posted May 03, 2004 01:09 PM
More physics - Part 3 My friend and I were working on a cabinet today. Of course using a square and a level to make sure it would sit level where we are putting it, which is not level ground. I realized that the "level" is straight. But with the curvature and roundness of the earth if you got a long enough level that is perfectly level to the ground for the full length of the level it would not be straight. I managed to get him to finally understand that. Then we started discussing the fact that things that are supposedly level like the concrete slab that a house is on. IF it were perfectly level at all points it would not be flat. But as they use very long 4x4 boards to make it flat. Now, thinking in perfect physics not real life actual earth physics, if you extend this perfectly straight line out for thousands of miles you would get a definite grade going out from the earth. I think that if you placed a ball on the end of this many mile surface, assuming there is no friction as there is in perfect physics, it would rill to the origin as it is closer to the center of the earth. He thinks that as the surface is level from and origin and is completely flat the ball will just it there and not rolls at all. Any light you could shed on this would be great.
posted May 03, 2004 02:31 PM
Holy smokin brain cells, now i have to worry about going in circles when i think i am going straight , while remaining Sober.
posted May 03, 2004 02:34 PM
If the one end of your line starts out level, and projects out straight, perpendicular to the radius of the earth, the line will be 1 foot away from the earth in a mere 1.225 miles.
____________
The problem with other countries is they are all ran by foreigners.
posted May 03, 2004 02:46 PM
sure it would roll to the point where it is closest to earth. the obvious way of looking at it is that it is on a slope relative to the earth, so it will roll same as it would roll down any other sloped surface. if he needs a more mathematical explanation, realize that any object wants to sit at the lowest place possible, and the lowest means the closest to the earth, so given zero friction of course it will roll (well, slide actually) to the point of the surface closest to the earth.
posted May 03, 2004 02:54 PM
Perhaps, beans, you should start a campaign to rename the "level" to the "perpendicular" .. .you may be more comfortable knowing that the center of you house, or surface you are "leveling" is infact not level, but "perpendicular" to an axis you have drawn to the center of the earth.... . from that point (your "leveling point" or where the "bubble" is) you can be assured that as long as you work outwards from your established "perpendicular" you can be assured that things are "level" or in reality the same plane as your established starting point...
you are correct in stating that if you were to check for level at one point of a foundation and then check, say 30' farther down, that it would not be level but instead be curved.
____________ What business is it of yours where I'm from, Friendo?
posted May 03, 2004 03:26 PM
If you placed a long, level rigid plank accross the north pole, a ball would roll to the pole. If the plank was extremly flexible, it would bend to conform to the ground. The plank would appear only to be level at the point of contact. At the extremities, a long, rigid plank would not "read" level, the bubble would float to indicate the ends of the plank were high. Sighting along a string and a weight tied to the plank would point to the center of the Earth.
Of course, if you want the ball to come to rest at the center/origin, you have to have some resistance, otherwise it would roll back and forth endlessly. And, since you have resistance, I doubt it would come to rest at the exact center/origin.
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posted May 03, 2004 05:12 PM
OK BEANS, YOU HAVE WAY TOO MUCH TIME ON YOUR HANDS....GET A JOB, OR GO RIDING DAM MAN.....LOL
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When in doubt, lean farther and go faster....
posted May 03, 2004 05:25 PM
Ok, Ok, Ok, let me just gather my-self for a minute and try to catch up . I have a college degree but not what you guys have one in. I will be back in just a minute..... I think I need to get me a cold drink.
posted May 03, 2004 08:41 PM
That's some shit you spend hours thinking about... when you're stoned ____________ Some day, you're going to run out of some days
quote:OK BEANS, YOU HAVE WAY TOO MUCH TIME ON YOUR HANDS....GET A JOB, OR GO RIDING DAM MAN.....LOL
Last time I went out riding I got a dang ticket haha...Havent you noticed I am not posting as much as my winter season norm since I am out riding all the time. Beautiful weather, but we talk a lot of physics when we are out riding during those rest stops...would make some great riding convo over a chatterbox I'm sure...
posted May 04, 2004 01:01 AM
This may sound like just talk with no real value in terms of real life. But that is not the case.
If you consider that anything level on the planet is affected by the gravity, then there is nothing truly flat that can be created with respect to the earth. In modern window and glass production, float glass using molten glass on a pool of molten tin does not create perfectly flat glass panels. The panels have the same curvature as the earth. Sure, this curvature is nearly flat and windows are windows. But what happens when you're creating a LARGE lens that's a few hundred feet in diameter?
Then there are also maritime simulations. You know those large boats? They design and build smaller models and use them in small pools first (very VERY long pools). If you want to simulate a moving boat, you will have to tow the boat on a rail. Guess what? If the rail is flat (really flat), it won't work. The rail must have the same curvature as the water's surface, which is the curvature of the earth. If not, the boat will start rising above the water as you move along as if the rail was a tangent (it's a line parallel to an actual tangent drawn to the water's curvature).
posted May 04, 2004 04:08 AM
Don't they grind and polish those lenses until they are within the scientists exacting standards?
I know somewhere I saw where they had to do that them to get them near perfect as they needed. (taking up to a year or more?)
Beans,I'm pretty sure that their method could fix "your problem".
posted May 04, 2004 08:17 AM
just because common practice leads to curved objects doesn't mean you couldn't create a flat object tangent to the earth's curvature. For the sake of theory, its possible.
quote:Erf...Maybe you need to stay outa 'northern utah'...
I'm thinking he needs to stay out of the sun . Beans you gotta get out and ride MORE. You have too much time to sit and think ____________
Hawaii no ka 'oi
Les
posted May 04, 2004 08:30 AM
Dang I've put 5000 miles on since I picked up my 12 from Dino's place at the end of March...on my second rear tire already too...riding to Seattle this weekend, all I do is ride, well most of the time
posted May 04, 2004 08:37 AM
Ride and think physics . Damn 5000 since March, I thought I was doing good at around a grand. ____________
Hawaii no ka 'oi
Les
posted May 04, 2004 09:55 AM
sounds about right to me miklos. i cant believe i just wasted half an hour calculating that not to mention that i couldnt even remember the definition of sin/cos/tan anymore!
posted May 04, 2004 10:35 AM
I gotta use that sin/cos/tan crap almost every day. Right now I'm programming C-17 parts for a horizontal machining center.
____________
The problem with other countries is they are all ran by foreigners.
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posted May 03, 2004 01:09 PM
posted May 03, 2004 02:31 PM
. I have a college degree but not what you guys have one in. I will be back in just a minute..... I think I need to get me a cold drink.
