A few questions on newtons law and black hole

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nafizishtiaque
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Re: A few questions on newtons law and black hole

Unread post by nafizishtiaque » Mon May 23, 2011 6:39 pm

just to point out, gravitational force may be fundamentally different from all the other forces. a massive object doesn't exert force on other objects, but bends the space around it so that the motion of any object passing by it is modified. and a black hole bends space so much that any straightest possible line (geodesic) bends back in, thus forbidding anything to go out. since photon doesn't feel any force, gravitation is the only way to trap light.

tanvirab
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Re: A few questions on newtons law and black hole

Unread post by tanvirab » Mon May 23, 2011 7:03 pm

hmm.. then my example of negatively charged black hole was wrong, because gravity is the only "force" that can completely trap any object regardless of it's energy.

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Re: A few questions on newtons law and black hole

Unread post by arnob54 » Wed May 25, 2011 3:15 pm

this seems really interesting, from studying my physics books i found the analogy between the formula for grav force and electric force that is directly prop to product of the constituents and inversely prop to the square of the dist.

is this analogy applicable for the other two fundamental forces as well?
Tanveer

nafizishtiaque
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Re: A few questions on newtons law and black hole

Unread post by nafizishtiaque » Wed May 25, 2011 8:50 pm

the nature of the force laws depends on the mediator of the respective forces among other things. the similarity between Coulomb's law and Newton's law of gravitation is attributed to the masslessness and some other similarities between the mediators of these forces (photon for EM and graviton for gravitation). but weak force and strong force are different. there are multiple carriers for weak force and strong force (W and Z bosons for weak force and gluons for strong force). W, Z bosons are massive, gluons are supposed to be massless and thy all carry an attribute called color (kinda like how the electrons and protons carry charge). also, W bosons are electrically charged. these make their respective force laws very different and considerably more complicated.

tanvirab
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Re: A few questions on newtons law and black hole

Unread post by tanvirab » Thu May 26, 2011 8:02 am

and W and Z bosons interact with each other using other W and Z boson. It's like there is a force on the force, and a force on that force, and another force on that force! So, basically weak force is like the mirrors in the hair dresser's place, where you see image of the image of the image of the image..... :) Good luck trying to solve that analytically!

On the analogy between electric force and gravitation : Apart from what Nafiz already said, it is not entirely clear whether graviton actually exists. All we know that if it exists than it must have certain properties like zero mass, spin=2 etc. It might be that the similarity of gravitation and electric force is purely accidental, and that's the case if you treat gravity as just curvature of space-time and not a force like the other ones.

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Abhijeet Dutta
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Re: A few questions on newtons law and black hole

Unread post by Abhijeet Dutta » Tue Jun 14, 2011 1:30 am

The latest version of Big bang answers how the universe comes. Its called the Inflation. At the time of Bang our visible universe was not the whole fireball infact its just a patch of the fireball and that patch was unconditionally uniform. And the time Bang happens there was an external force pushed the universe to expand by a factor 10^50. And that force comes from the vacuum. But still there's no clear concensus about how it was generated.
This Inflationary Model of the universe opens pandoras box for us. As its latest version says an universe can give birth to many universes due to spontaneous breaking and we are living amidst multiverse!
Shout aloud scream aloud let me hear you go

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leonardo shawon
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Re: A few questions on newtons law and black hole

Unread post by leonardo shawon » Tue Jul 19, 2011 12:41 am

you can also detect a black hole by
1.Mass estimates from objects orbiting a black hole or spiraling into the core
2.Gravitational lens effects
3.Emitted radiation
Ibtehaz Shawon
BRAC University.

long way to go .....

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leonardo shawon
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Re: A few questions on newtons law and black hole

Unread post by leonardo shawon » Tue Jul 19, 2011 12:48 am

when a black hole eats another black hole, will it emits energy, radiation, or create an explotion ... Anything?
Ibtehaz Shawon
BRAC University.

long way to go .....

tanvirab
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Re: A few questions on newtons law and black hole

Unread post by tanvirab » Tue Jul 19, 2011 3:46 am

Unlikely. Because whatever energy is created, will probably not be able to escape from two black holes.

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leonardo shawon
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Re: A few questions on newtons law and black hole

Unread post by leonardo shawon » Tue Jul 19, 2011 9:33 am

that means there will be one strong black hole right......?
Ibtehaz Shawon
BRAC University.

long way to go .....

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