- Trending Categories
- Data Structure
- Operating System
- MS Excel
- C Programming
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
By how much time the day would have been shorter if the earth had no atmosphere?
Due to the earth's atmosphere, light coming from the sun gets refracted and it appears two minutes before it is actually above the horizon (advanced sunrise). Also, it can be seen about two minutes even after it is actually below the horizon (delayed sunset). Thus, the time from sunrise to sunset is increased by about four minutes because of the refraction of sunlight through the earth's atmosphere.
So, if the earth had no atmosphere, then the length of the day would have been shorter by about four minutes.
Due to the refraction of sunlight caused by the atmosphere, we can see the sun 2 minutes before it's actually above the horizon (advanced sunrise), and 2 minutes even after the actual sunset (delayed sunset).
This happens because when the sun is slightly below the horizon, then the sun's light coming from the less dense air to more dense air is refracted downwards as it passes through the atmosphere. Thus, due to this atmospheric refraction, the sun appears to be raised above the horizon when actually it is slightly below the horizon.
- Related Articles
- If there was no air on the earth, would air travel by aeroplanes, helicopters be possible?
- The atmosphere is held to the earth by?
- Why is the atmosphere much rarer on the moon than on the earth?
- A train covered a certain distance at a uniform speed. If the train would have been 10 km/h faster, it would have taken 2 hours less than the scheduled time. And, if the train were slower by 10 km/h, it would have taken 3 hours more than the scheduled time. Find the distance covered by the train.
- How much time does the sunlight take to reach on the earth?
- A train covered a certain distance at a uniform speed. If the train could have been 10 km/hr. faster, it would have taken 2 hours less than the scheduled time. And, if the train were slower by 10 km/hr; it would have taken 3 hours more than the scheduled time. Find the distance covered by the train.
- The day is longer on the earth by about 4 minutes because:(a) the earth is round in shape (b) the earth rotates on its axis(c) the earth revolves around the sun (d) the earth has atmosphere
- How much time does the sunlight take to reach the surface of Earth?
- An article is sold at a gain of 15%. Had it been sold for â‚¹27 more, the profit would have been 20%. Find the cost price of the article.
- What would happen if the ozone layer in the atmosphere completely disappears?
- How much time it takes for moonlight to reach the earth's surface?
- A student claims that because of atmospheric refraction, the sun can be seen after it has set, and the day is, therefore, longer than if the earth had no atmosphere.(a) What does the student mean by saying that the sun can be seen after it has set?(b) Do you think that the students conclusion is correct?
- The present ages of Sunita and Anita are in the ratio $3:5$. If Sunita had been $4$ years older and Anita $4$ years younger, the age of Sunita would have been $3$ times the age of Anita. Find their present ages.
- Sunset is red because at that time the light coming from the sun has to travel:(a) lesser thickness of earth's atmosphere (b) greater thickness of earth's atmosphere(c) varying thickness of earth's atmosphere (d) along the horizon
- A train travels 180 km at a uniform speed. If the speed had been 9 km/hour more, it would have taken 1 hour less for the same journey. Find the speed of the train.