Speed of Light Dilemma: Einstein's Formula E=MC^2 Explained

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Discussion Overview

The discussion centers around the interpretation of Einstein's formula E=MC^2, particularly the meaning of "C" and "C^2" in the context of energy-mass conversion. Participants explore the implications of the speed of light as a constant and its role in the equation, addressing potential contradictions and clarifying mathematical relationships.

Discussion Character

  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions how "C" can be squared if it is an ultimate constant, suggesting a possible contradiction.
  • Another participant asserts that C^2 serves as a conversion factor rather than a speed, indicating no contradiction exists.
  • Several participants clarify that C^2 has different units than C, comparing it to different types of measurements.
  • A participant provides a mathematical example to illustrate the conversion of mass to energy using the formula, seeking further clarification.
  • Another participant emphasizes that while C represents the speed of light, C^2 does not imply any mass traveling at that speed, noting that the energy represented is for mass at rest.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of C and C^2, with some asserting clarity in the mathematical relationships while others remain puzzled about the implications of squaring the speed of light. The discussion does not reach a consensus on the initial question posed.

Contextual Notes

Participants highlight the importance of unit consistency in the equation and the distinction between speed and energy, but some assumptions about the nature of C and C^2 remain unresolved.

Who May Find This Useful

This discussion may be of interest to individuals exploring the fundamentals of physics, particularly those seeking to understand the implications of Einstein's mass-energy equivalence and the mathematical relationships involved.

N99JH
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While listening to "Science Friday" on NPR today, I heard a Swiss physicist explaining that scientists can now produce Ant-Matter in a process based on Eintein's formula E=MC^2 whereby energy is converted into matter. Given that "C" in the formula is the speed of light and knowing that the speed of light is the fastest speed possible, left me puzzled regarding the "C^2" notion. My question is: If "C" is an ultimate constant, how can there be "C^2"? Isn't it an inherent contradiction there? If not - what am I missing?
 
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C^2 is not a speed of anything. It is a conversion factor from mass to energy or energy to mass. There is no contradiction.
 
c^2 is not greater than c. They have different units. It is literally comparing apples and oranges.
 
It's just to make the units come out correctly. In fundamental units, mass is in kg and energy is in kg*m^2/sec^2 so we have to multiply mass times the speed of light squared (m^2/sec^2) to get the equation to have the same units on both sides.
 
Well, there's a surprise than! Everyone I ever talked to said that the "C" in the E=MC^2 formula represents the speed of light. Is this true or is it not? To clarify my thinking, here is a mathematical example:
If I wanted to convert a mass of 1 kg into energy, using the formula, would I not have to write it in this form?
E= 1(kg)x299,792,458(m/sec.)x299,792,458(m/sec.)=(299,792,458)^2(Kg.M^2/Sec.^2)
 
Last edited:
c does represent the speed of light but c^2 does not. This is nothing unusual. Consider meters.

m is a measurement of length
m^2 is not
3 m > 1 m, but you cannot compare 3 m and 1 m^2
 
N99JH said:
Well, there's a surprise than! Everyone I ever talked to said that the "C" in the E=MC^2 formula represents the speed of light. Is this true or is it not?

I think you're just missing some algebra here. C is the speed of light, but it's a constant in the equation. Nothing goes faster than C. The resultant answer to "e = mc^2" is not a velocity, but represents energy. The equation shows the relationship of light, matter, and energy.

Here's a page showing the derivation of the formula, if this helps: http://www.adamauton.com/warp/emc2.html

-Dave KA
 
Also, e=mc^2 does not imply that there is any mass actually traveling at v=c. A mass has that much energy when it is at rest (v=0)
 
OK, I got it now.
Thanks to all that helped clarifying.
 

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