The sun can be seen before the actual sunrise by abouta)2 minutesb)4 m...
The Sun is visible to us about 2 minutes before the actual sunrise, and about 2 minutes after the actual sunset because of atmospheric refraction. By actual sunrise, we mean the actual crossing of the horizon by the Sun. Fig. shows the actual and apparent positions of the Sun with respect to the horizon. The time difference between actual sunset and the apparent sunset is about 2 minutes. The apparent flattening of the Sun’s disc at sunrise and sunset is also due to the same phenomenon.
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The sun can be seen before the actual sunrise by abouta)2 minutesb)4 m...
The Sun can be seen before the actual sunrise by about 2 minutes.
The phenomenon of seeing the Sun before it actually rises is called "atmospheric refraction." Atmospheric refraction occurs because the Earth's atmosphere acts like a lens, bending the path of light from the Sun as it enters the atmosphere. This bending of light causes the Sun to appear slightly higher in the sky than its actual position.
Explanation:
Atmospheric Refraction:
- Atmospheric refraction occurs due to the variation in the density of the Earth's atmosphere.
- The Earth's atmosphere is made up of several layers, each with a different density.
- As sunlight enters the atmosphere, it passes through these layers, and each layer causes the light to bend slightly.
- This bending of light is responsible for various optical phenomena, including the apparent position of the Sun.
Apparent Position of the Sun:
- The apparent position of the Sun is the position where it appears to be in the sky when observed from the Earth's surface.
- Due to atmospheric refraction, the apparent position of the Sun is slightly higher than its actual position.
- The amount of displacement depends on several factors, including the altitude of the observer and the atmospheric conditions.
- On average, the Sun appears to be about 0.5 degrees higher than its actual position due to atmospheric refraction.
Time Difference:
- The time difference between the actual sunrise and when the Sun becomes visible is approximately 2 minutes.
- This time difference can vary depending on factors such as the observer's location, atmospheric conditions, and time of the year.
- The 2-minute time difference is an average estimate and may not be accurate in all situations.
Conclusion:
- The Sun can be seen before the actual sunrise by about 2 minutes due to atmospheric refraction.
- This phenomenon occurs because the Earth's atmosphere bends the path of light from the Sun, causing it to appear higher in the sky than its actual position.
- This time difference can vary depending on various factors but is generally around 2 minutes.
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