Electrostatics question. just need a bit direction.

AI Thread Summary
The discussion revolves around a theoretical scenario proposed by Lyttleton and Bondi regarding the expansion of the Universe due to net charge in matter, specifically hydrogen atoms. The problem involves determining the critical value of y for the proton's charge and establishing that the expansion velocity is distance-dependent. Participants note that the repulsive electric force from the charged protons must exceed the attractive gravitational force between hydrogen atoms for expansion to occur. Clarification is sought on whether the forces discussed pertain to interactions within atoms or between them, confirming the focus is on interatomic forces. The conversation highlights the balance between electric repulsion and gravitational attraction as a key factor in cosmic expansion.
PrashntS
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I was trying to solve this one, but couldn't come up with any way to start.

In 1959 Lyttleton and Bondi suggested that the expansion of the Universe could be explained if matter carried a net charge. Suppose that the Universe is made up of hydrogen atoms with a number density N, which is maintained a constant. Let the charge on the proton be: ep = – (1 + y)e where e is the electronic charge.
(a)Find the critical value of y such that expansion may start.
(b)Show that the velocity of expansion is proportional to the distance from the centre.

Attempt at solution-

since charge assumed on proton is -(1+y)e, there is net charge in atom. also the force is repulsive, not attractvie. I started with taking a spherical gaussian surface and thts it! i couldn't go any further.
 
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Gravity between the hydrogen atoms is an attractive force. The extra charge has to be so great that electric repulsion overcome gravitational attraction.

ehild
 
ehild said:
Gravity between the hydrogen atoms is an attractive force. The extra charge has to be so great that electric repulsion overcome gravitational attraction.

ehild

by this, do you refer to force inside the atom, between electron and proton, or between atoms.

and thanks fir quick reply. :-)
 
PrashntS said:
by this, do you refer to force inside the atom, between electron and proton, or between atoms.

and thanks fir quick reply. :-)

Between the atoms.

ehild
 
Thread 'Variable mass system : water sprayed into a moving container'

Thread 'Variable mass system : water sprayed into a moving container'

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