If you know that light. must always follow the geodesic, and that light is following a curve, then that automatically implies that space must be curved, since a geodesic in flat space is a straight line.02-Nov-2019
Does light travel in a geodesic?
A null path is a path through your spacetime whose tangent vector is always null. A null geodesic is a null path that happens to also be a geodesic. Light travels along null geodesics.
Does light follow the curvature of spacetime?
Light travels through spacetime, which can be warped and curved—so light should dip and curve in the presence of massive objects. This effect is known as gravitational lensing GLOSSARY gravitational lensingThe bending of light caused by gravity .
Why do particles follow geodesics?
Geodesic motion is simply a statement of Newton's first law, that in an inertial reference frame, inertial objects remain at rest or in uniform motion in a straight line. Curvature of spacetime means that, on larger distance scales, inertial objects follow curved paths, like the orbit of the moon about the Earth.
Is gravity a geodesic?
The concept of "gravity" is then that objects are falling along the bending of spacetime. The path that objects follow is called a "geodesic".
What is the speed of light in seconds?
The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 feet) per second. That's about 186,282 miles per second — a universal constant known in equations as "c," or light speed.
What is a timelike path?
My understanding of a timelike path, is one which always stays inside a light cone, defined by lines with gradients c and -c that cross at the origin. What does it mean to say that time coordinate itself is timelike or spacelike (and the same for space-coordinates?)
Can gravity bend time?
Gravitational time dilation occurs whenever there is difference in the strength of gravity, no matter how small that difference is. The earth has lots of mass, and therefore lots of gravity, so it bends space and time enough to be measured.
Does light have mass?
Light has no mass so it also has no energy according to Einstein, but how can sunlight warm the earth without energy? Light indeed carries energy via its momentum despite having no mass.
What does geodesic mean in physics?
In general relativity, a geodesic generalizes the notion of a "straight line" to curved spacetime. Importantly, the world line of a particle free from all external, non-gravitational forces is a particular type of geodesic. In other words, a freely moving or falling particle always moves along a geodesic.