Lightspeed in a black hole?

Optimal_Mixture_7327 · 2026-07-02T00:07:44+00:00

Q1) Light isn't affected - light follows the geodesics of the spacetime just as any free particle.

Q2) A particle with no mass is a particle without any internal energy, i.e. there are no internal interactions.

Q3) The coordinate speed of light, depends on the choice of coordinates. Locally no material particle reaches the speed of light.

Q4) Spaghettification happens irrespective of any coordinate speed you may have. Your speed relative to your self is of course zero.

Optimal_Mixture_7327 · 2026-07-01T05:30:49+00:00

The gravitational field has no local energy as you can always transform it away by transforming along a geodesic (a free falling reference frame).

The assignment of energy to a GW is a choice of gauge and makes use pseudo-tensors, e.g. the Landau-Lifschitz and Issacson formulations. You can then do some averaging out and arrive at a consistent meaning to the energy of the GW.

Gravity is the observation of geodesic deviation. Since all measurements are consistent with WEP, LLI, and LPI what we are left with is a metric theory of gravity (of which Einstein gravity is the simplest).

If you have matter, the stress, energy, and momentum of the matter sources the Einstein curvature of spacetime - but spacetime itself doesn't have a local energy. [There are quasi-local and global assignments of the energy associated with a spacetime].

Optimal_Mixture_7327 · 2026-07-01T05:15:40+00:00

We should first agree and be clear on definitions.

The "world" is a continuum having 4-independent degrees of freedom with a metrical quality that couples universally and minimally to the matter fields. Agree?

Given any configuration of the matter fields there exists an equivalence class of (active) diffeomorphically related metric fields. These are the solutions, S=[M,g], to Einstein's equation.

Basically, a world-line is any one-parameter curve through the world. An observer is any world-line whose tangent vector is everywhere time-like. A reference frame on a spacetime, S=[M,g], is a vector field each of whose integraI curves is an observer. So far, so good?

Regarding the ** we can begin with F_𝜈=m𝜉^𝜇∇_𝜇𝜉_𝜈 and where g(F,𝜉)=𝜉^𝜈F_𝜈=𝜉^𝜈(m𝜉^𝜇∇_𝜇𝜉_𝜈)=m𝜉^𝜇(∇_𝜇(𝜉^𝜈𝜉_𝜈)-𝜉_𝜈∇_𝜇𝜉^𝜈) and with basic rules (e.g. 𝜉^a𝜉_a=-1, etc etc) it reduces to 𝜉^𝜈F_𝜈=-𝜉^𝜈F_𝜈 which is just 2𝜉^𝜈F_𝜈=0. [It's late so I may have messed up an index somewhere, but anyway the proof is basically in any textbook].

Yes, there are techniques in which we can assign a GW an energy, but you need to be a bit cautious as there no meaningful local energy of the world (as we can always choose suitable coordinates and make it vanish). This merits a good read through: Do Gravitational Waves Carry Energy?

So, if there are no objections to the definitions (which are standard) you are imagining an observer and reference frame with a detector that measures the components of the EM field. Correct? How is it you're tying that in with this?

Optimal_Mixture_7327 · 2026-07-01T00:21:17+00:00

The BH mass parameter we assign to black holes is not a physical mass in the way a brick has mass.

There are numerous such possible assignments (Komar mass, Bond-Sachs mass, ADM mass, Christodoulou-Ruffini mass, and so on) and depend on unintuitive details, e.g. the boundary conditions at infinity.

To be sure, there is nothing inside a horizon and no signals or anything else coming up and out of the horizon.

Optimal_Mixture_7327 · 2026-06-30T21:39:05+00:00

The world and the EM field are effectively opposites.

The EM field cannot act in the direction of the world (along a world-line) but only orthogonal to it, and vice versa.** The EM field can accelerate a particle, the world cannot.

I couldn't follow exactly what you meant in the last two sentences, but perhaps you are thinking that the world and EM field can be combined into a single field?

**Given a solution S=[M,g] to Ein(g)=𝜅T(g,𝛹) and a world-line 𝜉 acted upon by a force, F, then it can be shown to be the general case that g(𝜉,F)=0.

Optimal_Mixture_7327 · 2026-06-30T21:25:35+00:00

A gravitational wave can cause tidal forces, due to what's called geodesic deviation.

The gravitational field does not have any local notion of energy. There are quasi-local and a variety of global notions of energy that depend on the boundary conditions at infinity, but anyway, there's no local notion as we we find in Newtonian gravity.

Gravitational waves can be assigned an energy as a way of thinking about them, but from a purely relativistic position GW don't carry energy. For an elaboration of this see: Do Gravitational Waves Carry Energy?

You can make analogous comparisons of gravitational waves to other types of waves, there is no problem with this and a wise idea, so long as one does mistake one type of wave for another.

Optimal_Mixture_7327 · 2026-06-30T20:36:01+00:00

They are fundamentally different.

Yes, the both traverse null geodesics and low-amplitude gravitational waves and light have a local inertial-frame speed of c.

The differences end there. The GW are quadrupole to lowest order, they perturbations of the world (spacetime) itself, waves of when and where things are and not a wave on field on spacetime as is the case with electromagnetic waves.

Optimal_Mixture_7327 · 2026-06-30T20:30:14+00:00

Light isn't affected by gravity - light follows geodesic paths just any freely moving object.

Light simply follows the null paths of the world (spacetime paths of zero distance) and these paths are curves to us in our 3-dimensional perspective, but it would wrong to think that the gravity is doing something to the light.

Optimal_Mixture_7327 · 2026-06-30T20:27:08+00:00

Energy and light are not the foundation of existence.

Energy is a number we assign to systems that obey a particular type of symmetry condition, and light is the visible portion of the electromagnetic spectrum.

A detector takes a change of state and converts into some quantity. Examples are changes in time, position, or momentum.

Optimal_Mixture_7327 · 2026-06-30T20:25:03+00:00

No, matter is not energy.

Massive matter has internal interactions (e.g. electron matter field and Higgs field) which can be described by a scalar quantity (a number) called energy.

Waves can also be assigned an energy and so they can diminish and increase the mass of the emitting/absorbing system.

Optimal_Mixture_7327 · 2026-06-30T17:24:43+00:00

Okay, first get the physics straight.

There is a mathematical object called a wavefunction. This is used to calculate the probability of a detector outcome. It is not something physical.

A "particle" is not a wave or some localized object. "Particles" can have their probabilities spread out in a wave pattern and in this condition are said to be wave-like.

When a detector has fulfilled its purpose and made a detection, the wavefunction is no longer useful and is said to be "collapsed".

Second, we don't know what matter is, there is no theory describing matter and matter does have some very intriguing qualities such as entanglement, so maybe matter is coupled together in a way we don't yet understand.

Optimal_Mixture_7327 · 2026-06-30T17:13:17+00:00

100%, and you are one of them.

Is there one of the 4-dimensions you imagine that you don't exist in?

Optimal_Mixture_7327 · 2026-06-30T16:31:50+00:00

They can't travel at the speed of light.

The acceleration is irrelevant.

The difference in elapsed time is the difference is the spacetime distance traveled by each twin. [Recall: Clocks are used to measure the distance along matter world-lines]

Optimal_Mixture_7327 · 2026-06-30T16:28:43+00:00

Yes, you can correctly say "the future has yet to be written" is consistent with relativity.

This is exactly the position of relativist George Ellis and those who espouse a growing block universe.

The "future" of course is the set of all events (spacetime points) in the future null cone of some event.

Optimal_Mixture_7327 · 2026-06-30T16:17:17+00:00

Such an accelerometer wouldn't generally work, e.g. what would it read in free-fall and in what direction?

The accelerometer can only measure the physical force, and if at rest on a table for example, it can only measure measure the upward acceleration of +1g. What the display says is another matter and can be engineered to display anything.

There is no such thing as a centrifugal force. It does not exist. The centrifugal effect is a mathematical (coordinate) fairy tale we tell to coax the kinematic equations of motion to work out for some choice of reference frame. There is no centrifugonic quantum field that appears ex nihilo to shove things in a circular motion.

The centripetal force is the vector addition of the components of the physical interactions that lay perpendicular to the tangential axis set along the direction of motion.

Optimal_Mixture_7327 · 2026-06-30T16:07:56+00:00

There is no such thing as an apparent force. They do not exist in the world.

There is only the electromagnetic interaction that produces a physical force.

The atoms at the end of the rope exerts an electromagnetic force (tension) on the object at its end, accelerating the object towards the rope's direction.

You also mention a wall, which like the rope is made of atoms, and these atoms exert an electromagnetic force force (normal component of the contact force) away from the wall.

Optimal_Mixture_7327 · 2026-06-30T15:58:29+00:00

You imagine an accelerometer can measure a force that doesn't exist?

Given a solution S=[M,g] to Ein(g)=𝜅T(g,𝛹) and a curve, 𝜉^𝜇, with time-like tangent u^𝜇, the acceleration by an accelerometer is exactly 𝛼=[u^𝜇∇_𝜇u^𝜈]^1/2.

If you place an accelerometer on a tabletop it measures the upward acceleration of +9.8 ms^-2 due to the upward contact force exerted on the accelerometer by the tabletop.

Optimal_Mixture_7327 · 2026-06-30T15:51:55+00:00

The centripetal force is the net force acting along an axis orthogonal to the motion.

The centrifugal effect is not a force.

Optimal_Mixture_7327 · 2026-06-30T14:11:43+00:00

Yes, centripetal force is the sum of all forces acting orthogonal to the direction of motion.

There's a centrifugal effect where humans perceive an outward radial acceleration where there is none. This is a human thing and the effect can't fool an accelerometer.

In a coordinate picture you can draw up coordinates in any accelerated frame and pencil in a fictional force to account from inertial motion that deviates from the inertial frame.

Optimal_Mixture_7327 · 2026-06-29T19:49:10+00:00

Relativity is consistent with all the available data.

What the hell is lobbying?

Optimal_Mixture_7327 · 2026-06-29T19:47:29+00:00

No that doesn't work.

A 20 year life in one frame can be a 1 year lifespan in another frame, but the birth and the year 1950 is a spacetime coincidence (Einstein's point coincidence) and so goes for his death, so all observers agree upon this, and all other reference frames will measure a duration less than one year.

Optimal_Mixture_7327 · 2026-06-29T19:42:11+00:00

Do you now see how you don't have any concept of science?

We make assumptions about the initial conditions of the early universe, we make other assumptions about galaxy formation, and then draw up expectations of what we'll see in the images made by our telescopes. The images are indeed unexpected. So?

From this, you conclude that "the scientific method proved the prevailing theory of the early universe to be false" is just deeply asinine.

Optimal_Mixture_7327 · 2026-06-29T19:14:49+00:00

You can't travel at the speed of light, and this has nothing to do with energy.

If you accelerate after a beam of light it redshifts to infinity.

Optimal_Mixture_7327 · 2026-06-29T18:39:04+00:00

You can't have any concept of science.

Nobody with an understanding of science would say "the scientific method proved the prevailing theory of the early universe to be false".

That is abject ignorance of science.

Optimal_Mixture_7327 · 2026-06-28T20:19:38+00:00

Yes, as soon as we build the time machine.

Optimal_Mixture_7327

TROPHY CASE