speed than it does when it is not moving. The essence of Einstein's paper was that both space and time are relative (rather than absolute), which was said to hold true in a special case, the absence of a gravitational field. Relativity was a stunning concept at the time; scientists all over the world debated the veracity of Einstein's famous equation, E=mc2, which implied that matter and energy were equivalent and, more specifically, that a single particle of matter could be converted into a huge quantity of energy. However, since the special theory of relativity only held true in the absence of a gravitational field, Einstein strove for 11 more years to work gravity into his equations and discover how relativity might work generally as well.

 

 According to the Theory of General Relativity, matter causes space to curve. It is posited that gravitation is not a force, as understood by Newtonian physics, but a curved field (an area of space under the influence of a force) in the space-time continuum that is actually created by the presence of mass. According to Einstein, that theory could be tested by measuring the deflection of starlight traveling near the sun; he correctly asserted that light deflection would be twice that expected by Newton's laws. This theory also explained why the light from stars in a strong gravitational field was closer to the red end of the spectrum than those in a weaker one.

 Proofs of theory of relativity.

1.
The latest test of Einstein's theory of relativity,, looks specifically at time dilation, a piece of the theory that predicts that two identical clocks resting at different heights or moving at different speeds will tick at different rates. Time dilation is most commonly thought of in terms of the twin paradox: If one twin goes asteroid-hopping on a rocket moving at extremely high speeds, he'll have aged less than his earthbound sibling when he gets home. Now, however, physicist Chin-Wen Chou and his colleagues at the National Institute of Standards and Technology have shown that time dilation can be observed even without a far-flung, fast-moving trip.

PROOFS.
Using super-sensitive optical clocks, they measured changes in the clocks' tick rates at speeds of less than 25 miles per hour and at differences in altitude of about a foot. The optical clocks, each powered by a single aluminum ion, are nearly 40 times as accurate as the international-standard cesium-powered atomic clocks, giving researchers the ability to look at minute differences in tick rates. Sitting still at the same height, the clocks had the same tick rate. To move one clock, the researchers simply started one of the ions oscillating at a speed of their choosing. "It can be as slow as you sitting on a swing, swinging back and forth, or as fast as a bullet train," Chou says. When he set the ion moving at 15 meters per second (a little under 50 miles per hour), Chou found that that clock ticked at a measurably slower rate than the stationary clock. The same thing happened when the clocks were at slightly different heights. When Chou and his team used hydraulic jacks to lift one clock just over a foot, the lower clock's tick rate was ever-so-slightly lower than that of the higher clock. Because optical clocks allowed them to measure carefully enough, the researchers could see that Einstein's predictions played out even in everyday circumstances like the height of a footstool and the speed of a car on a residential street. 

2.

Sending communications to and from the Viking lander on Mars in 1979, scientists showed that signals traveling between Earth and Mars took slightly longer when they passed the Sun, due to the curvature in space-time caused by the massive star.
PROOFS.
  As the spacecraft Cassini was heading towards Saturn in 2002, scientists again measured the effect of solar gravity, looking at how the round-trip time of a radio signal changed when it went near the sun. Although the Cassini test showed the same result as that of the Viking, it was 50 times as accurate—within 20 parts per million, thanks to a better communication system that could filter out interference from the solar corona

3.

Like all falsifiable scientific theories, relativity makes predictions that can be tested by experiment. In the case of special relativity, these include the principle of relativity, the constancy of the speed of light, and time dilation.The predictions of special relativity have been confirmed in numerous tests since Einstein published his paper in 1905, but three experiments conducted between 1881 and 1938 were critical to its validation. These are the Michelson–Morley experiment, the Kennedy–Thorndike experiment, and the Ives–Stilwell experiment. Einstein derived the Lorentz transformations from first principles in 1905, but these three experiments allow the transformations to be induced from experimental evidence.

Maxwell's equations – the foundation of classical electromagnetism – describe light as a wave which moves with a characteristic velocity. The modern view is that light needs no medium of transmission, but Maxwell and his contemporaries were convinced that light waves were propagated in a medium, analogous to sound propagating in air, and ripples propagating on the surface of a pond. This hypothetical medium was called the luminiferous aether, at rest relative to the "fixed stars" and through which the Earth moves. Fresnel's partial ether dragging hypothesis ruled out the measurement of first-order (v/c) effects, and although observations of second-order effects (v2/c2) were possible in principle, Maxwell thought they were too small to be detected with then-current technology.

The Michelson–Morley experiment was designed to detect second order effects of the "aether wind" – the motion of the aether relative to the earth. Michelson designed an instrument called the Michelson interferometer to accomplish this. The apparatus was more than accurate enough to detect the expected effects, but he obtained a null result when the first experiment was conducted in 1881,and again in 1887.Although the failure to detect an aether wind was a disappointment, the results were accepted by the scientific community.In an attempt to salvage the aether paradigm, Fitzgerald and Lorentz independently created an ad hoc hypothesis in which the length of material bodies changes according to their motion through the aether.This was the origin of FitzGerald–Lorentz contraction, and their hypothesis had no theoretical basis. The interpretation of the null result of the Michelson–Morley experiment is that the round-trip travel time for light is isotropic (independent of direction), but the result alone is not enough to discount the theory of the aether or validate the predictions of special relativity.

General relativity has also been confirmed many times, the classic experiments being the perihelion precession of Mercury's orbit, the deflection of light by the Sun, and the gravitational redshift of light. Other tests confirmed the equivalence principle and frame dragging.