# Does time dilation cause gravity as explained in this video?

Watch it around 2:00 minutes. https://youtu.be/gcvq1DAM-DE

Do objects move closer to Earth because they experience time at different rates, really? Does it make sense? The video also represents the object kind of rotating, when in reality they would just fall straight to Earth, right? What is the best way to explain gravity in layman’s terms? In this sense, the rubber sheet analogy makes much more sense...

Edit: trying to explain more what’s in the video... the uploader argues that objects move closer to Earth because they experience time differently, so they kind of rotate. It’s difficult to explain more because most of my problems with the video are with the graphical representations and not so much with what’s being said.

Edit 2: changed the title of the question as well.

• Hi Roberto, I hope you get an expert answer, but I can only agree with the shortcomings of the rubber sheet model emphasised in the video. His videos are not physically rigorous, in a lot of areas, but personally I think you have a better chance of getting an answer by, rather than asking people to look at a video (lots won't), instead put the subtitles from the video into your post. I say this because, no offence, I don't think you have fully followed his assumptions. This will improve it a lot, imo. – user175021 Nov 14 '17 at 21:57
• The video has clear disclaimers on where it is not physically rigorous. With this in mind, the video is correct. According to the Least Action Principle, stuff is "lazy" and moves to where energy is lower. Time and energy are Fourier conjugates (two sides of the same medal). Thus energy is lower where time moves slower. So yes, stuff moves to where time moves slower. Also, this is fully equivalent to the "rubber sheet" view, because the curvature on the sheet represents the speed of time. See this: physics.stackexchange.com/q/350854 – safesphere Nov 14 '17 at 22:08
• Related: physics.stackexchange.com/a/13839/2451 , physics.stackexchange.com/q/90592/2451 and links therein. – Qmechanic Nov 14 '17 at 22:16
• @safesphere you could put that (great) comment as an answer. I was a bit worried that, although his videos are imo, far better than most, on other videos he claims the total energy of the universe is conserved and that the laws of physics are not observed, (wrt virtual particles). Natch, of course, I can't now find those videos, (momentum and angular momentum in the universe). But you have, imo given an answer to this question. – user175021 Nov 14 '17 at 22:29
• Just adding more to the discussion. I found another link who disputes what’s being said in this video as well: physicsforums.com/threads/… – Roberto Valente Nov 14 '17 at 22:31

There is much to dislike about the popularized video, but its basic idea isn’t far from the truth. If you work through the equations of weak-field GR, you will find that ${{g}_{00}}$, which measures the rate of passage of proper time (i.e., aging) along a world-line relative to coordinate time, can be identified with $1+2\Phi$, where $\Phi$ is Newton’s gravitational potential. The geodesic equation predicts the same deflection of trajectories as Newton’s equation of gravitational force.