Is the Earth growing?

[Narz]

http://www.youtube.com/watch?v=VjgidAICoQI

This guy claims the Earth is growing and the world's oceans are only about 70 million years old (there were isolated seas before this but not huge vast oceans like today).

I don't know much of anything about plate tectonics or about the possibility of a planet growing (it makes sense that the energy from the sun we convert to matter would eventually cause growth but I didn't think it would be THAT fast).

Is this theory valid?

If it is than wouldn't that mean that dinosaurs had to deal with only half the gravity of modern man?

Anywayz, please discuss!

[-Tomasz-]

Gravity depends on the mass of a celestial body, suppose we can assume that the earth is expanding in diameter, how in the world would its mass increase?
And then again, if there is such phenomenon as gravity, then all the particles that make up earth would be attracted to the common centre of mass of the system (in this case Earth), so instead of expansion we should experience a big crunch (which is why spheres are the perfect shapes in the universe, for they are the only stable shape under the forces of gravity).

One more thing, I thought this was a science forum, what the hell with the conspiracy theories? Growing Earth? Hollow Earth? People living on the far side of the moon? Mission to land on the sun at night???

[Narz]

Originally Posted by -Tomasz-

One more thing, I thought this was a science forum, what the hell with the conspiracy theories?

How do you know the difference between conspiracy theory & science if you don't educate yourself? The first I ever heard of this theory was twenty minutes ago so I thought I'd ask about it here.

[Cutlass]

No. The planet adds mass a bit all the time through meteorites and dust. However, that's a slow process. The planet isn't going to expand much without adding a lot of mass. Though if heat were added there would be a small expansion.

[-Tomasz-]

Fair enough, however, science has a generally accepted, and verified through the scientic method and thus peer review, viewpoint on the universe. What we have now at the beginning of the 21st century is a huge heritage of research and experimentation of different theories. In my opinion, our view on the basics of planetary motion and behaviour are farely accurate (consider Newton's three laws of motion). They explain phenomena observed in real life, and permit to predict new phenomena in the future.

Now coming to conspiracy theories, they are generally not forwarded by scientists, and if they are scientists, then they are alone for they cannot support their ideas with peer proof proof (I hope that that makes sense). If you are watching a video on youtube that shows an apparently incredible fact, and this is the first time you've heard about it (and in addition its a fact that would touch the very essence of our understaning of the universe - an expanable celestial body) then the chances that there is no proof to support such claims are almost irreefutable.

If the Earth was really expanding, don't you think that you would have heard about it earlier? From several sources, including school?

[-Tomasz-]

Originally Posted by Cutlass

No. The planet adds mass a bit all the time through meteorites and dust. However, that's a slow process. The planet isn't going to expand much without adding a lot of mass.

Meteor mass is neglectable. I read somewhere, that if we could crash into each other all the meteorites in the asteroid belt, we still would not be able to create a fair size planet.

[uppi]

Originally Posted by Narz

I don't know much of anything about plate tectonics or about the possibility of a planet growing (it makes sense that the energy from the sun we convert to matter would eventually cause growth but I didn't think it would be THAT fast).

Quick and dirty calculation for the amount of matter that COULD be produced by the energy coming from the sun:

Sun light intensity I ~ 1400 W/m^2
earth radius: R ~ 6400 km

maximum Power absorbed by earth: P = R^2*Pi*I = 5.7*10^16 W
mass equivalent m = P/c^2 = 0.6 kg/s

mass of the earth: 5,9*10^24 kg
amount of time needed to generate this mass: 10^25 s
age of the universe: ~4*10^17 s

amount of sense in the idea that any significant mass is added to the earth by sun energy: 0


I don't know what the guy is claiming, as I have no intention to listen to someone babble something about the earth expanding on youtube, but the idea that the earth is (or was) rapidly expanding seems to be kind of stupid at first glance.

[linfeixb27]

Originally Posted by uppi

mass equivalent m = P/c^2 = 0.6 kg/s

Does energy convert into mass in this way? I thought E=mc^2 is used to calculate the mass lost and energy released.

[Perfection]

No, I've seen it before it's psuedoscience.

[uppi]

Originally Posted by linfeixb27

Does energy convert into mass in this way? I thought E=mc^2 is used to calculate the mass lost and energy released.

E=mc^2 also works in the other direction: energy "lost" and mass "created". Of course usually not all energy is converted into mass. The calculation above only gives the upper bound of mass the earth could get without violating energy conservation. The actual mass the earth gains from sunlight is certainly much smaller and if you take the energy into account that the earth loses through its own radiation it is probably about zero.

[Perfection]

radiation from the sun doesn't turn to mass (even temporarily).

[brennan]

It's sad that I can't say:

'This doesn't even deserve an answer'

...without answering.

Good analysis Uppi.

[History_Buff]

Why do all these YouTubers assume that a young universe would be simple and easy to understand? I'm always surprised when people think the fundamentals should be self-evident and logical.

[GoodGame]

Well in retrospect, the original idea of plate tectonics (from James Hutton) was considered madness in its time. Same for Galilleo.

But Narz does re-post a lot of you-tube videos as 'academic' evidence. ;*).

[Narz]

Originally Posted by GoodGame

Well in retrospect, the original idea of plate tectonics (from James Hutton) was considered madness in its time. Same for Galilleo.

But Narz does re-post a lot of you-tube videos as 'academic' evidence. ;*).

I never said anything about evidence. I'm not trying to make an argument, just creating a discussion thread. Trust me, when I have a definite opinion I make it known.

[uppi]

Originally Posted by Perfection

radiation from the sun doesn't turn to mass (even temporarily).

Some of it certainly does. Every time a photon is absorbed in photosynthesis it is stored as "chemical energy" which is nothing else but (a very tiny amount of) mass.

[Mise]

Originally Posted by uppi

Some of it certainly does. Every time a photon is absorbed in photosynthesis it is stored as "chemical energy" which is nothing else but (a very tiny amount of) mass.

The tiny amount of mass is converted from other tiny amounts of mass elsewhere. The photonic energy facilitates this conversion by overcoming the activation energy required for the reaction.

Unless there's something I'm missing?

[uppi]

Originally Posted by Mise

The tiny amount of mass is converted from other tiny amounts of mass elsewhere. The photonic energy facilitates this conversion by overcoming the activation energy required for the reaction.

Unless there's something I'm missing?

That would only be true if the reaction was energy neutral. Because you gain energy when you burn glucose, that energy has to come from somewhere. And that would be the photons absorbed in photosynthesis. The larger part of the photon energy is indeed used as activation energy, but some part of it is stored as bound energy. And bound energy is mass.

[Mise]

Originally Posted by uppi

That would only be true if the reaction was energy neutral. Because you gain energy when you burn glucose, that energy has to come from somewhere. And that would be the photons absorbed in photosynthesis. The larger part of the photon energy is indeed used as activation energy, but some part of it is stored as bound energy. And bound energy is mass.

If you burn glucose, the mass of the products and the mass of the reactants is the same (assuming you capture the CO2 released).

The energy is indeed stored in the chemical bonds. Breaking those bonds releases that energy. But you don't lose mass in doing so.

I think you're just getting confused between regular chemical reactions, where mass is mass and energy is energy and the two are uniquely conserved, and nuclear reactions, where mass and energy are interchangeable.

[uppi]

Originally Posted by Mise

If you burn glucose, the mass of the products and the mass of the reactants is the same (assuming you capture the CO2 released).

The energy is indeed stored in the chemical bonds. Breaking those bonds releases that energy. But you don't lose mass in doing so.

I think you're just getting confused between regular chemical reactions, where mass is mass and energy is energy and the two are uniquely conserved, and nuclear reactions, where mass and energy are interchangeable.

Mass and energy are interchangable in chemical reactions, too. The energies are just so low, that the mass defect is not really measurable and is therefore ignored in any practical case. The seperate conservation laws are just an approximation for very low energies.

In nuclear reactions the mass defect is large enough to be noticed, so the seperate conservation laws had to be merged. The energy/mass relations of chemical and nuclear reactions are not fundamentally different, only the useful approximations are different.