What if inertial mass did NOT = grav. mass?

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The discussion explores the hypothetical scenario where inertial mass does not equal gravitational mass, prompting participants to consider how daily life would change. Key points include the implications for basic activities like walking or throwing objects, where differing mass types could lead to unexpected behaviors, such as heavier objects falling faster or lighter objects resisting motion more. Participants also discuss the equivalence principle and its significance in physics, noting that if the two masses were not proportional, it could disrupt fundamental laws of motion. The conversation touches on gravitational interactions between massive bodies, such as planets, and how they would behave under altered mass conditions. Overall, the thread creatively examines the potential consequences of a universe where inertial and gravitational masses are not equivalent.
  • #91
Noted Jorrie. It's an interesting one this. That 2a means the falling is faster, but dropping two objects also says it isn't. Hmmn.

I wonder if the Earth would have a different orbit if the moon wasn't there?
 
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  • #92
Farsight said:
Noted Jorrie. It's an interesting one this. That 2a means the falling is faster, but dropping two objects also says it isn't. Hmmn.

I wonder if the Earth would have a different orbit if the moon wasn't there?

I think there would have been a minor difference - instead of the Earth cycling around the Earth-Moon baricentre every 28 days or so, the Earth would have had a more standard elliptical orbit around the Sun.

IMO, the crucial point is that the mass of the orbiting object has negligible effect on the orbit, as long as its mass is small compared to the primary mass (the Sun in this case). So the Earth-Moon baricentre follows an orbit that is roughly independent of the mass of the Earth-Moon system.
 
  • #93
Thanks Jorrie.
 

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