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Garden Gnome Tests Earth's Gravity
sciencehabit writes "Researchers have long hypothesized that objects weigh less at Earth's equator because the planet's spin and shape lessen gravity's pull there versus at the poles. Satellite accelerometers have confirmed this, but a digital scale manufacturer decided to test things the old-fashioned way. Enter the Kern garden gnome. When placed on a scale at the South Pole, the intrepid ornament weighed 309.82 grams versus 307.86 grams at the equator, a difference of 0.6%."
I buy my drugs at the North pole.
So it has come to this.
That should be more than enough for heavy metal arbitrage.
If video games influenced behavior the Pac Man generation would be eating pills and running away from their problems.
Next to the standard kilogram, there will be a standard garden gnome.
0.6% is not a small number. I'm looking forward to discussing the next international health survey and asking "Did you normalize your weights for gravitational variance?"
NB: The message above might reflect my opinion right now, but not necessarily tomorrow or next year.
I know that, whenever I see a garden gnome, I feel a powerful urge to use it to test gravity. Especially if there's a large asphalt or cement driveway nearby.
#DeleteChrome
Occupy the South Pole!
"When placed on a scale at the South Pole, the intrepid ornament weighed 309.82 grams versus 307.86 grams at the equator..."
The grams is a unit of mass, which is invariant depending on gravity. The metric unit of weight is the kilopond.
-- Insert witty one-liner here. --
Does it also test the Earth's travelocity?
(I'm so, so sorry. I'm a sick man. I need help.)
the mass of the earth is the same whether it's spinning or not. the spin causes centripetal acceleration, which is in the opposite direction of the acceleration due to gravity. i.e. the 'centrifugal force' cancels out a little bit of the 'gravitational force', but the gravity force itself is only slightly different because of shape, not because of the spin itself.
or am i missing something?
It's sometimes an acceptable shorthand to express a weight in grams, but not when that's the whole point of the story. The _mass_ in grams is (hopefully) not changing. The _weight_ in newtons (or any other dimensionally-correct unit you prefer) is what's changing.
If you're using a device that measures weight and reports it in grams, then you need to re-calibrate it against a known reference mass at each new location.
p.s. don't forget about buoyancy. Accurate measurements need to be done in a vacuum chamber.
how much was lost during transport?
Pretty certain it had the same number of Gnomons (Gn) at both locations, but we'll have to wait for the reports to come in from GIT (Gnomic Institute of Technocracy)
A feeling of having made the same mistake before: Deja Foobar
Does it also test the Earth's travelocity?
Imagine a travel agency called "Traspeed". It'd be like Hotwire or Priceline, filling unused seats on a flight and unused rooms in a hotel. Except you wouldn't even get to pick where your vacation will be, just "a ski resort" or "a beach resort" or "an amusement park" or the like. So you never know where you're going, but you know how fast you'll get there.
The earth's shape is a geoid, which is flattened compared to a sphere. Because the distance from center of mass to the surface is smaller at the poles than at the equator, gravity is stronger at the poles, and the weight of an equal mass is greater.
1) The object's mass
2) The object's theoretical weight difference at the different locations
3) The error bounds on the measurement.
Without any of this, I have no idea if this is shocking news, or merely expected. And I'm on slash dot, while it might be contained within the article, I don't come here to RTFA.
Afterwards, did they blast it into space?
Ignorance and prejudice and fear
Walk hand in hand
and if the earth sped up by a huge amount, things would 'weigh' a lot less. in fact, some things would go flying off into space... if earths outer edge somehow managed to reach escape velocity (in some unimaginable cataclysm). gravity itself wouldn't have changed though.
This sentence is completely without sense. Barring relativistic effects, the object's mass in grams remains constant. One of those masses is correct (possibly), the other is a measuring error introduced by a scale not calibrated correctly for local gravity. The actual discrepancy is in the weight of the object in Newtons. This is, like, middle-school physics stuff.
That's like using an iron yardstick to determine that one meter in summer is equal to about 1.005 meters in winter, and conclude that space itself expands and contracts.
an interesting question about your point is this - if you take stuff to the top of a mountain, does it weigh 'more' or 'less' than at sea level?
More. High school physics teaches us that F=(GM1M2)/R squared
You mean less, I hope. It weighs less at the top of a mountain than it would at sea level because the distance(R) is bigger.
sent from my slashdot browser.
changes gravity.
i.e. they are specifically claiming that 'gravity is different due to the spin'. but the spin is only relevant in that the earth's "geoid" shape is thought to be due to the spin. the spin itself doesnt change how gravity works. at least not that i am aware of. if the earth stopped spinning all of a sudden, but remained a geoid... then the gravity at the poles wouldn't change, nor would the gravity at the equator. the only thing gone would be the centripetal acceleration due to spin. things would 'weigh less' because they lacked centripetal acceleration not because gravity suddenly changed.
an interesting question about your point is this - if you take stuff to the top of a mountain, does it weigh 'more' or 'less' than at sea level?
The spin does cause the Earth to be shaped like an oblate spheroid as you mention but it does alter the gravity you experience as well. The local balance of forces if you are at rest relative to the Earth involves gravitational force and an apparent force (centrifugal) caused by centripetal acceleration. This alters your effective gravity that you experience ever so slightly (ie g_eff = g_newtonian + f_cent, where f is a specific force [units ms-2 or N/kg]) .
I once heard that the reason everything falls downwards is that everything that falls UPWARDS (or sideways) have long since disappeared into space, and have therefore not been able to breed. So everything that's still here on Earth has the "fall downwards"-gene still present.
Source: http://www.youtube.com/watch?v=8SNZuOHnFDk (In Swedish, but you get the idea.)
"Bees!" - Eddie Izzard
Has an equivalent test been done with KDE?