Posts by Martin

Welcome Aeneadum!

Here is my comment to Patrikios' thought experiment:
Placing the object outside Earth’s gravity would not be enough because then it could be in the Sun's gravity. Placing it outside the Sun’s gravity would still not be enough because then it could be in the gravity of the Milky way.
We might find a point between two galaxies at which the gravitational forces of both galaxies cancel out each other and where the gravity of further away galaxies is too small to be significant for a reasonably long time of observation.
We can define a frame of reference there at which the object would stay at rest once placed there without initial speed in that frame of reference. (There is a logical circle in it because the definition of an inertial frame of reference is that an object without external force keeps moving with its initial speed, i.e. stays at its place if initially at rest.)
If we want to move that object, we need to apply a force to accelerate it. The proportionality constant between force and acceleration is the inertial mass. (I would not call that "potential for movement".)
If we place the object in a gravitational field, the gravitational mass of the object is the proportionality constant between the force on the object and the gravitational field strength.
Gravitational mass and inertial mass are conceptionally different. We have defined our system of measurement units such that both masses are measured in the same units.
In a system, in which the units are not the same, the two types of masses are proportional to each other but not identical, which makes the conceptional difference more obvious. This is an ongoing topic of research into the foreseeable future. Physicists keep designing new experiments to test the proportionality between gravitational mass and inertial mass with ever increasing measurement accuracy.

Here are my answers to Cassius' questions:

Gravity is one of four fundamental forces which can be considered as independent and their own entities in easy-to-understand models. There is a unified theory for the other three forces. Moreover, there are attempts toward a grand unified theory which would include gravity as well. I have no expertise in the unified theories. I am not aware of a generally accepted grand unified theory at this time.

In the easy-to-understand models, gravity appears to be uncaused. This might not by the case in more sophisticated models and is not the case in one type of monism.

Gravity is associated with "matter" in the adequate models I know.

I agree with the answer from Grok. There is one caveat which I mentioned in one of our Zoom calls. That mass (or energy) produces a gravitational field and curves spacetime is only one of three possibilities and assumes that mass and space exist independently (dualism) but affect each other. The other possibilities are that mass creates space (monism) and that space creates mass (monism). Each of the three possibilities is compatible with observations and the currently best models to explain the observations. Choosing one over the other three possibilities is rather belief akin to religion than knowledge at this time. In practice, publications typically imply dualism like in the quote from Grok.

Today's meaning of "weight" is indeed a poor fit. The modern term "inertial mass" seems to be accurate for βάρους in the context of Epicurean atoms moving with constant speed. There was no proper understanding of gravity in ancient times, but anyone could sense the effects of inertial mass.

Welcome M.Dango!

Welcome ReiWolfWoman!

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Here’s a good video I recommend everyone watch

No, it is a bad video which you should not waste your time to watch (unless you are into refuting nonsense statements on mathematics and reality.) Moreover, it is far out of the scope of our site.
Steve Patterson presents a string of truthful statements mixed in with nonsense. Among other falsities, he makes the claim that his mathematical nonsense proves something on our reality, like Plato. Mathematics is a useful tool to describe reality but not the other way round, that mathematics prescribes reality. That is already enough to refute the Kalam cosmological argument as well.
Where can I reimburse the 14 minutes which I wasted on that video?

Welcome Lamar!

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just like Lucretius and Diogenes of Oinoanda and many others let the size of the job stop them from what they accomplished

should be "just like Lucretius and Diogenes of Oinoanda and many others let the size of the job not stop them from what they accomplished".

Those are incorrect. Whereas Plato's school apparently degenerated into plain skepticism, Kant's version of idealism was not that skeptic. Within Kant's epistemology, certainty with respect to knowledge about phenomena is possible but the metaphysical claim that that knowledge is the truth about how things actually are is unfounded. Moreover, Kant's epistemology can be restated in a materialistic framework. Therefore, the classification of Kant as an idealist is not relevant in this discussion.
With trivial matters, the distinction between knowledge about phenomena and how things actually are does not matter: When I am hungry, I eat, then feel full.
The distinction matters when we want to get a deeper understanding or when knowledge expands.
Maybe this example can clarify this:
If we kick a stone resting on Earth into motion on a horizontal surface, its speed will gradually decline and eventually stop. A simple theory can be stated that the natural state of non-living heavy things on Earth is to be at rest, and after they have been forced into motion, they gradually relax into their natural state of rest. (Aristotle came up with something similar to that). At that stage, people might have thought that the simple theory is the truth about how things actually are. Until a few hundred years ago, there was no experimental setup which could refute that theory. Even today, we could still use that simple (but ontologically wrong) theory for accurate solutions of engineering problems in cases which stay within its limitations. Newton had no way to experimentally refute it when he came up with a more general theory of mechanics of which the first "axiom" contradicts that simple theory. His theory was quickly accepted because it could explain more phenomena and at a deeper level. At that stage, people might have thought that Newton's theory is the truth about how things actually are. However, they had no superior knowledge from which they could justify that thought. Later, we found out that Newton's theory fails when high speeds are involved, contradicts electrodynamics and needs to be replaced by Einstein's special theory of relativity to resolve these issues. We might think that now, Einstein's special theory of relativity is the truth about how things actually are. But again, there is no superior knowledge from where we could justify that thought.

It is exactly that sentence ("On one side stands a tradition stretching from Plato...") which is false because Kant rejected dogmatism and did not reject the senses. In Kant's view, we know about the world through the senses. His epistemology examines how we make sense out of the input of the senses. That sentence is false with respect to modern academic philosophy, too, and maybe even with respect to some Stoics.
A correct revision could be:
"On one side stands a tradition stretching from Plato through medieval theology into much of modern religion: the view that what is genuinely real must be eternal, unchanging, and accessible not through the senses but through some higher faculty — pure reason, divine revelation, or the intellectual intuition of necessary truths."

In this context: The article is excellent with respect to Plato and Epicurus. My own position is that Epicurus extreme affirmation on the real world made sense at his time as opposition to Plato's nonsense, but it is obsolete now, thanks to Kant and others. As this forum is focused on authentic Epicurean philosophy I refrain from elaborating on my heretic view here.

It should be made clear that the article is rather against Plato's idealism. Putting Kant in the same bucket as Plato is wrong because Kant removed the ideal forms and Plato's nonsense that reality is truthfully revealed only by the logic of philosophers like Plato. There are other issues with the text but just removing Kant from the text would already improve the credibility.

Welcome J.Tycherne!

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Would a Kantian take the position that it is not true that there are no supernatural gods, not true that there is no life after death, and not true that pleasure is the guide of life?

Kant himself does take these positions. However, later Kantians may differ. I am an Epicurean, not a Kantian. My reference to being "Kantian" is limited to him as being named as the original source of the distinction between a model and truth. He used different terminology and an idealistic framework. Others reformulated his epistemology within materialism. Other than that and his version of the golden rule, I do not know much about other aspects of his philosophy. I have read very little from Kant himself but more from those who refer to him.

I found two references for dummies on Kant's epistemology and one reference for professionals. Although the one frome Nature has been created with A.I. (which I usually would not want to read or share) I have to concede that it is convincing and easy to understand. The second reference is riddled with mistakes but seems to correctly present Kant's epistemology. The third one is mostly above my league:

Kantian Philosophy and Epistemology | Nature Research Intelligence

https://yohanesnuwara.medium.com/the-epistemology-of-immanuel-kant-5e5e7fbd1e48

Kant’s Ongoing Relevance for Philosophy of Science | Kantian Review | Cambridge Core

Kant’s Ongoing Relevance for Philosophy of Science - Volume 28 Issue 3

www.cambridge.org

The rejection of both plain rationalism and plain empiricism is an overlap between Epicurus and Kant.
Kant replaced them with a unified epistemology drawing from parts of both of them. Based on his new approach to epistemology, scientists usually present their theories as models of reality instead of truth on reality.
Epicurus replaced rationalism and empiricism with another unified epistemology within which the most basic theories still claim truth on reality. This claim is an unproven belief which is akin to religion and Platonism and not necessary for a materialist world view.
A philosophy which rejects Plato's idealism more profoundly and does not make superfluous claims on truth is more convincing. Under this aspect, my choice is Kantian instead of Epicurean.

Welcome Ludenbergcastle!

Welcome Cornelius Peripateticus!

Welcome Hania!

Welcome Martijn!

I started a conversation between us.

For now, I see the isotacheian model as something complementary, e.g. as an exercise for students, but not as an alternative way of teaching special relativity.