Metsfanmax wrote: (hopefully it's pretty clear that a human actually pulling something exerts more force on that object than proxima centauri does)
Is that necessarily obvious to someone who doesn't know the intrinsic strength of the gravitational force? I don't see why.
Hmm, well if proxima centauri exerted that much force then the force exerted by our sun would have to absolutely dwarf the pulling power of a human, so then I guess you'd expect to see objects wildly flying about as the earth gets closer or farther away to the sun.
Though yeah, maybe it's not obvious if you've never thought about it / have no idea how gravity works.
saxitoxin wrote:How did you arrive at a factor of six, Haggis/Max?
Gravitational force between object 1 and 2 situated at distance d is roughly g*mass1*mass2 / d^2
So force exerted by star divided by force exerted by nurse is: mass_star * dist_nurse^2 / (mass_nurse * dist_star^2 ).
mass of proxima centauri is 0.123 solar masses = ~ 2.5 * 10^29 kg
distance to proxima centauri is 4.24 light years = 4 * 10^16 meters
mass of nurse is 70kg
assume distance to nurse is 1m
Plug those in and you get that force_star / force_nurse = ~ 2 * 10^-6. So the force exerted by the nurse is about a million times stronger than that exerted by the star.
saxitoxin wrote:Would it be the same if it were BBS instead of a nurse (assume BBS also weighs 70kgs)?
As an economist BBS is not allowed within a 1 mile radius of any maternity wards. Modifying the distance to BBS from 1 meter to 2000 meters actually means proxima centauri would have a sliightly stronger gravitational pull on the baby than BBS would.
