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An interesting one - I seem to remember reading somewhere that no matter how fast the surface of the earth rotates, it still only rotates once per day - any object on a sphere that rotates once per day, no matter how big the sphere, will feel the same (miniscule) centripetal effects.
Is it true that the only effect of the earth's rotation that we all see day to do is the fact that water swirls going down a plughole? I guess it must go straight down on the equator?
On the subject of inertia, a agree with other posters, since the Earth isn't slowing or speeding, we don't feel any sense of inertia
And lastly, the Earth hasn't significantly changed in mass in a couple billion years I sbouldn't think - due to coastal erosion, weathering and tectonic / volcanic / glacial activity however the surface is constantly being worn down and build up, hence archaeologists specialising in the digging stuff.
Is it true that the only effect of the earth's rotation that we all see day to do is the fact that water swirls going down a plughole? I guess it must go straight down on the equator?
On the subject of inertia, a agree with other posters, since the Earth isn't slowing or speeding, we don't feel any sense of inertia
And lastly, the Earth hasn't significantly changed in mass in a couple billion years I sbouldn't think - due to coastal erosion, weathering and tectonic / volcanic / glacial activity however the surface is constantly being worn down and build up, hence archaeologists specialising in the digging stuff.
water swirling one way or the other is a myth..
the direction of swirl is due to surface imperfections etc and not the coreolis effect..
the direction of swirl is due to surface imperfections etc and not the coreolis effect..
O
oompah
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Mickymoody
I believe I saw some scientist saying that the Earth is slowing, and the Moon is getting closer.
What I don't understand, is what Rusella confirms....ancient artefacts are buried deep withing the earth. Go a few meters down, and it's recent, a few more it's roman, a few more, its prehistoric..so where has this earth build up come from? So therefore, logically, the planet is larger than what it once was. It wasn't people burying stuff. So the planet was once smaller, and that would affect gravity, hence large animals, ie Dinosaurs. but where does this build up come from?
...Where are you suggesting the extra mass came from?
Think of it this way. We are on a giant ball of rock. The centre is iron, and solid. We call this the core. We then have many layers of molten rock, i won't bore you with the names, but while it is rock due to it being molten it can be compressed, and finally the tiny tiny layer of crust on top.
This crust is divided into many plates that 'float' around on the surface and crash into eachother, rip apart from eachother.
when they crash into each other they have 3 options. One they both go up (rare), they both go down (rare), one goes up on the other (common).
When two plates both go down they push into the mantle(molten rock), or when they both go up and create mountains, this creates gaps at their seems where magma seeps out, creating volcanos.
This is pretty rare and commonly one of the plates spring back creating what we call earth quakes.
When one plate mounts the other you commonly you get mountains. Hence the name.
That is half the story.
Secondly, have you ever noticed how if you don't sweep your garden that the path after only a week has a layer of dust/dirt. This is due to the elements constantly 'trying' to flatten a rough object (the earth).
Mountains get worn away, and flows or blows into the compressions into the earth, which because they are heavier, sink slowly and are compressed.
This is the rock cycle in action, which is how limestone (which is ancient river bed and ocean floors are made.)
Basically to cut a long story short, because the plates are surfing around you can't always be sure of the age of something because of how deep it is. You can have sealife fossils found on mountain tops where an old ocean plate has mounted another plate and been pushed up...(causing silly people to believe in a flood that covered the entire world HAHAHA)
...BUT the chances are, though the weight of the crust and it sinking into the molten rock, the lower something is, the older it is.
Here endth the lesson.
...and just so we are clear gravity is a law. It doesn't change.
Dinosaurs in particular were probably big for many reasons, increased vegetation due to the atmosphere, hence more food, hence bigger dinos eating the veg, hence bigger dinos eating the dinos.
Secondly their metabolism..if they were cold blooded, would mean that their size would act as insulation meaning they are cool in the day and warm at night.
Insects used to be a lot bigger because of increased oxygen.
http://www.sciencedaily.com/releases/2006/10/061012093716.htm
Dinosaurs in particular were probably big for many reasons, increased vegetation due to the atmosphere, hence more food, hence bigger dinos eating the veg, hence bigger dinos eating the dinos.
Secondly their metabolism..if they were cold blooded, would mean that their size would act as insulation meaning they are cool in the day and warm at night.
Insects used to be a lot bigger because of increased oxygen.
http://www.sciencedaily.com/releases/2006/10/061012093716.htm
russella said:
I'm afraid you read wrong.
The centripetal force on a mass m is given by the formula:F = m x v^2 /r (mv squared over r)
where v is the surface velocity and r is the radius of rotation.
But w = v / r where w is the angular velocity and so the formula can be rewritten as:
F = m x w^2 x r
This form is more convenient when you know the number of rotations per day, which is an angular velocity.
From this, you should be able to see that, for constant w, the force is proportional to the radius.
or in other words you weigh less at the equator than you do at the pole..
ColJack said:
You do indeed, and not just because of the rotation. That same rotation caused Earth to solidify into an imperfect sphere whose radius increases as you move from the poles to the equator. The further you are from the centre, the less you weigh.
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lifesagasman
and here's me thinking that the actions of earthworms and vegetation were responsible for burying archaeological items....
I'm sure worms and vegetation play their part. Early this year, I put five paving slabs in place around a tap outside our new caravan, just to see what they would look like. I just plonked them down on the grass, the intension being to cut the turfs out later and set them in flush.
But I didn't need to. By some unknown process, they slowly sank down into the ground - or maybe the ground built up around them. I wish I'd positioned them more accurately in the first place.
But I didn't need to. By some unknown process, they slowly sank down into the ground - or maybe the ground built up around them.
I wish I'd positioned them more accurately in the first place.
O
oompah
Why haven't the pyramids at Giza disappeared
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lifesagasman
Why haven't the pyramids at Giza disappeared
No worms.
L
lifesagasman
I'm sure worms and vegetation play their part. Early this year, I put five paving slabs in place around a tap outside our new caravan, just to see what they would look like. I just plonked them down on the grass, the intension being to cut the turfs out later and set them in flush.
But I didn't need to. By some unknown process, they slowly sank down into the ground - or maybe the ground built up around them.
You have a caravan?? Eeeeh! Luxury! When I were a lad there were 14 of us....
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