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My guess is the equator. Since the earth is not a sphere and bulges at the equator by about 20 km in radius, maybe this is in fact further from the centre of the earth than the top of Everest.

Edited by willowbrookfarm

My guess is the equator. Since the earth is not a sphere and bulges at the equator by about 20 km in radius, maybe this is in fact further from the centre of the earth than the top of Everest.

Hmm, good point... now to combine both theories and find the highest point of elevation along the equator!

TOMTEC

Edited by TOMTEC

My guess is the equator. Since the earth is not a sphere and bulges at the equator by about 20 km in radius, maybe this is in fact further from the centre of the earth than the top of Everest.

I kinda like this idea. Why are all them satellites directly over the equator and would you weigh less during a full moon or a low tide?

Q: where is the lightest place on earth

Mount Everest would be my guess since it's the furthest point from the center of the Earth and hence might have less gravity pulling you down.

I'm with Res on this one... The force of gravity you feel at any point on the earth should be related to the distance (radius) you are from the centre of the earth (mass) and the amount of mass enclosed within that radius. Theoretically, if you could get to the exact center of the earth, you would experience zero gravity as the radius would now equal zero, but we're talking "on" earth... not "in" earth. So we increase the radius by 8km or so (~height of everest) above sea level, without adding an equal amount of mass (not much earth up here!) so the effect of gravity will be reduced... but probably not enough to be noticed due to the lack of oxygen! Atleast that's what I seem to remember from all those Physics classes when I wasn't blowing things up!

TOMTEC

I would also agree with you had I not read an article a few years ago.

It basically said that the force of gravity is not universal but varies and the place with the most variation in favor of lightness was in a body of water just south of ________.

For a answer I will except the name of the country its closest to.

Edited by QuigleyJones

The force of gravity you feel at any point on the earth should be related to the distance (radius) you are from the centre of the earth (mass) and the amount of mass enclosed within that radius. Theoretically, if you could get to the exact center of the earth, you would experience zero gravity as the radius would now equal zero, but we're talking "on" earth... not "in" earth. ... Atleast that's what I seem to remember from all those Physics classes when I wasn't blowing things up!

Actually, if you assume that the shape of the Earth is a sphere (for mathematical ease), the force of gravity inside the Earth is constant from the centre of the Earth until you reach the surface. It's a simple proof we learned in a second year mechanics course.

The force of gravity you feel at any point on the earth should be related to the distance (radius) you are from the centre of the earth (mass) and the amount of mass enclosed within that radius. Theoretically, if you could get to the exact center of the earth, you would experience zero gravity as the radius would now equal zero, but we're talking "on" earth... not "in" earth. ... Atleast that's what I seem to remember from all those Physics classes when I wasn't blowing things up!

Actually, if you assume that the shape of the Earth is a sphere (for mathematical ease), the force of gravity inside the Earth is constant from the centre of the Earth until you reach the surface. It's a simple proof we learned in a second year mechanics course.

The force of gravity you feel at any point on the earth should be related to the distance (radius) you are from the centre of the earth (mass) and the amount of mass enclosed within that radius. Theoretically, if you could get to the exact center of the earth, you would experience zero gravity as the radius would now equal zero, but we're talking "on" earth... not "in" earth. ... Atleast that's what I seem to remember from all those Physics classes when I wasn't blowing things up!

Actually, if you assume that the shape of the Earth is a sphere (for mathematical ease), the force of gravity inside the Earth is constant from the centre of the Earth until you reach the surface. It's a simple proof we learned in a second year mechanics course.

The force of gravity you feel at any point on the earth should be related to the distance (radius) you are from the centre of the earth (mass) and the amount of mass enclosed within that radius. Theoretically, if you could get to the exact center of the earth, you would experience zero gravity as the radius would now equal zero, but we're talking "on" earth... not "in" earth. ... Atleast that's what I seem to remember from all those Physics classes when I wasn't blowing things up!

Actually, if you assume that the shape of the Earth is a sphere (for mathematical ease), the force of gravity inside the Earth is constant from the centre of the Earth until you reach the surface. It's a simple proof we learned in a second year mechanics course.

Hmmm...not sure why, but my previous post appeared three times. Is there a way I can delete two of them?

Edited by shearzone

My guess is the equator. Since the earth is not a sphere and bulges at the equator by about 20 km in radius, maybe this is in fact further from the centre of the earth than the top of Everest.

Hmm, good point... now to combine both theories and find the highest point of elevation along the equator!

TOMTEC

In fact, the top of Mount Everest is closer to the centre of the earth then the bottom of some of the deepest ocean trenches.

(But I still don't have an answer.)

I would also agree with you had I not read an article a few years ago.

It basically said that the force of gravity is not universal but varies and the place with the most variation in favor of lightness was in a body of water just south of ________.

Just south of... the Bermuda Triangle, perhaps?

Are you looking for the dead sea, which is the saltiest sea, and therefore you would be the most buoyant in it?

Are you looking for the dead sea, which is the saltiest sea, and therefore you would be the most buoyant in it?

How about just south o f Hawaii? The ocean is deep there (and water is less dense than rock therefore less gravitational pull since gravity is related to mass) also, the earth's diameter is bigger at the equator than at the poles, therefore one would be farther from the centre of gravity. Does this work?

Any point near the equator at high noon when the moon is also at its peak around the spring or fall equinox. It could also be the same alignment, but at the Tropic of Cancer during the summer solstice, or the Tropic of Capricorn for the summer solstice in the southern hemisphere.

I thought the earth was flat?

Well, one would be lighter at the equator due to the centrifugal force of the earth's rotation. Water is less dense than rock and higher elevation would mean less weight so I'll guess Lake Victoria.

Some people are getting close as it is along the equator.

Some people are getting close as it is along the equator.

Some people are getting close as it is along the equator.

The Maldives?

or perhaps here:

I am having a hard time imagining what -- if anything -- can have any appreciable effect on gravity at the earth's surface other than the moon and the sun?

Is this an effect that could be measured on a household scale, or does it require sophisticated instruments to measure?

I was thinking of Sri Lanka but after looking at the below map I'll except Maldives. Congrats shearzone.

"The Earth's gravity field is shaped by the materials deep within the planet. This exaggerated map shows the unequal distribution of gravity due to the amount or density of materials beneath the Earth's crust. The purple regions represent areas of particularly low gravity while the orange regions represent regions with the highest gravity."

"The Earth's gravity field is shaped by the materials deep within the planet. This exaggerated map shows the unequal distribution of gravity due to the amount or density of materials beneath the Earth's crust. The purple regions represent areas of particularly low gravity while the orange regions represent regions with the highest gravity."

Can you post the source for that? I'd like to look into it further.

Thanks

"The Earth's gravity field is shaped by the materials deep within the planet. This exaggerated map shows the unequal distribution of gravity due to the amount or density of materials beneath the Earth's crust. The purple regions represent areas of particularly low gravity while the orange regions represent regions with the highest gravity."

Can you post the source for that? I'd like to look into it further.

Thanks

Is this an effect that could be measured on a household scale, or does it require sophisticated instruments to measure?

You looking for an easy way to lose weight, Dano?

I remember from grade 8 science that mass and weight are 2 different things. So I guess the bathroom scale would show less weight, but if you used a T scale you'd have the same mass.

Is this an effect that could be measured on a household scale, or does it require sophisticated instruments to measure?

You looking for an easy way to lose weight, Dano?

Well, I know some people won't want to hear this, but I have to struggle more to keep my weight UP where it belongs.

I checked out the links, and my skepticality has been satisfied but my crazing for more info was not, since there was basically no info. I still think you would need ingenious instrumentation along these lines to even measure the difference.

By the way, for any one who wants to weigh less without moving to the Maldives, just move slowly, because the faster you move, the more mass you have, compared to others who are moving slower. Yeah, that's it. (And remember, mass turns into weight in a gravity field.)

What was the question ?

What was the question ?

What was the question ?

WooHoo I finally got one!!! Sorry about the delay. I was camping in Jasper NP and soaking in the Miette Hot Springs. OK, here's a question that does not involve mass, proper mass or any other form of special or general relativity.

GPS monitoring has greatly enhanced the observation of the motions of tectonic plates and the deformation of the Earth's crust.

1) What is the name of the fastest moving plate and how fast is it moving?

2) What is the geologic feature to which this motion is referenced to?

What was the question ?

WooHoo I finally got one!!! Sorry about the delay. I was camping in Jasper NP and soaking in the Miette Hot Springs. OK, here's a question that does not involve mass, proper mass or any other form of special or general relativity.

GPS monitoring has greatly enhanced the observation of the motions of tectonic plates and the deformation of the Earth's crust.

1) What is the name of the fastest moving plate and how fast is it moving?

2) What is the geologic feature to which this motion is referenced to?

I'll take a stab at this one --

1) The Pacific Plate

2) Continental Drift

2) What is the geologic feature to which this motion is referenced to?

This is a good question! If all the land mass is moving, then what frame of reference are the measurements taken from?

The only thing I can think of is the poles.

2) What is the geologic feature to which this motion is referenced to?

This is a good question! If all the land mass is moving, then what frame of reference are the measurements taken from?

The only thing I can think of is the poles.

My guess.. the fastest moving plate is the Pacific Plate

The reference point I would think would be hot spots in the oceanic crust, most notably the Hawaiian Islands.

2) What is the geologic feature to which this motion is referenced to?

This is a good question! If all the land mass is moving, then what frame of reference are the measurements taken from?

The only thing I can think of is the poles.

Oops... forgot to mention how fast it is moving. Considering most plates move about 2-3 cm each year. My guess is that the Pacific plate is close to 10 cm per year.

1) What is the name of the fastest moving plate and how fast is it moving?

2) What is the geologic feature to which this motion is referenced to?

1) Isn't that the Indian subcontinent that's moving the fastest (in a northerly direction?)

2) This motion is creating the Himalayan mountains

2) What is the geologic feature to which this motion is referenced to?

This is a good question! If all the land mass is moving, then what frame of reference are the measurements taken from?

The only thing I can think of is the poles.

Oops... forgot to mention how fast it is moving. Considering most plates move about 2-3 cm each year. My guess is that the Pacific plate is close to 10 cm per year.

You got it! The Pacific plate is moving at ~ 10 cm/year or 10 km/million years with respect to the hot spot responsible for the Hawaiian Islands. On to you Freelancer.

Ahh.. I knew that BSc in Physical Geography would come in handy one day!! Okay, to continue with the same theme:

Name the Canadian geophysicist / earth scientist who first popularized the concept of "hot spots" in the Pacific Plate? He was a follower of early plate tectonic gurus Alfred Wegner and Harry Hess and was also the first principal of the "college" where I received my B.Sc.

That's gotta be John Tuzo Wilson... and for a related cache, check out GC8535 - Every Cache Moves

TOMTEC

Correct. J. Tuzo Wilson. UofT Professor for nearly 30 years, one time Director of the Ontario Science Centre, and the first principal of Erindale College, now University Of Toronto at Mississauga. When I was a student at Erindale my email address (and you could hardly call it email, at the time I was the only one I knew with an email address) was @tuzo.erin.ca. Thanks for the link to the cache... I had no idea it existed, it is on my to do list now. On to you TOMTEC.

Alright, let's go for a simple cycling related math question… Haven't had one of these yet. Take a standard 26” wheeled mountain bike with a 42-32-22 toothed crankset and a 11-32 toothed cassette (rear cog). If you were pedaling in the fastest gear at exactly 100rpm, what speed (in km/h) would you be able to maintain?

Bonus Points… what is the distance traveled (in inches, rounded to the nearest inch) during one complete pedal revolution in this gear?

TOMTEC

Alright, let's go for a simple cycling related math question… Haven't had one of these yet. Take a standard 26” wheeled mountain bike with a 42-32-22 toothed crankset and a 11-32 toothed cassette (rear cog). If you were pedaling in the fastest gear at exactly 100rpm, what speed (in km/h) would you be able to maintain?

One turn of the crank is 42/11 turns of the back wheel.

One turn of the back wheel is 26*pi*.0254 meters is .0000254 km.

100 turns of the crank in one minute is 6000 turns in an hour.

So throw everything into the blender and you get

(42/11) * (26*pi*.0000254) * 6000

I understand that this is TOMTEC's usual crusiing speed on his bike.

Bonus Points… what is the distance traveled (in inches, rounded to the nearest inch) during one complete pedal revolution in this gear?

(42/11) * 26*pi ~= 312 in.

dave

312 in.

Hey, it's a basic math question... you don't need me to confirm that you are, indeed, correct!

As far as 47.5km/h being my cruising speed... you're close! That's actually pretty much the average speed we run at for the midweek crit races. Maybe next time I'll get people to guess the highest speed I've obtained during a sprint finish... he he.

Over to you...

TOMTEC

One of the items from Dave Ulmer's Original Stash was recently for sale on eBay.

1. What was it?

2. What did it sell for? (Or if it didn't sell, what was the reserve price?)

dave

(Edit: embarrassing t7po)

Edited by dabhid07

One of the items from Dave Ulmer's Original Stash was recently for sale on eBay.

1. What was it?

2. What did it sell for? (Or if it didn't sell, what was the reserve price?)

It's gotta be the can of beans! And they are probably still safe to eat...

As for the selling price, I have no idea... But it's replacement cost should only be around 99 cents!

TOMTEC

- Mental Note: Add can of beans to contents of next cache.

The original can of beans was up for sale last month on EBay with a reserve of \$7500. but I don't think there were any bidders. I saw it discussed on the gc.com forums and also on vigps.com.

The original can of beans was up for sale last month on EBay with a reserve of \$7500. but I don't think there were any bidders. I saw it discussed on the gc.com forums and also on vigps.com.

Landsharkz wins the kewpie doll. eBay listing is here. The can has been through a shredder, so whatever bean fragments are still in the can are probably not edible.

Next question is from Landsharkz.

dave

We asked Jeremy for some downtime in the forums because we needed time to think up a new question

Question:Where is the world's largest lake inside a lake?

We asked Jeremy for some downtime in the forums because we needed time to think up a new question

Question:Where is the world's largest lake inside a lake?

I believe that would be lake Manitou on Manitoulin island.

chris-mouse has got it! A large morcel of cheese for the mouse!

The world's largest lake inside a lake, Manitou Lake, is located on the world's largest lake island, Manitoulin Island, which is located on Lake Huron.

I did my elementary geography schooling in the UK (before we emigrated), so when I went looking for a cool Canadian fact yesterday I was quite surprised to find this little tidbit.

Over to the clever little rodent

OK, this one might be a bit harder:

What is special about the location at N47° 19.013'; W80° 45.930'?

What is special about the location at N47° 19.013'; W80° 45.930'?

I believe that is Ishpatina Ridge, the highest point in Ontario... at something like 690 meters (That's a speed bump to you West coasters) It's a great view from the top of the fire tower at the summit though!

TOMTEC

What is special about the location at N47° 19.013'; W80° 45.930'?

I believe that is Ishpatina Ridge, the highest point in Ontario... at something like 690 meters (That's a speed bump to you West coasters) It's a great view from the top of the fire tower at the summit though!

TOMTEC

Yup, you got it. Over to you TomTec

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