A Year was 450 days and one day was 21 hours

www.spacedaily.com...

The Earth rotates once per day, but the length of this day varies. A year, 300 million years ago, lasted about 450 days and a day would last about 21 hours. As a result of the slowing down of the Earth's rotation the length of day has increased.

Professor Richard Holme, from the School of Environmental Sciences, studied the variations and fluctuations in the length of day over a one to 10 year period between 1962 and 2012. The study took account of the effects on the Earth's rotation of atmospheric and oceanic processes to produce a model of the variations in the length of day on time scales longer than a year.

Several have wondered if the days were shorter way back when but this particular study confirms the earths rotation is variable although trending to slower.

reply to post by 727Sky


I find this a very interesting topic.

I have always wondered if the Earth is eventually going to slow down until it stops rotating.

Also I read where huge earthquakes like the one in Japan, have an effect of speeding the Earth's rotation up.

www.nasa.gov...

So would this mean that while time slows us down, geological upheaval speeds us up, thereby creating a balance ensuring our Earth will continue rotating indefinitely?

reply to post by Caroline13456


Thanks for the reply. I posted another thread about the Earths core and some of the latest finding @ www.abovetopsecret.com...

(Phys.org) —We all know that the Earth rotates beneath our feet, but new research from ANU has revealed that the center of the Earth is out of sync with the rest of the planet, frequently speeding up and slowing down.

To me that is weird and I would have never thought such a thing possible

"It's stunning to see that even 10, 20 or 30 years apart, these earthquakes look so similar. But each pair differs very slightly, and that difference corresponds to the inner core. We have been able to use that small difference to reconstruct a history of how the inner core has rotated over the last 50 years," he said.

Amazing what can be found out with the scientific instruments at our disposal today and they scientist who can reason and use them!

Its called tidal drag and earth has two tidal drags.
The moon and the sun .even if earth didnot have a moon the earths spin would still be slowing down .Having a moon just makes this happen faster.
Billions of years from now EARTH its self will BE TIDAL LOCKED with one side always facing the sun just as the moon is tidal locked to earth with the same side always facing earth.
Ps that will be around the time our sun will havew become a red giant . Earth will be a very different place then . will life still be here under thous conductions?
((Ps any one have a delorean a friend of mine has a flux capaster we can go see what happens to earth .

450 years x 21 hours = 9450 hours
9450 hours / 24 hours = 393.75 days

So millions of years ago
the year was longer,
but the days were
much shorter.


Mike

reply to post by mikegrouchy

So millions of years ago the year was longer,

Yes. If you use one rotation of the Earth as a unit.
But using a variable quantity as a unit is not really a very good way of measuring anything.

Originally posted by Phage
reply to post by mikegrouchy

 

So millions of years ago the year was longer,

Yes. If you use one rotation of the Earth as a unit.
But using a variable quantity as a unit is not really a very good way of measuring anything.

Conceded,
and mea culpa.

I just wanted to translate it into
a unit I was more familiar with and get
a sense of the change in orbital velocity over the years.

The follow up question, for me, being
If the earth was orbiting slower,
was it further from the sun.

I would hazard a yes.

Implication in the form of a question:
Does that mean the earths' orbit is slowly decaying?



Mike

reply to post by mikegrouchy

Does that mean the earths orbit is slowly decaying?

Considering the amount of angular momentum that the Earth has, probably not a lot

But since the Sun has been gradually losing mass (through the Solar wind), that would imply that Earth's orbit would have expanded. Probably not a lot.

I've often wondered if a rather large chunk of space rock hit the Earth a Glancing Blow, roughly around the equator, and i mean something the size or say.. Germany. what would happen..?
Obviously it would go two ways, Earths rotation would either Speed up or stop completely and go the other way...But what would happen to us..

Yes the earths orbit is also slowing being drawn in twords the sun just like the decaying orbit of a earyt sat.
there is no perfict orbit for a body as the oposing forces pull and push at the planets evental the planets would also be pulled into the sun But for the fact this pulling ((orbit decay is so slow that the sun its self will have become a red giant first.
So yes earth orbot is closer to the sun now then say 500 million years agaio but then the suns out put was much higher 500 million years agaio as well.

Originally posted by Phage
reply to post by mikegrouchy

 

Does that mean the earths orbit is slowly decaying?

Considering the amount of angular momentum that the Earth has, probably not a lot

But since the Sun has been gradually losing mass (through the Solar wind), that would imply that Earth's orbit would have expanded. Probably not a lot.

True.

Now the question of what changes the angular momentum of the Earth,
or does it remain constant, is large in my mind.


Mike

The one thing I find odd about this article is the apparent decrease in the length of time it takes to perform one orbit of the Sun.

According to the SPACEDAILY article, it took approx. 9450 hrs to orbit the Sun once and it currently takes roughly 8765.8 hrs. That would indicate that in the last 300 million years either the average orbital speed of the Earth has increased or the orbit itself has decreased in distance covered.

Previous estimates have indicated that the length of day was 21.9 hrs and the year was approx 400 days long some 600 million years ago. This would indicate no significant change in the orbit of the Earth around the Sun between then and now.

Makes me wonder if the person who wrote the SPACEDAILY article misinterpreted the research results published in Nature.

Seems others have had a similar concern regarding the Earth's orbit since I started writing this comment.

Probably expansion of solar orbit instead of slowing or maybe both? I think that if earth were slowing it would be shrinking too?

If asymmetries in the Earth's core are that significant, I wonder if the Earth ever has operated like an "inertial propulsion" engine and moved, under its own power, so to speak, closer or further from the Sun.

The question of how the earth moves, its path, etc., is a very complex one. The article linked by the OP is interesting but, personally, I think it is still early days in our understanding of why we are where we are. My two cents worth.

Originally posted by 727Sky
www.spacedaily.com...

The Earth rotates once per day, but the length of this day varies. A year, 300 million years ago, lasted about 450 days and a day would last about 21 hours. As a result of the slowing down of the Earth's rotation the length of day has increased.

Professor Richard Holme, from the School of Environmental Sciences, studied the variations and fluctuations in the length of day over a one to 10 year period between 1962 and 2012. The study took account of the effects on the Earth's rotation of atmospheric and oceanic processes to produce a model of the variations in the length of day on time scales longer than a year.

Several have wondered if the days were shorter way back when but this particular study confirms the earths rotation is variable although trending to slower.

Did this guys serious JUST NOW come up with this idea? I swear I've read this before, because I've been telling people that this was the case for years now.

Originally posted by Caroline13456
reply to post by 727Sky

 

I find this a very interesting topic.

I have always wondered if the Earth is eventually going to slow down until it stops rotating.

Also I read where huge earthquakes like the one in Japan, have an effect of speeding the Earth's rotation up.

www.nasa.gov...

So would this mean that while time slows us down, geological upheaval speeds us up, thereby creating a balance ensuring our Earth will continue rotating indefinitely?

The force that pushes the moon further away also causes the Earth's rotation to slow down.

Thank you for your thread.

I've always been interested in Velikovsky's theories that things, be they planets or whatever, in the universe change, move, alter, do not keep their course, speed, position etc.
People judge everything by their own experience and their own 'education' as to what is or isn't possible and the FACT that something as basic as length of days and year change is really important to help understand our position in the universe now and potentially more importantly, in the past.

reply to post by 727Sky


Thanks to everyone for their replies and input. This topic is really beyond my understanding and I will have to do more research on it.

BTW 727Sky, I love your avatar!

Caroline

reply to post by Caroline13456


Thank you Caroline it is nice of you to say. The moon has been moving further and further from the earth at a rate of about 3.8 centimeters per year and if you had a time machine to go back and survive 100 million years ago the moon would be very impressive with regards to it's apparent size.

QUOTE:
As the result of Earth's spin and it's effect on the tide, the moon gains energy (speed) by stealing Earth's spin energy and uses it to gradually expand its orbit, moving away from the earth.

As the earth spins, the gravity of the moon pulls water, air, and land up towards itself causing a bulge called the tide. Earth's spin then pulls this tidal bulge ahead of the moon. So the tide moves slightly faster than the moon and just east of it. Then the increased gravity effect from the bulge racing ahead of the moon, gradually, almost imperceptibly, pulls the moon forward in its own orbit even faster. This also slows Earth's spin but at a much less perceptible rate.

The end result is a kind of Earth-sponsored sling shot effect. The moon has distanced itself (receded) from Earth in this way, by hundreds of thousands of kilometers, in its long association with Earth. END QUOTE: www.google.com... o-d2dXZh8X4dxn4Qfa4A3O4gd8y-nohYAH5or0JQ&sig=AOD64_3zuRfSm-Q6l8LwPXjIenn9MXcB7Q&adurl=http://find5.blog.co.uk/search/%3Fq%3Dmovement%2520of%2520the%25 20earth%26source%3Degooglelt%26c%3Dlt

reply to post by 727Sky
I had to stop reading, at this point:

300 million years ago

hahahaha That's funny. We have a hard time believing 2,000 years ago, let alone 300 million years. I like this theory, better.

1In the beginning God created the heavens and the earth. 2Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters. 3And God said, “Let there be light,” and there was light. 4God saw that the light was good, and he separated the light from the darkness. 5God called the light “day,” and the darkness he called “night.” And there was evening, and there was morning—the first day. -(Genesis 1:1-5)

"What time is it?" "Daytime!" Clocks are devices used by people living on the clock. Clock out, and enjoy the days.