Gravitational forces that affect us

[Homunclus]

I was thinking about the way gravity affect us. Now we all know that gravity is the force that keeps us grounded.

That is the most obvious effect gravity has on us. But isn't it true that it isn't the only one nor even greatest?

We, all of us, are currently being affected by the gravity of the sun aren't we? But the reason we don't notice it is because it affects everything on earth in an equal fashion. And yet, the gravity exercised by it is much greater than the gravity exercised by the earth, is it not?

So the question I would like to ask is: What would happen if suddenly humans became immune to the suns gravity? Nothing? Or would people on one side of the globe suddenly find themselves being crushed against the floor while people on the opposite side would find themselves being thrown into space?


PS. It's been years since I last posted here, I wonder if I will recognize anyone :lol:

 

[Nemesiah]

I was thinking about the way gravity affect us. Now we all know that gravity is the force that keeps us grounded.

That is the most obvious effect gravity has on us. But isn't it true that it isn't the only one nor even greatest?

We, all of us, are currently being affected by the gravity of the sun aren't we? But the reason we don't notice it is because it affects everything on earth in an equal fashion. And yet, the gravity exercised by it is much greater than the gravity exercised by the earth, is it not?

So the question I would like to ask is: What would happen if suddenly humans became immune to the suns gravity? Nothing? Or would people on one side of the globe suddenly find themselves being crushed against the floor while people on the opposite side would find themselves being thrown into space?


PS. It's been years since I last posted here, I wonder if I will recognize anyone :lol:

We, all of us, are currently being affected by the gravity of the sun aren't we? But the reason we don't notice it is because it affects everything on earth in an equal fashion. And yet, the gravity exercised by it is much greater than the gravity exercised by the earth, is it not?

Not.

http://en.wikipedia.org/wiki/Gravitation

http://www.quora.com/If-the-Suns-gr...-to-keep-planets-in-orbit-why-cant-we-feel-it

The equation for gravity is inversly proportional to the square of the distance between the bodies and proportional the mass of the bodies, and while the sun is much more masive than the earth we are much less masive, at the same time the sun is really far away, so the actuall pull the sun has on each human is rather a miniscule one so, people becoming inmune to the sun's gravity would probably pass unnoticed.

 

[Vivre]

Hello Homunclus,

nice to meet you

Interesting question you bring along and the idea to become 'immune' towards gravitation makes me smile.
I like the picture you draw of people suddenly being crushed to the floor or fly away into space.

Think of the moon - it is closer to us and has observable effects on the earth pulling on the waters of the oceans and thus causing high and low tide. Now this strong effect (if you imagine the amount of water) should already be enough to push and pull the lose objects on the planet every day and night ... but it doesn't.

I once saw a comparison that the gravitational force the full moon has on us is equal to the amount of lost gravitational pull by the earth if we step up on a 1 meter high ladder. I found this very remarkable to visualise and to exercise if I could feel the difference.

But mind you - if you climb on our very high mountains you'd already experience the effects of lesser earthly gravitational pull ... but it still is too much for to simply take a jump and fade into space.

greets ~ Vivre

 

[Master_Ghost_Knight]

I remember Homunclus.
Well gravity is very very week compared to the other forces. Do you know why when you sit in your char you don't fall straight to the core of the earth?
That force responsible for keeping you in your chair (or pretty much cross things) is the electromagnetic forces. We don't feel it that force at a distance because the atoms in our bodies are essentially neutral so the charges pretty much cancels itself out, but the electrons and the protons are not on the same place and that is enough to cause a difference when atoms are pretty close. Now you have the entire mass of the earth pulling down on you, yet only a couple of layers of atoms is enough to produce sufficient electromagnetic force so that you don't fall trough the ground.

As to what would happens if the sun would all of a sudden be gone, well first of all the sun can't just disappear out of nothing, that would implicate a discontinuity of force that simply can not exist in current models of gravity. It just doesn't happen, you can't just throw physics out the window and still expect correct answers. However if e throw part of physics in the bin and employ a trick of asking what is the net force you fell now and the net force you feel then, it would be remarkably insignificant.

 

[forgotten observer]

Dear homunclus, Good to see your return, Both as you were a valued member of the forum and It's nature as a sign for the return of others.
You won't remember me as I was a long time lurker who finally made an account. Anyway were we to suppose that the world and the sun were point masses ,with the point lying in their center, We can calculate the gravitational forces exerted upon us by the sun and earth using the equation

where G is the constant 6.67384 × 10-11
For the earth where a typical human weighs 50Kg F= (6.67X10^-11X50X6X10^24)/(6.371X10^6)^2=493N
While for the sun: F=(6.67X10^-11X50X1.989X10^30)/(150295500X10^3)^2 =0.293N

As you can see comparatively low force
P.S these results aren't completely accurate and I'll happily give my number sources to anyone who wants them.

 

[Homunclus]

Thanks everyone.

This idea seemed perfectly logical and intuitive to me when I more or less spontaneously came up with it, which is why I strongly suspected it wasn't true

That example of the moon and how it affect tides without really affecting us is particularly enlightening. Why didn't I think of that?