Does it make any difference that the Earth is not round?

[phoenixy]

Hi, I'm writing a philosophy paper and one of my argument is the fact that the Earth is not a perfect sphere is quite significant. I need a couple sentences with scientific facts to support this position. I'm thinking something like tidal wave, but I'm not too sure

Any input will be appreciated. I don't need incredibly detail research(although I will be interested to read it if time permits). Links to some sites will also do the trick.

If anyone want to know, the paper is for a first year university class. I'm a second year electronic engineering student

 

[HallsofIvy]

Well, it's surely significant to a mountain climber!

Are you telling us that you have reached a conclusion WITHOUT knowing the "scientific" facts and now you want someone to give you facts that will fit your conclusion?

(Oh, my God! An electronics engineering student in a PHILOSOPHY class!)

 

[FZ+]

Heh.

Presuming you are referring to the ellipsoid nature of the earth, the biggest difficulty I am aware of is in map making - ie what projection would best represent such an earth.

It probably also makes a difference to the Earth's magnetic field. It should also affect the eath's gravitational attraction at various lattitudes. Don't think tides are much influenced, though.

 

[Nereid]

Er, doesn't the oblateness, combined with the rotation period, tell you rather a lot about the bulk properties of the Earth? Make a comparison with the oblateness of Jupiter or Saturn.

Also, why do we only see one face of the Moon from the Earth?

 

[phoenixy]

Hi, I decided to drop my Earth is not round argument(philosophy sucks, engineering all the way!).

Oh and I know for sure that the Earth is not round, I just don't have enough information =)

Isn't tiday wave created by the uneven gravitational force from the moon? I remembered something about gravitational force is stronger on parts of the Earth that's closer to the moon.

 

[Chemicalsuperfreak]

Originally posted by phoenixy
Hi, I decided to drop my Earth is not round argument(philosophy sucks, engineering all the way!).

Oh and I know for sure that the Earth is not round, I just don't have enough information =)

Isn't tiday wave created by the uneven gravitational force from the moon? I remembered something about gravitational force is stronger on parts of the Earth that's closer to the moon.

Yes, the parts of the Earth that are closer to the moon feel a stronger gravitational force. This is a basic concept of gravitation. But the radius at the equator is, what, only a few feet longer than at the poles? Not a terribly significant difference. Furthermore, you're not assuming that the moon orbits directly above the equator, are you?

 

[FZ+]

Originally posted by Nereid
Also, why do we only see one face of the Moon from the Earth?

The moon's rotation has become tidally locked relative to the earth.

 

[phoenixy]

Originally posted by Chemicalsuperfreak
But the radius at the equator is, what, only a few feet longer than at the poles? Not a terribly significant difference.

Pole to pole: 12714 Km
Equator: 12756 Km

if you square these number the difference would be about 0.66%

you're not assuming that the moon orbits directly above the equator, are you?

no

 

[enigma]

It makes a difference if you're trying to sight satellites. If you're finding out where they are relative to the center of the earth, you need to know where you are relative to the center as well.

 

[Nereid]

why do we only see one face of the Moon from the Earth?

FZ+ said: The moon's rotation has become tidally locked relative to the earth.

And the Earth's oblateness played a significant (dominant?) part in establishing that locking.

Hyperphysics (http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html)
has a brief summary of tides (scroll down to tides in the index). There would still be tides whether the Earth were a perfect sphere or not.

enigma wrote: It makes a difference if you're trying to sight satellites. If you're finding out where they are relative to the center of the earth, you need to know where you are relative to the center as well.

Where the satellites are is also affected by the Earth's gravitational field, which depends upon its shape, and departures from a perfect sphere are significant (not just oblateness, though that's the biggest departure).

phoenixy, it's good to see that you're still interested in the topic, even if you're not going to use it for your philosophy talk.

 

[phoenixy]

hehe yeah. And you guys very helpful =)

Next time I will ask some "real" questions.

Just joking. Since my paper was due, philosophy is once again one of my favorite subject.

 

[Nereid]

See how much fun you can have doing physics? Drop EE, switch to physics! No, on second thoughts, don't; electronic engineers earn more money.