21 grams is the total mass of electrons that make up a 70kg body
This e mass comes from Higgs Mechanism ie as the electrons are moving in space time (as localized variation in electron field), they interact with the Higgs Field, which slows them down from travelling at speed of light and hence gives them mass
So Most of the mass of body doesn’t come from Higgs Field. It comes from Protons and Neutrons.
Protons and Neutrons are made of Quarks and though the quarks too interact with the Higgs field, that gives them only 1% of their mass. The rest comes from the Potential Energy of these quarks which they derive from their interactions in the Gluon Field using the Strong Nuclear Force. Remember m = E / c2
Time (sequence of events) and space (distance) are different for observers in different frames
A good starting point for objective reality is Causality ie space-time interval (SI) between events. This will be the same for all observers in all frames of reference observing the same event. SI = (Square of Distance b/w events) – square of(speed of light times the time b/w events)
+ve SI means event A has influenced/caused B
Space-Time is a 4D Non Euclidean Mathematical Space that’s just there and points in which correspond to events, instead of the previous belief that Universe is 3D space growing with time
Events that have geometric relations in this 4D space-time (ST) are the only objectively real events.
So your life from birth to death is a line segment on the FLAT 4D ST. So your future is not only predetermined, it already exists
A future event is simply “The next Causally connected point of ST”
Mass of an atom is more than just the sum of masses of it’s constituent atoms. For instance, the mass of a working clock is more than that of a stopped one. Why? Running clock has more:
Kinetic and Potential Energy
Heat Energy (due to friction b/w moving parts)
This extra mass of the running clock = Total Energy (from above) / square of c
The mass of Sun drops 4 billion kg/sec coz it shines ie gives off energy
Hot tea has more mass than cold tea
Also, all atoms in the periodic table weigh less than the sum of their parts (constituents). This is coz their potential energy is negative (potential energy of 2 electrons at infinite distance is 0, so for electrons in atom, PE is always -ve) and though they have +ve KE by virtue of the spin, the net is -ve. Hence for all atoms, Mextra = Additional Mass dut to Energy of substance = E/c2 < 0
Same is true for Molecules as the energy of bond is -ve
But, the mass of Protons and Electrons, that are made of Quarks is 2k to 3k times the mass of constituent quarks. This is due to Quark Potential Energy that it derives from Interaction with the :
1% mass from Higgs Field
99% mass from Gluon Field (that they themselves produce, like electron produces electric field)
Mass is basically not fundamental. It’s just a property that energy exhibits.
But in Accelerating FOR, that’s not true. In Fact for a person inside acc FOR like accelerating train, there appears to be an acc of outside things outside the train. This can be thought of as artificial gravity in the opposite direction. THis is also explained here.
So basically Gravity and Accelerated FOR is the same thing.
There is no way to distinguish b/w a free fall and lack of gravity. This is called the Equivalence Principle. So falling frames are inertial. So the gravity that we feel can be seen as a consequence of being in an accelerated FOR
Einstein preoved that Gravity is not a Force, but a consequence of SpaceTime curvature
In General Relativity (GR) objects that seem to fall (apple to ground) or Orbit (Earth orbiting sun) aren’t being pulled by any Force. They’re simply following strainght line constant speed path in curved straight line
What is Straight Line: A curve is straight when tangent vectors stay tangent, when parallel transported to along the curve
Curvature is similarly defined as the change in vector when it is parallel transported from A to B. If vector direction remains same, curve is flat else its Not.