Every curious mind has lots of unanswered questions about our universe and celestial bodies. So let's begin the question answer session. Sir, I have read that due to collisions of other astronomical objects the orbits may change. So collision is a very what we and what you would understand by collision is a very specific restricted form of interaction and two things come and hit each other. But in astronomy this hitting need not be only with contact this pushing each other can be at a distance also gravitationally they push each other right or they attract each other. So, in physics we talk of collision as any modification of movement because of another object right. So, in that sense there is collisions happening all the time and as the Prasad said they could be small changes that we ignore at the moment because we cannot design it but cumulatively it can cause some very drastic change to happen after a million years. That is what happens in chaotic systems right. Small changes which are barely designable suddenly we lead to some big jump sometime in the future that could that can happen. It has mostly seen that astronomers they float in the space. Because there is only gravity is that. This is very little gravity very little micro gravity. No, but like my physics source said to me that because there is only gravity present. See for example if I stand here and push against the air right it generates a little bit of push again it pushes my body upwards a bit but gravity here is so strong that it makes no difference. So, I actually move but in space I go and move my hand right. The reaction to that is large enough to push me away because there is so little gravity you understand. It is the absence of gravity and of course anything else which makes the difference out there. Probably the fairest way to interpret your physics teachers answer is that this is the fact that you are floating around in space is purely because of the absence of it I mean or the fact that gravity is very very small but it can be explained purely with gravity. Nothing else that is all that is needed to explain it.