There are more Olsen twins on Earth than there are stars in the solar system
Isn’t God just amazing?
Batteries weigh less after discharging.
Hard drives weigh more with data stored on them.
There is a minimum amount of energy required to erase one bit of information (Landauer’s Principal).
This begs the question: how “heavy” IS the earth?
We know it’s massive, but weight is not mass, and weight is a function of mass accelerating through space-time because of gravity… Which… Is… relative?
So could I say that the entire earth weighs… the same as… me? Since I am the body by which the earth’s space-time relatively warps around? Or… Because I’m accelerating away from the ground at my feet, but then also thus the earth from me because of newton’s third law?
Checkmate, atheists.
Tldr: The earth weighs the same as you do, because of special relativity and newton’s third law.
Disclaimer Edit: I realize there are some semantics between force, weight, mass, etc. The purpose of this post is not the rigor of the mathematics but the enjoy-ability of being able to abstract interesting measurements. Sorry if I made any mistakes physicists! Always open to corrections :)
Of course we can weigh the earth. In your example the earth weighs nothing because you didn’t define a reference frame. Since earth is the usual reference frame we use to weigh objects, choosing the earth itself as an object to weigh does stretch our minds a bit, but we can do it.
In order to weigh something, first we must understand what weight is expressing. Weight is the measure of the gravitational pull of an object A with mass M_a on a second object M_b summed with the gravitational pull of object B on A.
Weight = G_a-on-b*M_b + G_b-on-a*M_a
In our scenario, if A is the earth and B is a non-planetary-sized object, then the pull G_a-on-b is so much larger than G_b-on-a that we can set G_b-on-a to zero for convenience.
Weight = G_a-on-b*M_b + 0
However if we are weighing an earth-sized object we will not be able to do that ;-)
Now, lets talk about the reference frame for this question.
On earth, the weight of some object B is recorded in a reference frame 6,367km from the center of a 5.97E24 kg mass object (object A).
With M(ass) and G(ravity) now defined, we can work toward W. G is easy since we are working with earth-like objects.
Back to the question “how heavy is earth”. There is only one earth, so the answer is, “In what reference frame?” Without defining a reference frame, no conclusion of any significance can be drawn.
If we want to weigh the earth in the reference frame of the surface of another earth, we would need two earths. Place a 5.97E24 mass object 6,367km from the center (radius of earth R=6.367E6m) of another 5.97E24 mass object, we will arbitrarily assign a diameter of 1,000km to each, this assignment has no bearing on the result since density is irrelevant in this context.
Where G = 9.81m/s², and the weights/masses of object A wrt B and B wrt A are W_ab/M_a W_ba/M_b respectively. In this case, M_a and M_b have the same value so we’ll reduce to M.
W_ab = G*M + G*M = 2GM
…where M is the mass of earth and G is gravitational acceleration. Voila, our answer.
I’ll leave you to do the math as that task is trivial.
I digress.
I must insist that the real question is what is the weight of a third object C (the husband of A) at a distance 8R (the distance from the bedroom door to the foot of AC’s bed) when it catches A and B (at relative distances R_ab=2Ra, assuming R_a=R_b) in AC’s bedroom when A said it was picking up their son D at a distance 2,700R (soccer practice) and B came home early from work to find them entangled in the passionate embrace of ecstasy when A told C they were too young to get married and have kids but they had a surprise pregnancy and did the best they could. Calculate the weight of C wrt AB and C wrt D assuming the positions of AB, C, and D form a straight line.
Yo momma so fat, she weighs the same as the earth!
Our planet actually gets roughly 50,000 tonnes lighter every year. (We gain 40,000t from meteors but also lose about 90,000t of hydrogen.) https://www.cbc.ca/radio/quirks/sept-1-2018-gene-editing-in-dogs-wildfire-prediction-zika-fizzles-and-more-1.4804892/is-earth-getting-heavier-or-lighter-1.4804900
Math does not check out.
40 - 90 = -50. Not 50,000.
Edit: from the source, the correct statement is “We gain 40 000 t from meteors but also lose about 90 000 t of hydrogen.“
What is heavier, one ton of meteors or one ton of hydrogen?
African or European?
Depends on gravity ;-)
Only if you use imperial units. The article uses tonnes, which is a unit of mass, not weight.
Yes but I would interpret “heavy” to be a function of weight, not mass.
Steel is heavier than feathers
Well meteors are heavier than hydrogen
Whoops my bad, my brain was in a different place while I typed.
Don’t forget to account for all the helium leaking out of balloons. That’s part of the reason the earth gets lighter too.
And every time they manufacture a Bic, the world gets a little lighter.
There’s two men in a boat, and they have three cigarettes but no matches. How do they manage to smoke?
Two men in a boat is already pretty hot for some people.
Yeah, and when you burn that fuel it gets hotter, and that makes it a little lighter too.
Wait… Weight is a until of gravitational force right? And that force weakens as objects move away from each other. So wouldn’t the planets weight become less if you made tall buildings?
Feels like the answer must be technically yes, but practically no. Would make a great xkcd “what if.”
Supernova explosions are so damn bright that they can outshine the rest of their host galaxy, but in reality, most of their energy is not even released as light. It’s carried away by an ungodly amount of neutrinos
skatole occurs naturally in the feces of mammals and birds and is the primary contributor to fecal odor.
In some ice creams, it’s added as a flavour enhancer.Conservation of mass is niche
To follow that logic, this must also be niche: when you eat a hamburger, you gain weight exactly proportional to the hamburger.
Earth actually gets lighter ever so slightly from solar winds blowing shit off the planet, and gains less back from meteor strikes than it loses.
The filling of large hydro-electric dams slows the rotation of the Earth by a measurable amount.
First pass googling this returns very low information quality. I suspect “calculable” is more more like it than “measurable” but would love to see a source where measurements had been made that showed this effect greater than standard error.
Then I also process parts of meteorites and exoplanet-like materials are used that enrich the planet with mass.
When water turns to ice it increases about 9% in volume but ice weighs about 9% less than the water.
Wouldn’t the mass remain the same, it’s the density that drops and that is why it floats
Imagine believing that relatively subtle changes in temperature change the mass of a quantity of mass.
deleted by creator
However, ice is less dense than liquid water, a property that is unique to water. Having a lower density means that ice floats when placed in liquid water. When water freezes, it occupies more space than in its liquid form because its molecules expand. Therefore, if we have 1 liter of ice and 1 liter of water, the water will weigh more because it is denser.
https://www.worldatlas.com/science/do-water-and-ice-weigh-the-same.html
Isn’t that just an explanation of density? When you freeze some water it will still have the same mass, just a slightly higher volume. As the density is lower.
Yes. You are correct.
Where does the 0.81% of the original mass disappear?
