State the method by which heat is transferred :
from the sun to the earth.

Answer

To answer the question regarding the method by which heat is transferred from the Sun to the Earth, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Source of Heat**: The Sun is the primary source of heat for the Earth. It emits energy in the form of light and heat.

2. **Understand the Medium of Transfer**: The space between the Sun and the Earth is a vacuum. A vacuum is an area that does not contain matter, which means there are no particles to facilitate heat transfer through conduction or convection.

3. **Recognize the Methods of Heat Transfer**: There are three main methods of heat transfer:
- **Conduction**: Transfer of heat through direct contact between materials.
- **Convection**: Transfer of heat through the movement of fluids (liquids or gases).
- **Radiation**: Transfer of heat in the form of electromagnetic waves.

4. **Determine the Applicable Method**: Since there is a vacuum between the Sun and the Earth, conduction and convection cannot occur. Therefore, the only method of heat transfer that can take place in a vacuum is radiation.

5. **Conclude the Answer**: The heat from the Sun reaches the Earth primarily through radiation.

### Final Answer:
The method by which heat is transferred from the Sun to the Earth is **radiation**.

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