Time is undoubtedly real. If I were to ask you to meet me somewhere, we would be utterly lost without some reference to time. If you have school at 8 am, and show up at 9 am, you are late. Now in regards to whether it is illusion or not, the answer can be reached if you accept the normal conventions that we exist, and have knowledge of our surroundings and don't dispute the otherwise trivial facts by which we live.
The real phenomenon, according to einstein, is not whether or not time exists, but how it interacts with reality. Also, you said
einstein and newton describe spacetime as a force that effects us all, like gravity. Does it really though? how so if so?
Oddly enough, it is gravity that affects spacetime
Here's a good example of how time affects things
First, imagine a rocket ship with a man inside sitting down, moving very fast in one direction, close to the speed of light. Unfortunately, our fellow needs to turn around (he couldn't use google earth to get where he was going and as such took a wrong turn), so he turns on its big ol' rocket thrusters (with a constant thrust of course and enough fuel to last a very very long time) and starts to slow down and go the other way (imagine this on a single line, 1 dimension). Since the speed of light is the speed limit of sorts of our universe, our rocket is never quite going to reach it, but the important part here is it's going to move on a hyperbola, which never reaches the speed of light. So what do we have here? The object wth a constant acceleration moves on a hyperbola. Now consider a person sitting on the surface of a planet. He, while sitting down on a chair on a planet will feel the exact same force on his bum that an astronaut in our rocket ship would feel while his ship is turning around. Now, consider our second fellow sitting on the planet. He happens to have a small box with a third tiny fellow inside, which he then throws up in the air (straight up, 1 dimension) for the purposes of scientific experiment, despite the inherent danger to the tiny fellow in the box. Now, it makes sense that the box is going to go up, then come down on a parabola. You know, Y = VoT- )1/2)gT². Standard Newtonian equation for motion in one dimension. Now, why do we have three fellows here and how do they relate to time? The first fellow is just to show a similarity to the second fellow, and a difference to the third fellow. If each fellow were to hold onto an accelerometer, the first two would show a reading, and the tiny third fellow (excepting the instant he was actually thrown) would not. (If this seems wrong to you, consider if the tiny fellow in the box just magically appeared and started falling, his accelerometer wouldnt show a reading because it's moving with him). Now, the fellow in the rocket ship, and similarly, the fellow on the chair on the planet are moving on a hyperbola with respect to spacetime because they are accelerated. The third tiny fellow is not accelerated. If we take the fellow in the chair and the tiny fellow (the rocketman served his purpose of relation already) and examine them, we find that the fellow in the chair sees the tiny fellow moving on a parabola and the tiny fellow sees the man in the chair moving on a hyperbola. How can this be? It is because their times are different. So gravity has an effect on time as well. Since we have mass, we have gravity, and can actually affect time
Not only does time affect us, but we affect time.. So yes, there is a quantitative effect to time. It's sort of like adding vectors: you have to account for gravity and the speed of light and the reference frame and if you mix them all together the right way you get the resultant vector time.
None.
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