gravity and space time

[PSB]

I am really, really&nbsp;new to all this and was wondering if anyone could clarify the following for me - is gravity an actual force or is there no actual 'pull' but just rather a 'push' of space-time, and&nbsp;do the same rules apply on earth as in space?&nbsp; <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I am really, really&nbsp;new to all this and was wondering if anyone could clarify the following for me - is gravity an actual force or is there no actual 'pull' but just rather a 'push' of space-time, and&nbsp;do the same rules apply on earth as in space?&nbsp; <br />Posted by PSB</DIV><br /><br />Not sure if this will make sense, but the best sense of current theories is that mass bends space-time, so it's not a pull or push, but rather a different shape. </p><p>Welcome to Space.com!!</p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[aphh]

<p>Gravity is one of nature's principle forces, but it is not really a force-field in the same sense as an electromagnetic force. It is more like a geometry of space-time. <br /><br />Think of it a bit like stepping into a room with curved mirrors. You would see your image bent, but not because of any measurable force, but because of a geometry of the reflecting surface.</p><p>Gravity is inherently tied to mass.&nbsp;</p>

 

[PSB]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not sure if this will make sense, but the best sense of current theories is that mass bends space-time, so it's not a pull or push, but rather a different shape. Welcome to Space.com!! <br />Posted by MeteorWayne</DIV><br /><br />Yes, it does make sense and thanks for the welcome! <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<p>Gravity is currently regarded as a pseudoforce.&nbsp; Objects follow along a geodesic (straight line in curved space) path within a 4d manifold that is 'warped' by the mass within it.&nbsp; The more massive an object, the more it warps the spacetime manifold and thus the more curved the geodesic path becomes... this makes it seem as though the 'force' of gravity is stronger as it requires more acceleration to break free of that geodesic path.</p><p>Think of a bowling ball on a rubber sheet (2d manifold) and roll a marble passed it.&nbsp; The bowling ball isn't physically attracting the marble, rather the marble is following a path around the bowling ball.&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>