Alpha Particles of Uranium 238

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Discussion Overview

The discussion revolves around the behavior of alpha particles emitted from Uranium-238, specifically whether they arc and fall under the influence of gravity after leaving their source. Participants explore the implications of gravitational laws on these particles, their trajectories, and interactions with surrounding matter.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that alpha particles are subject to gravitational laws, but their high speeds result in negligible deflection.
  • One participant suggests calculating the speed of alpha particles from their energy to estimate their behavior in a gravitational field, comparing it to a simpler physics problem.
  • Another participant questions the nature of the arc in the trajectory of alpha particles, seeking clarification on why they do not fall in a straight line.
  • It is noted that when an alpha particle is emitted, it may collide with other atoms, slowing down and eventually capturing electrons to become helium gas.
  • Participants discuss the initial angle of emission affecting the trajectory, comparing it to the motion of a cannonball.
  • Concerns are raised about the negligible effect of gravity on alpha particles due to their light mass and short travel distance.
  • One participant mentions that electric fields may have a more significant effect on the positively charged alpha particles than gravity.

Areas of Agreement / Disagreement

Participants express differing views on the significance of gravitational effects on alpha particles, with some arguing that gravity is negligible while others suggest it plays a role depending on the initial conditions of emission. The discussion remains unresolved regarding the nature of the arc and the factors influencing particle trajectories.

Contextual Notes

There are limitations in the discussion regarding assumptions about initial angles of emission and the presence of external fields, which may influence the behavior of alpha particles but are not fully explored.

On_A_Quest
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I have a simple question. Do alpha particles from radiation arc and fall after leaving its source? Are these particles bound by the same gravitational laws as us?
 
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Yes. However, typical particle speeds are so high that you will not really see much of a deflection.
 
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In general - yes. That is, assuming they don't collide with other atoms present in their surroundings (bulk metal, air).

You can try to find out their speed (you can calculate it from their energy, which should be easy to google), and estimate their behavior on the Earth surface assuming no air, just a gravitational field. This is a rather simple physics problem, actually not different from all these questions about John throwing a stone from a window :wink:
 
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I guess my next question would be why the arc? Why now just fall from a linear plain?
 
On_A_Quest said:
I guess my next question would be why the arc? Why now just fall from a linear plain?
When an alpha particle leaves a nucleus, two electrons are also released by the nucleus. The alpha particle will collide with other atoms until it slows to equilibrium in the surrounding environment. At some point the +2 nucleus will capture two electrons and become a Helium (4) atom, and so in the atmosphere it will be He gas. Underground, it will also be gas, which will collect in whatever porosity is available. In deposits of natural gas, one will find He and sometimes Rn, from decay of U and other heavy radionuclides.

All matter is subject to effect of gravity.
 
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Did you do the calculation suggested by Borek? You'll see that the effect is absolutely negligible.
 
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On_A_Quest said:
I guess my next question would be why the arc?
You were the one` to bring it up. My question is "why"?
 
On_A_Quest said:
I guess my next question would be why the arc?
Well, the trajectory depends on the initial angle (relative to "down," the direction of gravity) just like for a cannonball. If the initial direction of the particle happens to be straight down, then no, there is no arc.

Why now just fall from a linear plain?
I don't understand what you are asking here.
 
gmax137 said:
Well, the trajectory depends on the initial angle (relative to "down," the direction of gravity) just like for a cannonball. If the initial direction of the particle happens to be straight down, then no, there is no arc.I don't understand what you are asking here.
I think he meant that if the alpha is emitted say horizontally from the nucleus then it would essentially start a linear descent forming a traced line hat is roughly 45 degrees.

The arc example I understand was meat to be similar to how one would throw a basketball up and sideways ad then it would travel up before falling back down and the line that traced the ball would roughly resemble an arc. But then mfb already gave the main answer
mfb said:
Did you do the calculation suggested by Borek? You'll see that the effect is absolutely negligible.
which is that for something that light and traveling that short of a distance on average gravity is a negligible effect
If there was even a slight E field somewhere (realistically there always is I think) it's effect would be far more noticeable on the overall positively charged alpha than gravity
 
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The OP hasn't been back. Just a hit and run post.
 

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