Earth dimensions

[michel123456]

A thread was closed prematuraly. IMO

 

Have you ever looked at what looks the globe without water?

It is something like this

 

You can have a look here:

http://veimages.gsfc.nasa.gov/8411/a000054.mpg

 

To me it looks like an old apple.

I have also the feeling that the Earth is shrinking.

But there is no need to relate this the flood, and I don't believe it happened suddenly. It can happen smoothly, as a natural continuation of the formation of the planet Earth from an accretion disk.

 

There are very few elements supporting the idea, since the general point of view* is that the Earth's dimensions never changed in the past and don't change today (except for the expanding earth theory defenders).

 

Here what I found:

http://news.nationalgeographic.com/news/2007/07/070709-earth-size.html

http://www.newscientist.com/article/dn14255

http://spectrum.ieee.org/aerospace/astrophysics/the-case-of-earths-incredible-shrinking-field

And another finding, from 1953, with some reservation:

 

http://jgslegacy.lyellcollection.org...ct/109/1-4/217

 

From wiki at

 

http://en.wikipedia.org/wiki/Expandi...Current_status

 

"Modern measurements have established very stringent upper bound limits for the expansion rate, which very much reduces the possibility of an expanding Earth. For example, paleomagnetic data has been used to calculate that the radius of the Earth 400 million years ago was 102 ± 2.8% of today's radius.[2] Furthermore, examinations of earth's moment of inertia suggest that no significant change of earth's radius in the last 620 Million years could have taken place and therefore earth expansion is untenable."

 

If data gives 102 ± 2.8% , it is a gap between 99,2% (expanding earth), and 104,8% (shrinking earth). If it is correct, IMO, it is some evidence.

 

102% of earth's radius is 6371 kmx102%=6498 km or a decrease of 127km in the past 400 millions years.

 

* corrected after Swansont's remark.

Edited May 31, 2010 by michel123456

[swansont]

http://jgslegacy.lyellcollection.org...ct/109/1-4/217

 

From wiki at

 

http://en.wikipedia.org/wiki/Expandi...Current_status

 

1. These links are broken. You can't copy/paste a link from within a post if it has an ellipsis in it — the link has been shortened.

 

2. view, not vue

——

 

What accretion disk?

[michel123456]

Sorry:

 

http://jgslegacy.lyellcollection.org/cgi/content/abstract/109/1-4/217

 

Wiki's

http://en.wikipedia.org/wiki/Expanding_earth_theory#Current_status

 

Accretion disk?

_Clouds of gas and debris which exist in space have centers of gravity which cause the debris field to collapse toward a central point. This process is known as planetary accretion. As the field collapses angular momentum is conserved and primary rotation(s) begin. from http://wiki.answers.com/Q/What_are_various_theories_regarding_the_formation_of_Earth

 

also

http://en.wikipedia.org/wiki/Protoplanetary_disc

&

http://en.wikipedia.org/wiki/Protoplanetary_nebula

---

Merged post follows:

Consecutive posts merged

2. view, not vue

 

Thanks. "chassez le naturel il revient au galop" (something like " a leopard cannot change its spots")

[insane_alien]

that picture above is highly exaggerated

 

if you scaled the earth down to the size of a pool ball, the earth would be the smoother of the two. even with all the water and atmosphere removed.

[michel123456]

Yes it is exaggerated.

I cannot find anywhere an image of what would look the Earth like, without hydrosphere.

 

only this

 

-------------------

and from http://www.celestiamotherlode.net/catalog/show_addon_details.php?addon_id=993 (also exaggerated)

 

Edited June 1, 2010 by michel123456

[Moontanman]

I think it's already been stated but if you had an image of the earth that was not exaggerated it would look like a cue ball. Possibly a thin coat of paint would allow details to be close to life size in thickness?

[J.C.MacSwell]

I think it's already been stated but if you had an image of the earth that was not exaggerated it would look like a cue ball. Possibly a thin coat of paint would allow details to be close to life size in thickness?

 

Slightly flattened at the Poles, due to the spin.

[michel123456]

Let's see it another way:

Is it possible that Earth diameter was different in the past?

 

If it was not different, it means the Earth from the right beginning had always the same diameter. The Earth came into existence with exactly the same dimensions as today, & never evoluted.

Does that make sense?

[insane_alien]

well, of course its diameter changed as it formed. but seeing as collisions with significant bodies of rock are now a relatively rare occurance, the diameter doesn't change.

[Sisyphus]

The mass currently being added to Earth from incoming debris is supposedly about 10^8 kg per day, which is basically totally insignificant. At that rate it would take 3 trillion years for the Earth's mass to increase by 1 percent. When the solar system was younger, this rate would be greater just by virtue of there being more debris. Though it does appear that the change has still been very slight since the Earth was very young, billions of years ago.

 

Also, the depicted exaggerated picture is impossible. Structures that large would collapse under their own weight. The Earth's gravity prevents it from being anything other than as smooth as a cue ball.

[michel123456]

No, my suggestion has nothing to do with any increase of mass.

How to put it?

Earth surface is a thin crust. It is supposed to be floating upon a viscous mantle. It has been showned that the crust is broken in tectonic plates that rise or sink at their common edges. And I suppose that the tangential forces that make the plates move are in dynamic equilibrium.

And I suppose also that the whole structure of the planet is in equilibrium. Gravity has a pulling effect, and all other interactions must counter act the effect of gravity in such a way that the globe remains the way it is.

 

But what if those suppositions were not accurate. What if the Earth, and the other planets & stars, were dynamical systems constantly evoluting?

i.e. not exactly in equilibrium.

[swansont]

And I suppose also that the whole structure of the planet is in equilibrium.

 

Why would you suppose that?

[Sisyphus]

So your suggestion is that the mass is constant, but the size, by some unspecified mechanism, is changing? You say you have a feeling it is shrinking. Why?

[John Cuthber]

Well, the Earth started out as a big cloud of stuff and shrank under gravity to the size it is now. It's not absolutely unreasonable to wonder if that shrinkage has stopped.

 

However, the evidence (from things like the near constancy of the rotational speed) proves that it had certainly pretty much settled to its current size by the time civilisations were able to record the length of months and years.

We can now track the length of the day to very great accuracy, and the Earth's not shrinking.

[michel123456]

So your suggestion is that the mass is constant, but the size, by some unspecified mechanism, is changing? You say you have a feeling it is shrinking. Why?

 

Feelings, only feelings.

 

_I am a 200% evolutionist. It makes sense to me when things evolute. I find it very unphysical to examinate something and consider it absolutely stable. That's a feeling of the philosoph.

_the Earth is structurated in layers, with the most dense in the center (the core) and the less dense at the perimeter (the atmosphere). As I conceive it, it must be the result of a movement of dense materials toward the center, expulsing the light elements outside, something comparable to the Archimedes principle, due to gravity. I don't see any reason why this movement must have stopped.

_between the light elements expelled at the surface, there is water. it looks logical to me that the oceans were created from the expulsion from the whole mass, like juice coming from a squeezed orange. explaining by the same way the salinity of ocean's water.

_a shrinking Earth would maybe give some other explanation to the gigantic horizontal forces that drive the tectonic plates and give birth to mountains, valleys and abyss.

_a greater Earth in the past, in dimension, with the same mass , with smoother relief, would have been the living place of ancient animals. with a bigger radius, and the same mass, I just can guess gravity at the surface must have been lower, and larger animals & plants could have lived without annoyance.

_when shrinking, gravity must have increased, pushing some species to adapatation in another environnement (aquatic mammals) or making other species disappear.

-I have to go. See you tomorrow.

[insane_alien]

Feelings, only feelings.

 

so no hard data then... right...

 

_I am a 200% evolutionist. It makes sense to me when things evolute. I find it very unphysical to examinate something and consider it absolutely stable. That's a feeling of the philosoph.

 

remember that there are a number of different meanings to the word evolve.

 

_the Earth is structurated in layers, with the most dense in the center (the core) and the less dense at the perimeter (the atmosphere). As I conceive it, it must be the result of a movement of dense materials toward the center, expulsing the light elements outside, something comparable to the Archimedes principle, due to gravity. I don't see any reason why this movement must have stopped.

 

it is called differentiation, it does not result in a change in volume.

 

_between the light elements expelled at the surface, there is water. it looks logical to me that the oceans were created from the expulsion from the whole mass, like juice coming from a squeezed orange. explaining by the same way the salinity of ocean's water.

 

ehhh, not really, current best fit is that most of the water came after the bulk of the planet formed a crust in the form of comets. makes sense since before the earth formed a crust it was hot enough to boil the water off into space.

 

_a shrinking Earth would maybe give some other explanation to the gigantic horizontal forces that drive the tectonic plates and give birth to mountains, valleys and abyss.

 

also explained by thermal convection currents within the earth which don't require massive volume change.

 

for shrinkage to produce the movement seen, it would need to be considerable, very very noticable.

 

_a greater Earth in the past, in dimension, with the same mass , with smoother relief, would have been the living place of ancient animals. with a bigger radius, and the same mass, I just can guess gravity at the surface must have been lower, and larger animals & plants could have lived without annoyance.

 

there's nothing but selective pressures stopping larger animals developing now. selective pressures are not what they used to be nor what they will be in the future.

 

_when shrinking, gravity must have increased, pushing some species to adapatation in another environnement (aquatic mammals) or making other species disappear.

 

aquatic animals are largely gravity agnostic.

[John Cuthber]

Michael,

if your feelings don't agree with the evidence then it's not reality that's wrong.

[michel123456]

If you don't ask the question in the first place you won't find any evidence.

The only elements I could find are summarized in my first post. Evidentally not enough to make a claim. It is one of my few "theories" I use to keep in a drawer. Maybe some day it will find some support.

[insane_alien]

If you don't ask the question in the first place you won't find any evidence.

The only elements I could find are summarized in my first post. Evidentally not enough to make a claim. It is one of my few "theories" I use to keep in a drawer. Maybe some day it will find some support.

 

actually, science works the other way round. you typically start with an observation that doesn't fit with any known theories and then you investigate the hell out of it, construct models that do allow for it and still fit everything else and then test the hell out of that model to make sure it actually fits reality.

 

if it does not fit reality then it is wrong.

 

a shrinking earth would require some effects that simply aren't seen at all. therefore it is wrong. no amount of extra support helps when there are contradictions with reality.

 

although, if you isolated the earth from the universe, it would eventually show a reduction in size from thermal contraction. but we are talking more than the age of the universe for it to measurable. the radioactive decay within the earth keeps it nice and warm, which incidently is the cause of the convection currents that give rise to plate tectonics.

[Moontanman]

If you don't ask the question in the first place you won't find any evidence.

The only elements I could find are summarized in my first post. Evidentally not enough to make a claim. It is one of my few "theories" I use to keep in a drawer. Maybe some day it will find some support.

 

Your idea is not as far off the mark as you might think, it just can't account for the amount of folding and such as we see on the earth. An old theory held that mountain ranges and valleys were the result of the earth wrinkling as it cooled.

 

Plate tectonics is a much better description of what we see than a cooling shrinking earth. I like your idea of a much bigger earth having less gravity, this is counter intuitive to what most would think of a "bigger" earth. But if it had the same mass and was bigger the gravity would indeed be less at the surface.

 

BTW I am pretty sure that creationist ideas say the earth is expanding not shirnkign and that the dinosaurs were possible because the planet was much smaller and less massive then.

[michel123456]

actually, science works the other way round. you typically start with an observation that doesn't fit with any known theories and then you investigate the hell out of it, construct models that do allow for it and still fit everything else and then test the hell out of that model to make sure it actually fits reality.

 

if it does not fit reality then it is wrong.(...)

 

I think this way you loose a lot.

Have you ever lost a pencil on your desk? A green pencil? Well, I can assure that you will not find your green pencil, if you are wrong in the first place and your pencil was not green but red. You will look for hours searching a green pencil that do not exist. From the moment you realize your error, and remember that your pencil is red, you'll find it very quickly. It was there in front of you, all the time.

My point is: if you don't know what you are searching for, you will never find anything.

I strongly believe that someone must first have the enlightment (the falling apple ), and then can find an explanation.

I agree with you that in the specific case, it looks rather a somber enlightment.

 

Example:

I was looking at the globe, wondering why continents looked so random: the coastlines are totally chaotics, there is no regular shape anywhere, no axis, no preference, no obvious law, except the match of west Africa with East America. No such a match for west America & Asia. Thinking. Wondering.

After a while, I asked myself, what am I looking at?

Answer: continents.

Question: are continents a structure of randomness? If randomness was the law, would there be continents in the first place? Or would there be a huge amount of small islands distributed equally around the surface, the same way craters spread around the Moon surface?

Or: why are there continents? Why are there (tectonic) plates? Why are these plates so immense? Why aren't there a lot of small plates, and a much larger amount of volcanoes? Everywhere. Is there a kind of equilibrium between the internal structure of the Earth and the number & the dimension of plates & volcanoes ? I guess there must be some kind of equilibrium, otherwise the Earth wouldn't look so stable. Without such an equilibrium, the Earth would obviously and quickly expand, or collapse.

 

If you don't ask the question, you won't find the answer.

 

Just an example.

[michel123456]

From wiki at

 

http://en.wikipedia.org/wiki/Expandi...Current_status

 

"Modern measurements have established very stringent upper bound limits for the expansion rate, which very much reduces the possibility of an expanding Earth. For example, paleomagnetic data has been used to calculate that the radius of the Earth 400 million years ago was 102 ± 2.8% of today's radius.[2] Furthermore, examinations of earth's moment of inertia suggest that no significant change of earth's radius in the last 620 Million years could have taken place and therefore earth expansion is untenable."

 

What is the pure scientific mathematical conclusion of this?

 

That the Earth was an average of 102 ± 2.8% of today's radius, 400 million years ago.

 

Or that the Earth's radius today is approximatively 98% of what it was 400 million years ago.

 

Or that we have to close our eyes to the average value, reject it, and choose the other convenient one: the one that gives 100%.

Is there any scientific reason to do that ?

[Spyman]

Your Link is broken, is this the correct one: http://en.wikipedia.org/wiki/Expanding_earth_theory#Current_status ?

 

One prominent present day advocate of an expanding Earth is comics artist Neal Adams, who calls his ideas "Growing Earth Theory". He believes that an Earth with half its present radius would allow the continents to fit together perfectly, completely closing both the Atlantic and Pacific oceans.

http://en.wikipedia.org/wiki/Expanding_earth_theory#Current_status

 

In the light of ideas with the Earth growing from HALF it's radius, a scientific calculated estimate from measured data reveling a change of 102 ± 2.8% of today's radius in the past could be interpreted as "no significant change" and that "therefore earth expansion is untenable".

[michel123456]

Your Link is broken, is this the correct one: http://en.wikipedia.org/wiki/Expandi...Current_status ?

yes.

 

Correction:From wiki at

 

http://en.wikipedia.org/wiki/Expanding_earth_theory#Current_status

 

"Modern measurements have established very stringent upper bound limits for the expansion rate, which very much reduces the possibility of an expanding Earth. For example, paleomagnetic data has been used to calculate that the radius of the Earth 400 million years ago was 102 ± 2.8% of today's radius.[2] Furthermore, examinations of earth's moment of inertia suggest that no significant change of earth's radius in the last 620 Million years could have taken place and therefore earth expansion is untenable."

 

What is the pure scientific mathematical conclusion of this?

 

That the Earth was an average of 102 ± 2.8% of today's radius, 400 million years ago.

 

Or that the Earth's radius today is approximatively 98% of what it was 400 million years ago.

 

Or that we have to close our eyes to the average value, reject it, and choose the other convenient one: the one that gives 100%.

Is there any scientific reason to do that ?

 

end of correction.

 

------------------

 

The data used into dismissing the expanding earth theory tells something. It is just a matter of what you want to hear.

 

"no significant change"

 

127km in the past 400 millions years

 

0,0003175 meter/year

 

or a decrease of perimeter about 2 mm/year if I made no mistake.

Edited June 14, 2010 by michel123456

[swansont]

102 ± 2.8% does not exclude zero. How is acknowledging this "closing our eyes?" Especially in light of the implication of your quote that the moment of inertia data are even more restrictive.

 

The problem here is burden of proof. You need data that statistically excludes zero change in r in order to support your conjecture. It is not incumbent on anyone else to prove you wrong.