# How much does a second weigh?

Substituting “Distance divided by Time” in the equation "E=MC2 and then solving for "Time = ", how much does a second weigh at sea level?

c in E = mc^2 is a fundamental constant. You can’t pick it apart.

I’m no physicist, but I don’t think that’s the reason.

To the OP:

the question is nonsense. The equation shows as much because the units on the left side (energy) are also on a “time-squared” basis. For instance, a “joule” is a kilogrammm/(sec*sec). (kilogram times meters squared over seconds squared)

Energy is the amount of work done over a period of time, like the constant ‘c’ is a distance travelled over a unit of time.

IOW, the “seconds” come out of the equation.

treat C as a constant and then substitute “Kmm/Sec2” for E then solve for seconds.

1 Joule is defined as 1 kg m[sup]2[/sup] s[sup]-2[/sup]. So I guess you could say 1 second is equal to 1 m kg[sup]1/2[/sup] J[sup]-1/2[/sup].

You might as well ask “How much does a mile weigh?”

A second is 186,000 miles long however.

No, don’t use the two answers.

Use mine.

The left side of the equation has sec^2 in the denominator; the right side has sec^2 in the denominator. They cancel when you try to solve for “1 second” (unless you want to solve for seconds in terms of “joules” but joules is not a weight. It has time in it.)

The speed of light in a vacuum is a constant, but it still has units, and the units are meaningful.

seconds is a measure of time. you can ask “if I use 5 joules of energy, how much mass can I move in one second” but that doesn’t tell you how much “mass” is in a second.

Are you folks serious, or is this going to come around to the Henway?

So you’re saying seconds have a proportional amount of mass and energy, that if seconds have such and such mass they also have to have a certain amount of energy?

I’m serious. I can understand that something traveling at the speed of light has /0 mass and is mathematically meaningless, well except for photons, but is solving for seconds as a unit of mass yield a result, even if it is one not easily understood?

A second is a DISTANCE in spacetime. Distances don’t have mass. As I said above, it’s equivalent to asking “How much does a mile weigh?”

You can’t describe the second using only the unit of mass.

Mass doesn’t have weight until you get within a certain distance to another mass! So a mile can be expressed as a relationship between two masses for a given weight, right?

But we can describe it using a proportion of mass and energy?
or mass and energy and distance?

No, energy has seconds in it.

Simply put (but not perfectly accurate) energy is how much mass is moved in a second.

If I tell you

A) how much energy and mass I used, you can tell me the second

B) how much mass I moved in a second, you can tell me the energy

C) how much energy I used in a second, you can tell me the mass

Energy is an expression of how much mass is moved in a second. That doesn’t mean that a second has mass any more than a barbell has time.

Why not? What’s snew? Yes, but when you do that the terms that represent the weight will cancel out, leaving only distance behind:

weight = (G * mass1 * mass2) / (distance * distance)

Where G is the gravitational constant.

distance = squareroot ( G * mass1 * mass2 / weight)

Looking at the units:

distance = squareroot ( newton * meter * meter * kilogram * kilogram / kilogram * kilogram * newton )

The kilograms and newtons cancel out.

distance = squareroot (meter * meter)

distance = meter

See … no mass or force in the final answer. You can’t use gravitiational attraction to express distance as a weight. Time works the same way.

1 s = 4.04x10[sup]35[/sup] kg

(Hint: convert everything into Planck units.)

Quod erat demonstrandum, or, as my old Math teacher used to say, Quite Enough Done.