Dinosaur question -- Was Earth's gravity lower in the past?

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In summary, a theory proposed by various authors suggests that the great size of dinosaurs and pterosaurs can be explained by lower Earth gravity in ancient times. However, there is debate about how this lower gravity could have occurred, with some proposing that the Earth shrunk as it cooled, leading to stronger surface gravity. Others argue that this would have caused a significant increase in spin rotation, which is not observed in the fossil record. Further research is needed to fully understand the relationship between Earth's gravity and the size of ancient creatures.
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GregM
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New poster has been reminded that links to peer-reviewed papers or mainstream textbooks are required in the technical PF forums.
Hello everyone,
I have researched about dinosaurs and pterosaurs and a theory by various authors claiming the only way to explain their great size is with ancient lower Earth gravity . If this is supported theory among scientists then the next question is: How could the Earth have lower gravity? One idea I've had is as the Earth cooled it also shrunk and therefore by the inverse square law the same mass would have stronger surface gravity. However it seems unlikely the Earth shrunk so much in 100 million years, also if the Earth was much larger in the past, wouldn't shrinking cause a massive speed up in spin rotation? The Earth may had very long days in the past.
Can it have happened this way? Or is there a better simpler theory of why the dinos got so large? Any links to acedemic debates and conclusions on this question?
Thanks
 
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I would look into the climate side of things. Temperature, O2 CO2 levels.
@jim mcnamara @BillTre very knowledgeable on this
 
  • #3
GregM said:
I have researched about dinosaurs and pterosaurs and a theory by various authors claiming the only way to explain their great size is with ancient lower Earth gravity .
Do you have references for these claims?
 
  • #4
GregM said:
I have researched about dinosaurs and pterosaurs and a theory by various authors claiming the only way to explain their great size is with ancient lower Earth gravity
Here of PF it is not acceptable to say "I read that ... " (or your "I have researched ... " . You have to provide specific citations from refereed journals otherwise we might just be discussing nonsense.
 
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Thread closed for Moderation...
 
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Thread will remain closed. @GregM -- check your PMs. You may start a new thread about this question if you can find links to peer-reviewed journal articles about your question.
 
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Likes pinball1970, BillTre and jim mcnamara

1. What evidence suggests that Earth's gravity was lower in the past?

One of the main pieces of evidence is the size and weight of dinosaur bones. The larger size of dinosaurs compared to modern-day animals suggests that they were able to support their weight in lower gravity conditions.

2. How much lower was Earth's gravity during the time of dinosaurs?

It is estimated that Earth's gravity was approximately 2-3 times lower during the Mesozoic Era, when dinosaurs roamed the Earth. This is based on calculations using the size and weight of dinosaur bones.

3. What caused Earth's gravity to be lower in the past?

There are a few theories as to why Earth's gravity was lower during the time of dinosaurs. One theory suggests that the Earth's rotation was faster, causing a decrease in gravity. Another theory proposes that the distribution of landmasses and the position of the continents may have played a role in altering the Earth's gravitational pull.

4. Did lower gravity have an impact on the evolution of dinosaurs?

It is believed that lower gravity may have played a role in the evolution of dinosaurs. The lower gravity conditions may have allowed for larger and heavier dinosaurs to exist, leading to the development of their unique characteristics and behaviors.

5. Could humans have survived in lower gravity conditions during the time of dinosaurs?

It is unlikely that humans would have been able to survive in lower gravity conditions during the time of dinosaurs. Our bodies are adapted to function in the current gravity of Earth, and a significant decrease in gravity could have had negative effects on our physiology and ability to move and function properly.

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