What is frame of reference?

By definition we know that The frame of reference is defined as any coordinate system with respect to which one can study the motion of the another object. For example, a moving car can be a frame of reference with respect to which anyone can study the motion of another moving car by being in the first moving car itself.

All About Gravity Explained, The Mystery of Space-Time Relativity Part 1----------https://youtu.be/7CeNjYzpmgM

SPACE TIME MYSTERY EXPLAINED, The Mystery of Space-Time relativity Part 2----------https://youtu.be/s7VbXhD73bQ

But before understanding this lets understand a case.

Let us say a car is moving on a highway with a speed of 100km/hr. Now while calculating the speed of the car, we are completely ignoring the fact that the earth’s surface is rotating at the equator at about a speed of 1670km/hr and also the velocity of earth’s orbit around the sun is about 30km/sec and the sun along with the solar system is moving round in the milky way at a speed of 20km/sec and the milky way galaxy is moving towards the Andromeda galaxy in the universe at about a speed of 230km/sec.

So with all this motion going around if we calculate the speed of the car with respect to the universe, we will get that the car is moving with tremendous speed as all the speed of the earth,sun, solar system, galaxy getting added. So here the frame of reference comes into play.

Let’s understand this mathematically.

Now if we take the frame of reference inside the earth, then the earth seems to be stationary hence the speed of car is 100km/hr.
Now if we take our frame of reference from outside the earth say from the moon then we would see the car is moving with a speed of 100+1670=1770km/hr where the speed of car and the rotating speed of the earth gets added.

Now if we take our frame of reference with respect to the sun, we will get the speed of the car as 100+1670+108000=109770km/hr. one hundred nine thousand seven hundred seventy

Now if our frame of reference is with respect to the galactic centre of the milky way then we get the speed of the car as 100+1670+108000+72000=181770km/hr. one hundred eighty-one thousand seven hundred seventy

Now with respect to the universe we get the speed of the car as 100+1670+108000+72000+828000=1009770km/hr which is approximately equal to One million ten thousand km/hr.

So that’s a lot of speed to imagine.

But for us the car doesnot appear to be of that huge speed but it appears to be about 100km/hr this is because of frame of reference as the observer is in the frame of reference inside the earth and for the observer, the earth is stable. This is what frame of reference is.

Hope you understood what frame of reference is. There are two types of frame of reference Inertial frame of reference and non-inertial frame of reference. We will discuss about them briefly in our next video. And stay tuned for our next video of the series The Mystery of Space-Time Relativity which will be on