So is this true about time travel?

[RonMaverick]

Is it true that you can only go back in time to the day the time machine was built if you're traveling from the future?&nbsp; So the common myth of seeing Dinosaurs and ourselves at 2 years old impossible? <div class="Discussion_UserSignature"> </div>

 

[oklahoman]

<p>One current hypothesis about a method that may or may not be possible postulates this.&nbsp; If time travel is possible at all, some physisists think this is the way it would be.</p><p>The physical requirements for the hypothetical machine&nbsp; are such a daunting task that it is all science fiction at this point, though, requiring the ability to manipulate huge masses greater than the sun and create probably impossible stuff like negative energy. </p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<font size="2">Time travel to the past via a time machine would violate the first law of thermodynamics.&nbsp; If you traveled back in time and suddenly appeared, you would be adding to the total energy to that universe.</font> <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>