How does light speed up after slowing down?

Question: Light slows down when it enters water or a glass (causing it to bend) but how does it return to its original speed?

It's either HAARP, or The Powers That Be influence the light through various social/political psy-op agendas, like Beyonce videos and Kanye West.



Welcome.

reply to post by mike365


Im quite sure lightspeed is relative to gravitational effect, light is slowed down by relective matter but its speed stays constant if it isnt blocked by Solid matter.

reply to post by PaidDisinfoAgent


Well think of it like.....when you open up a parachute you slow down your fall but if you re-close it you will go back to the same speed you were falling down.
And Inevitability die...

Doesn't light travel through water 30% slower?

It might be water or some sort of gas im not sure. So would light immediately speed back up after passing through say a glass of water?

But im also interested in how light speeds back up after slowing down.

reply to post by mike365


The speed of light in a given medium is inversely proportional to permittivity multiplied by permeability. Permittivity is the ability of the medium to sustain an electric field. Permeability is the ability of the medium to sustain a magnetic field.
Specifically,

c = 1/sqrt(ue)

where,
c is the speed of light
u is the permeability
e is the permittivity

A vacuum has both the lowest possible u and e values, so it has the highest possible c value. Other media have higher values of u and e, which decreases the speed of light through them.

Light doesn't really speed up once it enters a medium with a lower refractive index, as if it's a physical object travelling through the different media. Rather, the light is able to self-propagate faster, due to the new medium's greater ability to sustain electric and magnetic fields.

It is still traveling at light-speed it is just that it takes the light longer to pass trough the medium bouncing it's way trough it. Between the bounces it is still traveling at light-speed.

There is still confusion over what light is in the first place. Is it a particle, a wave or both?