Could the dinasours what been wiped out by a sudden or gradual change in gravity?

[Mikespike]

Could the dinasours have been wiped out by a sudden or gradual chance in gravity, prompting the end for the dinasours but an evolutional boost for smaller creatures. This gravitaional change could have resulted in a sudden expansion of the earth as it moves away from the universes centre. A bit like a balloon with a small amount of air in it rising from the sea bed and expanding as it moves to the surface.

[ugly_bob]

The expansion of the balloon is due to decreasing pressure, rather than gravity.

Even if the Earth had suddenly moved further from the centre of the universe, it wouldn't have suddenly expanded, since it is encased in a vacuum and has no external pressure applied to it.

An increase in the size of the Earth would decrease gravity on it's surface, since gravity is proportional to the mass of the object (unchanged) and inversely proportional to the square (or is it cube) of the distance from the centre of mass (simply), so if the Earth doubled in diameter, the surface gravity would be 1/4 (1/8) of it's original value

[Loosehead]

I can see by this and your previous question you are working on some theory for the extinction of the dinosaurs. Well extreme changes in gravity would wipe out anything. The Earth however has had pretty much the same gravity for most of its life. The gravity in dinosaur times would be largely indistinguishable from what it is now.

The "centre of the" universe location is pretty much unknown but can be estimated but the effects of our Earth moving in our solar system,galaxy, local cluster, supercluster have no measurable bearing on its proximity to then centre of the universe. Earth is not even a grain of sand in our galaxy, let alone on a universal scale it's limited movements within the galaxy move it a tiny amount in relation to the centre of the Universe.

[steveb]

i thought everything was at the centre of the universe, and the centre had just expanded?

[Zevon]

Earth's gravity has been pretty constant since its creation ans it's size and shape has been pretty constant, this is due to the conservation of angular momentum and astronomical calculations regarding Earth's orbit and spin crossed wiht geological evidence of what Earth is and was made of.

[Zevon]

the only thiung at the centre was everything true. But everything was just energy which became particles, which became elements etc.

Taking your idea to its logical conclusion then you, your car and all you possessions where at the centre and just expanded outwards until you all came together agian billions of years in the future.

Neat idea.