00:00In the previous video, I told you that we measure the mass of the earth, but before that, let us see the principle of Newton's magic ball again.
00:20Newton said that in this world, any two objects are attracted to each other by their corresponding linear equations.
00:29This attraction ball is equal to the mass of any two objects and is perpendicular to their distance.
00:37In numerical language, f is proportional to m1 into m2 and f is proportional to 1 by r square.
00:48If these two are joined together, f is proportional to m1 into m2 by r square.
00:58To represent this relation in equations, Newton mentioned a constant, capital G, which he called the universal gravitational constant.
01:12If he could not say the value of this constant, he assumed that its value would be very small.
01:19In numerical language, f is equal to G into m1 m2 by r square.
01:28G is equal to f into r square by m1 m2.
01:38Now, if the mass of the two objects is perpendicular to each other, that is, m1 is equal to 1, m2 is equal to 1, r is equal to 1, then G is equal to f into 1 or G is equal to f.
01:54From here, we can draw a generalization of capital G.
01:58If the mass of two objects is perpendicular to each other, the attraction ball acting on them is equal to the mass of the universal gravitational constant.
02:08There is another property of this gravitational constant.
02:11You must have noticed that on the left side of this equation, there is f, that is, the ball, which is perpendicular to Newton, and on the right side, there is 1 kg square by m square.
02:23If we combine the equations of these two equations, the equation of this equation will be n m to the power 2 by kg square.
02:35G is equal to f into r square by m1 m2 is equal to m l p to the power minus 2 l to the power 2 by m to the power 2, which is equal to m to the power minus 1 l cube p to the power minus 2.
03:01We know the mass of the universal gravitational constant, but we do not know its magnitude.
03:07Before knowing the magnitude, you need to know an incident.
03:10As I said before, Newton said that the magnitude of the universal gravitational constant will be very small if its magnitude cannot be accurately determined.
03:18So how did he think that its magnitude will be small?
03:22Let's try to understand.
03:24As you can see from the equation, the magnitude of the universal gravitational constant is equal to the magnitude of the mass of the two objects.
03:31If the magnitude of G was not very small, the attraction of the object would be very high as per the equation.
03:38That is, the video I shot, I attracted the light, camera, cameraman with such a magnitude, the video would be made.
03:47Newton thinks that the magnitude of the universal gravitational constant is small just to reduce the complexity of mathematical equations.
03:55About 110 years after the invention of Newton's universal gravitational constant, the British scientist Henry Cavendish determined the magnitude of G.
04:03For this test, he used a special device called the torsion balance.
04:11According to Cavendish's test, the magnitude of G in 1798 is only 1% less than the current magnitude.
04:21That is, even after 200 years, we have only been able to determine 1%.
04:27The current magnitude is 6.67 x 10-11 kg-1 m3 sec-2
04:39This is very important, so try to keep it in mind.
04:44Now let's talk a little fast.
04:46I have been thinking about the universal gravitational constant for a long time.
04:51Have you ever wondered why it is called universal?
04:56If so, that would be great.
04:58G is called the universal constant because its magnitude does not depend on the magnitude of the objects or the medium of the objects.
05:07That is, two objects, air or water, will experience the same magnitude for any medium for the same distance.
05:16In this regard, the universal gravitational constant is not just universal.
05:22It is a fundamental constant.
05:26That is, G cannot be obtained with the help of any other constant.
05:31Other constants can be obtained with the help of G.
05:35An example of such a fundamental constant is the Planck constant.
05:44We will learn more about the Planck constant in our next video.
05:51To be honest, the scientists who could not explain the meaning of all these constants,
05:55have been referred to as fundamental constants.
05:59If we know that the magnitude of G is 6.67 x 10-11 kg-1 m3sec-2,
06:09but we still do not know why it is 6.67.
06:13That is why it is a fundamental constant.
06:16The proof of G is incomprehensible.
06:18Not only in Newtonian mechanics, but also in Einstein's theory of relativity, it can be used.
06:25Planck's length, which is considered to be the shortest distance in relativity,
06:31can also be written as the magnitude of G.
06:35In fact, it is impossible to have a distance less than this in relativity.
06:41We can see that the formation of the universal gravitational constant has existed since ancient times.
06:47We will not be able to apply it to the rest of the universe.
06:50Now we will see how important a small g like a big G is in our lives.
06:55Stay tuned for the next episode of Abhikarsha Jyotaram.
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