Now, we can see that the speed of CarB relative to CarA is 30 KM/H, yet the speedometer indicates 50 KM/H. Can we say that the speedometer's reading is wrong?! Not really, because the speedometer measures the speed relative to the ground not CarA!! The two values indicate the speed of CarB, but each one has a different reference, which means that speed is in fact a relative value.
So what exactly is the speed of CarB?! This question is unanswerable! You cannot ask about the speed without defining a reference object... The speed and the reference are inseparable. Is there any objective value of the speed of CarB?! YES!! We can objectively say that the speed of CarB is 30 KM/H with respect to CarA... As we can see, although speed has a relativistic property we can objectively state the speed. It is meaningless to say: "The speed of CarB is 30 KM/H", without qualifying the claim with its reference. Yet, once the reference is defined nothing is ambiguous!
Within this context we can define at least 4 points of view [POV as a shorthand]; one for each car. Each car has a different POV. From the POV of CarA, CarC has speed 80 KM/H. From the POV of CarB, CarC has speed 50 KM/H. It is evidently obvious that with respect to each POV CarC has a different speed value! One car with different speeds values from every POV!! Does this mean that one POV is correct and the other is wrong?! Not really. We cannot assign a truth value to a POV. We cannot say that the speed calculated from CarA's POV is correct and that of CarB is wrong. Somepeople may intuitively claim that the parking car's POV is more correct. As intuitive as it may seem, the last claim is flawed!
So does this mean that anyone claiming to know the speed of CarC is necessarily correct? Absolutely not. Consider the the driver and the passenger in CarA each make a different claim; The driver says: "From my POV, CarB is moving at 30 KM/H", while the passenger says: "From my POV, CarB is moving at 40 KM/H"... Both claims are initiated with the magic words "From my POV", yet the driver has made a truthful claim, while the passenger has made a false claim. The speed of CarB is 30 KM/H from the POV of the driver, and is 30 KM/H from the POV of the passenger as well since both are in CarA and moving with equal velocities.
A POV is different from an opinion. As in the previous example, the driver and the passenger in CarA each had the same POV, but with different opinions. Unlike a POV, an opinion can be assigned a truth value as being either true or false. A person may be wrong even from their own POV. We cannot say that the driver and the passenger had different opinions and both opinions are true. It is possible that two different opinions are both true - there is no contradiction, but nonetheless we cannot say that all opinions are necessarily true.
As a final twist, the driver in CarA may use this inference: "From my POV, CarB is moving at 30 KM/H. From my POV, CarC is moving at 80 KM/H. Thus, the speed of CarC with respect to CarB is (80-30) KM/H = 50 KM/H." - In this simple example, we see that the state from a certain POV can be calculated from other POVs, as the driver figured the POV of CarB from his own car.
- Some quantities are relative. eg. velocity
- Relative quantities are inseparable from the reference.
- Relative quantities coupled with their respective reference are objective facts.
- POVs are defined on references.
- POVs cannot be assigned truth values.
- Opinions are statements.
- Opinions evaluate to truth values.
- POVs can be evaluated from other POVs.
- Relativism and Objectivism DO NOT contradict.
- Relativism DOES NOT imply all opinions are true.