Gravity, like time, is magnitive; time is imperceptible and gravity is undetectable. Gravity exists, is undetectable and measurable. Gravity is such a weak force that it can not be detected with anything; we only see its effects on bodies.
Magnitive is the magnitude that we only have indirect evidence of its existence. Magnitive is imperceptible (time) or undetectable (gravity). I should have said quantifiable
You can use a bathroom scale to measure gravity. If you want to get a more precise idea of the local gravity you could use a Gravimeter. I realize this will have no impact on your preconceived notions, whatever they are, but I thought I would just point out that you have no idea what you are talking about.
The bathroom scale measures the weight, a manifestation of gravity, but no device has detected the supposed gravitons. That's what I mean.
By the same token, you might say that no device can detect electrical charge. We only see the effects of electrical charge. Would you say that electrical charge is "magnitive", too?
GRAVITY 1- We can perceive and measure its effects (weight). 2- The supposed gravitons are not detectable (nature). 3- It is magnitive. ELECTROMAGNETISM 1- We can perceive and measure its effects (attraction and repulsion). 2- There is evidence that electric charges exist. They are detectable. 3- It is not magnitive.
You're not comparing like and like there. You say gravitons (the messenger particles of gravity) are undetectable. But then neither are the virtual photons that carry the electromagnetic force. Nevertheless, we have detected gravitational waves, and obviously we detect light in many ways. Also, there is no direct detection of electric charge. It is only detected through its effects on particles and the like that are said to carry charge. The analogue for the gravitational case is, of course, mass. So, while you might say that there is no direct detection of gravity, we certainly see its effects on particles that are said to have mass. Given all this, I don't see how electromagnetism can be magnitive while gravity can't. It looks like you're applying your definitions inconsistently.
No. I said that gravity is magnitive and electromagnetism is not. But if the electric charges are not detectable, then electromagnetism is also magnitive, that is, it exists, undetectable and quantifiable.
Okay, so we have that gravity and time and electromagnetism are magnitive. It would seem that the strong and weak nuclear forces must both be magnitive as well. And the Higgs field, while we're at it. If all four fundamental forces in nature are magnitive, and those govern all interactions seen in nature, is there anything that isn't magnitive? What use is this magnitive concept?
The physical magnitudes can be magnitive and not magnitive. Magnitive: time, the four fundamental forces and the Higggs field. Non-magnitive: length, mass, force, speed and acceleration. It describes the ineffable quality of some magnitudes.
You say that magnitive means we have only indirect evidence of its existence. What do you mean by indirect evidence, in this context? There's only indirect evidence of things like speed and acceleration, arguably.
We do not see or detect things in themselves, but their effects. In the case of particles, they change their behavior when they are observed.
If true Why is that ? Why do particles change their behaviour when observed ? And if so , then you should be able to change it back to the behaviour it had before being observed .
Not quite. In one case, the effects of a particle are studied, in another case a camera is used to observe the particle directly. This is where his behavior changes.