Earth's rotation

[NitroBall]

Earlier this week i was checking up on my 11 year old lad, making sure he was doing some revision for his exams.
I noticed he was revising from his text book on physics. Looking at the page he was reading from, the info in the printed text book states the planet we live on (Earth) rotates 23 hours and 56 minutes each day.

Now i never really got along with school or teachers, apart from PE. So im there asking my lad where does the other 4 minutes go in the day ? And yes i seriously asked that question to a 11 year old. Poor lad looked at me in a puzzled way, and couldnt give me a deffinate answer, its been bugging me for the past 3 days.

So does anyone know where the other 4 minutes go

 

[robof9]

Earlier this week i was checking up on my 11 year old lad, making sure he was doing some revision for his exams.
I noticed he was revising from his text book on physics. Looking at the page he was reading from, the info in the printed text book states the planet we live on (Earth) rotates 23 hours and 56 minutes each day.

Now i never really got along with school or teachers, apart from PE. So im there asking my lad where does the other 4 minutes go in the day ? And yes i seriously asked that question to a 11 year old. Poor lad looked at me in a puzzled way, and couldnt give me a deffinate answer, its been bugging me for the past 3 days.

So does anyone know where the other 4 minutes go

if it has been bugging u for 3 days it is 12 mins now

 

[Darkwerks]

You get your 4 minutes back every four years- 29th of February on a Leap Year.
A common year is 365 days = 8,760 hours = 525,600 minutes = 31,536,000 seconds.

A leap year is 366 days = 8,784 hours = 527,040 minutes = 31,622,400 seconds

 

[pyroLX]

but four minutes every day for 4 years makes it 5840 minutes lost, while on a leap year you only get 1440 minutes back.

I guess it is just a typing error, you'd notice a 2 hour change in the Time / daylight relation in a month (30 days x 4 minutes = 2 hours)

And then you have the +-1 hour adjustments every year..

edit: found that: http://novan.com/earth.htm
not quite sure it is one of those "reliable" sources though.

 

[Tom Allen]

I guess it's not a constant thing, as the other planets will make our orbit around the sun vary a little bit.

Any change in the mass of the earth will also make changes to the orbit.

 

[Rider]

have you noticed that the sun doesn't rise and set at the same time every day, but that it creeps a little every day?

combined effect of a not-quite-24-hr rotation and the fact that the axis of rotation changes in relation to the sun a little every day.

there is an animation on the web somewhere about how it all works......i remember showing it to a 2nd year class last year.........

 

[Tom Allen]

you've got to remember which is the constant force, and that's the sun. We revolve around the sun and the moon revolves around us. Time is only relative to these factors.

 

[Tom Allen]

Here's another wierd one, as there's 12 months in the year and January is the 1st month and december is the last month explain this.

1. January
2. February
3. March
4. April
5. May
6. June
7. July
8. August
9. September - Sept = seven
10. October - Oct = eight
11. November - Nov = nine
12. December - Dec = ten

It seems December was the 10th month

 

[Rider]

roman calendar only had 10 months of 30 or 31 days.
winter was extra days beyond those calendar months.

Martius (31 days)
Aprilis (30 days)
Maius (31 days)
Iunius (30 days)
Quintilis (31 days)
Sextilis (30 days)
September (30 days)
October (31 days)
November (30 days) and
December (30 days

 

[SAMUEL.D.RYAN]

The measure of a second (which is defined as a number of periods of radiation of a certain specification of caesium atom) changes as technology progresses.

Originally a minute would have been just some division of an hour, and it would have been undefined. As soon as someone found a way to divide an hour into 60, they called any division of a minute a second. Then they eventually defined a second etc.

As said above, the "not-quite-24-hr rotation" means we have to compensate to the nearest minute, I suppose. It's not quite 4 mins a day though, i'm sure.