I got a science project I need help my topic is "Speed if light in liquid"
Answers
How fast does light travel, and does it travel faster in water or air? The fastest thing in the whole universe is the speed of light in a vacuum (like outer space!), clocking in at a great 2.99 x 108 m/s. Light travels in waves, and we call this traveling propagation. Propagation of waves has both a speed and a direction, called the velocity. The velocity of light changes depends on the material it travels through.
Light waves can be changed in a few different ways. Reflection is when the waves bounce off a surface and change direction, like when they hit a mirror or pool of water. Diffraction spreads out light waves; an example of this is water vapor in the air diffracting light from the sun to create a rainbow. The third type of light behavior is refraction. Refraction is where light waves pass through a material (what scientists call a medium) and change direction. Have you ever stuck your arm beneath the surface of the water in a fountain or swimming pool, and wondered why it looks like it has a sharp bend in it right at the surface? This is because of refraction!
Answer:
The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its exact value is defined as 299792458 metres per second (approximately 300000 km/s (186000 mi/s)[Note 3]). It is exact because by international agreement a metre is defined as the length of the path travelled by light in vacuum during a time interval of 1⁄299792458 second.[Note 4][3] According to special relativity, c is the upper limit for the speed at which conventional matter and information can travel. Though this speed is most commonly associated with light, it is also the speed at which all massless particles and field perturbations travel in vacuum, including electromagnetic radiation and gravitational waves. Such particles and waves travel at c regardless of the motion of the source or the inertial reference frame of the observer. Particles with nonzero rest mass can approach c, but can never actually reach it. In the special and general theories of relativity, c interrelates space and time, and also appears in the famous equation of mass–energy equivalence E = mc2.[4]