that pete thread actually made me think (SHOCKING)

[R00k]

3) Why are there only 6 general directions? There are an infinite number of directions. Natural forces do not discriminate based on human normative conceptions.

*sigh* this was a simplification relative to the 'norm', which sees the earths mass present on only one side of an imaginary cube around a person.

Purely for illustrative purposes.

Your needless use of complex terminoligy I find to be so utterly juvenile that this discussion ceases to be entertaining.

For that reason, I'm not even tackling the rest.

That's a respectful way to leave a discussion without having to admit you didn't know what you were talking about. :icon27:

[Fender]

That's a respectful way to leave a discussion without having to admit you didn't know what you were talking about. :icon27:

Ding ding ding! We have a winner. (Not Foo).

[Foo]

3) Why are there only 6 general directions? There are an infinite number of directions. Natural forces do not discriminate based on human normative conceptions.

That's a respectful way to leave a discussion without having to admit you didn't know what you were talking about. :icon27:

Yes, and that's also a reason why I'd normally shy off posting what I did, despite it being my actual real opinion, and you being a jaded fuck who could probably function just as well with less useless sniping.

Again, not that this won't be seen as something you'll 'read' more into, like you're managing to somehow get one over on me by 'telling me what I'm saying'.

I probably need to finish this off with a ;dork; icon, right?

[[xeno]Julios]

I've got a question about the oscillation thing...

Since we're talking about the earth, and the laws of friction apply, wouldn't terminal velocity prevent the ball from returning almost all the way to the opposite side of the planet? That is to say, the speed that the ball is traveling when it passes the center of the earth can't possibly be enough to make it all the way back to the surface on the other side. Right?
So won't the oscillation be uneven? Wouldn't it only travel a short distance past the core before turning around again?

terminal velocity is a function of friction/air resistance. If, as has been qualified in the discussion so far, there is a vacuum, there is no terminal velocity.

[[xeno]Julios]

Your needless use of complex terminoligy I find to be so utterly juvenile that this discussion ceases to be entertaining.

For that reason, I'm not even tackling the rest.

heh i've seen this behaviour from you in the past

gg

-btw, if you don't understand what I'm talking about, then you could ask for clarification, or give me some constructive criticism about the way in which I'm communicating myself.

[Foo]

Your needless use of complex terminoligy I find to be so utterly juvenile that this discussion ceases to be entertaining.

For that reason, I'm not even tackling the rest.

heh i've seen this behaviour from you in the past

gg

-btw, if you don't understand what I'm talking about, then you could ask for clarification, or give me some constructive criticism about the way in which I'm communicating myself.

:icon26:

[dzjepp]

so if I shovelled through the bottom long enough I would come out upside down in China staring down those funny people at their nostrils? :icon28:

[werldhed]

I've got a question about the oscillation thing...

Since we're talking about the earth, and the laws of friction apply, wouldn't terminal velocity prevent the ball from returning almost all the way to the opposite side of the planet? That is to say, the speed that the ball is traveling when it passes the center of the earth can't possibly be enough to make it all the way back to the surface on the other side. Right?
So won't the oscillation be uneven? Wouldn't it only travel a short distance past the core before turning around again?

terminal velocity is a function of friction/air resistance. If, as has been qualified in the discussion so far, there is a vacuum, there is no terminal velocity.

In a vacuum, yes. But that hasn't been qualified in this discussion, GFY simply gave a case of "if it was a vacuum, this would happen." Also, if it really was a vacuum, in theory oscillation would not diminish until the object came to rest at the core.
Since it's been stated a couple of times that this would happen (even in that article Fender posted), it must not really be in a vacuum, in which case I'm asking if terminal velocity would affect the movement of the object in a different way than everyone seems to believe.

[R00k]

*sigh* this was a simplification relative to the 'norm', which sees the earths mass present on only one side of an imaginary cube around a person.

Purely for illustrative purposes.

Your needless use of complex terminoligy I find to be so utterly juvenile that this discussion ceases to be entertaining.

For that reason, I'm not even tackling the rest.

That's a respectful way to leave a discussion without having to admit you didn't know what you were talking about. :icon27:

Yes, and that's also a reason why I'd normally shy off posting what I did, despite it being my actual real opinion, and you being a jaded fuck who could probably function just as well with less useless sniping.

Again, not that this won't be seen as something you'll 'read' more into, like you're managing to somehow get one over on me by 'telling me what I'm saying'.

I probably need to finish this off with a ;dork; icon, right?

Maybe I am a 'jaded fuck' but you're the one who threw a fit and got aggressive when someone tried to correct you.
Trying to "get one over on you?"

[Foo]

'no you'

?

[[xeno]Julios]

In a vacuum, yes. But that hasn't been qualified in this discussion, GFY simply gave a case of "if it was a vacuum, this would happen." Also, if it really was a vacuum, in theory oscillation would not diminish until the object came to rest at the core.
Since it's been stated a couple of times that this would happen (even in that article Fender posted), it must not really be in a vacuum, in which case I'm asking if terminal velocity would affect the movement of the object in a different way than everyone seems to believe.

Assuming I understand your concern correctly:

Well terminal velocity is not a property above and beyond that of air resistance. It can be explained fully in terms of air resistance and velocity and the like.

(it is not an example of epistemological emergence - see http://plato.stanford.edu/entries/prope ... mergent/#2 )

So if you were to just talk about air resistance (and shape of object of course), you would find that as the velocity of the falling object increases, so does air resistance. Air resistance, just like other forms of friction, is also a function of the velocity of the object. Terminal velocity is simply the velocity at which the force of friction is equal to the force of gravity, at which point the object ceases to accelerate.

As such, our intuitions about what would happen to a falling object that experiences air resistance do not differ from those about an object that experiences terminal velocity.

[R00k]

'no you'

?

No, that's not what I said at all.

[Guest]

I'd just walk around the earth, much more scenic.

[werldhed]

In a vacuum, yes. But that hasn't been qualified in this discussion, GFY simply gave a case of "if it was a vacuum, this would happen." Also, if it really was a vacuum, in theory oscillation would not diminish until the object came to rest at the core.
Since it's been stated a couple of times that this would happen (even in that article Fender posted), it must not really be in a vacuum, in which case I'm asking if terminal velocity would affect the movement of the object in a different way than everyone seems to believe.

Assuming I understand your concern correctly:

Well terminal velocity is not a property above and beyond that of air resistance. It can be explained fully in terms of air resistance and velocity and the like.

(it is not an example of epistemological emergence - see http://plato.stanford.edu/entries/prope ... mergent/#2 )

So if you were to just talk about air resistance (and shape of object of course), you would find that as the velocity of the falling object increases, so does air resistance. Air resistance, just like other forms of friction, is also a function of the velocity of the object. Terminal velocity is simply the velocity at which the force of friction is equal to the force of gravity, at which point the object ceases to accelerate.

As such, our intuitions about what would happen to a falling object that experiences air resistance do not differ from those about an object that experiences terminal velocity.

Sorry, my response wasn't very clear. I know terminal velocity is an expression of air resistance, and in a vacuum, it wouldn't come into play. But it should have an effect in the real world. It seems to me that in order to get from the core to the surface of the earth, an object would have to leave the core with more velocity than terminal velocity allows.
As an illustration, let's assume to reach the surface, an object must leave the core at 1000 mph. However, let's say terminal velocity for that object is limited to 500 mph. Thus, leaving the core at only 500 mph, it would not return anywhere near to the surface.
For that reason, it seems to me that the gradual oscillation wouldn't really occur in the way people have described.

[tnf]

. It seems to me that in order to get from the core to the surface of the earth, an object would have to leave the core with more velocity than terminal velocity allows.

Leave the core...are you meaning that it starts at the core...or that it passes the core with a given velocity, lets say Vi...so that Vi is equal to the velocity of the object as it passes the core?

Drop the ball, it begins to accelerate at 9.8m/s/s downward, toward the core. Now, as it passes the core, its acceleration (from our reference point of having dropped it) will be reversed, and it will slow down (at 9.8m/s/s) until it reversed direction, and comes back towards us. Now, if there was not air resistance, the process would continue indefinitely. But lets say there was.
Go to this website...and you can figure it out.
http://www.kineticbooks.com/physics/16270/20217/sp.html

Click on the equation in orange..below the parachute pic, and you will get a nice audio explanation of calculating the velocity with air resistance.

[[xeno]Julios]

Sorry, my response wasn't very clear. I know terminal velocity is an expression of air resistance, and in a vacuum, it wouldn't come into play. But it should have an effect in the real world. It seems to me that in order to get from the core to the surface of the earth, an object would have to leave the core with more velocity than terminal velocity allows.
As an illustration, let's assume to reach the surface, an object must leave the core at 1000 mph. However, let's say terminal velocity for that object is limited to 500 mph. Thus, leaving the core at only 500 mph, it would not return anywhere near to the surface.
For that reason, it seems to me that the gradual oscillation wouldn't really occur in the way people have described.

Yes - good point - the gradual progression toward rest would start off with a fast decrease in the oscillatory period (due to terminal velocity) and from then on would oscillate in a gradually decreasing manner.

[tnf]

Sorry, my response wasn't very clear. I know terminal velocity is an expression of air resistance, and in a vacuum, it wouldn't come into play. But it should have an effect in the real world. It seems to me that in order to get from the core to the surface of the earth, an object would have to leave the core with more velocity than terminal velocity allows.
As an illustration, let's assume to reach the surface, an object must leave the core at 1000 mph. However, let's say terminal velocity for that object is limited to 500 mph. Thus, leaving the core at only 500 mph, it would not return anywhere near to the surface.
For that reason, it seems to me that the gradual oscillation wouldn't really occur in the way people have described.

Yes - good point - the gradual progression toward rest would start off with a fast decrease in the oscillatory period (due to terminal velocity) and from then on would oscillate in a gradually decreasing manner.

So it would be a logarithmic/exponential relationship..

[[xeno]Julios]

I dunno enough about the mathematics of aerodynamics to know what sort of function deceleration due to air resistance is.

But even if it's a linear function, you'd still get this sudden oscillatory kink that werldhed is on about.

[losCHUNK]

and my once simple question has erupted into a headache

[tnf]

I dunno enough about the mathematics of aerodynamics to know what sort of function deceleration due to air resistance is.

But even if it's a linear function, you'd still get this sudden oscillatory kink that werldhed is on about.

If its linear, how could you get a 'sudden' kind?

I think I am missing something here about what werdheld is on about.

[[xeno]Julios]

If its linear, how could you get a 'sudden' kind?

I think I am missing something here about what werdheld is on about.

Well an empirical inspection of the situation should confirm it:

Imagine instead a bouncing ball (easier to imagine, yet same principles involved).

If i drop ball from plane, it will start off a certain acceleration. Let's assume that because of air resistance, the acceleration will decrease over time, until there is none left, at which point the ball has reached terminal velocity. Furthermore, let's suppose that the decrease in acceleration is linear.

So if i drop the ball from really high up, it will reach terminal velocity early on, relative to the whole height. Therefore, when it bounces back up, it will only reach a tiny fraction of its initial height. But from that point on, it will lose height in a gradual fashion after each bounce. It's only the first bounce that has the kink in it.

Now i'm not saying that acceleration decreases linearly - most likely it is nonlinear since the force of air resistance is a function of the velocity of the ball, which is a function of air resistance. They are dynamically coupled.

What I'm saying is that the kink that werldhed is talking about is not kinematically related to the nature of the function of air resistance - the kink is "incidental".

[GONNAFISTYA]

And so is your sex life you fucking nerd.

[[xeno]Julios]

And so is your sex life you fucking nerd.

:lol:

[werldhed]

...What I'm saying is that the kink that werldhed is talking about is not kinematically related to the nature of the function of air resistance - the kink is "incidental".

I didn't think about the fact that terminal velocity would only affect oscillation once - after the object was dropped for the first time. After that, you're right, the oscillations would occur as normal. You confirmed that I was right about it having an effect, but for theoretical purposes, I was essentially wrong. :icon32:

[Guest]

If I may give it a try...

I was thinking of a vacuum like kind of a tunnel that could aspired an underground ship chuttle by the core 0 gravity and with the help of a human made arm tunnel vacuum that would help the chuttle to continue it's travel once it passed the core. Once it passed the core at a precise moment a door should be shut behind it in order to keep the suction of the artificial human made vacuum arm to propel it to the surface. The rest of its travel would be just made from the suction velocity it would have acquired after passing the closing door.


Pete