What is weight? Does it really exist? Or, more to the point, would it exist without gravity?
We all know approximately what our weight is; at least here on earth. Of course, on other planets the gravity will vary, so consequently, weight will vary accordingly. And everybody knows that in zero gravity, we all become weightless.
Thus, weight is only relevant to where we are. However, surely mass, as in the human body, for example, which is what we are, is composed of chemicals, molecules, atoms, should have weight. Or should it?
I refer back to an old blog, that I posted a while ago about hard drives being heavier when they are full of information as opposed to being devoid, and the general consensus is that a hard drive full of data is indeed heavier than a hard drive devoid of data. Therefore, weight must have a direct correlation on mass? A person or an object's weight (W) can be determined by the product of its mass (m), and the magnitude of the local gravitational acceleration (g), thus W = mg.
The previous paragraph may or may not have any relevance to the point in question. However, is weight only pertinent to our own existence? In other words, do we really need the word “weight” in our language simply to draw a parallel to our own personal existence?
Any time we feel our “weight”, we are invariably in contact with another surface. That surface might be the floor or something comparable. Therefore, a person’s weight is the contact force exerted upon him by whatever is sustaining him, in any state. Your weight, as defined herein, is what is calculated by, for example, a simple weighing machine placed between you and whatever is exerting a force against you.
The dictionary describes weight as: “The force that gravitation exerts upon a body, equal to the mass of the body multiplied by the local acceleration of gravity: commonly taken, in a region of constant gravitational acceleration, as a measure of mass”. So much for dictionaries!
Further, mass became identified as a fundamental property of matter related to their inertia, while weight became identified with the force of gravity on an object and subsequently dependent on the context of the object.
The same logic applies, in my opinion, to the word ’time’. However, wait, that will be addressed at a later juncture. For now, let’s get back to “weight”’.
If you weigh yourself, you will, for example, weigh, for argument's sake, 80 kg. And, as asserted earlier, that weight will reduce or increase depending on the atmosphere that you are within. And, also, as previously asserted, in zero gravity you will be weightless.
Should we even discuss weight in terms of kilograms? The correct terminology is Newtons (symbol: N), after Sir Isaac Newton.
My question is this. What does the word weight really mean?