It does. You have an X-axis, a y-axis and a z-axis for a coordinate system of 3 dimensions. Or, to make it familiar to you, one can travel along the east-west axis, the north-south axis or the up-down (some prefer to use the term "inward-outward" instead) axis or a combination of all three. Momentum can be measured for all three and it can come to zero for any one or all three if you just remain put and do not move with respect to earth. But you are still displaced through time when you sit still. You do not stop aging and neither does rock lying on the ground. when time is the dimension that your energy is most displaced, then time has a positive sign and all the three spatial dimensions have a minus sign in front.No it is along a geodesic. No. The proper time is fixed, the coordinate time is not. If all of time were fixed then muons in a lab would decay no slower than those created by cosmic ray collisions with the earth's atmosphere which should never make it to earth's surface. Yet, they do and their decay rate, their time is different. If time dilation was not valid, old CRT TVs would not be focused.You cannot alter its proper timeNope. Sorry, the universe is a special frame of reference. You still fail to understand Einstein's hypotenuse.You need to study Einstein's clock towers and how they function.So you are telling me that you cannot travel northeast and uphill or downhill at the same time? That is momentum in 3 spatial dimensions.All axes are axes of volume in three dimensions.Don't you really mean that I cannot move without going through it? You seem to be implying that I am taking space-time with me. That does not happen. space-time is not at rest with respect to me. Only my reference frame is. Is English your native tongue? It doesn't sound like it.That is not an example of relativity. Instead, put a float in a homecoming parade going down the street. Two people are playing catch with a photon while riding on the float and the photon's path is at a right angle to the motion of the float. The photon moves at speed c.

You are standing along the road and measure the displacement of the photon differently than the two playing catch do on the float. They simply see the photon moving straight forward and backward. Their coordinate system is the float, sharing their motion. Your coordinate system is on the ground, where you share its motion. You don't measure the displacement of the photon going in any straight back and forth travel as they do. You measure the photon to take a zig-zag path. Those zig-zags are hypotenuses of right triangles while they just have heights to triangles. The photon travels at speed c to you and it travels at speed c to them. But the very same photon takes a longer journey in your frame of reference than it does in their. Since time is equal to space divided by speed and speed is the same for both, then time and space is changed for each. Yet, it is the same photon.Momentum of the volume of what? If you mean "mass" then you are right. If you mean light then you are wrong. Photons do not age. They do not travel through time. The stars above your head are the proof. We are seeing them as they were many years ago. The photons that left your body in some old photo you have of yourself as an infant are still traveling and spreading outward at speed c. The image of your face has weakened and obey the inverse square law just as the distant stars do to you. But they are still there are they are bring the message of your birth to some civilization billions of light-years away.Why are you trying to take on relativity? There are more experiments that vailidate it than there are nails pounded into wood by carpenters in the history of the human race. Only quantum physics has more vailidation. Go to www.teach12.com and take up a video course in science for non-scientists. Then pick up a physics textbook and start working out some problems. After that..?