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Warning: This may or may not be a really stupid question.
Does the weight of the earh change? Has the population increase over the history of man and before caused the earth to get "heavier"? Or does it balance itself out by the amount of food we eat? What about construction? We build all these huge buildings which obviously we consume natural resources to make them, but does that really matter?
Just something thats been on my weird mind as of late and I thought I would offer it up for comment.
Just because there is more people doesn't equate to weight change. The same molecules were already here. Something isn't made from nothing, in other words. It's curious because as I think of it, gravitational effects on the earth change. If you take a bowling ball and move it around the earth, you will notices slight differences in the gravitational pull on the object. So the "weight" of the earth should be constantly shifting. Then you could get into the argument off mass vs. weight vs. gravity vs. acceleration etc. Short answer, yes? The earths mass is constantly being redistributed effecting weight, depending on how it's measured. What does happen for sure though; is space debris is constantly hitting earth and that adds to weight.
The old girl gains weight as well. The amount of space dust and other materials that drop into the atmosphere and are added to the planetary mass amounts to several (hundreds? thousands?) tons per year, IIRC.
My guess is that it would only be significant, in comparison to the total planetary mass, if measured over hundreds or thousands of years.
By the same token...
If I burn or consume combustibles, such as wood and oil, I have a small amount of residue and smoke. Do the byproducts add up to the whole? (I don't know myself, I'm just offering the thought)
I got into one of these discussions about HEAT , it's never lost, its just transferred somewhere else. When you refrigerate you don't cool anything , you remove the heat from it
matter can't be destroyed ...if you smoke a joint and collect all the smoke and ash and everything that burned up you'll have the same mass. Also if you build something matter doesnt dissapear it just goes into another form.
I think people do matter, first you were a sperm so you didnt do much to the weight but later you becoma a baby and a man and then old and die. So the molecules weren't there, at least not that many in the start as in the end. So the wight does change but not in such large numbers. If a man is born the earth wights more. When somebody dies it doesnt matter because matter can't be destroyed even if you burn the man it doesnt matter. Hope i make sense to someone. And also if you think it looses weight because the smoke goes into the atmospehere and it is not on Earth anymore you are wrong because they form clouds and then it's raining, even chemicals come down because there is Acid Rain.Quote:
Just because there is more people doesn't equate to weight change. The same molecules were already here.
Ok let's say you remove all the heat from the let's say some "meat" and the temperature is 0 Celcius, but the refrigirator aint gonna stop cooling it just because there aint heat anymore.Quote:
When you refrigerate you don't cool anything , you remove the heat from it
MemorY: I beg to differ on both of your "that's not true"-statements...
People being born does not matter to the weight of the earth (although the term "weight" should not be used in this discussion, imo... "mass" would be better"... the weight of the earth depends on the circumstances it's in (literally). Every second, the weight of the earth changes, simply because of the surrounding environment. Compare it to going to the moon: your weight will change (you'll weigh less), but your mass won't...).
People growing up get their energy from the earth's resources. You eat something (taking away from the weight of the earth itself, but making up for it by putting it in your tummy), you digest it (taking away some of the stuff in your tummy, making up for it by putting it in your muscles/whatever - the rest of the stuff, well, we all know what happens to that). The weight of the earth never changes.
Fourdc is right when he says that cooling something is taking away from its heat:
Everything on this earth is energy, for everything is build from molecules. Molecules move, therefore they are "in heat"...heh. Try using the Kelvin scale in stead of Celsius/Fahrenheit:
the absolute zero in Kelvin is -273 Celsius. The absolute zero is the point where all molecules stop moving. Cooling something is simply reducing the speed of the molecules, or taking away the heat from it.
Hrm, good points there. I love it when i'm wrong because i learn something :).
In physics we learn all this conservation of this and conservation of that. This has lead me to believe that everything on earth is conserved and that the weight is also conserved.
The only mass the earth loses is what little we send into space, that goes beond earth orbit. We gain much more from the constant bombardment of metorites impacting the earth.
Heres a thought: Since your weightless when you go into space, would this mean that the earth doesnt' actually weigh anything? I mean theres nothing holding it. I t just sits in space held in place by the gravity of the plancets.
That's why I don't like the use of "weight" in this thread, cheyenne: the weight of the earth is determined by the gravitational forces 'holding it into place', just like your weight on the earth is determined by the gravitational forces of our earth. This doesn't influence the mass of the earth, but it indeed influences the weight of the earth. Therefore, the weight of the earth depends on your point of view (literally): the weight of the earth seen from the standpoint of the moon is different than the weight of the earth seen from the standpoint of the sun, etc. etc...
Your right cheyenne1212, it doesn't wiegh at all, but it has one hell of alot of mass.
Since Mass is the size of an object though, then mass doesn't actually weigh anything if it is in space? right?
I'm starting to become lost.
cheyenne1212 you are confusing size and mass. If you have two balls the exact same size, but one was made of wood and the other of lead....the lead ball would have the greater mass.
Right, I understand that part.
So when we ask the weight of the earth, we are actually asking what is the density of earth? Since earth doesn't actually weigh?
Thats right. The mass of the earth directly affects its gravitational pull. The mass of the moon likewise. If you increased the mass of the moon significantly, the tides here on earth would be directly affected, as its gravitatioal pull would also be affected. If you increased it enough, you would cause major disastors here on earth, and it could even affect the other planets also. Our solar system is a balenced system, and to significantly change the mass of any part would cause havack with the rest of the system.
Yes, things from space come to earth.
Our atmosohere escapes into space
It gives us a small margin for change.... not to mention things we've sent into space.
But the things that we send into space, that wouldn't be considered part of earths mass would it, as it isn't actually part of earth?
Aren't we all cool scientists here. :p
...
Okay, where do you get metal?
Part of the eath is made from iron drakain.
Go take a class in geography. lol
heres one more question I have here for my fellow scholars. :cool:
If there is a fly flying around in a plane, or a glass jar, does that increase the weight (not mass) of the plane or jar?
if it's flying around without hitting the walls of the jar it doesnt increase the wight if it does then it increases the wight of the plane an jar. my best guess :)
Wow, I didn't expect to return to my thread with it having so many intelligent posts.
On the fly in a glass jar thing...
I asked this question once when I was a kid, because I was a curious nerd.
I was told that if you were to theoretically put a fly into a jar without having
the fly land on anything, and you were to seal it up, then the scale would read
the same wether or not the fly lands. I was told that this is because the air
encapsulated in the jar is part of the jars environment, and the fly's body will
cause the air to be "heavier" (remembering that you are also weighing the
air inside the jar).
I'm really not sure if this is true. It is a really hard thing to imagine. It's just
what I was told.
Cheers.
Just do the experiment yourself... stand on a scale and jump up :)
OH BOY....now I get to really confuse things.
If the fly is flying around and not touching the jar.... it has no effect on the wieght of the jar, but it does add to the overall mass of the jar, if you could measure it from a distance.
I just read Volcanics reply, and I don't know about that.
But my example would be, the mass of our solar system taken together would be much higher than the sum of the planets. You would be collecting the mass's of not only the planets, but the asteriods, meteor, comets, and any other space juck as well.
Quote:
Originally posted here by Negative
Just do the experiment yourself... stand on a scale and jump up :)
I don't think it works that way. :brickwall
perhaps a better question is does the mass change? the mass of course changes, even tho matter is never lost since matter is a form of energy.
and on the fly in the jar. if i put in a dense gas the weight of the jar would of course be greater, and the mass, then regular air. weight=mass*gravity
Ok.. moxnix seems to have handled questions quite well but the fly in the jar thing I would have to disagree.. my reasoning:
since the fly is flying around, the mass wouldn't change at all and thus no change in weight.. but let's assume the fly crocked and fell to the bottom and thus added mass to the jar...
weight = mass * gravity, where gravity is a constant of 9.81
Thus assuming that mass increases, it is obvious that weight will increase with it... so in order for weight to increase, the fly needs to be somehow on the jar... it cant be suspended in air because it then does not add mass to the jar thus making it irrelevant to the jar's wieght..
BTW, I'm taking most of this straight from my Physics book so I don't think it can be disputed..
Back to the earth mass thingy. This is my view on this subject:
Though I'm sure it does change slightly, I don't think its enough to even measure (even if we took the earth, and dropped it onto a scale on something like the sun that has gravity to make the scale work).
My reasoning:
The Earth, with a few exceptions, is basically to the extent of my still completing Grade 12 knowledge is a closed system. (Though we should all know it isn't because we accept energy input from the sun, thus its open) But aside from that, its basically closed. Things seem to be pretty much at equilibrium right now, (eg. while water is evapourating into the air, water is condensing back into liquid water from the air, etc) and since matter cannot be created nor destroyed, only converted from one form to another, the weight technically shouldn't change. Same goes for energy. Therefore, other than stuff falling into our atmosphere from outside the planet and us sending stuff into orbit, it should stay the same.
Oh well, I'm just a wee little grade 12 student who doesn't know much anyways. ;)
About the fly thingy, I also don't believe it is changing the weight of the jar while its flying. I think its just converting energy. (Using chemical energy stored in its body to flap its little wings creating kinetic energy, and it is also potential because it can fall if its wings fail to create lift, etc.) If anything, I think it would make the jar slightly lighter, as the fly would displace air (unless its a closed system) which would reduce the pressure and therefore reduce the weight of the jar. (Because the air is hitting the sides, and assuming the fly isn't)
I hope I made sense, lol, its late for me. (almost midnight, I can't think now)
Hmmm, maybe I can use this as a science experiment. Oh heck, I will just ask my science teacher if I remember tomorrow! ;)
Peace,
Dave
what abt all that dust coming from space. but on earth , whatever we build , we use earth's resources itself so it doesn't matters
Does the mass of the earth change - yes, but not be a great deal. The mass is reduced by the loss of the top of the atmosphere, which escapes into space ( and is blown by the solar wind, I gather ). At the same time, we are bombarded by dust, some of which is captured by the earths gravity, and adds to the mass.
Which means that it does fluctuate, although whether it tends to increase or decrease I don't know. I guess it tends to decrease, meaning that the earth is gradually being eroded into space.
The fly in a jar will increase the weight of the closed jar system, because the flapping of its wings, will provide a pressure on the base of the jar, which will be reflected in extra weight. This downward pressure needs to be equal to the weight of the fly, because that is what keeps it airbourne.
The mass of the jar-fly system would also be unchanged, as mass relates to the amount of matter in the object. The behaviour of the objects is then irrelevant.
That's my take on these at least.
1. earth is very much not a closed system, we gain mass on earth via metior impacts, space dust ect. we lose mass via satalight launches (unless they come crashing back to earth) and atmosphirac bleed off We also lose a lot of mass into energy that is bleed off (useualy as heat) in fires (natural and things like inernal cumbustion engins) and in nuclear reactions..Quote:
Originally posted here by dstevens1958
Back to the earth mass thingy. This is my view on this subject:
Though I'm sure it does change slightly, I don't think its enough to even measure (even if we took the earth, and dropped it onto a scale on something like the sun that has gravity to make the scale work).
My reasoning:
The Earth, with a few exceptions, is basically to the extent of my still completing Grade 12 knowledge is a closed system. (Though we should all know it isn't because we accept energy input from the sun, thus its open) But aside from that, its basically closed. Things seem to be pretty much at equilibrium right now, (eg. while water is evapourating into the air, water is condensing back into liquid water from the air, etc) and since matter cannot be created nor destroyed, only converted from one form to another, the weight technically shouldn't change. Same goes for energy. Therefore, other than stuff falling into our atmosphere from outside the planet and us sending stuff into orbit, it should stay the same.
Oh well, I'm just a wee little grade 12 student who doesn't know much anyways. ;)
About the fly thingy, I also don't believe it is changing the weight of the jar while its flying. I think its just converting energy. (Using chemical energy stored in its body to flap its little wings creating kinetic energy, and it is also potential because it can fall if its wings fail to create lift, etc.) If anything, I think it would make the jar slightly lighter, as the fly would displace air (unless its a closed system) which would reduce the pressure and therefore reduce the weight of the jar. (Because the air is hitting the sides, and assuming the fly isn't)
I hope I made sense, lol, its late for me. (almost midnight, I can't think now)
Hmmm, maybe I can use this as a science experiment. Oh heck, I will just ask my science teacher if I remember tomorrow! ;)
Peace,
Dave
. s for the fly the weight in the jar would increase, the mass of the fly would exert an equal amount of presure on the air to kep it aloft, that presure would be exerted as a force on the jar adding to its weight.
Great discussion. Here are a few factoids from many sources.
The earth’s weight and mass are in constant flux. Particles are coming and going changing mass; and weight is associated with gravitational pull from planets, the moon, the earth and the sun. All of which are constantly changing. Meaning the relation to earth's mass and gravitational alignments in reference to it's location with other solar objects is in constant change.
Earth is hit and absorbs thousands of objects daily. Last estimate on the amount is 40,000 metric tones a year. WOW! That is a lot of weight and there was original concern about earth becoming too heavy and altering its orbit. This would be very bad! It makes sense, because only a small percentage of what hits earth actually leaks into space. But if you do the math and use the average estimate of the earth at 6 sextillion metric tones, that large amount of incoming mass and weight becomes rather trivial at that size of numbers. The actual current number is:
5,972,000,000,000,000,000,000 tons
Now when you look at 40,000 metric tones of incoming mass/weight it doesn't look so bad. Some large ocean going ships are bigger than that when loaded. The amount of incoming mass versus outgoing mass is large but on the planetary scale it’s a very tiny amount.
Here is another interesting fact. Light particles bombard the planet continually, but light is overly accepted as having zero mass as a property. However; when plants convert the energy from light into chemicals, mass increases very slightly but it does change. I wonder how many other influences there are. There are many that haven't been mentioned like the direct effect on CME (since we just had one) on increased space ejection of matter from the upper atmosphere, decaying organic matter, etc.
decaying organic matter...forgot about that one, it generates a stupidlylarge amount of heat...infact all life uses up a large amount of heat, every time we eat we take some matter and turn it into energy to keep our bodies at body temperature.
Quote:
Originally posted here by Schrodinger
The fly in a jar will increase the weight of the closed jar system, because the flapping of its wings, will provide a pressure on the base of the jar, which will be reflected in extra weight. This downward pressure needs to be equal to the weight of the fly, because that is what keeps it airbourne.
The mass of the jar-fly system would also be unchanged, as mass relates to the amount of matter in the object. The behaviour of the objects is then irrelevant.
This is how I see it, very good explination.