Light speed {speed of light} {light speed}| is the same relative to any observer, moving or not. Light speed is invariant and absolute, in space with no electric fields.
speed
Light speed depends on electric-force strength, which determines electromagnetic-induction strength. In vacuum, light speed is 3.02 x 10^8 m/s (Hippolyte Fizeau and Bernard Foucault) [1849]. Light speed is fast, because electric forces are strong. All zero-rest-mass particles travel at light speed, because added energy does not affect them. Gravity does not affect zero-rest-mass particles.
space
Light does not travel through time, because it has no medium and so no reference frame or space-time. Light only travels through space, not time. Light has zero time.
cause
Observers see invariant speed, because light never has time component and so cannot go slower. Light cannot go faster, because it uses all of space already. When observers see light, light length appears to be zero and time appears to be at maximum dilation. Observer motion does not affect light speed observed, because light has no medium. Observer motion contracts length and dilates time, but light already has maximum length and shortest time. If observer moves at higher velocity, both time dilation and space contraction happen, so light speed stays the same.
space-time velocity
All objects travel through space-time at light speed. Light travels only in space. Stationary objects travel only in time. Moving masses travel in space and time.
terminal velocity
Light speed is like terminal velocity through space-time. Electromagnetic induction pushes wave, and forces in universe retard wave. Resistance to light motion can come from effects of all universe masses and charges.
mass
No object with mass can go faster than light. For mass at light speed, stationary observers see infinite mass, zero length, and zero time. To make infinite mass requires infinite energy. Infinite mass exerts infinite gravitational force. Infinite mass attracts and red-shifts light, dimming universe. Infinite mass, moving at light speed, appears to have infinite frequency and zero wavelength.
phase velocity
Light pulses contain wave sets. Light-pulse envelope carries energy. Envelope speed {group velocity} must be light speed or less. However, individual waves can have speed higher or lower than light speed {phase velocity}. Negative refraction cannot exist.
Physical Sciences>Physics>Wave>Electromagnetic
5-Physics-Wave-Electromagnetic
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Date Modified: 2022.0224