If we say there are three types of time — historical time, chronological time, and biological time —, the main character is younger than his daughter in all but historical time. — Lionino
Should we count age as being the time of duration or physical change? — Janus
So, in durational terms she is always going to be older than her daughter, and since the very meanings of 'mother' and 'daughter' presuppose that the mother exists antecedently to the daughter, then to say that the child could be older than the mother would involve a logical contradiction. — Janus
So, yes if that were possible then the main character would be biologically younger than his long dead daughter. On the other hand, since Earth time is really what counts for us, we would say he has been gone for a thousand years, and is thus one thousand plus years old, even though relatively unaged. — Janus
In the fable presented, the protagonist’s age as measured by his own personally experienced duration of time will factually be that of twenty-some years. This though, in the fable, relative to the duration of time as would be measured by all those he departed — javra
This puts me in mind of some of Kant's CPR i've gone over in the alst couple of days.
The relation of time is individual in that an external impression of another person doesn't exist in their time, it exists in the perceiver's time. I would think that this means we can just see any subjective notion of time as legitimate. It only exists as a relation, so there's no other benchmark. — AmadeusD
As concerns objective time, however, the same dichotomy between a relativistic time and cosmically absolute time will present itself. With all indications now pointing to time being relativistic rather than absolute. — javra
And yet the claim is that the Universe began around 14 billion years ago. — Janus
And in general, when we talk about the age of anything, existing things which came into being earlier than other existing things are considered to be the older. On this criterion a daughter could never be older than her mother while they are both still alive, although of cause the daughter could live to a greater age. — Janus
How does this connect with General Relativity and GPS? As predicted by Einstein’s theory, clocks under the force of gravity run at a slower rate than clocks viewed from a distant region experiencing weaker gravity. This means that clocks on Earth observed from orbiting satellites run at a slower rate. To have the high precision needed for GPS, this effect needs to be taken into account or there will be small differences in time that would add up quickly, calculating inaccurate positions. — https://www.nasa.gov/image-article/einsteins-theory-of-relativity-critical-gps-seen-distant-stars/
Since the different gravitational forces would not make for much of a difference, — Janus
and hence significant differences in aging probably remain in the realm of fiction or fantasy. — Janus
But I guess considering what is a "significant difference in different gravitational forces" would embark us too far astray — javra
... and in the realm of metaphysical possibility, which this thread is in part about. — javra
We don't know what is metaphysically possible, — Janus
p is metaphysically possible iff p is true in at least one possible world.
p is metaphysically necessary iff p is true in all possible worlds.
p is metaphysically possible iff p is consistent with the laws of metaphysics.
p is metaphysically necessary iff p follows from the laws of metaphysics.
I'll say that, if by no other means, then via acquaintance with there so being different ontologies out there — javra
It's logically possible that abstract objects exist, but their existence is metaphysically impossible if physicalism is true.what would something metaphysically impossible but logically possible be? — Lionino
The empirical meaning of SR is demonstrated by the experiment and results of the Michelson Morley experiment that partly motivated it. This empirical meaning does not refer in any obvious way to the sentiment that "faster-than light travel is impossible". If a physicist is asked to describe the meaning of this impossibility, he will likely refer to empirically observable Lorentzian relations that he argues are expected to hold between observable events. In other words, his use-meaning of the "physically impossible" is in terms of the physically possible!
So physical impossibilities shouldn't be thought of in terms of impossible worlds, but rather as referring to the application of a linguistic-convention that supports the empirical interpretation of language. — sime
I would say there are historical (Earth or chronological) time and phenomenological time — Janus
unless we count possibility as being simply what we can coherently imagine. — Janus
we don't know what the laws of metaphysics are, unless, again, they are what we can imagine without contradiction — Janus
It's logically possible that abstract objects exist, but their existence is metaphysically impossible if physicalism is true.
In general one would judge as metaphysically possible, anything that is consistent with one's prior ontological commitments. If contradicted by ontological commitments, you'd judge it metaphysically impossible.
If you prefer to judge metaphysical possibility from a perspective that's devoid of ontological commitments, then metaphysical possibility = broadly logical possibility. — Relativist
100% agree.I would also raise that if physicalism is true, metaphysical possibility = physical possibility. — Lionino
If we adhere to the idea of universal natural law and assume that what we understand about that law is valid and reflects necessary or universal invariances, then within that context, we can talk about physical impossibilities. But the caveat will always be 'given that the laws of nature are themselves invariant". — Janus
The laws of metaphysics do not follow necessarily from logical possibility. — Lionino
If naturalism is true, and there are laws of nature, I suggest the true natural laws would be invariant. The way they manifest might be contingent on local conditions. That's why I think its important to refer to laws of nature, as you have done, rather than the laws of physics- which are based on our current understanding, and subject to revision as we learn more. — Relativist
There are different ontological theories; there is one ontological subject and object of study, which is existence. Having different ontological hypotheses doesn't alter the nature of the real. — Pantagruel
Synthetic a priori judgments are the crucial case, since only they could provide new information that is necessarily true. But neither Leibniz nor Hume considered the possibility of any such case.
Unlike his predecessors, Kant maintained that synthetic a priori judgments not only are possible but actually provide the basis for significant portions of human knowledge. In fact, he supposed (pace Hume) that arithmetic and geometry comprise such judgments and that natural science depends on them for its power to explain and predict events. What is more, metaphysics—if it turns out to be possible at all—must rest upon synthetic a priori judgments, since anything else would be either uninformative or unjustifiable. — http://www.philosophypages.com/hy/5f.htm
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