How do I know that this world isn't all a dream?
Let all your phenomenological conscious experience be a dream. That dream is reality. If reality is, in itself, a dream in itself, just repeat the process eternally. The phenomenological conscious experience remains the same.
Does God exist, and is it possible to prove it?
"God". Semantics... What are the properties of "God" and how these properties are entangled to your phenomenical experiences? Let "God" be the entity that garantizes consistency in reality. Let reality be the inter-determination of your phenomenical experiences and external non-phenomenical experiences. Let that inter-determination be integrated by "transduction". Reality exists. Therefore, "God" exists. Clarify "God" first and ask again.
Is it possible to do absolutely nothing?
No.
Analitically: Descartes proved that syntax proves syntax... paraphrasing: "I am, I exist". Phenomenical conscious experience proves semantics. "I experience qualia, therefore, I exist with the property of qualia". Syntax is proved. Semantics is proved. A unifying consistent bottom-up theory that unifies syntax and semantics must necessarily exist, because reality exists (addressed before). Therefore, it is not possible to do absolutely nothing. My interpretation of Heraclitus: “If movement is an illusion, then the illusion must have the propery of movement to generate the illusion of movement. If the second order illusion generates the property of movement in the first order illusion, the second order illusion must have the property of movement to generate blah blah blah...”.
Empirically: mass-energy conservation, since 1932.
What if I wasn't walking around in a body, but was really just a brain in a jar that thinks it has a body?
This question is redundant having answered the previous ones.
What if a tree falls in a forest and no one is around to hear it, does it make a sound?
This question goes directly into the mind-body problem, probably the most important open problem in, at least, analytical analysis (let’s assume this post is boosting everyone’s morale to fight and mitigate x-risk and let’s keep science aside, the last just for the sake of brevity). If you followed through the answers to the previous questions, then you can conclude that if a tree falls in a forest and no one is around to hear it, it makes a sound. My recommendation: immerse yourself deeply with discipline in Bayesian Epistemology and, if you do agree to the answer this epistemological paradigm gives, then we can apply Aumann's Agreement Theorem and discuss.
Hope this comment was useful. Good luck,
How do I know that this world isn't all a dream?
Let all your phenomenological conscious experience be a dream. That dream is reality. If reality is, in itself, a dream in itself, just repeat the process eternally. The phenomenological conscious experience remains the same.
---
Does God exist, and is it possible to prove it?
"God". Semantics... What are the properties of "God" and how these properties are entangled to your phenomenical experiences? Let "God" be the entity that garantizes consistency in reality. Let reality be the inter-determination of your phenomenical experiences and external non-phenomenical experiences. Let that inter-determination be integrated by "transduction". Reality exists. Therefore, "God" exists. Clarify "God" first and ask again.
---
Is it possible to do absolutely nothing?
No.
Analitically: Descartes proved that syntax proves syntax... paraphrasing: "I am, I exist". Phenomenical conscious experience proves semantics. "I experience qualia, therefore, I exist with the property of qualia". Syntax is proved. Semantics is proved. A unifying consistent bottom-up theory that unifies syntax and semantics must necessarily exist, because reality exists (addressed before). Therefore, it is not possible to do absolutely nothing. My interpretation of Heraclitus: “If movement is an illusion, then the illusion must have the propery of movement to generate the illusion of movement. If the second order illusion generates the property of movement in the first order illusion, the second order illusion must have the property of movement to generate blah blah blah...”.
Empirically: mass-energy conservation, since 1932.
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What if I wasn't walking around in a body, but was really just a brain in a jar that thinks it has a body?
This question is redundant having answered the previous ones.
---
What if a tree falls in a forest and no one is around to hear it, does it make a sound?
This question goes directly into the mind-body problem, probably the most important open problem in, at least, analytical analysis (let’s assume this post is boosting everyone’s morale to fight and mitigate x-risk and let’s keep science aside, the last just for the sake of brevity). If you followed through the answers to the previous questions, then you can conclude that if a tree falls in a forest and no one is around to hear it, it makes a sound. My recommendation: immerse yourself deeply with discipline in Bayesian Epistemology and, if you do agree to the answer this epistemological paradigm gives, then we can apply Aumann's Agreement Theorem and discuss.
---
Hope this comment was useful. Good luck,