if the world span around the other way

[El Salsero Gringo]

... meaning that even space is not a "perfect" vacuum.

In Quantum Field Theory, even vacuums aren't empty. They are a seething mass of particles instaneously appearing and disappearing in little puffs of energy. See for instance this.

[bobgadjet]

Hmmm
All this is very thoughtful.
I am now so full of thought I am going to take all my thoughts away to bed, and think about them some more.
I will awake and sort it all out for you tomorrow..........
But wait..... When it is tomorrow, then tomorrow will become today.....

Oh bugger, then I will have to sleep on it again, and when tomorrow comes I can again say that I can sort it out for you tomorrow......

But wait..... when I do actualy get to tomorrow, it will again be today......

This si getting quite painful and I really must go to bed to think about it a bit more....vacuums......space........spinning the other way............gravity......voidzzzz zzzzzz zzzzzzzz zzzzzzzz zzzzzzz

[Clive Long]

Hey it's Di's son here, (Alex) and i must admit that the knowledge in this conversation is very high, although the question i asked my mother wasn't for h/work I could wirte many esay's on what has been posted, , here's one to confuse you (not even my physics teacher could think of an answer shame i cant include the drawings)
I have in my hand a vacuum, i have been told that a vacuum is nothing ness, but how can you say that nothing is something, how can you say that there is nothing in there when we cannot say for sure, we cannot say what is at the bottom of our oceans, thus how can we say what is in a void? We do not << cut >>

In my great tradition of not answering your question (because I can't, and others have given very thorough answers already) I suggest you might attempt "The Book of Nothing " by John Barrow (a Cambridge professor). I can't lay my hands on it now to check its level but I vaguely remember you need to be at around A-level standard to get going with its content. The "back-end" of the book gets very sophisticated & "unreachable" - but don't let that put you off attempting it.

Having said the above, Barrow approaches the vacuum from the concept of mathematical zero (a late import from India?) into calculation and then extends the idea of "something" (zero) representing "nothing" (the value of zero) into the idea of a vacuum. I dimly remember that somehow he argues the empty vacuum is not empty but a seething quantum jumble and this is the basis for how the universe (multiverse?) just popped into being.

Sorry if the above is a load of rubbish - but the book is only 7 quid so may be worth looking at the first chapter if you can get someone to donate a copy to your school library.

Another wonderful book (if I have the title right) is "Creation Revisited: The Origin of Space, Time and the Universe" by Peter W Atkins - an Oxford professor - a great writer on a difficult subject. Again tackling the "how did we get something out of nothing" question. Not good reading if you are a committed believer in a divine creator.

I'd also recommend Ian Stewart for more mathematical topics.

Alex, keep asking the "what if" questions - and try to follow them through - you'll be following in the footsteps of Clerk Maxwell and Einstein. But don't ignore the basic knowledge of school science - otherwise you are building your ideas on quick-sand.

Clive

[Graham]

In Quantum Field Theory, even vacuums aren't empty. They are a seething mass of particles instaneously appearing and disappearing in little puffs of energy. See for instance this.

As an electronics engineer, I tend to the view that we should use the simplest model which captures the operation of the system. In this case I took the view that there were no relevant quantum effects, and therefore provided a Newtonian explanation. Then again, perhaps that's just because I don't really like working with field equations.

[Clive Long]

As an electronics engineer, I tend to the view that we should use the simplest model which captures the operation of the system. In this case I took the view that there were no relevant quantum effects, and therefore provided a Newtonian explanation.

Then again, perhaps that's just because I don't really like working with field equations.

We love you anyway Graham.

People like ESG and me kind of inhabit a world of existence and non-existence because we have managed to scale-up quantum effects to the macroscopic (although there isn't much room with most of the space occupied by ESG's brain)

[Rhythm King]

We love you anyway Graham.

People like ESG and me kind of inhabit a world of existence and non-existence because we have managed to scale-up quantum effects to the macroscopic (although there isn't much room with most of the space occupied by ESG's brain)

All that quantum foam no doubt

[stewart38]

You wouldn't notice it yourself - the centripetal effect of the earth's rotation which appears to push you away from the centre of rotation is a very small fraction of the gravitational attraction of the earth's mass:

In order for objects to appear weightless at the equator, the earth would have to turn about every 70 minutes (from memory) at which speed every object at the equator would actually be in orbit around the planet.

If the direction of rotation of the earth were suddenly to change there would be catastrophic effects on:

- Weather patterns (the coriolis effect that makes cyclones turn one way, and anti-cyclones the other in each hemsiphere would be reversed)

- Possibly on the earth's magnetic field (which I think is believed to be caused by rotating flows in the earth's molten iron core)

- The tides, and eventually on the orbit of the moon. The Earth-Moon system is weakly coupled - with the earth's rotation gradually slowing (because of tidal braking) and so transferring angular momentum to the moon which is both slowing it's orbit around the earth and increasing it's orbital distance. Since the moon currently orbits pro-grade (in the same direction as the earth's rotation) a reversal the direction of rotation of the earth would increase the speed of the tides, and make the tidal braking effect greater. The moon would therefore recede faster.

I stand to be corrected on these details since they are from memory.


(edited to add: If there were an effect on the Earth's magnetic field which reduced the field strength significantly, life on earth would be very severly impacted by a hugely increased level of ionising radiation from the sun from which we are largely shielded at the moment because of the magnetic field. )

Interesting comments and others, all this is memory so flame away if there is any left after it turns the other way

If the earth was to 'stop' and then been 'turned' to go the other way (bit like superman did.) your stopping roughly 8 *10 raised to the power of 35 grammes

That takes a bit of energy, enough to melt the earth crust to about 10 miles so im afraid were all dead fairly quickly.

[El Salsero Gringo]

Interesting comments and others, all this is memory so flame away if there is any left after it turns the other way

If the earth was to 'stop' and then been 'turned' to go the other way (bit like superman did.) your stopping roughly 8 *10 raised to the power of 35 grammes

That takes a bit of energy, enough to melt the earth crust to about 10 miles so im afraid were all dead fairly quickly.

An interesting point, but not necessarily true. There is no need for any thermal energy to be dissipated because the rotational kinetic energy after reversing the direction would be the same as before. If you had a 100% energy-efficient mechanism for achieving this stupendous feat, then nothing would melt. Of course a 100% efficient mechanism is even more fundamentally nonsensical a concept than the idea of reversing the direction of rotation of a planet in the first place. If your mechanism wasn't 100% efficient (a very big piece of elastic being twisted up, with something even bigger than the earth to anchor it to, say) then the wasted energy would be dissipated in the mechanism itself (like the elastic) not in the earth.

Another good question is where to get all the angular momentum that you would need to put into the planet to change it's rotation (i.e. to what do you anchor the other end of the elastic), but presumably you could harness the rotation of the sun, or one of the other planets.

Good luck to anyone who wants to give it a go.

[El Salsero Gringo]

People like ESG and me kind of inhabit a world of existence and non-existence because we have managed to scale-up quantum effects to the macroscopic (although there isn't much room with most of the space occupied by ESG's brain)

I sometimes feel I only really exist while I'm dancing, and that the whole of life is like a giant game of pass-the-parcel, waiting for the music to stop.

It's only the thought of Clive and his red dress that keeps me going as I quantum-tunnel my way from one Ceroc night to the next.

[El Salsero Gringo]

And I also forgot to mention in my original answer, the most profound consequence of all: that the water in your bath would immediately spiral down the plug-hole the other way round.

Honestly, it would.

[foxylady]

I sometimes feel I only really exist while I'm dancing,

I only exist when I am dancing. When I am not dancing I am not me, I am some sort of automated simulacrum....

and that the whole of life is like a giant game of pass-the-parcel, waiting for the music to stop.

surely begging for the music not to stop at you......

[stewart38]

An interesting point, but not necessarily true. There is no need for any thermal energy to be dissipated because the rotational kinetic energy after reversing the direction would be the same as before. If you had a 100% energy-efficient mechanism for achieving this stupendous feat, then nothing would melt.
.

Nope because Im assuming your stopping the planet ie you bring to a halt then 'push' it the other way. There isnt a transfer of energy . The rubber ban idea is fundemetally correct. . It could be sort true if i stopped the earth and absorbed all the energy but if a wall stops a car it doesnt absorb all the energy

Plug and water thing yes but not immediately and thats my last comment !

If the sun disappeared now (without looking it up !) what would people die first

[ducasi]

And I also forgot to mention in my original answer, the most profound consequence of all: that the water in your bath would immediately spiral down the plug-hole the other way round.

Honestly, it would.

I presume you're talking of the Coriolis Effect?

When it comes to plug-holes, it's a bit of a myth.

[DianaS]

Hey it's Di's son here, (Alex) and i must admit that the knowledge in this conversation is very high, although the question i asked my mother wasn't for h/work I could wirte many esay's on what has been posted, Hope to have not confused you too much

Just got back to this thread I have been poorly and left the computer on and went to bed, when I came too Alex new my darkest secret cas I'd left he window open

however am most relieved that we are not to be hot by meteorite and even bears wtih much larger brains who aren't struggling with poorliness struggle with these sorts of questions.
Thank you kind sirs for your tutorage i will buy yon lad said books and further his education. Let he boldly go whjere i have never been before...

The thread is interesting yet i maintain when the earth spins the other way and stops wont all the oceans swim about and it will be rather terrible... won't the technonic plates all crash and splatter and won't tehre be vioplent eruptionns OPpps where the bucket I've set myself off again

[DianaS]

Tis alex, mother is now V miffed that i no longer see her as font of all wisdom, and have hacked into internet to further education , however, all i can say is she seems to be fairly relaxed now i know her secrets, (AKA real answers not cloned!) Will be in Bham on the moro to purchase said books and will request further tuition via teh e-mail from all and sundry as a legitimate displacememnt activity from studying my GCSE syllaus material :P, many thanks to all, you will be acknolaged in my memoirs, although you may be demised at the time ,

[El Salsero Gringo]

Tis alex, mother is now V miffed that i no longer see her as font of all wisdom, and have hacked into internet to further education , however, all i can say is she seems to be fairly relaxed now i know her secrets, (AKA real answers not cloned!) Will be in Bham on the moro to purchase said books and will request further tuition via teh e-mail from all and sundry as a legitimate displacememnt activity from studying my GCSE syllaus material :P, many thanks to all, you will be acknolaged in my memoirs, although you may be demised at the time ,

It sounds like someone's been reading "Down with Skool"!