Question

1..who discovered the fact that the light travels at finite but very high speed and explain how he done so..


2.. write something about space time..


3.. how mass of sun curves space time ..

4 prove e= mc²

Answer 1

$\huge \bf{hey}$
$\huge \underline{here \: is \: the \: answer}$
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1.▶
$\bf{speed \: of \: light}$

⏩ the fact that the light travels at finite but very high speed was discovered in 1676 by the Danish astronomer Ole Christensen Roemer.

he observed that the times at which the moons of Jupiter appeared to pass behind Jupiter were not evenly spaced, as one would expect if the moons went round Jupiter at the constant rate . as the earth and Jupiter orbit around the sun , the distance between them varies . Roemer noticed that eclipses of Jupiter's moon appeared later the farther we were from Jupiter . he argued that this was because the light from the moons took longer to reach us when we are farther away. his measurements of the variations in the distance of the earth from Jupiter were not accurate ,so his value of speed of light was 140000 miles / sec.
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$\bf{space \: time}$

⏩2. an event is something that happens in particular point in space at a particular time . so one can specify it by four numbers of coordinates . one can use any well - defined spatial coordinates and any measure of time . in relativity there is no real distinction between space an time coordinates .

it is often helpful to think of four coordinates of an event as specifying it's position in four dimensional space called space - time . it is impossible to imagine four dimensional space .


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$\bf{mass \: of \: sun \: curves \: space \: time}$
⏩3. the mass of the sun curves space time in such a way that although the earth follows a straight path in four dimensional space time , it appears to move along a circular orbit in three dimensional space . infact the orbits of planets predicted by general relativity are almost exactly the same as those predicted by Newtonian theory of gravity.

⏩4. it is in pic . at last

$\huge \boxed{hope \: it \: helps}$
$\huge \color{red}{thanks}$