Pool trivia: smoothness of the Earth

[RED LITE]

THIS FROM NEW YORK TIMES, SCIENCE SECTION (1989):

Q. Is the Earth really as smooth as a billiard ball?

A. ''On average, certainly yes,'' said John O'Keefe of the Goddard Space Flight Center in Greenbelt, Md.

Dr. O'Keefe, who was formerly a geodesist, or expert on the size and shape of the Earth, for the Army Corps of Engineers, pointed out that the Earth is more than 12,000 kilometers in diameter. Mount Everest is less than 10 kilometers high, and the profoundest depths of the ocean are around 11 kilometers. Thus, the most extreme variations in the Earth's surface ''are roughly on a scale of one part in a thousand,'' he said, ''and an Everest is very rare.'' The equivalent bump on a 2 1/4-inch billiard ball would be about two-thousandths of an inch, ''so most parts of the Earth are a lot smoother,'' he said.

''But smoothness is one thing and roundness is another,'' Dr. O'Keefe said. ''The Earth is flattened from top to bottom, so it is an ellipsoid, not a sphere.''

The deviation between an equatorial radius and a polar radius is about 20 kilometers, he said, so no one would want to play billiards with a ball shaped like the Earth. :smile:

 

[skor]

Depends on who's playing....

 

[TX Poolnut]

Interesting post. Thanks.

 

[ironman]

THIS FROM NEW YORK TIMES, SCIENCE SECTION (1989):

Q. Is the Earth really as smooth as a billiard ball?

A. ''On average, certainly yes,'' said John O'Keefe of the Goddard Space Flight Center in Greenbelt, Md.

Dr. O'Keefe, who was formerly a geodesist, or expert on the size and shape of the Earth, for the Army Corps of Engineers, pointed out that the Earth is more than 12,000 kilometers in diameter. Mount Everest is less than 10 kilometers high, and the profoundest depths of the ocean are around 11 kilometers. Thus, the most extreme variations in the Earth's surface ''are roughly on a scale of one part in a thousand,'' he said, ''and an Everest is very rare.'' The equivalent bump on a 2 1/4-inch billiard ball would be about two-thousandths of an inch, ''so most parts of the Earth are a lot smoother,'' he said.

''But smoothness is one thing and roundness is another,'' Dr. O'Keefe said. ''The Earth is flattened from top to bottom, so it is an ellipsoid, not a sphere.''

The deviation between an equatorial radius and a polar radius is about 20 kilometers, he said, so no one would want to play billiards with a ball shaped like the Earth. :smile:

Oh yea, go play on the reservation.

 

[swrooster]

Man oh Man

Oh yea, go play on the reservation.

The four corners area, good players, bad equipment!! Advantage locals, they are used to playing with flat spots and sloping tables. LOL debris flew off the balls on the break.

 

[Bob Jewett]

THIS FROM NEW YORK TIMES, SCIENCE SECTION (1989):
.....The deviation between an equatorial radius and a polar radius is about 20 kilometers, he said, so no one would want to play billiards with a ball shaped like the Earth. :smile:

That's true, but I've seen pool balls that were out of round more than that. You could get some interesting rolls if the big end was on one side.

 

[PoolBum]

THIS FROM NEW YORK TIMES, SCIENCE SECTION (1989):

Q. Is the Earth really as smooth as a billiard ball?

A. ''On average, certainly yes,'' said John O'Keefe of the Goddard Space Flight Center in Greenbelt, Md.

Dr. O'Keefe, who was formerly a geodesist, or expert on the size and shape of the Earth, for the Army Corps of Engineers, pointed out that the Earth is more than 12,000 kilometers in diameter. Mount Everest is less than 10 kilometers high, and the profoundest depths of the ocean are around 11 kilometers. Thus, the most extreme variations in the Earth's surface ''are roughly on a scale of one part in a thousand,'' he said, ''and an Everest is very rare.'' The equivalent bump on a 2 1/4-inch billiard ball would be about two-thousandths of an inch, ''so most parts of the Earth are a lot smoother,'' he said.

''But smoothness is one thing and roundness is another,'' Dr. O'Keefe said. ''The Earth is flattened from top to bottom, so it is an ellipsoid, not a sphere.''

The deviation between an equatorial radius and a polar radius is about 20 kilometers, he said, so no one would want to play billiards with a ball shaped like the Earth. :smile:

Yep, it's true. The surface of the earth is smoother than a baby's behind.

A really, really, big baby.

With a lopsided behind.

 

[Jaden]

smoothness....

Even with a variance of twenty KM, that is a 1 in 318 difference when the earth's radius is over 6,000 km. So a 1 in 318 difference in a 2.25 inch ball would be 7000ths of an inch, still not much when looking at it in scale and prbably not enough to make the ball do anything funky.

Jaden.

 

[Nostroke]

what about that old deal where 'IF' you put a steel band around the earth and tightened it snug. Now you add a 10 feet in length to the band-How snug is it now?

It's 18" above the earths surface all the way around or very close to it IIRC.

 

[dr_dave]

That's true, but I've seen pool balls that were out of round more than that. You could get some interesting rolls if the big end was on one side.

If you can't find balls with "big ends," novelty weighted balls allow for some creative shot making, especially if you use the magical "cue swoop and twist" method. :wink: For example, see:

http://billiards.colostate.edu/normal_videos/new/NVB-33.htm​

Regards,
Dave

 

[Bob Jewett]

If you can't find balls with "big ends," novelty weighted balls allow for some creative shot making, especially if you use the magical "cue swoop and twist" method. :wink: For example, see:

http://billiards.colostate.edu/normal_videos/new/NVB-33.htm​

Regards,
Dave

I've played on a table where the eight in the side was no problem except to judge the speed.

 

[Scott Lee]

Jaden...Since a human hair is 4/1000's of an inch, this brings new meaning to "missed it by a hair", or "I hit a hair too much english"! LOL :grin:

Scott Lee
www.poolknowledge.com

Even with a variance of twenty KM, that is a 1 in 318 difference when the earth's radius is over 6,000 km. So a 1 in 318 difference in a 2.25 inch ball would be 7000ths of an inch, still not much when looking at it in scale and prbably not enough to make the ball do anything funky.

Jaden.

 

[dr_dave]

I've played on a table where the eight in the side was no problem except to judge the speed.

... because of how far out the pocket was cut?

Dave

 

[Poolplaya9]

what about that old deal where 'IF' you put a steel band around the earth and tightened it snug. Now you add a 10 feet in length to the band-How snug is it now?

It's 18" above the earths surface all the way around or very close to it IIRC.

I would have guessed that an extra 10 feet would only have raised the band just fractions of an inch. I calculated it myself because at first thought 18 inches doesn't sound accurate, but I came up with roughly 19.1 inches if the band was at the equator, so you are definitely right on. After thinking about it for a minute it does make sense, but it isn't what you would expect at first thought.

 

[Bob Jewett]

... because of how far out the pocket was cut?

Dave

No, because of the tilt. A spot shot on that table could be played as a full-ball shot as medium-slow speed.

 

[Fatboy]

THIS FROM NEW YORK TIMES, SCIENCE SECTION (1989):

Q. Is the Earth really as smooth as a billiard ball?

A. ''On average, certainly yes,'' said John O'Keefe of the Goddard Space Flight Center in Greenbelt, Md.

Dr. O'Keefe, who was formerly a geodesist, or expert on the size and shape of the Earth, for the Army Corps of Engineers, pointed out that the Earth is more than 12,000 kilometers in diameter. Mount Everest is less than 10 kilometers high, and the profoundest depths of the ocean are around 11 kilometers. Thus, the most extreme variations in the Earth's surface ''are roughly on a scale of one part in a thousand,'' he said, ''and an Everest is very rare.'' The equivalent bump on a 2 1/4-inch billiard ball would be about two-thousandths of an inch, ''so most parts of the Earth are a lot smoother,'' he said.

''But smoothness is one thing and roundness is another,'' Dr. O'Keefe said. ''The Earth is flattened from top to bottom, so it is an ellipsoid, not a sphere.''

The deviation between an equatorial radius and a polar radius is about 20 kilometers, he said, so no one would want to play billiards with a ball shaped like the Earth. :smile:

wow the timing of this is a trip, i was thinking about this the other night, it just popped into my mind, i was gonna make a post about it, the deepest ocean is about 37,000 feet which is nothing, the ocean is just a film of water on the globe.

 

[Renegade]

maybe that's the reason the planets are spherical. God likes to play pool!

 

[memikey]

maybe that's the reason the planets are spherical. God likes to play pool!

Thankfully not too often, the last time he tried to carom the earth off the moon and into a black hole all the dinosaurs were wiped out:smile:

 

[BigDogatLarge]

Thankfully not too often, the last time he tried to carom the earth off the moon and into a black hole all the dinosaurs were wiped out:smile:

so, Armageddon is a break and run???

Dwight

 

[smoooothstroke]

1889

Were the balls made of ivory then,or bakelite or..?