[brilight (OP)]

We all know that as we dig down we go back in time. Relics from Saxon times will be deeper than ones from Elizabethan times, and Roman relics deeper still.

Does this mean the Earth is getting bigger, and if so where does the extra mass come from?

[Don_1]

Archaeological finds, such as you describe, sink into the ground or get buried by new constructions. Some of the older items get buried by land heave, volcanic activity, silt and the laying down of new layers of the Earth's crust. This is not 'new' material, but rather a cycle.

That said, new material does arrive here from space by way of comets and a multitude of bits and pieces, such as the shooting stars which we saw earlier this month. But this is a very small amount and would not be considered significant to the Earth's size.

[Nizzle]

And every time we set fire to something, we burn matter and create radiation, which escapes earth, so maybe the earth is getting smaller even

[Vern]

Most of the stuff we create when we burn stuff is smoke; I suspect that only a very small amount of the radiation created escapes earth. So even burning produces particles in the air that rains back down.

[Nizzle]

But we do create a lot of heat all over the world, no?
And all that heat is radiation i thought...

[Vern]

I seem to remember reading somewhere that the earth actually radiates more energy back into space than it receives from the sun. The explanation was that atomic reactions in the earth were creating heat.

[Titanscape]

I learned long ago about how many tonnes of space dust falls to Earth each year.

I sure it gets bigger over hundreds of millions of years. Dust from the sun and distant stars, and other sources. Certainly at the era of the comets impacting Earth, it got bigger. With seas, organics...

Light and heat going into space from a flame is not nuclear and no mass is lost.

In the Earth's core, nuclear reactions keep the mantle very hot. I suppose some of that energy makes it to the crust and space.

New crust appears at the rim of fire.

I suppose old daggers... get buried under grass, which absorbs minerals from the roots, and carbon from the air. And like in the science world, famous peat beds, layer grows on layer.

Also in some places the reverse naturally happens, and things like prehistoric river beds, now fossilized turn up with dinosaur prints, showing chases... Also ancient forests now rocks, with wood rings... Just look at the Grand Canyon, high up if you climb, you can dig out ancient fossil shells, or maybe they are not fossils. It was once the sea bed.

There may even be an equilibrium. Dust from space, core fission or fusion. Does anyone know which it is? And will it run out, or does the compression and heavy element substance of the core mean it goes forever, making new fissile material? Is the dusting faster than the nuclear action?

[Vern]

I am not an expert in this field, but my guess is that the incoming debris is greater than the equivalent mass loss by radiation into space. I suspect this because of the mass energy equivalence equation. It takes a bunch of energy to make a little bit of mass.   

[JimBob]

The increase is slight on the human time scale but appreciable on the geologic time scale.

[brilight (OP)]

My original question has been subsumed into a question about the Earth accumulating debris from space. Stuff even a few centuries old is buried so deep this can't possibly account for it. And Don 1, stuff doesn't just 'sink' - think of foundations of old temples etc. It gets buried by new vegetation etc. But where does this extra mass come from?

[Don_1]

Place a large stone on the soil in your garden and leave it. After just a short while you will notice it has sunk. This is caused by wind and, to a greater part, rain. The soil underneath is washed away.

Look at the Egyptian temples, they were buried by the ever moving sands, whipped up and deposited again by the wind.

A tree takes nutrients from deep in the ground, nitrates, phosphates, potassium salts etc. These become part of the tree. Its trunk, branches and leaves. The leaves die, fall off and rot down to become nitrates, phosphates etc once again, burying that which they fall on.

Movement of the Earths tectonic plates cause hill and mountain ranges where one plate is pushed up and valleys where the corresponding plate is pushed down. Then over centuries or millions of years, wind and rain level the ground by erosion, mud slides and displacement.

Volcanoes spill millions of tons of lava over surrounding areas and millions more tons of ash over vast areas.

Look at the Grand Canyon, this was carved out by the Colorado River, wind and rain, but the soil and rock did not disappear, it has just been redistributed elsewhere.

There are a great many factors invovled in the cycle of the Earths crust. Many of these factors can bury, or indeed, unearth many things.

The Dorset town of Lyme Regis is a good example of the unearthing of fossils.

[Titanscape]

I think in short, the Earth is getting bigger by space dust, but depthing of artifacts comes by plant growth, with the absorption of carbon from the atmosphere, and the falling of leaves and dead layers forming, with minerals from the soil as well as carbon in the leaves. Also by water and wind moving soil over things.

[Mr. Scientist]

We all know that as we dig down we go back in time. Relics from Saxon times will be deeper than ones from Elizabethan times, and Roman relics deeper still.

Does this mean the Earth is getting bigger, and if so where does the extra mass come from?

Sure, it's getting bigger. Just not very fast. There are billions upon billion of cosmic particles in one second which hit a very small region of earth: About the same as a human body in just one second. Particles though are so small, so by larger, weare inferring to the earth being like a mesh in which particles travel into and usually are bound to due to the gravitational force of the earth. More lighter particles, like nuetrino's or axions will easily pass through the earth without contributing much to the mass of terra firma.

[JimBob]

Yet this cosmic stuff is insignificant if compared to the amount of mass from micrometeorites, meteorite and other types of macro space debris accreting to the earth.

[Mr. Scientist]

Yet this cosmic stuff is insignificant if compared to the amount of mass from micrometeorites, meteorite and other types of macro space debris accreting to the earth.

True.

[yor_on]

Nice.

[jimbo]

the earth is expanding therefore getting bigger, as the earths plates push further apart, not as first thought like a conveyor where magna spews from the earth at one side and the rock is taken in at the other to be made molten again,but still pushing apart from all sides that is why scientists can find the oldest date on the sea floor is only 60-70 million years old but on the surface it is 200 million years old, that is because the plates are growing apart on the sea floor, and some say this is to blame for globle warming ie the continents are shifting.

[RD]

the earth is expanding therefore getting bigger

The expanding earth "hypothesis" has been discussed in this forum before ... http://www.thenakedscientists.com/forum/index.php?topic=17097.0

http://en.wikipedia.org/wiki/Neal_Adams[comic book artist]#Advocacy_of_Expanding_Earth_theory

http://en.wikipedia.org/wiki/Expanding_Earth#Scientific_consensus