Gravity affect size

[Red Charley]

In my opinion and some of my own observation, I have come to a teori that,more dense the earth because of increasing gravity(mass),the smaller in size also the life in it.

 

It base on theory about energy.

Bigger gravity means more weight,more weight means more energy,so our body need to reduced the size factor to efficient the energy needed.

 

And another factor is,in molecular base,the weight is influenced by the gravity too...so our molecule also become smaller smaller and smaller.......

 

So if one is searching for ET in another planet, they also need to consider size factor.

 

CMIIW

Edited May 9, 2011 by Red Charley

[michel123456]

In my opinion and some of my own observation, I have come to a teori that,more dense the earth because of increasing gravity(mass),the smaller in size also the life in it.

 

It base on theory about energy.

Bigger gravity means more mass,more mass means more energy,so our body need to reduced the size factor to efficient the energy needed.

 

And another factor is,in molecular base,the mass is influenced by the gravity too...so our molecule also become smaller smaller and smaller.......

 

So if one is searching for ET in another planet, they also need to consider size factor.

 

CMIIW

 

If I follow your idea correctly, we should observe minuscule life form on gigantic planets, and enormous animals on small planets. That sounds counter-intuitive, although we have no other example than our own planet so far.

[TonyMcC]

I don't know if this is very scientific, but in the place on this planet where gravity has little effect on life can be found the largest animals (whales). However you can also find very small animals - plankton.

[Red Charley]

As due to small and large(size) factor there are also simple cell and complicated cell (what ever the term in use) factor in life form....

A minuscule life form cannot considered as small being,they just a more simple cell being...and that also being the factor of their size.....

 

But if you see some majority from our history...you can see that we turn to be smaller and smaller as times go......because our earth,or a lot of planet gravity (mass) become denses and denses to a singularity.

 

I am no expert nor scientist,but I just figured it out from my own observation........so I maybe some expert can give us more clue.......?????

sory for my bad english.

Edited May 9, 2011 by Red Charley

[michel123456]

But if you see some majority from our history...you can see that we turn to be smaller and smaller as times go......because our earth,or a lot of planet gravity (mass) become denses and denses to a singularity.

 

I suppose you mean that remains of dinosaurs are huge, together with insects , plants & sea shells of the same period, compared to the environment we know today.

 

You are making the supposition that size is related to gravity, which implies that gravity on Earth was less in the past.

I have exactly the same views. Unfortunately, I am not aware of any research on the relation between gravity and life form size, except that of Galileo some time ago.

 

It is supposed that dinosaurs were heavy animals, barely able to support their own weight, some of them not even able to raise their head above their shoulder.

 

I like to see them living like todays creatures, running, jumping and dancing their love parade.

I like to see some of them jumping so easily that they slowly changed in birds.

I like to see some of them getting heavier and heavier, dying under their own weight in the mud. I like to see other animals, under the pressure of evolution, changing slowly in order to bear their weight into a lighter environment: water.

But this is very speculative.

There is no indication that gravity on Earth was different in the past than it is today. So I keep that in one of my many speculation drawers.

If anyone here has some information on the subject it would be very interesting.

 

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

edit:

there are 2 ways to make gravity different on Earth in the past:

1. change the mass of the Earth

2. change the diameter of the Earth

 

as I stated before, there are no indications neither for point 1 or 2.

 

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

second edit:

first edit was jumping into conclusions. Sorry.

Your title is the most correct first step: is size connected to gravity?

Edited May 10, 2011 by michel123456

[csmyth3025]

But if you see some majority from our history...you can see that we turn to be smaller and smaller as times go......because our earth,or a lot of planet gravity (mass) become denses and denses to a singularity.

 

I am no expert nor scientist,but I just figured it out from my own observation........so I maybe some expert can give us more clue.......?????

sory for my bad english.

Bad English isn't your problem - but bad science definitely is. More to the point, what you "just figured out from....observation" is based on no science.

 

The Earth is not getting denser to any measurable degree. The gravity on the surface of the Earth is the same today as it was over 200 million years ago.

 

Very large land animals (dinosaurs) did rather well from then until about 65 million years ago - and they experienced the very same gravity that we enjoy today.

 

Chris

[michel123456]

That does not answer the question.

Is it possible to encounter a life form on Earth that is big as a mountain? Can we expect to encounter a life form big as a planet? What is that makes living animals (and plants) the size they are? Is it gravity?

[Moontanman]

I think it's probable that gravity would have an effect on the size of land animals. (The cube square law would apply) I have seen it postulated that a being like an octopus would be able to walk around on it's tentacles on Mars (no bones required) but of course Mars has such a thin atmosphere that large aerobic animals are not likely. As for the ancient Earth it is not true that dinosaurs were slow creatures barely able to move their own weight, that is an old idea that came into being before it was realized that dinosaurs were not reptiles but archosaurs and had fast metabolisms and moved around pretty much the same as animals of similar size and fast metabolisms do today. Yes there were very large dinosaurs but they moved at a rate comparable to large mammals today almost certainly.

 

An animal the size of a mountain would present some real mechanical problems, I'm not sure if any present day or past animals had a body structure or respiratory systems that could allow such a thing.

 

Higher gravity might result in animals evolving with many legs instead of four but still arranged like the legs of mammals and dinosaurs as we see on the earth today. For example, a high gravity version of an animal might have six legs, an intelligent hexapod might look vaguely like a centaur. Such creatures would have to adapt to a denser atmosphere but I see no problem with that. I'm not sure about life as big as a mountain, low gravity would seem to indicate a thin atmosphere and that would indicate a very large animal might have problems getting enough oxygen.

 

If indeed the Earth had low gravity 200,000,000 years ago i would expect to find a thin atmosphere not dense and to find smaller animals as well.

Edited May 10, 2011 by Moontanman

[csmyth3025]

That does not answer the question.

Is it possible to encounter a life form on Earth that is big as a mountain? Can we expect to encounter a life form big as a planet? What is that makes living animals (and plants) the size they are? Is it gravity?

The proposition of the OP was that animals on Earth today are smaller than they were a long time ago because "...more dense the earth because of increasing gravity(mass),the smaller in size also the life in it..." and, more specifically: "... But if you see some majority from our history...you can see that we turn to be smaller and smaller as times go......because our earth,or a lot of planet gravity (mass) become denses and denses to a singularity..."

 

These statements are simply wrong.

 

The OP didn't ask "...What is it that makes living animals (and plants) the size they are?..." He stated his theory that animals are smaller today because the gravity of the Earth has increased over time.

 

Chris

[michel123456]

(...)

These statements are simply wrong.

 

The OP didn't ask "...What is it that makes living animals (and plants) the size they are?..." He stated his theory that animals are smaller today because the gravity of the Earth has increased over time.

 

Chris

 

Right Chris.

 

Lets see the first part:

"animals are smaller today"

 

 

 

 

 

Edited May 11, 2011 by michel123456

[Moontanman]

Right Chris.

 

Lets see the first part:

"animals are smaller today"

 

 

 

Where did you get that illustration michel? I'd like to know the source, I have my doubts that it is accurate. (not the size ratio but the illustration does not show a truly large dinosaur, it looks like a bird mimic and I don't think they were that large) It is not true that animals were any bigger overall than now, we dwell on the larger animals of the age of dinosaurs but we forget about all the small dinosaurs. There were enormous numbers of smaller dinosaurs, down to chicken sized and then as now small dinosaurs out numbered large one several to one.

 

I think it is more probable that plants were more productive then due to higher CO2 levels and this allowed the really large plant eaters which of course required larger predators. Mammals have been larger than we see now as well but it is also arguable that mammal body plans might not be as advantageous to large animals as the dinosaur body plan was. Dinosaurs had better bones and better respiratory systems, these two facts alone could account for the large size of some dinosaurs.

 

The idea that the Earth's gravity was some how lower 200,000,000 years ago is unsupportable and if it was true I would expect to see much less air then as well but we see indication the air pressure was if anything higher then than now.

 

 

As well as leaving out all the small dinosaurs your illustrations are showing dinosaurs from widely scattered areas and time frames as though they all lived together, the large ones were not as common as your illustrations seem to show and it leaves out all the small ones who dominated the scene with numbers.

Edited May 11, 2011 by Moontanman

[michel123456]

Where did you get that illustration michel? I'd like to know the source, I have my doubts that it is accurate. (not the size ratio but the illustration does not show a truly large dinosaur, it looks like a bird mimic and I don't think they were that large) (...)

 

the source is about Gigantoraptor see http://news.bbc.co.uk/2/hi/science/nature/6750005.stm the picture in the article under Growth spurt.

 

 

 

 

It is not true that animals were any bigger overall than now, we dwell on the larger animals of the age of dinosaurs but we forget about all the small dinosaurs. There were enormous numbers of smaller dinosaurs, down to chicken sized and then as now small dinosaurs out numbered large one several to one.

I think it is more probable that plants were more productive then due to higher CO2 levels and this allowed the really large plant eaters which of course required larger predators. Mammals have been larger than we see now as well but it is also arguable that mammal body plans might not be as advantageous to large animals as the dinosaur body plan was. Dinosaurs had better bones and better respiratory systems, these two facts alone could account for the large size of some dinosaurs.

 

The idea that the Earth's gravity was some how lower 200,000,000 years ago is unsupportable and if it was true I would expect to see much less air then as well but we see indication the air pressure was if anything higher then than now.

 

 

As well as leaving out all the small dinosaurs your illustrations are showing dinosaurs from widely scattered areas and time frames as though they all lived together, the large ones were not as common as your illustrations seem to show and it leaves out all the small ones who dominated the scene with numbers.

 

You are right that there were also small dinosaurs, and that the time span is enormous, most probably they did not live all together and in the same place. they may have been exceptions, like the largest animal ever, the blue whale, traveling in our oceans today.

 

But the question is not the average size.

Where big is possible, little is possible too: if you can build the Empire State Building, you can build a single storey house too.

I don't know if you have seen in full size a real skeleton of dinosaur. There are some at Brussels in the Royal Belgian Institute of Science where the famous iguanodons of Bernissart are exposed. They are really impressively out of scale.

Diplodocus is the most huge.

 

IMHO there is no doubt about gigantism in this early period of time.

There is an interesting article here from Biological Reviews of the Cambridge Philosophical Society where gigantism is explained in evolutionists terms. The question about gigantism is not even posed, it is considered as a fact.

 

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

edit

This paper from UBC/EOS suggests the reason for gigantism is a change of level of oxygen in early Earth's athmosphere.

(p124,"The most obvious zoological support for a postulated late Paleozoic rise in oxygen, however, is the contemporaneous expression of gigantism within numerous unrelated arthropod lineages (Briggs 1985; Kukalov´a-Peck 1985, 1987; Shear & Kukalov´a-Peck 1990; Graham et al. 1995).

Again, gigantism is not under question.

Edited May 12, 2011 by michel123456

[csmyth3025]

Right Chris.

 

Lets see the first part:

"animals are smaller today"

For me the issue with the OP isn't the fact that there were large land animals in the past (and, as Moontanman points out, also many varieties of small animals).

 

I take issue with the OP assertion that the reason that there were very large land animals in the past and none today is that the Earth's gravity is greater today than it was in the past.

 

Chris

[michel123456]

For me the issue with the OP isn't the fact that there were large land animals in the past (and, as Moontanman points out, also many varieties of small animals).

 

I take issue with the OP assertion that the reason that there were very large land animals in the past and none today is that the Earth's gravity is greater today than it was in the past.

 

Chris

 

So half of the OP statement is correct.

 

For the other half there is this John Stojanowski on the net with his theory. Interesting speculation.

[Moontanman]

So half of the OP statement is correct.

 

For the other half there is this John Stojanowski on the net with his theory. Interesting speculation.

 

I'm not sure it even qualifies as speculation.... So we look at the possibility that the laws of physics was different 250 million years ago as a mechanism to explain large creatures instead of thinking that dinosaurs are different than mammals and seem to do large body types better? Dinosaurs were not just large reptiles or scaly mammals, they were as different as oranges and strawberries from mammals. Dinosaurs suppressed the existence of mammals, they had superior attributes that mammals lack and mammals have not had a similar length of time to evolve past those limitations.

 

http://www.dinoextinct.com/page12.htm

 

The author of this document has written several documents entitled “The Rise and Fall of The Dinosaurs- The Gravity Theory” in which the role of a gradually changing gravitational field is posited as the cause for dinosaur gigantism and the primary force behind the eventual extinction of the dinosauria. This happened during the end of the Mesozoic Era (of about 250-65mya). According to that theory, the breaking up and dispersal of the component continents of the super-continent Pangea resulted in a gradually increasing gravitational field, thereby eliminating what the author calls Reduced Gravity Growth (RGG) life forms, resulting in the disruption of dinosaur/mammal equilibrium and allowing the eventual displacement of remaining dinosaurs by mammals.

 

the source is about Gigantoraptor see http://news.bbc.co.uk/2/hi/science/nature/6750005.stm the picture in the article under Growth spurt.

 

 

 

 

 

You are right that there were also small dinosaurs, and that the time span is enormous, most probably they did not live all together and in the same place. they may have been exceptions, like the largest animal ever, the blue whale, traveling in our oceans today.

 

But the question is not the average size.

Where big is possible, little is possible too: if you can build the Empire State Building, you can build a single storey house too.

I don't know if you have seen in full size a real skeleton of dinosaur. There are some at Brussels in the Royal Belgian Institute of Science where the famous iguanodons of Bernissart are exposed. They are really impressively out of scale.

Diplodocus is the most huge.

 

IMHO there is no doubt about gigantism in this early period of time.

There is an interesting article here from Biological Reviews of the Cambridge Philosophical Society where gigantism is explained in evolutionists terms. The question about gigantism is not even posed, it is considered as a fact.

 

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

edit

This paper from UBC/EOS suggests the reason for gigantism is a change of level of oxygen in early Earth's athmosphere.

Again, gigantism is not under question.

 

 

Your own link describes the reason for this gigantism to be the morphological differences between mammals and sauropod dinosaurs, (as I have pointed out) not a change in the gravitational field of the earth... it is important o point out there are no mammalian equivalents of sauropod dinosaurs to start with, to make a fair comparison you would first have to find a mammal with a long neck and tail, bird like respiratory system and hollow bones. No such mammal exists nor do mammalian equivalents of theropods exist either. The two groups of animals are simply not easily compared.

[michel123456]

I will not engage supporting Mr Stojanowski's ideas. But "that the laws of physics was different 250 million years ago"

is somehow inaccurate. Members can read through the links and make an opinion by themselves.

 

There are several explanations about gigantism. I don't know if there is any scientific consensus on the question.

[Moontanman]

I will not engage supporting Mr Stojanowski's ideas. But "that the laws of physics was different 250 million years ago"

is somehow inaccurate. Members can read through the links and make an opinion by themselves.

 

There are several explanations about gigantism. I don't know if there is any scientific consensus on the question.

 

 

You are the one who brought Mr Stojanowski's idea into this and yes for gravity to be different then than now would require the laws of physics to have changed.

[michel123456]

I sympathize you so much i don't want to argue with you.

 

Here is how I see things:

 

Do you know St Exupery's http://en.wikipedia.org/wiki/The_Little_Prince? At some chapter, the little prince goes visiting a strange planet, very small and with a single inhabitant, the "allumeur de reverbere".

The ligt-man says "good morning" and "good night" each 3 seconds, because his minuscule planet turns so quickly.

It is evident that the scenario is unreal. The man is too big for this planet. Why? Is there a relationship between the size of a planet and the size of the living beings? Do small creatures live on a small planet and big creatures live on a big planet? Intuition says yes. That's it: if animals are big, they must have lived onto a bigger planet.

 

I follow intuition, but intuition may be wrong.

There is no support to this. Only a children book written by a french pilot in the 1940's.

 

Now you can shoot.

Edited May 12, 2011 by michel123456

[imatfaal]

When the size of the animal starts to approximate the size of the habitat then Antoine might have had a point but even with the most terrible of lizards that is not even close. The change in mass between the dinosaurs and creatures today is miniscule when compared to the mass of the earth; the difference between a 11000kg of a Bull Elephant and 60000kg of a Brachiosaurus is unimportant in the context of a 5 million million million million kg earth. And even though it is in the sea the largest animal ever known is still around today.

[Moontanman]

I sympathize you so much i don't want to argue with you.

 

Care to elaborate on that?

 

Here is how I see things:

 

Do you know St Exupery's http://en.wikipedia.org/wiki/The_Little_Prince? At some chapter, the little prince goes visiting a strange planet, very small and with a single inhabitant, the "allumeur de reverbere".

The ligt-man says "good morning" and "good night" each 3 seconds, because his minuscule planet turns so quickly.

It is evident that the scenario is unreal. The man is too big for this planet. Why? Is there a relationship between the size of a planet and the size of the living beings? Do small creatures live on a small planet and big creatures live on a big planet? Intuition says yes. That's it: if animals are big, they must have lived onto a bigger planet.

 

I follow intuition, but intuition may be wrong.

There is no support to this. Only a children book written by a french pilot in the 1940's.

 

Now you can shoot.

 

 

Your story is cute, i remember it from childhood as well, but the cube square law would suggest you are mistaken, a large planet implies stronger gravity, the cube square law would suggest even further that on such a planet animals would tend to be smaller due to the strength of materials and the weight of them as well. This is the reason the idea persists that the Earth must have had less gravity way back "when ever" because this would have allowed for larger but less heavy animals. But as i stated in an earlier post, low gravity, like on Mars, means no need for strong bones, flying would be much easier and the birds could be enormous... that is of course if a small planet could maintain a thick atmosphere, low gravity worlds would have little air, no magnetic field, no plate tectonics ... much like Mars, the case for low gravity but large animals hinges on a pretty big if....

Edited May 13, 2011 by Moontanman

[michel123456]

Care to elaborate on that?

 

That would be for the lounge. Don't be scared, you are not the only one I sympathize here. there are some few I don't sympathize, but that's my very personal opinion, and I change opinion on people very easily. Not to compare with my scientific views where I am profoundly stubborn.

 

 

 

 

Your story is cute, i remember it from childhood as well, but the cube square law would suggest you are mistaken, a large planet implies stronger gravity, the cube square law would suggest even further that on such a planet animals would tend to be smaller due to the strength of materials and the weight of them as well. This is the reason the idea persists that the Earth must have had less gravity way back "when ever" because this would have allowed for larger but less heavy animals. But as i stated in an earlier post, low gravity, like on Mars, means no need for strong bones, flying would be much easier and the birds could be enormous... that is of course if a small planet could maintain a thick atmosphere, low gravity worlds would have little air, no magnetic field, no plate tectonics ... much like Mars, the case for low gravity but large animals hinges on a pretty big if....

 

Well, going to the extremes, like in Antoine's story, suggests that the Galileo's cube square law is not the only law. I hope it is evident that Galileo's law does not forbid Antoine's description.

We can send an astronaut walking upon an asteroid (like in the Armagedon movie) but we don't expect to encounter that much life form to have evoluted upon it, only viruses or bacteria at most.

 

So, why don't we expect to find elephant-like animals upon asteroids:

_because there is no atmosphere, because there is no water, because blah blah blah, at the end because there is not enough gravity.

 

But then, IMHO, there must be some other law that dictates the maximum size of living form upon a planet, and that "other law" must be related to gravity. That's my reasoning.

 

Now, as you said somewhere IIRC, nothing says that we have had enough time to develop like dinosaurs did, and that evolution will eventually drive mammals (including ourselves) to gigantism. King-Kong would be a description of a future situation. That is not a less wild speculation.

Edited May 13, 2011 by michel123456

[Moontanman]

That would be for the lounge. Don't be scared, you are not the only one I sympathize here. there are some few I don't sympathize, but that's my very personal opinion, and I change opinion on people very easily. Not to compare with my scientific views where I am profoundly stubborn.

 

I honestly do not see how sympathy can apply to a scientific discussion but if you insist on feeling sympathy for me give it your best "feeling" I guess....

 

 

 

 

Well, going to the extremes, like in Antoine's story, suggests that the Galileo's cube square law is not the only law. I hope it is evident that Galileo's law does not forbid Antoine's description.

 

How so?

 

http://en.wikipedia.org/wiki/Square-cube_law

 

Biomechanics

 

If an animal were scaled up by a considerable amount, its relative muscular strength would be severely reduced, since the cross section of its muscles would increase by the square of the scaling factor while its mass would increase by the cube of the scaling factor. As a result of this, cardiovascular and respiratory functions would be severely burdened.

 

In the case of flying animals, the wing loading would be increased if they were scaled up, and they would therefore have to fly faster to gain the same amount of lift. Air resistance per unit mass is also higher for smaller animals, which is why a small animal like an ant cannot be crushed by falling from any height.

 

As was elucidated by J. B. S. Haldane, large animals do not look like small animals: an elephant cannot be mistaken for a mouse scaled up in size. The bones of an elephant are necessarily proportionately much larger than the bones of a mouse, because they must carry proportionately higher weight. Because of this, the giant animals seen in horror movies (e.g., Godzilla) are unrealistic, as their sheer size would force them to collapse. However, it's no coincidence that the largest animals in existence today are giant aquatic animals, because the buoyancy of water negates to some extent the effects of gravity. Therefore, sea creatures can grow to very large sizes without the same musculoskeletal structures that would be required of similarly sized land creatures.

 

We can send an astronaut walking upon an asteroid (like in the Armagedon movie) but we don't expect to encounter that much life form to have evoluted upon it, only viruses or bacteria at most.

 

Agreed

 

So, why don't we expect to find elephant-like animals upon asteroids:

_because there is no atmosphere, because there is no water, because blah blah blah, at the end because there is not enough gravity.

 

Agreed

 

But then, IMHO, there must be some other law that dictates the maximum size of living form upon a planet, and that "other law" must be related to gravity. That's my reasoning.

 

There is, it's called the cube square law, and yes it applies to gravity as well...

 

 

Now, as you said somewhere IIRC, nothing says that we have had enough time to develop like dinosaurs did, and that evolution will eventually drive mammals (including ourselves) to gigantism. King-Kong would be a description of a future situation. That is not a less wild speculation.

 

 

No, the cube square law would prevent a "King Kong" I respectfully suggest you have no idea what the cube square law is or how evolution works. I have repeatedly said that a small planet would be expected to have larger organisms than a large planet (all things being equal) due to the cube square law, so far all you seem to be doing is baiting me by saying inane things that make no sense in regard to reality.

[michel123456]

I have repeatedly said that a small planet would be expected to have larger organisms than a large planet (all things being equal) due to the cube square law (...)

 

I have read what you wrote repeatedly.

The example of what you say is Antoine's allumeur de reverbere: it is a small planet with a large organism. And it is absurd.

[Moontanman]

I have read what you wrote repeatedly.

The example of what you say is Antoine's allumeur de reverbere: it is a small planet with a large organism. And it is absurd.

 

 

Yes, like many ideas taken to it's extreme your idea and the fictitious story used to promote it is indeed absurd as is your method of debate, merely waving your hands and saying something cannot be true because of your intuition is not science or even debate, it is just silliness personified.

[michel123456]

IMO we are getting out of tracks.

The prior question is wether gravity has an influence over size of living forms.

 

Moontanman argues it has an influence IIRC. He says

that a small planet would be expected to have larger organisms than a large planet

which I characterize a blind stupid statement, giving the childish example of Antoine's lightman.

 

In response, Moontanman says I am siliness personified, which statement does not give an answer to the prior question.

 

Could anyone here give an insight?