# Is Mechanics applicable in Space?

1. May 31, 2013

### Pushpam Singh

Please explain the term "mechanics and space" and then explain if Mechanics is applicable in Space.
My friend says that since there is no atmosphere and gravitation,Mechanics cannot be applied applicable in Space.
I know that Mechanics is applicable in Space, but I couldn't make her understand it.
So, please prove it with this regard.

2. May 31, 2013

### Staff: Mentor

Mechanics is basically Newton's 3 laws. Where does the atmosphere enter in to any of Newton's 3 laws? If there is no place in Newton's 3 laws for the atmosphere then its presence or absence doesn't impact mechanics.

3. May 31, 2013

### ZapperZ

Staff Emeritus
How do you (or your friend) think we are able to send space crafts to land or fly through other planets, or predict movements of celestial bodies? Via astrology?

Zz.

4. May 31, 2013

### mikkelh

As already indicated, the presence of atmosphere has nothing to do with mechanics (except, of course, that atmosphere must conform to mechanics). Similarly, the presence of gravity does not have a direct connection with mechanics either, although it does determine a frame of reference which mechanics operates under (it is an existing force, which must be balanced out with other applications of force).
It should be pointed out, however, that gravity is NOT, in fact, absent in space. gravity is present throughout the universe. Scientists use the term "microgravity" to more accurately reflect the gravitational environment in space...the gravity is there, but it is not locally measurable, because you are locked into its frame of reference. In order to measure its effects, you must measure the relative motion of objects outside your immediate frame of reference (for example, the earth does not "feel" the sun's gravity, as there is no means to locally determine its strength... however, the presence and strength CAN be measured by observing the circular path of the Earth in relation to the sun and other stars).

5. May 31, 2013

### Jorriss

I barely know how to use mechanics if it's not in space lol.

6. May 31, 2013

### SteamKing

Staff Emeritus
Obviously, the Laws of Physics don't apply outside of the city limits.