AbstractDreamer

Apologies for continuing my baseless thoughts: If expansion is defined as (change in volume)/(time), the only way for expansion to be non-zero and for change in volume to negligible, is through some function of time. With that in mind, is it possible that rather than space expanding, time is contracting? So rather than observing super distance objects are moving away from us faster than closer objects, and deducing that the intervening volume is expanding (which is the obvious answer), could you not interpret it as "The further the distance from an observer, the slower that time ticks at that very distant location, simultaneously". And to preserve isotropy of volume, then it must be that relative to that distant point, our time is ticking also slower, simultaneously". This would appear to both satisfy the inhomogeneity of time, and the isotrophy of volume. So consequently the speed of light is what it is locally for any observer in the universe. But very distantly relative to each and every location, it could be much slower due to time contraction, giving the illusion of volume expansion. What i think i mean is: the speed of light is 300,000 m/s locally relative to a location, at each and every location in the universe. But at the edge of the observable universe relative to each and every location in the universe, the speed of light could approach zero relative to that location. Sorry, i know this is speculation territory here. I will attempt to stay on track, once i have processed more information.

Therefore you are sock. Socks do not need air. This requires an exit. There is no exit, no air, no fish, in the room. Only socks.

I prefer to see it as as one of way writing both answers. If you just threw away the 3 boxes, we can deduce that "There would be no more boxes incorrectly labelled" Although that would not be quite the same as saying that the remaining boxes are correctly labelled, as there is no specification about any desire to keep the contents of the boxes, the nature of the problem in having incorrectly labelled boxes is solved. Therefore, throwing away the boxes is a valid solution. The nature of the riddle DOES suggest a desire to find an optimal solution. Whether it is easier to throw away the boxes, or to re-label them is a probably something that can never be answered.

No. When you touch someone you love, you transfer love too.

Given the spectral series of hydrogen is known, is there also proportionality between type 1a supernovae and quantity and rate of hydrogen emission? Or does this only apply to stars just normally burning their fuel and not for a supernova? Fermat's principle (which Snell's law is a derivation of) seems to require that a photon knows its final destination, in order to take the path of shortest time. Which is rather odd. Surely a photon travels in a straight line (along spacetime curvature) to where ever it might go, thus taking the shortest time to get there? If the entire mass of the type 1a supernova is converted into EM radiation, and all type 1a supernovae exhibit the same EM radiation spectrum of wavelengths and frequencies, then luminosity or intensity would be consistent, assuming conservation of energy. I've seen some references to supernovae remnants, such as the Crab Nebula, or strange cores, which leads me to think that the entirety of the mass is NOT converted to EM radiation. So if a type 1a supernovae leaves remnants such as gases or strange cores, then this matter could contain energy in the form of charge, kinetic, thermal, chemical? Would this account for the inaccuracy as described in wiki? https://en.wikipedia.org/wiki/Cosmic_distance_ladder For type1a supernova light curves (apparently rather accurate for extragalactic distance calculations) "The current uncertainty approaches a mere 5%, corresponding to an uncertainty of just 0.1 magnitudes." On homogeneity: So the observable universe has a sphere around us of 45 billion LY radius. If isotropic and homogeneous, An observer at the edge of that radius would also see a sphere of radius 45 billion LY. Then then things directly between us would be mutually observable, the things "behind" each of us would be mutually exclusively observable from each other, and some other volumes between might be observable by both due to curvature of the spacetime manifold? However if the universe has an age and a beginning, and spacetime started at the beginning of the universe, does that not contradict the homogeneity of time, if not the isotrophy of time as well? I'm starting to get an idea that expansion doesn't increase the volume of space, only it stretches it and wraps it around. Bit like a fractal set on the surface of a torus. Or like zooming in on a microscope. Observable boundaries are relative only, there are no edges, though singularities could be points of intersection (which don't exist on a simple torus). Can someone provide me some examples of 3D shapes, with finite surface area, no boundaries, point intersections, and can be formed from a finite 2D area.

Thank you for your thoughts and links. Need to read more and re-process.

What precisely is an observer, in the way they are referred to in Quantum Physics? After agreeing on a definition, can we try to answer this question by listing things that: Almost definitely observers, Maybe observers, Almost definitely not observers. We can start with the definition from wiki, a quote from Werner Heisenberg, Physics and Philosophy, p. 137 "Of course the introduction of the observer must not be misunderstood to imply that some kind of subjective features are to be brought into the description of nature. The observer has, rather, only the function of registering decisions, i.e., processes in space and time, and it does not matter whether the observer is an apparatus or a human being; but the registration, i.e., the transition from the "possible" to the "actual," is absolutely necessary here and cannot be omitted from the interpretation of quantum theory." Some initial thoughts: Is the definition of an observer relative to that which is being observed? For example, to observe or register the presence of an object photon P1. Could an observer be another photon P2? If the P1 collides with P2, then can it be said that P2 has registered something about P1, therefore has an observation has been made? What if P1 collides with a mirror M2? Can the mirror have registered P1 even in the smallest conceivable sense at the instant of reflection. Is this about preserving information? How long and how far can information be preserved and does it need to be retrievable to remain observed. If P1 passed the event horizon of a blackhole BH2, can it ever be retrieved?

There's also the refractive index of the atmosphere that will alter the direction of the velocities as experienced by the observer from their "true" direction. So if the observer is looking horizontally north and horizontal south, relative to him/her self, then for sure the velocities of the quasars relative to each other are not parallel. Overall its a poorly phrased riddle.

There are actually two solutions to that symmetry, but for there to be only one unique answer, both need to coexist. "nails and screws" "screws and nails"

When you pick something say a glass cup, a lot of "stuff" is transferred between you and the cup. Lots of molecules of oils on the surface of your skin, as well as dead skin cells, live bacteria and other contaminants will be deposited on the cup. The glass cup will probably be cleaner than your hand and not deposit much on your hand, as most of the glass molecules will be attached to other glass molecules that make up the cup. Thermal conduction also occurs when you get close enough to feel you are touching it.

Ah a little progress! So, negative values of times can be used mathematically in certain simple collisions? But only because the collision "looks" the same "playing the tape forwards" as it does in "rewind". If i understood that correctly. Still far from saying that negative time really exists, or that it has direction, only that in some circumstances it doesn't make difference to the description of the collision.

So reversible time invariance? whats that? Does that mean some classical physics can be mathematically performed backwards and forwards in time without changing the results? Wouldn't that indicate that at least time is mathematically directional? Or rather mathematically, time can be negative? I have argued on another thread against the validity of mathematics being any real, and now I'm hypocritically for its validity.

If there are only black and white socks in the room, how can you ever exit the room if there are no doors or exits?

I wouldn't need to open any boxes. Just replace all the labels with "Nails AND/OR Screws". Then they would all be labelled correctly.

because it has no direction? you cant go backwards? can you?

Shell theorem, seems to require perfect spherical symmetry. The existence of more than one black hole could imply that the universe is not perfectly spherical in volume, especially assuming space expansion does not operate within the volume of a black hole. This difference would most likely increase over time, resulting in a greater deviance from spherical perfection and consequently a higher net gravitational force (from the greater infinite density) over time, as well a shift in the gravitation "center" of the sphere.

Forgive my ignorance, I haven't looked into super symmetry yet. I was blurting out thoughts. Can i ask how super symmetry includes time, but that time is not symmetric? I'm sure the answer probably cant be explained in English.

Admittedly tenuous at best in #52:

Is mass directly proportional to luminosity? What if energy can be dissipated via mechanisms other than intensity of EM radiation, such as charge or angular momentum or other weird stuff? Could this result in a lower luminosity, and subsequently a false distance calculation? Is isotropism not a superset of homogeneity? Can anyone give me an example of something that is isotropic but not homogenous? If the cosmos is described as isotropic, does that mean the properties and direction of the "4D spacetime" is uniform everywhere in the universe? I think i mean, the spatial axes and time are always in the same "direction" (though time arguably has no direction)? How is this possible within blackholes? Or do we just describe black holes as not within our universe? Doesn't that contradiction invalidate the description? Consider the following: Imagine a block of glass that contains imperfections due to contamination. Glass is isotropic. The entire block (of glass and contaminants) is not isotropic. The glass within the block (but not including the contaminations) is isotropic. Imagine a universe of spacetime that contains imperfections due to blackholes. Spacetime is isotropic. The entire universe (of spacetime and blackholes) is not isotropic. The spacetime within the universe (but not including blackholes) is isotropic. Is it fair to say that spacetime is isotropic, and the universe is NOT isotropic? Following that potentially false premise above then, does expansion operate uniformly only within spacetime, and operate chaotically or not at all within black holes? Imagine a perfectly spherical volume of space containing multiple blackholes of significant volume, would the blackholes not affect expansion such that that over time, the volume is no longer perfectly spherical? Or is there an approximation to isotropism within limits, such as the tiny deviations found in the CMB? Could this variance be caused by black holes? But upon receiving a photon of red-shifted wavelength, there's no way of knowing if it initially had a long wavelength that has since red-shifted a lot because its far away, or a short wavelength that red-shifted a little because its near. Unless the original full spectrum is known, and compared. So how do we know the original full spectrum? Do all supernovae have the same spectrum? Or are the spectrums the same within the same types? Does this not beak causality? Sorry, sneaky baseless theory coming up!: Could outside of the universe be blackholeness of infinite density, "sucking" the universe outwards (via gravitation), affecting the universe to expand into its infinite density, at the same time receding due to the constance of dark energy density within the universe, pushing the blackholeness backwards, providing the cause to the effect of volume expansion? Can someone shatter this illusion for me?

baseless assertion: anti length? I thought by definition, symmetry means the quality of being made up of exactly similar parts facing each other or around an axis. If time is super symmetric, and time has an axis, am i wrong in concluding that there is negative (anti) time? What is the other part that is facing time, in the symmetry of time?

Makes a big difference to the answer!

But if super symmetry includes time, what is it's opposite?

No idea sorry baseless assertion. But if anti matter exists, and this stuff changes, how do you measure the rate of this change?

Around my head is sphere of space, but the surface of Earth is locally flat. Magnetic "North" lies on plane in this sphere around my head perpendicular to my latitudinal line. Magnetic "North" lies on a longitudinal line on the surface of the Earth. A direction on a plane should have two values, you cant just assume zero for a value if one is not provided. OP did not specify he was looking horizontally North, or any angle along the vertical axis. As North does not exist if you look straight up or straight down, therefore the velocities of the quasars are only relatively parallel IF the vertical angle is 0 (zero) Your calculations are based on the assumption he is looking horizontally North and horizontally South, which were not stated in your solution. Without specific values or assumptions, calculations and answers are meaningless though not necessarily wrong.

Does super-symmetry include time? Does anti-time flow "backwards"? How can time not have direction in this regard?