E=MC²

[glmadmin]

1st question
When using the equation E=mc², do you use the speed of light as km/sec or miles/sec?

2nd question
If E=mc², Shouldn't E/m always equal the speed of light²?

3rd question
If 2nd question is true, Does that mean there is a truer unit of measure for speed that we have not discovered yet or is Einstein's Big Idea inadequate?

 

[Deleted member 4993]

1st question
When using the equation E=mc², do you use the speed of light as km/sec or miles/sec?

2nd question
If E=mc², Shouldn't E/m always equal the speed of light²?

3rd question
If 2nd question is true, Does that mean there is a truer unit of measure for speed that we have not discovered yet or is Einstein's Big Idea inadequate?

(1) Depends on your choices of units for 'E' and 'm'.

(2) But by 'm' - are you referring to the 'rest mass' or the 'relativistic mass'?

(3) A question cannot be true or false - however it can be asinine or absurd or ignorant. Pick your adjective - I am already tired ??

 

[glmadmin]

(1) Depends on your choices of units for 'E' and 'm'.

(2) But by 'm' - are you referring to the 'rest mass' or the 'relativistic mass'?

(3) A question cannot be true or false - however it can be asinine or absurd or ignorant. Pick your adjective - I am already tired ??

1. Not sure I am following you as to what unit of measure for energy and mass.
2. invariant mass obviously
3. if you are Super Moderator, How can you decide it is ok to publicly attempts to shame someone by suggesting any question is asinine or absurd or ignorant?

“The only stupid question is the question that is never asked.” ― Ramon Bautista​

 

[topsquark]

1st question
When using the equation E=mc², do you use the speed of light as km/sec or miles/sec?

2nd question
If E=mc², Shouldn't E/m always equal the speed of light²?

3rd question
If 2nd question is true, Does that mean there is a truer unit of measure for speed that we have not discovered yet or is Einstein's Big Idea inadequate?

!) Use whatever unit system you like. My preference for speed is "furlongs/fortnight."

2) [imath]\dfrac{E}{m} = c^2[/imath], not c.

3) In higher level Physics there are a lot of constants in the equations. To reduce the number of these we commonly use the Heaviside-Lorentz system of units (or, more correctly, the rationalized Planck unit system) where we set [imath]c = \hbar = 1[/imath], so we tend to say that c = 1 and is unitless. (We are saying that 1 m = 1 s.) It's a little weird but you get used to it. That means E = m.

And Einstein's SR is perfectly adequate for the job. So far there are no substitutes that are anywhere nearly as good.

-Dan

 

[topsquark]

3. if you are Super Moderator, How can you decide it is ok to publicly attempts to shame someone by suggesting any question is asinine or absurd or ignorant?

“The only stupid question is the question that is never asked.” ― Ramon Bautista​

If you stay on the Forums long enough you find that most people that question SR or GR (I call them "anti-Einsteins") are either completely ignorant or trolls. His reaction is just part of the job. Please don't be insulted.

-Dan

 

[Deleted member 4993]

1. Not sure I am following you as to what unit of measure for energy and mass

You do not know that ? What is your level of Physics education?

invariant mass obviously

mass is not invariant under relativistic conditions. What do you mean by invariant mass.

I hear foot-steps of trolls - I better go hide under the bridge.....