# Newton's first law of motion

Discussion in 'Physics' started by logearav, Oct 11, 2011.

1. ### logearav Thread Starter Member

Aug 19, 2011
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Newton's first law of motion deals with inertia of bodies. According to this law, " Every body continues in its state of rest or of uniform motion in straight line, unless compelled by an external force."

My question is , " How spontaneous decay occurs in heavy elements resulting in alpha, decay and gamma emission, without any external force acting on it"?

2. ### Georacer Moderator

Nov 25, 2009
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I 'm not sure I follow. What do you mean by those words? Please give an example or elaborate.
Do you talk about classic Newtonian physics or atomic physics?

3. ### Wendy Moderator

Mar 24, 2008
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You are mixing apples and oranges. The two follow two different sets of laws that are not related.

4. ### logearav Thread Starter Member

Aug 19, 2011
248
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GeoRacer,
A body will deform only when we apply some force on it. In a similar way, we bombard a nucleus with a neutron to induce fission in the nuclei. But, how heavy nuclei spontaneously decay, without application of any external force, what we call it as radioactivity.

5. ### steveb Senior Member

Jul 3, 2008
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Bill hit the mark.

Newtonian physics is totally inadequate to describe nuclear reactions. The question of how spontaneous decay occurs falls into the realm of Quantum Field Theory. This theory is many layers removed from Newtonian physics because it incorporates key ideas from quantum mechanics and relativistic physics, and goes even further in that it is currently the only accepted working theory (and a pretty good one too) that can capture the destruction and creation of new particles to/from energy.

Last edited: Oct 11, 2011
6. ### schoolie New Member

Oct 5, 2011
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Newton's law can be interpreted as "center of mass of a body" will continue in its state of .....

when a particle is emitted the atom gains momentum in the other direction. It is something like floating in space and you throw away your shoes, whereby you yourself gain some momentum. There is no net change in momentum of center of mass. External force causes movement of the center of mass.

7. ### Wendy Moderator

Mar 24, 2008
20,772
2,540
You know, an idea just hit me (and it hurt). Particles spontaneously popping in and out of existence sure sounds like other dimensions are involved.

8. ### djsfantasi AAC Fanatic!

Apr 11, 2010
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I am getting used to the idea that our universe consist of 7 or 11 dimensions, of which 3 or 7 are wrapped up very tightly.