Who had the first ideas about Light , its composition and velocity?
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It has been pondered back to ancient times, including ancient greeks who believe vision was actually light emanating from the eyes and hitting objects. The first accurate accounting of light was from Newton who discovered that white light is made up of all the colours.
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He discovered that atoms are not indivisible and are actually made up of smaller particles, electrons. When he first discovered electrons, he formed three hypotheses:\n\n1. Cathode rays are charged particles (which he called "corpuscles"). \n2. These corpuscles are constituents of the atom. \n3. These corpuscles are the only constituents of the atom. \n\nThere were minor changes made to his first and second hypotheses, but the third was completely wrong.\n\nNOTE: The table of contents to the first link is on the bottom left of the page.
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The first telescopes may have been Assyrian crystal lenses[1], but the Visby lenses tentatively suggest that the technology was known to the Arabs and Persians, then to the Vikings, in the 10th century. Leonard Digges is sometimes credited with the invention in England in the 1570s, but usually credit for assembling the first telescope is given to an unknown Dutch spectacle maker in about 1608. Some name that person as Hans Lippershey (c. 1570 – c. 1619), but Jacob Metius and Zacharias Jansen also claimed to have invented a telescope during the same period. Even if Lippershey did not make the first one, he publicized it. Galileo Galilei made his own telescope in 1609, calling it at first a "perspicillum," and then using the terms "telescopium" in Latin and "telescopio" in Italian (from which the English word derives). Galileo is generally credited with being the first to use a telescope for astronomical purposes. Galileo's telescope consisted of a convex object lens and a concave eye lens, which is universally called a Galilean telescope (used as a viewfinder in many simple cameras). Later, Johannes Kepler described the optics of lenses (see his books Astronomiae Pars Optica and Dioptrice), including a new kind of astronomical telescope with two convex lenses (a principle often called the Kepler telescope). Optical interferometer arrays and arrays of radio telescopes were developed much more recently. Telescopes have been around for a while.
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it was an assumption of newtonian mechanics, you might be taught it in school but Einstein and I believe a couple others showed evidence for the curvature of light. Its a small curvature, so unless your looking at a very long distance the curvature is negligible.
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Anaxagoras.\n\n\nPythagoras first reasoned that the Moon must be a sphere because the line between light and dark is curved.\n\nAnaxagoras used the Earth shadow during eclipse to confirm the Earth is a sphere.\n\nAnd Aristotle came to the same conclusion because he noted how the constellations "move" when you get farther from the equator.
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Michaelson and Morely did some experiments to try to see if the speed of light incipient on the earth was different for light coming from different directions.  Th idea was that if light travels in waves (as it seems to in many regards), then these waves needed to travel through a medium (like when sound waves travel through the air).  This medium was termed "the ethereal ether" and was thought to pervade space, including places with a vacuum; light was thought to be a wave travelling through it.  So Michaelson and Morely decided to try to see our speed relative to the ether by using somthing called an interfereometer.  This compared the speed of lightcoming from different directions.  The idea was that a star we are headed towards should reveal a higher speed of light, while ones we're rushing away from should have a lower speed, due to the Doppler effect.  What they found was that the speed was the same in all directions, meaning that if there was an ether, then we we perfectly at rest relative to the ether.\n\nThen mathematicians and physicists looked at the theories of Scottish physicist James Clerk Maxwell.  Maxwell had taken all existing theories on electricity and megnetism and unified them into a single, cohesive set of equations.  These equations showed how electricity could create a magnetic field, and a magnetic field could induce an electric current.  This could happen in such a manner that an electric field would induce a magentic field, which in turn induced an electric field, which in turn induced a magnetic field, and so on.  The equations made it clear that this wave would travel at a certain specific speed.  Incidentally, that speed was similar to the speed of light measured by French scientist Fizeau in 1849 (several decades earlier) and confirmed by Foucault.\n\nIt was all of this that led Einstein to formulate his special theory of relativity.  Since light moved as an electromagnetic wave, and since those waves had a speed that was predicted directly by Maxwells equations and was independent of the velocity of the observer, Einstein came to recognize that simultaneity was not a universal concept, and that time changed with velocity.  The idea of the ether was discarded as needless baggage.
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einstein. he just sat in his chair and thought of theories. he did experiments in his mind
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Ther are two natures assigned to light\n1.It is made of particles called photons\n2.It is an electromagnetic wave.
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1) Light is both a wave and a particle phenomenon. Experiments can be devised to demonstrate either the particle or wave properties of light, just not at the same time (see 'particle wave duality').\n2) About 1,000 seconds. An astronomer named Christian Huygens (I think... might've been Oersted) first observed a 1,000 second discrepancy in the observation of Jupiter's moons eclipsing when observed in the summer as opposed to in the winter. This led him to the first good approximation for the speed of light, i.e. the extra time it took the light to cross the diameter of Earth's orbit could be measured, and since the approximate diameter of Earth's orbit was already known: Speed = Distance/Time or 186,000,000 miles divided by 1,000 seconds = 186,000 miles per second.\n3) The light year is a unit of DISTANCE, not TIME!! It is the distance that light travels in one year, or about six TRILLION miles. However even at this staggering speed it takes light over four years to reach the nearest star to Earth (other than the sun).
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Light does not intend to travel at the speed of light\nLight travels at a certain speed, it actually does not know its speed.\nWhen scientists measured this speed they found it 299 792 458 m / s or about 186000 miles per second \nso they make it fixed term, refereed as "the speed of light", used it in other physical equations...\nthen it "speed of light" became a famous term. \nBut Light still does not know that they called its velocity as the light speed..\nAnd I think it will not know!
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Hydrogen        : Henry Cavendish\nX-rays          : Wilhelm Rontgen\nOxygen gas      : Joseph Priestly\nRadium          : Pierre and Marie Curie\nElectricity     : The Greeks had some idea of electricity. \n\nIn the 18th century Franklin and other Europeans knew a great deal about it. Early in the century, Alessandro Volta invented the first source of continuous electric current - the battery. Later, Hans Christian Oersted discovered that an electric current produced magnetism. \n\nBut it was Michael Faraday who described the nature of the phenomena. In his electromagnetic induction theory he stated that an electric current flows in a conductor if that conductor is in a moving magnetic field and is part of a circuit. \n\n\nSmall-pox Vaccination  : Edward Jenner
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Nikola Tesla.\n\nBecause he thought it wouldn't cause lights to flicker for anyone.
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william gilbert\n\nWilliam Gilbert first coined the term "electricity" from the Greek word for amber. Gilbert wrote about the electrification of many substances in his "De magnete, magneticisique corporibus". He was also the first person to use the terms electric force, magnetic pole, and electric attraction.
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People sort of understand waves and they understand particles, light might be a disturbance in the space time continum. Just a definate bit energy with an uncertainty where it is, traveling. Some "particles" exist for such a short time , they are more a resonance. I am looking forward to new research and thoughts on nature of light.
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While, indeed, Michał Sędziwój first wrote about oxygen. \n\n A Swedish person named Carl Wilhelm Scheele was a little more scientific in his description and used scientific methods. But, he did not published his findings until after the discovery of Oxygen by Joseph Priestley. Priestley published his discovery, consequently Priestley is usually given the credit.\n\nGet an "A".
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Part of the Beauty of Einstein's work on relativity is how easy it applied all the existing work, including Newton's work. When it comes to calculating forces necessary to bend light around a sun relativity does come into play.  And you are right early attempts were thwarted by weather and such. As I recall the first such measurements were carried out by a party that journeyed down to South Africa to make observations during a solar eclipse.  They were doing it, not to prove Newton's work, but to test the need for Einstein's corrective formulas.  The measurements were a roaring success and Einstein's ideas concerning Spacetime was quickly excepted by the larger scientific community.\n\nAppended thoughts - Before we get all sanctimonious here, let us keep in mind Newton and Einstein were 300 years apart, both men were geniuses, both men were deeply religious and both men DEFENDED errors in their thinking.  This is what Kuhn talked of when he put forth his ideas on Paradigm Shifts.  It was Maxwell who punched holes in Newton's thinking on Aether and it was Bohr who ushered in Quantum Mechanics. And it was hundred other people making a hundred other contributions that have gotten us where we are today.  And there will probably be a hundred more in the future trying to sort out these difficult questions.
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Light is a particle. Wave is its function.