Does Earth Weigh Anything?

This thought popped into my head while i was talking to my friend about space.

Right....So we all know that there is no Gravity in space, or we all should know that.

So given this information, Does Earth or any planet for that matter, even stars, Do any of these weigh anything in space?

reply to post by newcommer92


it has to weigh something or else the sun wouldn't be able to hold us in it's orbit ... simple as that ... if we didn't weigh anything then how would it be able to control us?

edited.Wrong

[edit on 27-2-2009 by Solomons]

Hi, newcommer92.

There is gravity **everywhere** ! !
Why do you think galaxies attract each others?

In the so called vacuum of space, there is minimum:
gravity, light, cosmic rays. . .
In some other vacuum spots, there is added to the minimum:
dust (future solar system), molecules, energy (zero-point),
and more. . .

** Now? if planets weigh anything in space? **

Consider that around the earth, the ISS weighs 75-80% of
its weigh on the ground.
Being in orbit does not mean you weigh nothing !
Your body is on the same orbit as the ISS's one.

Now suppose we could ""stop"" the earth from moving around
the sun, what will happen ? It will fall towards the sun, unless
we put a mega-BIG-scale between it and the sun, and. . . you
only have to read its weigh. . . B-)

Blue skies.

Thanks for replying, im new at this so i havent got all the information, was just a thought, i am learning alot though

"Weight" as we percieve it here on Earth is determined by the Earth's gravitational constant. An object's weight is subjective to the gravitational field that the object exists in. If there were two identical objects, equal in size and mass, one on Earth, and one on Jupiter, the two objects would have different percieved "weights" because of the difference in the planet's gravitational constants. Planets have a mass that is a relative constant, but their "weight" is determined by the gravitational fields that they are subject to.
That being said, yes all things in space have some weight because no matter your location in space, there is some gravitational pull (however small) from distant objects. The condition in space is not zero-gravity, but rather micro-gravity.

Originally posted by newcommer92
This thought popped into my head while i was talking to my friend about space.

Right....So we all know that there is no Gravity in space, or we all should know that.

So given this information, Does Earth or any planet for that matter, even stars, Do any of these weigh anything in space?

Hello

I think you might find this interesting enough

www.exploratorium.edu...

here you go

It would be more proper to ask, "What is the mass of planet Earth? "The quick answer to that is: approximately 6,000,000,000,000,000,000,000,000 (6E+24) kilogramsThe interesting sub-question is, "How did anyone figure that out?" It's not like the planet steps onto the scale each morning before it takes a shower. The measurement of the planet's weight is derived from the gravitational attraction that the Earth has for objects near it.

It turns out that any two masses have a gravitational attraction for one another. If you put two bowling balls near each other, they will attract one another gravitationally. The attraction is extremely slight, but if your instruments are sensitive enough you can measure the gravitational attraction that two bowling balls have on one another. From that measurement, you could determine the mass of the two objects. The same is true for two golf balls, but the attraction is even slighter because the amount of gravitational force depends on mass of the objects.

Newton showed that, for spherical objects, you can make the simplifying assumption that all of the object's mass is concentrated at the center of the sphere. The following equation expresses the gravitational attraction that two spherical objects have on one another:

F = G * M1 * M2 / R2

R is the distance separating the two objects.
G is a constant that is 6.67259x10-11m3/s2 kg.
M1 and M2 are the two masses that are attracting each other.
F is the force of attraction between them.
Assume that Earth is one of the masses (M1) and a 1-kg sphere is the other (M2). The force between them is 9.8 kg*m/s2 -- we can calculate this force by dropping the 1-kg sphere and measuring the acceleration that the Earth's gravitational field applies to it (9.8 m/s2).

The radius of the Earth is 6,400,000 meters (6,999,125 yards). If you plug all of these values in and solve for M1, you find that the mass of the Earth is 6,000,000,000,000,000,000,000,000 kilograms (6E+24 kilograms / 1.3E+25 pounds).

1 It is "more proper" to ask about mass rather than weight because weight is a force that requires a gravitational field to determine. You can take a bowling ball and weigh it on the Earth and on the moon. The weight on the moon will be one-sixth that on the Earth, but the amount of mass is the same in both places. To weigh the Earth, we would need to know in which object's gravitational field we want to calculate the weight. The mass of the Earth, on the other hand, is a constant.

can ya dig it


[edit on 27-2-2009 by constantwonder]

Essentially, what is happening here is the confusion between mass and weight.

Mass is the... well... mass of an object. How dense an object is.

Weight is the result of gravity affecting mass. How much pressure gravity can cause a mass to exhibit force in one direction.


So technically, in zero gravity, an object has no weight, but retains mass.
It exhibits weight when gravity acts upon it in one direction.
Without gravity to pull it, it has no weight... but the mass remains waiting to be affected. Mass still directly results in inertia.

I hope this helps.

but mass causes gravity there is no such thing as zero gravity around any object with mass its impossible. If their is mass present then their is also gravity anything with mass warps the spacetime causing gravity they go hand in hand mass causes gravity causing everything within the gravitational feild to have weight

[edit on 28-2-2009 by constantwonder]

Originally posted by constantwonder
but mass causes gravity there is no such thing as zero gravity around any object with mass its impossible. If their is mass present then their is also gravity anything with mass warps the spacetime causing gravity they go hand in hand mass causes gravity causing everything within the gravitational feild to have weight

Okay let me try to explain it a different way.

If you have an object, in space, with no other objects around close enough to get a measurable gravitational effect... the only thing you have to work with is the mass of the object. The object is in effect, weightless because it's not accelerating toward another object with any measurable force.

Yes, a SINGULAR object with mass has a gravitational field... but it can't accelerate toward itself, hence, it can't have weight until it has something else to accelerate toward.

Now, bring another object close to it, or at least enough to get a measurable gravitational effect, and then you can begin measuring how much pressure the objects are under in their acceleration toward each other.

Weight, is the resulting affect that TWO or more objects with mass have on each other.

Mass is the measured accumulated density of ONE object.

An object can't have weight unless it's accelerating toward ANOTHER objects mass. (Another, other than itself... as in, it only comes into play when there's MORE than one object to use for measurement.)

Yes, technically everything in the universe is being affected by all other objects, but not enough to be worthy of measurement. At least, not until they get close enough to actually witness their acceleration.


So,
Weight : Accelerative force exerted on two or more objects caught in each others gravitational pull... the level of force by which they attract each other, DEPICTED by their distance, and masses.

Mass : The accumulated density of an object, by which other objects can exert a gravitational force on.

They are NOT the same thing. But they are related.

You can't have weight without mass this is why people confuse the two... but you also can't have weight without the gravitational pull of ANOTHER object within a distance close enough to have a measurable effect.


Does this clear it up?


[edit on 28-2-2009 by johnsky]