Gravity

• Does Time Dilation Cause Gravity? What General Relativity Says
  Gravitational time dilation is linked to gravity and can help describe it, but it is not the whole cause: gravity is spacetime geometry.
• Does Gravity Slow the Expansion of the Universe?
  Gravity from matter and radiation decelerates cosmic expansion, but dark energy now causes the universe’s expansion to accelerate.
• How Is the Strong Equivalence Principle Stronger Than the Weak One?
  The strong equivalence principle extends universal free fall to self-gravitating bodies and gravitational experiments; here is how it differs from the weak principle.