Since the point at which the earth came into existance (note: carefully worded to avoid big bang Vs creation :) )
has it increased in mass
decreased in mass
stayed the same
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Since the point at which the earth came into existance (note: carefully worded to avoid big bang Vs creation :) )
has it increased in mass
decreased in mass
stayed the same
Increased. If you want to know why, explanations start a $5 a piece :p
We will have lost some atmosphere but have been hit by quite a few meteors/comets, intuitively you would expect the meteors to outweigh the loss of atmosphere by quite a lot, so i'd guess an increase.
On the plus-side we have metroids, comets, dust, solar wind and all kinds of other stuff raining down on us. On the minus-side we have... yeah, right, man-made satellites which left the earth. Whooooho. :-)
edit: no, honestly I believe she's getting lighter each day. :D
Planets start as planetismals then accrete into larger and larger planets, Terrestrial planets accrete rock/metal from surrending planetary nebula, while Jovian planets accrete frozen H compounds beyond the frost line (between Mars and Jupiter). Everything in the solar system is getting larger, even the Sun. Since the Sun is a Main Sequence star, and fuses Hydrogen into Helium, the outer surfarce will continue to expand, and the core will shrink, until it turns into a White Dwarf (cold solid rock of Carbon).
Does thate explain it?
Presumeably the sun is losing mass though, even if it is expanding.
It's around the holidays, so I'm going to say it's a little heavier. Gaia's never been one to turn down planetoid drumsticks or the stuffing nebula.
Wasn't personally interested in the earth mass loss/gain issue but I did find a couple websites dealing with the sun. They all said the sun is lossing mass. Here is one of them.
It has increased in mass.Quote:
Originally Posted by iain
Here's recent movie that looks in to some of the aspects of the problem.
All the material we have burned would decrease the mass
All the births would increase the mass
I'm afraid both those statements are basically wrong.Quote:
All the material we have burned would decrease the mass
All the births would increase the mass
Burning stuff doesn't decrease mass, it just moves it around a bit.
The earth will lose mass by radiating it, but on average we will probably be gaining pretty much the same amount through absorption as we're losing through emmision.
Edit: Though on reflection (hah) we've probably emitted more than absorbed since the Earth has cooled down.
Ok, so either the board hates me or someone didn't like my reply and deleted it.
A little from column a, a little from column b.Quote:
Originally Posted by ober
;)
I see. :: shrugs :: Oh well.
>Presumeably the sun is losing mass though, even if it is expanding.
I don't have an A in AST 2002, I did catch a little info though.
Energy is mass. The sun is radiating a lot of heat, so of course it's losing mass.
If you're not a creationist, the question is still imprecise, because the earth gradually came into existence by cosmic dust clumping together.
But taking the end of this process as a starting point, I'm pretty sure the mass has decreased. Why? Well, while asteroids hitting the earth generally increase its weight, at one point it was hit by one so large that it broke off a very large chunk: the moon. I don't think the combined weight of all the asteroid dust that remained on earth can make up for that loss.
So I think the mass has decreased overall, although it is increasing gradually.
>at one point it was hit by one so large that it broke off a very large chunk: the moon.
i took a full year of astronomy courses and ive never even heard that mentioned as a theory. I was told the moon was most likely a large asteroid that was caught by the earths gravity and pulled into orbit.
+1 increasionalists.
I've heard of it. Seen computer models too (or rather, videos or computer screens running the simulations). Seems like a viable theory.
At any rate, it is probably increasing, but at a truly, remarkably negligible rate (barring any large meteor strikes, of course :) ).
In other news, thirty seconds with Google trumps a year of education. :pQuote:
Originally Posted by Perspective
Quote:
http://www.psi.edu/projects/moon/moon.html
At the time Earth formed 4.5 billion years ago, other smaller planetary bodies were also growing. One of these hit earth late in Earth's growth process, blowing out rocky debris. A fraction of that debris went into orbit around the Earth and aggregated into the moon.
...
Thus, the giant impact hypothesis continues to be the leading hypothesis on how the moon formed. Is it right? Can it be disproven by more careful research? Only time will tell, but so far it has stood up to 25 years of scrutiny.
Quote:
24 Hours of Chaos: The Day The Moon Was Made
For 25 years, scientists have pondered a theory that the Moon was created when an object the size of Mars crashed into Earth less than 100 million years after the Sun was born, some 4.6 billion years ago. The general idea has been run through the paces and massaged into shape and is now the favored explanation.
>In other news, thirty seconds with Google trumps a year of education. :p
hey, i said i was in the classes, i didnt say anything about being awake... :p
edit: but i actually hadnt heard that once in either course, though we didnt talk all that much about earth. Next thing you'll be telling me that man has actually visited the moon :rolleyes:
The earth slowly leaks air into outer space.
It also picks up a small amount of material from falling rocks (meteorites).
But that's offset by the material we sent out into space on rockets.
The earth picks up some radiation from the sun (which as has been stated is mass), but also radiates itself.
There's probably a slight net loss in mass/energy but it may take geological timespans to see any significant amount.
oh, oh. this one im sure about ;)
>>It also picks up a small amount of material from falling rocks (meteorites).
This is incorrect. A meteroite is a meteor (or piece of meteor) that resides on earth. The falling rock that hits the earth is a meteor, the resulting peice of rock on earth is a meteorite ;)
oh yeah, that year of astronomy wasnt wasted after all, it helped me point out a grammer error :rolleyes:Quote:
Meteorite Me"te*or*ite, n. Cf. F. m'et'eorite. (Min.)
A mass of stone or iron which has fallen to the earth from
space
So, if we send a meteorite back out into space, does it become a meteor again? Or are our top scientists still working on this one?
it becomes a meteroriteor. then if it comes back to earth its a meteoriteorite, and so on... :pQuote:
Originally Posted by PJYelton
I have a good elementary Astronomy question.
If our Sun was replaced with a 1 solar-mass Black Hole, How would this change Earth's orbit?
Quote:
Originally Posted by B0bDole
Since the mass is the same, the gravitational forces it would exert would be the same so I would say that it wouldn't. At the current distance, the sun can be considered a gravitational point source and just replacing it with a true gravitational point source wouldn't seem to have any impact on us. That's my guess anyway, I could be wrong.
Shouldn't change the orbit at all. Might get a little dark though.
well, considering a black hole is a star that becomes so massive it collapses on itself, id say this isnt feasable. Not just the replacement but the existance of the entity itself. Now, if our sun was replaced by a one solar mass fork, it would have no effect on our orbit.Quote:
Originally Posted by B0bDole
To be totally pedantic, would the lack of heat change the orbit?
It is theoretically feasible. Black holes can be of any size and mass. The existance doesn't depend on mass, but on density. Scientists hope to be able to create extremly tiny black holes within particle accelerators in the future.Quote:
Originally Posted by Perspective
If you build and blow up a really large hydrogen bomb (but possible to construct on earth) the extreme pressure would create a black hole.
But for a star to turn into a black hole by its own gravity, it takes a lot more mass than the sun.
I don't think so; I don't imagine that heat has much to do with our orbit.Quote:
Originally Posted by Govtcheez
>To be totally pedantic, would the lack of heat change the orbit?
Not at all. Orbits are solely based on gravity and (rare) collisions.
And of course everyone got the answer right, pretty simple question.
The theory of Black Holes has a lot of evidence supporting it, with no evidence defeating it. But like a lot of astronomy, it can't be proven for sure, so it's just a really respected theory.
>But for a star to turn into a black hole by its own gravity, it takes a lot more mass than the sun.
It takes a totally different type of star. The Sun will eventually turn into a White Dwarf.
But the difference is still mass. Although the larger star will have heavier elements in it, its initial composition could have been quite nearly identical to that of the Sun, and it would still form a black hole. The cutoffs, if I remember them correctly (absolutely no guarantee there) are:
M < 3S(olar Masses) -> White Dwarf
3S < M < 10S -> Neutron Star
M > 10S -> Black Hole
>M < 3S(olar Masses) -> White Dwarf
3S < M < 10S -> Neutron Star
M > 10S -> Black Hole
you're pretty close
>different type of star.
This should read- "different classification of star."
Finals have me running on caffeine, nicotine, sugar & no sleep. Errors will insue.
Ah... that makes sense... Yeah, those numbers were dragged out of my head from two years ago, so there is bound to be a bit of error. :)
it's no the absolute number that matters, we can get the point from using relative numbers.
>>The existance [of black holes] doesn't depend on mass
agreed, but the creation does.
I voted that it has increased. Because all the matter on the earth has stayed on the earth. But we have brought stuff back from the moon.
But then, I think, We have alot of man made satelites in space now. So it has most probably decreased..
*curses click happy finger*
Edit:
People are using math to figure out.
Ap is afraid
Of course, this question is a bit ambiguous unless you specify a reference frame. :)
Not on mass, but pressure. A lot of mass means high pressure, but the high pressure can come from other sources, for example a hydrogen bomb detonating, or a particle accelerator.Quote:
Originally Posted by Perspective
i think we're on different wavelengths here. Im refering to the [natural] creation of a black hole from a star, a star has to exceed a certain mass to be a candidate for a black hole.Quote:
Originally Posted by Sang-drax
You're both right. Lamens terms, it depends on the stars mass, if it's going to become a black hole, but technically the process is pressure (that's how they're close to creating a very very small black hole in a particle accelerator).
Mass is directly proportional to the amount of heat (energy) in an object. Any substantial increase in heat to a given body yields an equivalent increase in mass (although inversely proportional to the speed of light squared). With respect to a reference frame where the big bang is assumed to be t=0, if the earth has increased in heat energy it is more massive, else it is less massive. Although I think the earth has actually cooled significantly, and I don't know what role organisms play in this matter.
edit:
How did you think of this question? It's intriguing nonetheless
If you double the temperature of an object you do not double its mass.Quote:
Mass is directly proportional to the amount of heat (energy) in an object
There is a mass associated with the K.E of an object, (or the sum of kinetic energies of its constituent parts) but that mass is almost always miniscule compared to the rest mass.
an increase of 10 degrees celsius would increase the weight of a one pound cube of gold by about a millionth of a billionth of a pound.
Therefore the kinetic energy difference between a 'hot' and 'cold' earth might actually have a substantial mass contribution
Hmm fair point, i'm estimating a 10 degree loss in the temperature of the Earth translating into a loss of 10^11 Kg!
Now having said that i can't seem to find any info on what kind of total temperature change is likely to have occured since the core appears to be self-heating through radioactive decay.
http://www.expanding-earth.org/
the main claim is that it's expanding, but in the proof it shows the mass is increasing also.
This seems horribly confused.Quote:
Some scientists may dispute the notion that additional solid matter is created from solar energy by photosynthesis in plants and other living organisms, but they should consider coal beds that were formed in the Carboniferous (~360 to ~290 Ma) from living trees, and, on today’s surface, piles of leaves and wood chips are rapidly converted to soil by nematodes. They should also consider the massive deposits of limestone created by marine fauna (fish, coral, bivalves, microfossils, etc.) in earlier epochs
Indeed. Photosynthesis stores the sun's energy by using it to convert some chemicals that are low on energy (carbon dioxide, water) into some that are high on energy (oxygen, sugar). If you want, you can claim that energy equals mass and thus some mass is generated. However, you must not forget that this mass/energy relation is scaled by the light speed squared, in other words, the resulting mass is absurdly small.
Niiice! Now instead of figuring things out, we can just vote on it! =)
Well indeed but the way its phrased seems to imply something else:Quote:
Indeed. Photosynthesis stores the sun's energy by using it to convert some chemicals that are low on energy (carbon dioxide, water) into some that are high on energy (oxygen, sugar). If you want, you can claim that energy equals mass and thus some mass is generated. However, you must not forget that this mass/energy relation is scaled by the light speed squared, in other words, the resulting mass is absurdly small
"additional solid matter"
"coal beds that were formed in the Carboniferous (~360 to ~290 Ma) from living trees"
"They should also consider the massive deposits of limestone created by marine fauna (fish, coral, bivalves, microfossils, etc.) in earlier epochs"
and "on today’s surface, piles of leaves and wood chips are rapidly converted to soil by nematodes"
All suggest the author thinks that all of the mass associated with coal, or limestone somehow jumps into existence. None of the processes he lists (limestone deposition, coal formation, and respiration) actually increase the mass of the Earth at all.
>>This seems horribly confused<<
And more than a little absurd. Still, in fairness, ~1% of visible light is 'fixed' by photosynthesis - the recycling of carbon, nitrogen etc. should obviously be ignored as it's just that: recycling what's essentially already there (except as noted below).
The process of accretion is ongoing (except, perhaps, as noted earlier in the thread regarding the currently most favoured model concerning the formation of the Moon), assuming the accretion model of planetary formation is correct. If you're fortunate enough to be able to look up at a part of the night sky which is not polluted by city lights then it won't take you long to see, unaided, a small subsample of the crap constantly raining down on us. For those interested in back-of-the-envelope-type calculations, then the micrometeoroid flux may be of some interest, although that article only discusses those micrometeoroids within a certain range of masses (more here).
Contributions to mass would also come from those particles of the solar wind which are funnelled via the Earth's magnetic field into the polar atmosphere, giving rise to the northern and southern 'lights', although that process may actually result in a net loss of atmosphere. There would also be a component of the solar wind that would punch through the magnetic field, either because it was electrically neutral (eg, neutral atoms) or was of sufficient energy to only experience some deceleration as they ploughed through (presumably, the particle flux of the solar wind follows some kind of known energy distribution?).
In addition, there is a constant flux of cosmic rays which would also result in a mass increase over geological time. Consider the case of carbon 14 formation in the atmosphere from nitrogen 14 (n,p reaction: absorption of a neutron by N14, followed by proton emission). The hydrogen that results is unlikely to have the escape velocity to 'diffuse/leak' from the atmosphere, although this is likely to be temperature dependant. N14 (stable) can also be converted to O16(stable) by absorption of 2 neutrons (firstly by conversion to stable N15, then unstable N16) followed by beta emission. While not specific to this discussion, this article may be of some interest - particularly to those who live in Colorado. ;)
I don't think photosynthesis will actually have any effect, other than altering part of the spectrum, atleast not when you factor in the effects of respiration (which will turn the added mass back into heat).Quote:
And more than a little absurd. Still, in fairness, ~1% of visible light is 'fixed' by photosynthesis - the recycling of carbon, nitrogen etc. should obviously be ignored as it's just that: recycling what's essentially already there (except as noted below).
-----------------------------------------
The meteorite flux looks to be between 10^7 - 10^9 Kg per year. (Which negates the 10^4 Kg per year that leaves through heat loss, and presumeably is orders of magnitude higher than mass gains through solar wind or cosmic rays).
Of course as mentioned the moon trumps all of these influences, weighing in at a loss of 10^22 Kg.