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'fragments/reports', 'Why the Universe Exists' and 'Principia Mathematica'
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65 ideas
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
15866
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Newton reclassified vertical motion as violent, and unconstrained horizontal motion as natural [Newton, by Harré]
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27. Natural Reality / A. Classical Physics / 1. Mechanics / b. Laws of motion
15958
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Inertia rejects the Aristotelian idea of things having natural states, to which they return [Newton, by Alexander,P]
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17018
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2: Change of motion is proportional to the force [Newton]
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17019
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3: All actions of bodies have an equal and opposite reaction [Newton]
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17017
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1: Bodies rest, or move in straight lines, unless acted on by forces [Newton]
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20968
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Newton's Third Law implies the conservation of momentum [Newton, by Papineau]
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27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
17547
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Newton's idea of force acting over a long distance was very strange [Heisenberg on Newton]
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20966
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Newton introduced forces other than by contact [Newton, by Papineau]
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20967
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Newton's laws cover the effects of forces, but not their causes [Newton, by Papineau]
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16708
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Newton's forces were accused of being the scholastics' real qualities [Pasnau on Newton]
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13153
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I am studying the quantities and mathematics of forces, not their species or qualities [Newton]
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12724
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The aim is to discover forces from motions, and use forces to demonstrate other phenomena [Newton]
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27. Natural Reality / A. Classical Physics / 1. Mechanics / d. Gravity
13593
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Newton showed that falling to earth and orbiting the sun are essentially the same [Newton, by Ellis]
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21167
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Gravity is unusual, in that it always attracts and never repels [New Sci.]
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27. Natural Reality / A. Classical Physics / 2. Thermodynamics / c. Conservation of energy
20969
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Early Newtonians could not formulate conservation of energy, having no concept of potential energy [Newton, by Papineau]
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27. Natural Reality / B. Modern Physics / 1. Relativity / b. General relativity
21176
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In the Big Bang general relativity fails, because gravity is too powerful [New Sci.]
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27. Natural Reality / B. Modern Physics / 2. Electrodynamics / a. Electrodynamics
21147
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Quantum electrodynamics incorporates special relativity and quantum mechanics [New Sci.]
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21155
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Photons have zero rest mass, so virtual photons have infinite range [New Sci.]
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27. Natural Reality / B. Modern Physics / 2. Electrodynamics / b. Fields
21161
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In the standard model all the fundamental force fields merge at extremely high energies [New Sci.]
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27. Natural Reality / B. Modern Physics / 2. Electrodynamics / c. Electrons
21146
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Electrons move fast, so are subject to special relativity [New Sci.]
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27. Natural Reality / B. Modern Physics / 3. Chromodynamics / a. Chromodynamics
21148
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The strong force is repulsive at short distances, strong at medium, and fades at long [New Sci.]
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21152
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The strong force binds quarks tight, and the nucleus more weakly [New Sci.]
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21151
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Gluons, the particles carrying the strong force, interact because of their colour charge [New Sci.]
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27. Natural Reality / B. Modern Physics / 3. Chromodynamics / b. Quarks
21142
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Classifying hadrons revealed two symmetry patterns, produced by three basic elements [New Sci.]
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21150
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Three different colours of quark (as in the proton) can cancel out to give no colour [New Sci.]
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21143
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Quarks in threes can build hadrons with spin ˝ or with spin 3/2 [New Sci.]
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27. Natural Reality / B. Modern Physics / 4. Standard Model / b. Standard model
21154
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Three particles enable the weak force: W+ and W- are charged, and Z° is not [New Sci.]
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21156
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The weak force particles are heavy, so the force has a short range [New Sci.]
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21164
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Why do the charges of the very different proton and electron perfectly match up? [New Sci.]
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21170
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The Standard Model cannot explain dark energy, survival of matter, gravity, or force strength [New Sci.]
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21145
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The four fundamental forces (gravity, electromagnetism, weak and strong) are the effects of particles [New Sci.]
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21153
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The weak force explains beta decay, and the change of type by quarks and leptons [New Sci.]
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27. Natural Reality / B. Modern Physics / 4. Standard Model / c. Particle properties
21157
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Particles are spread out, with wave-like properties, and higher energy shortens the wavelength [New Sci.]
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21149
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Quarks have red, green or blue colour charge (akin to electric charge) [New Sci.]
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21158
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Fermions, with spin ˝, are antisocial, and cannot share quantum states [New Sci.]
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21165
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Spin is akin to rotation, and is easily measured in a magnetic field [New Sci.]
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21140
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Spin is a built-in ration of angular momentum [New Sci.]
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27. Natural Reality / B. Modern Physics / 4. Standard Model / d. Mass
21163
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The mass of protons and neutrinos is mostly binding energy, not the quarks [New Sci.]
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21168
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Gravitional mass turns out to be the same as inertial mass [New Sci.]
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27. Natural Reality / B. Modern Physics / 4. Standard Model / e. Protons
21138
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Neutrons are slightly heavier than protons, and decay into them by emitting an electron [New Sci.]
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21144
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Top, bottom, charm and strange quarks quickly decay into up and down [New Sci.]
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27. Natural Reality / B. Modern Physics / 4. Standard Model / f. Neutrinos
21141
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Neutrinos were proposed as the missing energy in neutron beta decay [New Sci.]
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21169
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Only neutrinos spin anticlockwise [New Sci.]
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27. Natural Reality / B. Modern Physics / 4. Standard Model / g. Anti-matter
21166
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Standard antineutrinos have opposite spin and opposite lepton number [New Sci.]
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27. Natural Reality / B. Modern Physics / 5. Unified Models / a. Electro-weak unity
21171
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The symmetry of unified electromagnetic and weak forces was broken by the Higgs field [New Sci.]
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27. Natural Reality / B. Modern Physics / 5. Unified Models / b. String theory
21175
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String theory might be tested by colliding strings to make bigger 'stringballs' [New Sci.]
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21177
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String theory offers a quantum theory of gravity, by describing the graviton [New Sci.]
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21179
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Supersymmetric string theory can be expressed using loop quantum gravity [New Sci.]
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21178
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String theory is now part of 11-dimensional M-Theory, involving p-branes [New Sci.]
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27. Natural Reality / B. Modern Physics / 5. Unified Models / c. Supersymmetry
21159
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Supersymmetry has extra heavy bosons and heavy fermions [New Sci.]
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21162
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Only supersymmetry offers to incorporate gravity into the scheme [New Sci.]
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21172
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The evidence for supersymmetry keeps failing to appear [New Sci.]
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21173
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Supersymmetry says particles and superpartners were unities, but then split [New Sci.]
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27. Natural Reality / C. Space / 4. Substantival Space
17013
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Absolute space is independent, homogeneous and immovable [Newton]
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21160
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The Higgs field means even low energy space is not empty [New Sci.]
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27. Natural Reality / D. Time / 1. Nature of Time / a. Absolute time
22915
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Newton needs intervals of time, to define velocity and acceleration [Newton, by Le Poidevin]
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22893
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Newton thought his laws of motion needed absolute time [Newton, by Bardon]
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17012
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Time exists independently, and flows uniformly [Newton]
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14012
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Absolute time, from its own nature, flows equably, without relation to anything external [Newton]
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27. Natural Reality / D. Time / 1. Nature of Time / h. Presentism
20819
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The past and the future subsist, but only the present exists [Chrysippus, by Plutarch]
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27. Natural Reality / D. Time / 2. Passage of Time / g. Time's arrow
22954
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Newtonian mechanics does not distinguish negative from positive values of time [Newton, by Coveney/Highfield]
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27. Natural Reality / D. Time / 3. Parts of Time / d. Measuring time
17015
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If there is no uniform motion, we cannot exactly measure time [Newton]
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27. Natural Reality / D. Time / 3. Parts of Time / e. Present moment
20818
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The present does not exist, so our immediate experience is actually part past and part future [Chrysippus, by Plutarch]
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20821
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Time is continous and infinitely divisible, so there cannot be a wholly present time [Chrysippus, by Stobaeus]
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27. Natural Reality / E. Cosmology / 8. Dark Matter
21174
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Dark matter must have mass, to produce gravity, and no electric charge, to not reflect light [New Sci.]
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