1. What is Speed of Light in a Medium?

Definition: This calculator determines how much light slows down when traveling through a transparent material.

Purpose: It helps physicists, engineers, and students understand light behavior in different materials.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( S \) — Speed of light in medium (m/s)
• \( c \) — Speed of light in vacuum (299,792,458 m/s)
• \( n \) — Refractive index of the medium (unitless)

Explanation: Light slows down in proportion to the medium's refractive index.

3. Importance of This Calculation

Details: Understanding light speed in materials is crucial for optics, fiber optics, lens design, and many technologies.

4. Using the Calculator

Tips: Enter the refractive index (must be ≥ 1). Common values: ~1.0 for air, ~1.33 for water, ~1.5 for glass.

5. Frequently Asked Questions (FAQ)

Q1: Why does light slow down in a medium?
A: Light interacts with atoms in the material, being absorbed and re-emitted, which creates an effective speed reduction.

Q2: What's the fastest light can travel?
A: In vacuum (n=1), light travels at 299,792,458 m/s - the universal speed limit.

Q3: Can refractive index be less than 1?
A: Normally no - this would imply faster-than-light travel which violates physics laws.

Q4: How is refractive index measured?
A: Typically by measuring the angle of light bending (refraction) at a material's surface.

Q5: Does this apply to all light wavelengths?
A: No, refractive index varies with wavelength (dispersion) - this calculator assumes a single wavelength.