Levitation Possible? How Electric Charge Balances Gravity

  • Context: Undergrad 
  • Thread starter Thread starter skepticwulf
  • Start date Start date
  • Tags Tags
    Levitation
Click For Summary

Discussion Overview

The discussion revolves around the feasibility of levitation through electric charge, specifically examining the relationship between electric fields, charge, and gravitational force. Participants explore theoretical scenarios involving static electricity and electric fields, as well as practical implications and limitations of such concepts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant calculates that a charge of approximately 5.5 C would be necessary to counteract the weight of a 187-pound person using the equation F=qE.
  • Another participant argues that achieving such a charge would result in discharging lightning bolts, suggesting that levitation would not be possible without severe consequences.
  • A participant proposes the idea of using a gadget or suit to achieve levitation, referencing the electric eel's ability to generate voltage without harm.
  • Concerns are raised about the relevance of voltage versus charge, with one participant emphasizing that 5.5 C is comparable to a small lightning bolt.
  • Questions arise regarding the control of such a charge, particularly in relation to air breakdown and the potential for electric arcs.
  • Another participant introduces Paschen's Law, discussing how various factors like pressure and temperature affect the breakdown voltage of air.
  • One participant highlights the extreme current that would result from discharging 5 C over a short time, warning of the dangers to the body.
  • Finally, a participant points out the immense repulsive force that would occur between two charges of 2.5 C, suggesting that the structural integrity of a person would be compromised long before achieving such a charge.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of levitation through electric charge, with no consensus reached on the practicality or safety of such an approach. The discussion remains unresolved regarding the implications of achieving high electric charges for levitation.

Contextual Notes

Limitations include assumptions about the ability to maintain high charges on a human body or device, the effects of environmental conditions on electric discharge, and the structural integrity of materials under extreme electric forces.

skepticwulf
Messages
74
Reaction score
1
I was solving a static electricity/electric field problem and I came across with one saying Earth has an electric field of roughly 150 N/C at the surface. The book also states that it's negative, direction is toward the center of Earth's core.
So from the equation of F=qE one can find easily the necessary charge needed to counter effect the gravity:
mg=qE

so for a 187 pond man the charge must be something like 5.5 C. I assume that means if "somehow" I could charge my body 5.5C negative, that would balance my weight and I could levitate.
Is that correct? Is something missing with this picture?
 
Physics news on Phys.org
Yes. If you put 5.5C on your body, you would start discharging lightning bolts. The only thing levitating would be your ashes.
 
Ok maybe not by producing with my own body but within a gadget or something, some sort of costume like Iron Man has.
By the way and electric eel can produce about 100V without "levitating his ashes" so it's not that far-fetched idea.
 
skepticwulf said:
By the way and electric eel can produce about 100V without "levitating his ashes" so it's not that far-fetched idea.
Volts? Volts aren't relevant here. What is relevant is the charge.

5.5C would be the charge of a relatively small lightning bolt, but a lightning bolt nonetheless.
 
skepticwulf said:
Ok maybe not by producing with my own body but within a gadget or something, some sort of costume like Iron Man has.
By the way and electric eel can produce about 100V without "levitating his ashes" so it's not that far-fetched idea.

100V for the eel but 1010V (shorthand of a vast amount) for the man to be charged with all those Coulombs. The two situations are not comparable.
 
OK, I'm not sure if I understood correctly , you mean to say if a person or his suit would have a 5.5C of electric charge on it, it would create a lightning bolt , so it's impossible to control it?
Is this due to air? electric charge that big can not be hold on a surface because en electric arc would form on air surround it and eventually jump around just like a natural lightning bolt would do?
How about space ? would that work on space?
 
The spark depends upon the breakdown voltage of the air or other insulator. There are formulas for varying air pressures - Paschen's Law: http://home.earthlink.net/~jimlux/hv/paschen.htm

If you look carefully it involves the materials, the distances, and the voltages as well as pressure, temperature, and humidity.

If you were to discharge 5 coulombs over a period of 1 millisecond the current running through your finger/foot/nose ... the body part where the discharge occurs ... will be 5,000 amps. The voltage from your height to the ground is the value 100 volts per meter; so assuming your belt buckle, the power is 5,000 amps x 100 volts = 50,000 watts for 1 millisecond.

As was said earlier, this will be very bad for the affected body parts!

Also see http://en.wikipedia.org/wiki/Atmospheric_electricity
 
Forget the sparks. Just consider the coulomb force needed to keep 5.5C of charge within the space occupied by a man. Two charges of 2.5C each, separated by a metre (i.e. two halves of your man) would experience a repulsive force of around 1012N. Your experimenter would fly to pieces long before he managed to get a fraction of that amount of charge on him.
 

Similar threads

  • · Replies 58 ·
2
Replies
58
Views
6K
  • · Replies 11 ·
Replies
11
Views
10K
  • · Replies 36 ·
2
Replies
36
Views
7K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
8K
  • · Replies 2 ·
Replies
2
Views
5K
  • · Replies 14 ·
Replies
14
Views
6K