Why is earth's rotation period < 24hrs

  • Thread starter Thread starter dowjonez
  • Start date Start date
  • Tags Tags
    Period Rotation
Click For Summary
SUMMARY

The Earth's rotation period is approximately 23 hours and 56 minutes, leading to a discrepancy with the 24-hour day used in clocks. This difference arises from the need to align timekeeping with the Sun, which is essential for biological rhythms. As the Earth orbits the Sun, it must rotate an additional degree each day to maintain its position relative to the Sun, resulting in a solar day that is about four minutes longer than a sidereal day. This phenomenon is crucial for understanding timekeeping and its relationship with celestial movements.

PREREQUISITES
  • Understanding of Earth's rotational dynamics
  • Basic knowledge of celestial mechanics
  • Familiarity with the concepts of solar and sidereal days
  • Awareness of timekeeping systems
NEXT STEPS
  • Research the difference between solar and sidereal days
  • Explore the concept of Earth's axial tilt and its effects on timekeeping
  • Learn about the historical development of timekeeping systems
  • Investigate the impact of Earth's orbit on seasonal changes
USEFUL FOR

Students, educators, astronomers, and anyone interested in the relationship between Earth's rotation and timekeeping practices.

dowjonez
Messages
21
Reaction score
0
Hey anyone who can give me a hand. I've been racking my brain over this question my teacher told me to think about for next class. Its not worth any marks or anything but it might impress him. I would rather ask here then google it. Why do we use a 24hrs on our clocks if the rotational period of the Earth is 23 hrs 56 minutes?
 
Physics news on Phys.org
The difference has to do with whether you want to define the rotation of the Earth with respect to the sun, or with respect to the distant stars. Maybe you should find out what one 365th of a day is, in minutes.

Carl
 
its about 3.9xxx minutes thanks carl
 
It's much more convenient for us to use the Sun as a reference for keeping time, since our biological behavior is inextricably linked to it.

On the other hand, we're moving around the Sun about one degree per day, while we practically don't move at all with respect to the very distant stars. This means that every day, the Earth has to turn about one degree further to return to the same position relative to the Sun as it does to return to the same position relative to the distant stars. That extra one degree of rotation takes about four minutes to complete, making the solar day about four minutes longer than the sidereal day.

- Warren
 

Similar threads

Replies
7
Views
2K
Replies
10
Views
3K
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
10K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 10 ·
Replies
10
Views
4K
  • · Replies 2 ·
Replies
2
Views
4K