h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

546

(13 x 42)



B

One of the best lines in an episode full of best lines was his explanation for his accent: "Lots of planets have a North". (I thought they all did, but maybe only ones with iron cores do).

Izzard was rumoured last time too - I think he'd be great in it. I've never really thought of him as a bloke in drag because he so isn't a drag queen. Barbara Windsor is more of a drag queen than he is. I like the idea of an assexual Doctor, and he is intelligent, which is probably the main thing.

Pretty boys? Puh-lease! Tom Cruise was s**te in 'Interview with the Vampire', Hoo, regardless of whether or not he played it as a Scientologist.

Ben

It's unlikely that the Earth's iron core is responsible for magnetism, given that it is way above the Curie temperature of iron. A lot of planets and stars, iron-cored or nay, have magnetic fields, so a great deal of them would have a North.

B

But in what circumstances *wouldn't* a planet have a North - or to put it another way in what circumstances wouldn't a planet have magnetic field?

I thought it was part of the recipe... You know, the one that starts "take some rocks...."



B

Time for a spot of pontificating...presumably all planets spin (all the ones in our Solar System seem to...), so must have an axis about which to spin. One end of which can be randomly called North, and the other South (there's no "up" and "down" in space).

RF

so if that's the case he could have a Scot's accent, even a Scandinavian one and the same principle would apply

But in what circumstances *wouldn't* a planet have a North - or to put it another way in what circumstances wouldn't a planet have magnetic field?


It's all to do with core temperature
The core needs to be rotating at a different rate from the sorrounding strata to make the Dynamo affect.


Take Mars it's core is too cold to create much of a magnetic field which is why it's atmosphere is being driven away by solar winds.
It's core

Earth has kept a relatively hot core because of it's size.

Smaller bodies like Io have tidal forces acting on them to keep the core hot.

The moon has no magnetic north or south for it is solid, it only has remnant magnetism in it's rocks from when it was formed.

Or if you are going to be philosophical about it.
What is North? What is South?
What is Matter? What is Anti-Matter?

They are just references to our perceptions.

Who's beginning to wish this subject had't been brought up

Don't blame me !!!

Some-one asked

(blame 2-legs)

Don't worry I generally blame him for something

So how's the lovely Reefgirl today

Bored, I've got to go to Excelsior's mum's birthday party tonight, lost count of how many times I asked mum whether she want's to go to Mass this evening (I'll babysit mum honest I don't mind, no I'm sure Stuart's mum will understand), now she's getting suspicious

The joys of family

The one good thing about a job where you work all hours is that you can plead that pressure of work is stopping you from participating in things you don't realy care for.(I think that is probably the only good thing about it though)

Right now after doing a sixteen and a half hour shift followed by a seven hour shift with four hours rest between I can tell you that those sorts of jobs are nackering.

Somebody take me out and shoot me

have this instead , I used to work one day early one day late now I do one week on one week off

Sounds like a good idea

onecomming up

*Gets a JCB to drag the conversation back on track. *

One of the planets in our solar system rotates on a horizonal axis rather than a vertical one, so they wouldn't have a north and a south. Neptune I think it is, mind you, you couldn't go there to find out because it's largely made of gas.

I was also thinking what it would be like if you were living on an moon with intellegent life forms, that was rotating around a planet with other intellegent life forms. And you could travel from one to another in say three or four days. But you were sort of rival worlds. Would you have a war and destroy each other. Or would you have system where species would emigrate from one planet to another?

But then again they'd have different diseases, so presumably on first contact the bacteria from one planet would destory another.

Dr Who seems to have got me into Science fiction.

Hang on a minute - you are a member of Hootoo and not into Science Fiction? We'll have to see what we can do about that.

Scrolling back a bit - Mars doesn't have a strong magnetic field and *therefore* doesn't have an atmosphere?



I mean....

I thought magnetism only applied to iron?

I really *am* confused now.

B

No, you can create a magnetic field in several ways, including a strong gravitational force.

Even on Earth, there are four magnetic metals: iron, cobalt, nickel and neodymium, and a few non-metallic compounds.

B

It's our magnetic field that protects us fron the worst of the solar wind.
It channels the charged particles around the earth but a little gets channeled into the polar regions hence the Aurora

If we didn't have a magnetic field we would be fried.

Try this link for a better uderstanding


http://www-ssc.igpp.ucla.edu/ssc/tutorial/magnetosphere.html

No, you can create a magnetic field in several ways, including a strong gravitational force.

Even on Earth, there are four magnetic metals: iron, cobalt, nickel and neodymium, and a few non-metallic compounds.


This is true but the earth and the other terestrial plannets are mostly silicon with a lower percentage of ferrous metals.

If an object is mostly metal then it wouldn't need a liquid (hot) core