Author Topic: Argument Dept  (Read 6516 times)

samdavo

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Argument Dept
« on: May 05, 2013, 02:46:27 PM »
Like the Monty Python Argument sketch ...
I'll throw this one out there,

But there's no such thing as a centrifugal force !
Proof: here's the moon happily waltzing around the Heavens with the Earth, (sketch courtesy of DCAD),  where's the Centrifugal Force?
(PS and I'm not talking Centripetal, I'm talking the other one)  :)

SciGraphics

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Re: Argument Dept
« Reply #1 on: May 05, 2013, 08:40:51 PM »
Centrifugal is the one that makes the planet want to continue straight ahead. The slope of the gravitational field prevents that and turns the straight ahead into turning in. Centripetal force is the one that makes the planet want to fly straight out from the sun into deep space. Jim a.

samdavo

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Re: Argument Dept
« Reply #2 on: May 06, 2013, 01:44:51 AM »
By way of introduction, a train driver I met on a plane once explained this to me, lol.  I tried to argue as you are, but he whipped my arguments with , let's say, bush logic.    Cheers.

a) Centrifugal is the one that makes the planet want to continue straight ahead.
b) The slope of the gravitational field prevents that and turns the straight ahead into turning in.
c) Centripetal force is the one that makes the planet want to fly straight out from the sun into deep space. Jim a.
Jim, since I've nailed my colours to the mast, I'm gonna
a) disagree on point a
b) agree on point b, and
c) disagree on point c.
 
You say "Centrifugal force wants the moon to go straight ahead" (?)  :)
m8, No force is required to make something go straight ahead.

However, you need a force to make it go around a circle ... i.e. to change its direction of motion... 
and that is called a centripetal force ( not a centrifugal one).
Certainly the centripetal force is provided by the gravitational field, however you want to visualise it.

I'll add another jpeg which includes the fact that
a) there is a force on the moon, and
b) the line of motion is changing.  (edit - which itself suggests a radial acceleration yes?)
cheers
sam


« Last Edit: May 06, 2013, 03:38:03 AM by samdavo »

samdavo

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Re: Argument Dept
« Reply #3 on: May 06, 2013, 02:14:13 AM »
Anyway, as we (this train driver and I) were having a beer waiting for a plane anyway, I countered with this one ...

Suppose you have a soccer ball with a string tight around its equator. 
and you add 1 metre/yard to the length of the string
and make that circle concentric with the ball
would the distance from the ball to the string-circle be closer to
a) 1 inch, 
b) 6 inches, or
c) a foot?

ok - if you do the same with a string around the Earth (assume a sphere for this exercise)
add the metre/yard
make it the same distance off the ground all the way around the Equator.
would the distance from the Earth be closer to
d) 1 inch,
e) 6 inches, or
f) a foot?

he guessed wrong.
I said same in each case .

And, since we were having a beer anyway, I said, and the same for all the other planets, including Uranus.
at which point we laughed, called it a draw, stopped arguing, and had another beer.  :)) 
« Last Edit: May 06, 2013, 02:17:29 AM by samdavo »

samdavo

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Re: Argument Dept
« Reply #4 on: May 06, 2013, 04:57:57 AM »
PS But we didn't get onto AGW (anthropogenic global warming) - too much at stake, too close to this possum's heart - I personally like David Suzuki's attitude that "politicians who ignore it should be held legally responsible" (2 cents)

SciGraphics

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Re: Argument Dept
« Reply #5 on: May 06, 2013, 09:53:15 AM »
Sorry, Samo: Got a) and c) mixed up. I get a) and c) mixed up all the time, regardless of the subject in question. ;-) Jim A.

samdavo

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Re: Argument Dept
« Reply #6 on: May 06, 2013, 02:33:39 PM »
Speaking of C...,  and also the parallel thread is talking about batteries :)  Especially since Lar lives in the Bahamas I believe ...

 A couple lived near the ocean and used to walk the beach a lot.   One summer they noticed a girl who  was at the beach almost every day.  She wasn't unusual, nor was the travel bag she carried, except for one thing; she would approach people who were sitting on the beach, glance around and then speak to them.   Generally, the people would respond negatively and she would wander off.   But occasionally someone would nod and there would be a quick exchange of money and something that she carried in her bag.
 
 The couple assumed that she was selling drugs and debated calling the cops, but since they didn't know for sure, they decided to just continue watching her.   After a couple of weeks the wife said, 'Honey, have you ever noticed that she only goes up to people with boom boxes and other electronic devices?'   He hadn't and said so.
 
 Then she said, 'Tomorrow I want you to get a towel and our big radio and go lie out on the beach.  Then we can find out what she's really doing.'   Well, the plan went off without a hitch and the wife was almost hopping up and down with anticipation when she saw the girl talk to her husband and then leave..   The man then walked up the beach and met his wife at the road.
 
'Well, is she selling drugs?' she asked excitedly.
'No, she's not,' he said, enjoying this probably more
 than he should have.
 'Well, what is it then?  What does she do ?' his wife fairly shrieked.   
 The man grinned and said, 'She's a battery salesperson.'
 
 'Batteries?' cried the wife.
  'Yes!' he replied
 !
 !
 !
 'She Sells C Cells by the Seashore!'

prl

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Re: Argument Dept
« Reply #7 on: May 06, 2013, 02:55:17 PM »
'She Sells C Cells by the Seashore!'

You do make me laugh . . . . frequently. 

So getting back to your trick centrifugal force question.  Having had the day to whip open my ancient engineering texts, I conclude nothing is holding up the moon.

samdavo

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Re: Argument Dept
« Reply #8 on: May 06, 2013, 03:03:26 PM »
prl
food for thought there ...  Atlas's assistant :)
Atlas and Robin maybe?
Atlas and Dictionary maybe?

Gotta feeling the old testament talks about tortoises or some such ?

Next question 
Had the Greeks twigged to the fact that the Earth was round  before JC came into the picture?
If they ran a poll back then, how many would have agreed with you if you told them the Earth was round?

Bob P

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Re: Argument Dept
« Reply #9 on: May 06, 2013, 03:55:15 PM »

samdavo

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Re: Argument Dept
« Reply #10 on: May 07, 2013, 03:21:10 AM »
... Thanks Bob - sounds like Pythagoras was there at the coalface again...

I guess I was speculating how many of the Disciples thought it was round  - maybe 6 to one and half dozen to the other you reckon?

ps As for Atlas, (below) there's a pink line there  where you'd better be careful - i.e. don't get caught between the Moon and New York City - (2cents)
« Last Edit: May 07, 2013, 03:26:39 AM by samdavo »

prl

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Re: Argument Dept
« Reply #11 on: May 07, 2013, 03:47:02 AM »
Don't get caught between the Moon and New York City

Good title for a book.


samdavo

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Re: Argument Dept
« Reply #12 on: May 07, 2013, 04:39:14 AM »
... I conclude nothing is holding up the moon.
They say it's difficult for astronauts to know which way is UP.

PS I personally feel it's Australia's turn to be "up over", and you can be Down Under for a change :)  cheers m8
« Last Edit: May 07, 2013, 01:37:11 PM by samdavo »

prl

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Re: Argument Dept
« Reply #13 on: May 07, 2013, 05:21:42 AM »
you can be Down Under for a change

Sure.

samdavo

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Re: Argument Dept
« Reply #14 on: May 07, 2013, 01:27:44 PM »
yep :)

and here's Atlas having a hellova time (Astronaut like) trying to work out which way's up (!!) :)
(heck, mum and dad send me out here, tell me to keep myself busy holding this damned thing up - , but where's the instruction book!? sheesh - and what about worker's comp for my back after 4 billion years !!)

How do we know he's not really holding up the base of that statue (?)

(Hint.  These sort of arguments are unlikely to get you into trouble, even in the public bar lol) 
except maybe in some ancient Grecian Bible Belt lol.

Lol,  I like the old Grecian testament according to Hesiod (?)
http://en.wikipedia.org/wiki/Atlas_(mythology)

Quote
Now Iapetus took to wife the neat-ankled maid Clymene, daughter of Ocean, and went up with her into one bed. And she bare him a stout-hearted son, Atlas: also she bare very glorious Menoetius and clever Prometheus, full of various wiles, and scatter-brained Epimetheus.

—Hesiod, Theogony 507–11


so next argument ...  Do you or do you not agree that Grecian history has been unkind to Epimetheus?

and after that "What exactly was it about Clymene's ankles that Iapetus thought was neat?

PS All I know is that I studied "Owed to a Grecian Earn" at school, and I've been owed a lot more that I've earned ever since - sheesh.  (2 cents)

Ahh finally found a way to change that avatar  , and since this webpage was open ... I think it's called "what the heck!" :)) 

(If anyone else wants to pick an avatar from the web, and like me didn't know how (doh - fool me once shame on ...  moving on) you simply have to burrow into a wiki photo (keep clicking ) until (hopefully) you get a picture without any surrounding text - and vuwal,  vwull, presto, you've got yourself an IRL avatar. (1.5 cents)
« Last Edit: May 07, 2013, 02:05:28 PM by samdavo »