Has anyone considered the weight of aircraft here? At any time there must be hundreds of aircraft not in contact with the earth. If they were evenly distributed around the planet their effect might be cancelled and simply reduce the overall weight by the total of all the planes but as most will be over North America and their combined gravitational influence would be cumulative this would mean that not only is weight missing from the Earth but actually most of it is from North America. Thus if you appear to put on weight when on vacation abroad don’t panic, you will lose it again back in the USA.
I tried the two scale thing through a glass table. The Earth officially weighs about -25 pounds.
That post above saeren’s really creeped me out.
I mean . . . dude.
What if all of the Chinese land their airplanes at the same time ??
It could lead to a tidal wave that would wipe out the coastline of west North America !
I think the great thing about this thread is that I cannot tell who is being serious and who is being silly. Super.
I for one, am dead serious.
Yours,
NM
Don’t forget about all of the birds. Seeing as it’s either this or doing my English assignment, I’ll calculate the number of birds in the world.
From my window, I see…uh…::counts on fingers:: 11 birds.
I’ll allow a brief pause while you think about the fact that I counted to 11 on my fingers.
OK, assuming I see .000000000000000000000000001 % of the birds in the world (a reasonable assumption, since none of you guys know how big my window is.). Multiply some numbers, and you get…47 billion birds, give or take 17. At…hmm…4 pounds (19 kilograms) per bird, that’s approximately a quarter trillion pounds of bird. Even taking into account that many of the birds are used to make food at Taco Bell, those winged demons still have the potential to cause some serious damage if they all decided to dive-bomb the White House at once.
Turned the scale upside down? ever think that maybe if you did this the weight of the scale would cause you to get 5 pounds? im no expert on weights of scales but i think 5 pounds would be a fairly good number, and after comparing the weight of the sclae and the earth, id have to go with believing that the scale weighed 5 punds not the earth.
Crwbr
Ya think?
Nah… nevermind. that was just another one of my delusional ramblings.
Crwbr
Hey, wait…crwbr might be on to something there…we need to be really accurate about this 5 pound deal…did you make sure there was no dust being weighed as well as the table? You might be off by .000003 pounds…you might want to double check.
The Scientific American article said that the 3 Trillion tons “missing” was due to the weight that the force of gravity contributes which is a negative amount. This force is what holds all the sub-pieces of the earth together and is what they said why “the earth weighs less than the sum of its parts”.
For your scale experiments to be scientifically valid you must weigh the earth whole AND disassembled.
Now I figure once we disassemble the earth there will be far too many pieces for just the two people who have done the scale measurements. We need everyone in here to recruit as many people as we can with scales to tackle an experiment this big.
And like all experiments of this type once all the fun work is over with, no one will want to clean up the mess. So we will also need a volunteer to reassemble the earth afterwards.
Nit picking about the dust on the scale is meaningless without a draft shield. How about a draft shield? No one has mentioned a draft shield for the scale.
According to my understanding, a flying object is supported on a column of air and, ultimately, by the earth. I learned this from an old puzzle book which proposed that an open bird cage was hanging from a scale inside a room. A bird weighing one pound occasionally entered the cage, not touching it but just flying around. The question was, would the scale register anything? The answer was that yes, the scale would register one pound while the bird was in the cage, because of the aforementioned column of air. Now flying planes would also have to be supported on, in effect, columns of air, albeit tremendously complicated ones, no? Therefore, wouldn’t all aircraft, birds, levitating humans, etc., ultimately be supported by the earth at all times?
DaveoRad, I think the cage would have to be air tight, or at least I hope so. What happens when a 747 flies over your house (or you for that matter)? Neither of you feels it. The weight of the plane is distributed far and wide.
DaveoRad, there’s not a whole lot here really, but here is a related thread.
I did some calculations, and found that the “binding energy” of the Earth (as mentioned by ZenBeam), would contribute to a mass loss of:
M[sup]2[/sup]G / Vc[sup]2[/sup]
This calculation is, of course, assuming all the goodies like a uniform density and a perfectly spherical, non-rotating planet, but even so, it only gives a value of missing mass equal to around 24 kg, for the Earth. Does somebody here know if my result is in error, because it sounds kinda low. Certainly not any Trillions of tons.
As for weighing the Earth with a bathroom scale, I think you’re all forgetting something critical. About a month ago, the planets were in syzygy, which throws off any gravimetric readings you get. I don’t know if they’re still closely enough aligned to be significant, but I’d give it a couple dozen years, just to be safe.
Sirdiesel:
I wanna know about those 4 pound birds out your window. Those are some big pigeons! Wouldn’t want to clean up after them.
Mjolnar, I want to thank you for the mental image of turning the scale upside down to weigh the earth, That will stay with me! Thank you again.
You’re all way off.
if you place the scale upside down, you missing yourself in the measurement.
You need to (carefully) stand directly between the earth and the scale, hoist it above your head. Now, take the reading. At least you will be included in the weight of the earth instead of pushing it down.
Dammit, do I have to think of everything.
Okay–I’m very pleased with the whole upside-down scale thing. It shows initiative in here. Unfortunately, two very crucial items have been mentioned in passing without their relevance to the experiment at hand being recognized:
First, the mass (and thus weight) of the earth would include the atmosphere, and therefore your five pound result does not include that added weight. I’m guessing another pound and a half, but we need a method of weighing it. The best bet, I think, is just to place the whole mess in a ziplock bag so we can weigh earth+atmosphere as a unit.
Secondly, no one is considering the effect of centrifugal force on the scale. That thing is zipping along at around a thousand miles an hour along its giant circular path. I’m thinking that to be reliable, you’ll either need to stop the earth’s rotation for a moment, or else head to the equator where you can more acurately calculate the forces involved.
When all is said and done, I predict that the earth will weigh nothing at all. Five pounds is merely a rounding error. Like Einstein clinging to a static universe, I will blindly maintain that the earth’s weight is exactly zero.
Achernar, I get the gravitational binding energy as
-3GM^2 / 5*R = -2.247 * 10^32 Joules
where M = Mass of Earth, R = Radius of Earth. Is V in your equation volume?
From Haliday and Resnick, c^2 = 8.99 * 10^16 J/kg, so the “missing” mass is
m = 2.247 * 10^32 / 8.99 * 10^16 = 2.5 * 10^15 kg or 5.5 * 10^15 lbs or 2.76 trillion tons
Of course, the mass isn’t all missing, a lot of it went into heating up the Earth’s interior.
Thanks, ZenBeam. I knew I had something wrong. Do you have a cite for that binding energy equation, or else a hint on how to derive it? And yeah, V is volume. By the way, I’m not as picky as most other Scientists. I won’t make you cite the speed of light. 
I was making a scientific guesstimate. I figure that with 3 small-to-mid-sized ostrichi and 8 unladen swallows, the average weight is around 4 pounds.