Recent content by thecosmos123456

why does light travels in a straight line?

special relativity says speed can be additive and subtractive ,our motion influences the speed , i did not get this part .how can our motion influence the speed of other object ?and how can speed be additive and subtractive

thank you

i wish to give physics mathematics and astronomy olympiad, how should I study for it? which books should i refer ?

the basic property of light is that ,it travels in a straight line but what causes it to travel in a straight line .in refraction of light ,what causes the refracted ray to bend towards the normal ,i am aware that it is related to velocity n material of medium but how does it influence the angle...

any books i should refer?

i wish to become a theoretical physicist but i am not that good in physics and mathematics,how should i improve in mathematics and physics

Inorder to start with calculus ,which topics in mathematics are required and are there any books for beginners to learn calculus?

when an object is thrown horizontally ,after some time when the effect of the applied force is less than the effect of gravity then it changes its path and bends towards the Earth and the path is called a parabola ,then in the same sense how can we define hyperbola?

but what causes gravity ,means what causes the particles to come closer to each other

we all know gravity but i was wondering how is it caused ? like in a nebula what causes the particles to come together and form a star or any object in the cosmos