Combining Texts

All the ideas for 'Necessary Existents', 'A Structural Account of Mathematics' and 'Theories of Everything'

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36 ideas

4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set
Realists about sets say there exists a null set in the real world, with no members [Chihara]
We only know relational facts about the empty set, but nothing intrinsic [Chihara]
In simple type theory there is a hierarchy of null sets [Chihara]
The null set is a structural position which has no other position in membership relation [Chihara]
4. Formal Logic / F. Set Theory ST / 3. Types of Set / c. Unit (Singleton) Sets
What is special about Bill Clinton's unit set, in comparison with all the others? [Chihara]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / a. Sets as existing
The set theorist cannot tell us what 'membership' is [Chihara]
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
ZFU refers to the physical world, when it talks of 'urelements' [Chihara]
4. Formal Logic / F. Set Theory ST / 8. Critique of Set Theory
A pack of wolves doesn't cease when one member dies [Chihara]
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
The mathematics of relations is entirely covered by ordered pairs [Chihara]
5. Theory of Logic / K. Features of Logics / 2. Consistency
Sentences are consistent if they can all be true; for Frege it is that no contradiction can be deduced [Chihara]
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Analytic geometry gave space a mathematical structure, which could then have axioms [Chihara]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / c. Nominalist structuralism
We can replace existence of sets with possibility of constructing token sentences [Chihara, by MacBride]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
If a successful theory confirms mathematics, presumably a failed theory disconfirms it? [Chihara]
No scientific explanation would collapse if mathematical objects were shown not to exist [Chihara]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
I prefer the open sentences of a Constructibility Theory, to Platonist ideas of 'equivalence classes' [Chihara]
19. Language / B. Reference / 3. Direct Reference / b. Causal reference
Mathematical entities are causally inert, so the causal theory of reference won't work for them [Chihara]
19. Language / D. Propositions / 3. Concrete Propositions
Propositions (such as 'that dog is barking') only exist if their items exist [Williamson]
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / b. Heat
Work degrades into heat, but not vice versa [Close]
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / c. Conservation of energy
First Law: energy can change form, but is conserved overall [Close]
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / d. Entropy
Third Law: total order and minimum entropy only occurs at absolute zero [Close]
27. Natural Reality / B. Modern Physics / 1. Relativity / a. Special relativity
All motions are relative and ambiguous, but acceleration is the same in all inertial frames [Close]
The electric and magnetic are tightly linked, and viewed according to your own motion [Close]
27. Natural Reality / B. Modern Physics / 1. Relativity / b. General relativity
The general relativity equations relate curvature in space-time to density of energy-momentum [Close]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / a. Electrodynamics
Photon exchange drives the electro-magnetic force [Close]
Electric fields have four basic laws (two by Gauss, one by Ampère, one by Faraday) [Close]
Light isn't just emitted in quanta called photons - light is photons [Close]
In general relativity the energy and momentum of photons subjects them to gravity [Close]
Electro-magnetic waves travel at light speed - so light is electromagnetism! [Close]
In QED, electro-magnetism exists in quantum states, emitting and absorbing electrons [Close]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
Quantum fields contain continual rapid creation and disappearance [Close]
27. Natural Reality / B. Modern Physics / 2. Electrodynamics / c. Electrons
Electrons get their mass by interaction with the Higgs field [Close]
Dirac showed how electrons conform to special relativity [Close]
27. Natural Reality / B. Modern Physics / 4. Standard Model / a. Concept of matter
Modern theories of matter are grounded in heat, work and energy [Close]
'Gunk' is an individual possessing no parts that are atoms [Chihara]
27. Natural Reality / B. Modern Physics / 5. Unified Models / a. Electro-weak unity
The Higgs field is an electroweak plasma - but we don't know what stuff it consists of [Close]
27. Natural Reality / C. Space / 6. Space-Time
Space-time is indeterminate foam over short distances [Close]