Yes, gravity does cause relativistic effects such as time dilation. According to Einstein's theory of general relativity, gravity is not just a force but a curvature of spacetime caused by massive objects.
In the presence of a gravitational field, time runs slower in regions of stronger gravity compared to regions of weaker gravity. This phenomenon is known as gravitational time dilation. It means that clocks in a stronger gravitational field tick slower relative to clocks in a weaker gravitational field.
For example, if you were near a massive object like a black hole, where the gravitational field is extremely strong, time would pass more slowly for you compared to someone far away from the black hole. This effect has been observed and measured in various experiments, including with atomic clocks on Earth and high-precision measurements in space.
The strength of the gravitational time dilation depends on the intensity of the gravitational field. The closer an object is to a massive body or the stronger the gravitational field it experiences, the more pronounced the time dilation effects become.
Gravitational time dilation has practical implications as well. For instance, it is taken into account in the operation of the Global Positioning System (GPS). Satellites in orbit around the Earth experience weaker gravity compared to observers on the ground. As a result, their onboard clocks run slightly faster. To ensure accurate GPS positioning, this relativistic effect must be accounted for in the satellite's timing systems.
So, in summary, gravity does cause relativistic effects like time dilation, and this has been experimentally verified and observed in various scenarios.