1

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: Today at 22:21:04 »

It is stated:
"The relative velocity of any two objects never exceeds the velocity of light. Applying the Lorentz transformation to the velocities, expressions are obtained for the relative velocities as seen by the different observers. They are called the Einstein velocity addition relationships."

This quote is taken out of context. It is speaking of inertial frames, and not non-inertial frames. Lorentz transformations do not directly apply to other kinds of frames, nor do Einstein's velocity addition formulas, nor is the speed of light a constant. They do make the mistake of referencing the velocity of light instead of speed, the former which is different from one inertial frame to the next.

The formula is as follow:
u = (v+u') / (1+ vu'/c^2)

Interesting that you quote this formula but then don't use it.

Do you see any error in this calculation?

You very much know it's wrong, at least for inertial frames.
Kryptid gives the correct value.

Cosmological coordinates are not inertial, and the formula is different. It is an absolute frame, not a relative one, so Lorentz transformations do not directly apply. Recession rates are expressed as a rapidity, not a velocity, so there is no limit to the rate and their addition. While not totally trivial, it is fairly straightforward.

2

Physiology & Medicine / Re: Can JUST a head survive ?

« on: Today at 19:56:35 »

Could my head(or anybody else's head) remain alive and well if attached to the appropriate equipment

The technology may not be currently up to the task, but since your body constitutes 'appropriate equipment', the answer is very much yes. All it has to do is what the rest of you does.

You could always attach the head to a different host like the other end of the neighbor sheep producing a sort of 'push me pull ewe'.

3

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: Today at 18:18:02 »

So you clearly confirm that we measure ONLY the galaxies!

That and the CMB. There's not much more to measure at great distances.

It is your obligation to explain the galaxies expansion without using the imagination that is called space expansion.

It's actually your job since you're the one asserting it. You're the one insisting that the workings of the universe are obligated to be understandable in terms a child with 3rd grade mathematics skills can understand.

Unless - you can really measure the space coordinates of the Universe and prove this wrong logic.

Coordinate systems are not measured. They're abstract tools used to express locations, sizes, times and such.

You can't ignore that era.

If space and time are part of a bounded universe, then it makes no sense to speak of either outside those bounds. I've given several examples of similar things.

This is a big mistake.

This is apparently something you say when you cannot find fault with whatever has been said. You saying you want it to be wrong, but cannot demonstrate why.

If the Big Bang represents the beginning of time, then it doesn't make sense to ask about what came before. You can't go back before the beginning of time because there is no such thing.

As you claim that there was energy and space before the bang

Nobody claimed this. This is not a meaningful statement.

If we don't know - then there is a fatal error in the BBT.

I don't know what gift I'll get for my upcoming birthday, but it does not follow that my lack of that knowledge constitutes a fatal error in the BBT.

You claim that nothing can move faster than the speed of light.

Nothing can move faster than c relative to an inertial frame. Cosmic coordinates are not inertial. Newton's laws of motion don't apply. The energy conservation laws derived from those laws do not apply.
So relative to our inertial frame, indeed, nothing can move faster than c, and the size of the universe cannot be larger than ~14 BY would allow. But that's only relative to inertial coordinates, and since real spacetime isn't Minkowskian, inertial coordinates do not work at the largest scales. Using such coordinates makes predictions that contradict empirical observations, but it's subtle. It wasn't until quite recently (25 years) that this became obvious.

So why do we need a space expansion to prove that galaxies are moving faster than the speed of light.
Please take a decision - do they move faster than light or not?

Because only in an expanding coordinate system do those recession rates exceed c (but they don't recede faster than light, since light recedes even faster than the galaxies). Speed of light is constant only in inertial frames, so using any other coordinate system, one cannot reference 'the speed of light' since there isn't one.

If I understand Halc correctly, the following CS is used by the BBT in order to find a solution for the H0.

No, the measured H0 is used for an initial approximation of of the universe age. It has nothing to do with any CS. It actually works in inertial coordinates as well.
If expansion was linear, H0 would yield the age of the universe exactly, but it isn't linear.

So, the idea is that our scientists think that H0 sets the age of the universe regardless of its size.

Approximately, but yes, and it works with any of the first three coordinate systems. The 4th, as I've said, isn't a CS at all.

the job of those commoving coordinates is to carry those galaxies

Coordnates are abstractions, and abstractions describe things, they don't carry them.

Hence, the universe must obey to the H0 formula.

No, the H0 formula must obey the universe. The universe is under no obligation to obey anything humans say such as all the nonsense you seem to insist for it.

Is it the observable universe or the real universe which could be infinite?

What is the universe as is distinct from the real universe?

I do recall that Halc has stated that in order to get a size of one millions times the size of the observable universe - about 30 B years are needed.

I said no such thing.

The BBT is based on the Idea that the Energy is fixed

No it isn't based on that. Energy conservation is frame dependent.

4

Physics, Astronomy & Cosmology / Re: Does The Universe Spin ?

« on: Today at 15:32:53 »

Everything spins, but the universe isn't a thing. An object without a bounded size cannot meaningfully spin.

Ewe spin me right round quickly,
tight round, getting dizzy,
ralph a one pound ground round mound

Spin in relation to what?

Spin is absolute, and need not be in relation to any particular frame, although something's angular momentum is at least relative to an axis, but angular moment and spin (RPM say) are different things.

5

General Science / Re: Are Black Holes The Blackest Things Ever ?

« on: Today at 15:28:22 »

They're not perfectly black, but they're blacker than a place in space with no stars in it.

The black sheep don't quite win, but close.

6

Physics, Astronomy & Cosmology / Re: Can A Gravitational Wave Cause Physical Damage ?

« on: Today at 13:43:20 »

Can Gravitational waves Cause Physical Harm ?  say, they were mega strong ? What am I going to feel as they pass through me ?  Will I puke sheepy sick ?

It affects large things before small sheepish size things. At a moderate distance, Earth would definitely feel it, being stretched this way and that, causing earthquakes and volcanoes and such.  But if one was close enough to a source of such gravitational wave energy, the tidal forces of the masses involved would already be tearing Earth apart in a similar way via tidal forces, even in the complete absence of the thing putting out gravitational waves.

So point is, try to keep the sheepy pasture reasonably far away from really massive objects.

7

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 25/05/2022 22:00:55 »

If I understand the classical BBT

Every time you say these words, it means you're spouting something that you know is wrong.

there was no universe, no space and no energy before the bang.

BBT is not a creation theory any more than evolution theory is an explanation of abiogenesis. It does not posit something from nothing. It only describes the evolution of the universe from the initial singularity.

That bang delivered almost infinite energy in infinite small space of the just born universe.

Not a small space. Just high density, but it specifies no size, which would be a number. Don't mistake the word 'singularity' for a thing with a size.

Now, let's move on to the universe with infinite space that was there long before the bang.

No. Time as we know it is not defined prior to the singularity any more than altitude above your house is defined lower than the center of Earth, and also as gravitational potential is not meaningful for values above (*) the potential of a zero-energy universe. ( * A white hole is arguably an exception to this, but it is a mathematical solution that doesn't seem to actually exist anywhere)
Spacetime itself is not defined at the singularity. These things emerged later, near say the Planck epoch. The universe has many temporal singularities. The big bang is just one of them.

What kind of energy could exist in the infinite universe while there is no matter at all?

The energy (sans 'matter') was arguably a function of the various fields, except even those took some time to separate out into the various distinct fields. A unified quantum field theory would give a better answer to the above question, and it is still a work in progress. Fields have been merged by different approaches, but never all of them into one unified field.

Why do you insist to give them the same name while they are so different from each other?

What two different things are you talking about?

Indeed, there was zero context to that question.

8

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 25/05/2022 21:30:53 »

Is an infinite universe easy, or hard to comprehend?

Most people have little trouble comprehending that part. It's not what's implausible. It's your physics that doesn't work. Matter suddenly banging into existence at some point in existing space, besides being a total violation of all conservation laws, also creates a gravitational singularity, even if it's only the mass of an apple, let alone a mass greater than that of the visible universe. There would be no light, new material, stars, atoms, or anything. It predicts a universe with zero light.
So I'm saying, push the idea on a non-science site, because it only works if a blind eye is turned to science.

So when I say in the title of this thread, "why not multiple big bangs?", it is not a reference to The Big Bang event, of which there is just one implied. It is a reference to possibly an infinite number of big bang type of events occurring all across space and over all time: an on-going and eternal/universal process.

Are you talking about spontaneous particles appearing like you get with pair production?  Nothing big like an apple? That would predict a steady state of greyness, with no receding objects, and everything sort of being born in a kind of heat-death state. Such a model was proposed a couple centuries back before entropy was understood and before expansion was observed.

Also, if new stuff gets periodically added for an infinite time, the universe necessarily must become full after some finite time. So is there a mechanism to remove old mass/energy?

However, from any local perspective, held by any past or present intelligent life form in the universe, infinity and eternity must be hard to fully comprehend.

Infinite time and eternity are very different things. Eternalism just says the universe isn't something that exists in time. It doesn't posit the boundaries of time or the lack of them.

9

Physics, Astronomy & Cosmology / Re: Can Gravity be a biproduct of a mass's momentum through a Higgs field?

« on: 25/05/2022 18:17:13 »

Can Gravity be a byproduct of a mass's momentum through a Higgs field?

My immediate answer is no to this.  Gravitational fields interact with everything in nature, not just particles. Higgs field only has direct interaction with particles that in turn interact with the EM and weak fields. The spins of the two fields is also different.

10

Chemistry / Re: How can I find the optimum ΔH and ΔS for passive T control?

« on: 24/05/2022 19:19:40 »

But this pales in comparison to the incredible latent heat of a phase change.

I don't get it. Suppose I have a material that melts/freezes at room temperature. This only works once, and then it's done. Say I want to heat my building in the winter.  I have liquid 'stuff' that freezes as the room temp drops just below where I want it, so it keeps the room warm until it's entirely frozen. Now what? How am I going to get it into liquid state again? I have to turn the heater on and it has all the much more work to do since it has to melt all this nice stuff on top of actually heating the place. It seems I've saved no energy at all, so I'm not sure what you're getting at.
Heating/cooling is all about insulation, not thermal capacity. The more thermal energy that passes from the hot side to the cold side, the more energy it takes to put it back.

Industry, the primary consumer of resources, seems not to care. In the middle of winter I watched the power consumed by the air conditioners in the computer lab. All it needed was a fresh air fan on the roof since it was well below freezing outside, and there they are pumping heat out of the lab to the radiator on the roof, and not even into the heating system keeping the offices warm.
Another building (built for IBM) had the heater break down on an August day.  We had the doors/windows open and still had to wear winter coats because there was no heat to mix with the cold system. Temp was set just like water in houses: by mixing just the right amount of hot and cold, and not just turning off the whole system when it was cool enough. Apparently the utility bill was of no concern.

11

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 24/05/2022 15:01:59 »

A variety of possible recessional velocity vs. redshift functions including the simple linear relation v = cz

That simple formula is useful only at very low speeds. A police radar gun uses it to measure car speeds, but it falls apart once speeds get up to tens of thousands of km/sec.

Recession velocity and cosmological redshift is based on the idea of expansion of space
https://en.m.wikipedia.org/wiki/Recessional_velocity

That page is indeed based on expansion since it references concepts such as v_pec which is an absolute (frame independent) concept. Cosmic coordinates are absolute, unlike inertial coordinates.
Origin's formula for recession velocity is for special relativity, which is not based on expansion. The formula assumes velocity is directly away from the observer and it gets more complicated if there is a significant tangential component.

Again, if we can observe the galaxy then obviously its recession velocity is less than c.

Careful. Relative to an inertial frame, recession velocity is indeed less than c. Relative to Earth's inertial frame, the entire universe is under 15 BLY in radius. Post 61 explains the differences. Hubble's law holds in both kinds of coordinate systems, so recession velocity is still about 70 km/sec/mpc.Relative to say an expanding metric, recession velocity is unlimited, as is the size of the universe, and we can see objects receding at up to about 2.3c (or more if Webb finds a more distant one).
I think only under some ancient theory that put light speed relative to the velocity of the emitter would one not be able to see light from an object receding at faster than c. But all known theories that suggest such things have been falsified.

Dave is rejecting the expanding metric that aligns with an expanding universe as described by BBT. That leaves special relativity unless Dave also rejects the constant speed of light.

Do you mean at any size, even if it is infinity universe? So is it possible that due to the big bang that took place 13.8 by ago the entire universe should be full with matter and in any space that we would be in that universe (even one billion of a trillion ly away) we should see a similar view as we see from our point in space.?

BBT is consistent with a universe without bounded size (cosmic coordinates). The view from the super distance place is the same as from here, per the cosmological principle, one of the premises of the BBT.

The bbt starts while there is no apace or matter in the universe.

No. Please don't tell us what the BBT says. Maybe no matter, depending on how you define it. Normal matter didn't start to form until after inflation epoch.

How can we deliver energy to a universe that already is there?

Don't need to. It's already there as you say.

If I understand Halc correctly

I think you are incapable of that.

a bang in a universe that is already infinite in its size can only set a Bh.

No. A bang at a location in otherwise empty space does that, and also violates conservation laws. Relativity forbids it. BBT happened everywhere, not at a location in space, so there's no black hole.

How the idea of space expansion could work while the space in the early universe is already infinite?

You seem to still be working on the assumption that this size is a number. It isn't. A size is something only applicable to a finite thing. Infinity isn't a number.
Look up discussion on Hilbert's hotel, which wonderfully illustrates how one can go about expanding infinite space.

12

Physics, Astronomy & Cosmology / Re: relativity paradox or misunderstanding?

« on: 23/05/2022 18:30:53 »

When light passes through a region with high relative permittivity it no longer travels at C and the denominator in the Lorenz expression will no longer be zero and the photon will now have an inertial frame of reference, albeit for a very short time.

First of all, you're mixing quantum and classic terms. So to keep it classic, we can send a pulse of light through rapidly flowing water.  Make a pipe with a straight section and flat ends and move water in a loop through it fast enough and light entering one end will in principle stand still, yes. So yes, in a medium like water, there is a frame where light moving against the current will stand still. But time doesn't 'stand still' in that frame for anything any more than it does in any other valid inertial frame.

13

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 22/05/2022 19:35:44 »

Redshift is all about velocity and ONLY about velocity.

Quite wrong. It is coordinate system dependent (as your wiki graph shows), and I can have say a ship approach Earth at say 0.8c and show zero red or blue shift all the way. Lack of redshift doesn't imply zero velocity. Presence of redshift doesn't imply nonzero velocity.

Converting from redshift z to velocity v measured in km/sec is easy - the formula is v = c z.

No valid coordinate system yields that figure, so this too is entirely wrong. It's just a cheap Newtonian approximation for slow moving thing that shows only Doppler effect and no relativistic effects at all.

We should focus only on linear relation.

Why just the wrong one?

Redshift can't give us any indication about the distance.

Unless you utilize the BBT.

In general we can assume that the faster it moves the further it is located.

Not unless you assume BBT. Without that, you're back to square 1.

Hubble verified that there is some sort of correlation between the distance to redshift

Yea, and it wasn't v=cz, a relation that had been discredited over half a century before the recession findings.

Hence, redshift is all about velociy and it is a severe mistake to extract the distance from the redshift.

Do you have empirical evidence (like Hubble does) that such a relation is wrong? You don't. So it's you making the severe mistake of ignoring empirical measurements. This is straight denial of evidence Dave. A new theory might better explain evidence, but if you need to deny the evidence itself, it turns into religion, not science. Again, don't make me lock the topic.

Based on that understanding we can't know the exact distance to that GN-z11 galaxy, however, it is still in a distance that we can observe.

They know it's distance pretty accurately. The error bars are not large.

If one day we would improve our tools, we might see other galaxys that are located further away (with higher or lower redshift).

Only a little further, beyond which galaxies have not yet formed enough to, well, be galaxies. Any more distant galaxy has to be well on this side of the CMB barrier since the 'dark ages' (at least 300M years worth) lie between.

It is not realistic to assume that galaxies that are moving away from us at 1100c (or higher) had been created just 13.8 By ago.

No. If it was moving that fast, it would have been here about 43 million years ago, so according to that bit of nonsense, the universe is only 43 billion years old when those most distant galaxies where here.
Cosmological coordinates very much supports a recession speed of 1100c. A galaxy currently ~15 trillion LY away would be receding about that fast. That's trivially calculated by Hubble's law. We'd not be able to see light from it since it is well outside the visible universe. No light that we see today has ever been further away than a proper distance of about 6 BLY away, or 7 BLY if you use inertial coordinates.

14

Just Chat! / Re: a suitable pseudonym

« on: 22/05/2022 01:22:45 »

I had assumed it was HAL from the space odyssey books, but version c  - so not trying to kill everyone.

So much for not trying to leave an impression. It's short for Halcyon.

NOAX   would have been hard to work out.  No-one would have known it was Non-Oxide Adhesive eXperimental,  or a pop singer.   Best guess -    "No Axe to grind".

Last one was closer.
If you remember my answer to one of your other threads about who we are, I put out an answer about identifying biases (a post which was copied by a spammer bot). To do that, one has to hold a minimum set of base assumptions, so it means no axioms.
So I'm way beyond 'cogito ergo sum' since that statement seems to beg at least two such biases.

15

Just Chat! / Re: a suitable pseudonym

« on: 22/05/2022 00:13:46 »

Consider the abbreviations
People often tend to shorten names online, which I leant by experience.

That they do, which is why I pick a name short enough that it's not likely to happen. Besides, I often need to refer to myself in the 3rd person, and a long name just means a lot of typing.

However, your name is what you start with and why make people start with an impression that is miles away from where you are?

My name here is just a shortened word and not meant to leave an impression. I could have used 'Noax', which isn't meaningful on first impression, but that name does mean something, even if it isn't quite 'wearing your heart on your sleeve'.

16

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 20/05/2022 20:46:11 »

The Proper distance, comoving coordinates & Comoving distance/coordinates are key elements in the BBT theory.

Coordinate systems (CS) are abstract tools, hardly key elements since any physical system can be expressed to a point using any coordinate system you want. But if you say some object is 10 BLY away, that's a fairly meaningless statement without identification of the coordinate system used to express that distance.

GN-z11
1. Redshift   11.09

A CS independent empirical measurement.

2. Helio radial velocity = 295,050 ± 119,917 km/s (which is almost the speed of light).

The 295050 seems to be the inertial velocity that would yield that redshift. The ±119917 is baffling in that context. That's 40% in either direction, which seems to make no sense. Typo in wiki?

3. Distance ≈ 32 billion ly (9.8 billion pc)  (present proper distance)

Now they switch to CS 2 or 3. If it is 10000 mpc away, per Hubble's law it should be receding at 700,000 km/sec which is about 2.3c, hardly the speed reported just above. But that speed was reported using CS 1, not CS 2. All very inconsistent of the wiki writers. Yes, in cosmological coordinates, it is receding at over 2c and is about 32 GLY away. It, like everything else, is currently accelerating, which is not true using CS 1 (inertial) where GN-z11 is currently still decelerating.

≈13.4 billion ly (4.1 billion pc) (light-travel distance)

Method 4, which is not a CS at all.

Do you agree that the understanding about the light-travel distance is fully based on the BBT concept that the space itself is expanding?

Light travel distance is based on pop articles aimed at people who don't understand the mathematics. No, it doesn't leverage the concept of space expansion at all. No clock would measure that time. No tape measure would measure that distance. I mean, if it traveled over 13 BLY to get here, it must have been emitted from 13.4 BLY away, and got there in only 400 MY, which is over 33c. Are they suggesting GN-z11 was initially moving at over 33c? And redshift of only 11??  Method 4 values are self contradictory, and as I said, only used in pop articles.

However, as we can only measure the galaxies and not the space itself ...
In this example we clearly measure a distance of  32 billion ly. (we call it - present proper distance)

Ooh, you just said we don't measure space, but then assert that we clearly measured the space of 32 BLY. Contradicting yourself I see. Stop asserting things that are 'clearly' when you have no idea what you're talking about. Almost every time you use the word 'clearly', you're asserting something you know to be wrong.
When you use the word 'vital', it means you know you're talking about something that doesn't matter.

However, that measurement breaks the fundamental understanding of the BBT that the age of the universe is just 13.8BY.

There was no mention of age in that distance measurement, so another nonsense assertion.

Therefore, it is vital to "normalize" that measured distance to the total age of the Universe as stated by the BBT. In order to do so, it is stated that the light travel distance is 13.4 billion ly while we measured that the present proper distance (real distance?) is 32 billion ly.

13.4 is nonsense. 32 is relative to cosmological coordinates. Distances are CS dependent, so none of them is more real than any other (except for that light-travel one which is definitely less real).

Hence, could it be that the idea about proper/comoving close the gap between the real measurements to the requested parameters of the BBT?

That's a word salad. No idea what 'parameters' you're referencing here. I don't think you know either.

Is there any possibility for us to look again on all the current observations/measurements without the BBT glass/filter?

Yea. You get redshift of 11 and not much more. Certainly no parallax. You need a model to get a distance from that.

So why do you kill any other candidate that could offer better  explaining for the observations?

We don't, but no candidate does better, and there have been a lot of them. But it doesn't take a rocket scientist (pun intended) to see that the motion of everything we see puts it all right here about 14 BY ago, not earlier or later, but all at once.

Do you agree that if one day we would discover that the real age of the Universe is 100Bly instead of just 13.8 BY

But using CS 1 (but a different inertial frame than that of Earth), it IS 100 BY old (BLY is a distance, not an age).So you can make it any age you want with correct choice of frame/observer.

So, why can't we just release the cosmic time?

You didn't explain what you meant by 'release', but in CS 2 and 3 (cosmological coordinates), time is measured by what is occasionally called 'cosmic time'. It's the time since all the stuff was right here.

What about  Bogie_smiles theory with regards to infinite bangs?

B_S suggests explosions of new material periodically occurring at random locations in existing space which would just form a black hole and not result in any matter at all. If anyone was actually capable of producing a new viable theory, they'd not be wasting their time posting it on a forum.

Would you kindly accept (for just one moment) the idea that the expansion is just in the galaxies while the space itself is fixed and there is no shrink in the universe space?

The galaxies are not themselves expanding. If they did, the space between them would be shrinking then, not growing. We'd see no redshift if there was no recession.
If you mean static space with galaxies moving through it away from each other, that's the first CS. It is known as the Milne solution to the FLRW equations, and only works with a zero-energy universe. Such a universe would currently be 13.8 BLY in radius, a ball with an abrupt edge, and it would look the same (isotropic) from any view point.

17

Physics, Astronomy & Cosmology / Re: relativity paradox or misunderstanding?

« on: 20/05/2022 19:11:02 »

Could you elaborate on "not having a valid inertial rest frame", please.

Per Galilean relativity (proposed 400+ years ago), the laws of physics are the same in any inertial reference frame. One of the properties of such a frame is that light moves at c, but in a hypothetical frame of the light itself, light would be defined as stationary, a contradiction.

I always assumed when the v squared/c squared in the Lorentz equation reached unity the universe would shrink to a singularity and time would cease to exist from the photon's frame of reference.

Except for the work 'shrink', yes. The physics of the universe would be singular, meaning time, space, speed, direction, and anything dependent of these things would be meaningless (which is different from zero or infinite). Being singular means the laws don't apply. They're meaningless. No conclusion can be drawn from them. So you can't say 'light would get from the distant galaxy to here' because there is no meaning to 'here' or 'there'.

So as for the horizon, in intertial coordinates in Minkkowskian spacetime, like will get from any location to any other location. The fact that it doesn't in our universe shows that spacetime isn't Minkowskian. Nobody uses inertial coordinates for really distant things. For one, nothing can travel faster than c relative to an inertial frame, but relative to cosmological coordinates, anything beyond the Hubble sphere recedes from us faster than c. Yes, we can very much see galaxies that recede faster than c and are currently beyond both the Hubble radius and also the event horizon, which is not far beyond it.

(for me, hope I don't start a row!)

... or even a column. 

18

Physics, Astronomy & Cosmology / Re: relativity paradox or misunderstanding?

« on: 20/05/2022 16:17:32 »

It is postulated that a horizon exists or will exist in the future whereby remote galaxies are receding so fast that the light from them will never be seen at some arbitrary distant(from the distant receding galaxies) point in space.

This horizon is due to distance, not due to the recession speed. Light travels at the same pace regardless of the speed of the emitting object. This event horizon is due to acceleration (due to dark energy), similar to the event horizon that forms in Rindler coordinates. Without dark energy, light from a galaxy however distant will eventually reach here.

A photon of light leaving such a galaxy will travel any distance in zero time in it's own frame of reference.

As Origin points out, light has no valid frame of reference. Speaking of distance relative to light is meaningless.

So the question is will the photon reach the the distant observation post or as the horizon theory would suggest will it be lost forever in the permanently stretching fabric of space?

It will not reach the distant observer, but also will continue to move at light speed, not being 'lost' at all.
Similarly, if I accelerate forever to the left at 1g, light emitted from over a light year behind me will never reach me in any amount of time.

FYI, no paradox is suggested anywhere in the OP, except the title. Perhaps you want to reword the title question.

19

New Theories / Re: What is the real meaning of the most-distant-quasar/galaxy?

« on: 20/05/2022 13:30:16 »

I know that Dave will continue to post things that conveys a lack of reading comprehension of this information.

How true this prediction already turned out to be.

Yes, it is changing over time, but today it is constant everywhere.

If you had actually comprehended my prior post, it say that which events constitute 'today' is frame dependent, and relative to Earth's inertial frame (the frame which you seem to imply), it is very much a different value at distant places 'today'.

"the "Hubble constant" itself is a misnomer. It has a value today that's the same everywhere in the Universe"
So what is the meaning of everywhere?

If you had actually comprehended my prior posts, this question has already been answered. It is literally every location in space, no matter how distant.

That graph goes only to about 2 billion light years away, so yea, it doesn't matter much.

Why do you limit the "everywhere" to only 2 BLY?

If you had actually comprehended my prior post, you'd realize that I did not mention 'everywhere' in that sentence. It was a comment about the graph you linked, not about 'everywhere'.

do you confirm that the current Hubble constant everywhere in the entire universe should be 70?

The universe consists of more than today, but H would be measured at 70 by comoving observers at events where the age of the universe and gravitational potential are both reasonably the same as here. This would not be true of distant events 'today' relative to Earth's inertial frame since such events do not meet the criteria above.

However, I still don't understand why do you insist that only the visible / observable universe was in the size of the grapefruit shortly after inflation?

I don't insist on it. I said estimates vary, but that's the approximate size that best explains empirical observations.

Based on the BBT calculation for Hubble constant there is no limit in the size of the Universe.

No, not based on that at all. The Hubble constant is not a function of the size of anything. If you had actually comprehended repeated prior posts by myself an others, you'd stop asking this.

So, why do you insist that only the observable universe can fit into that grapefruit size?

It fit into a lot smaller space than that. That's simply how very much it had grown by the end of inflation epoch.

Could it be that you say this message as you do understand that there is a contradiction?

Not if none has been identified. I only see you contradicting your own assertions, but not that of the BBT. It's like insisting that 2+2=4 is contradictory because you don't know the largest integer.

I assume that you mean that an infinitely-large Universe can't become smaller if all of space is shrinking at a finite rate at a given time.

Depends on what you mean by 'smaller'. If you shrink the universe by half, then the density octuples, so it has by that measure an eighth the volume for any given set of matter. But an infinite universe has by definition no meaningful size. There is no number that represents its size or volume, and thus no different number representing the size after the shrinking. This is what Kryptid means by 'cannot become smaller'. There is no size number to change.

20

New Theories / Re: If there was one Big Bang event, why not multiple big bangs?

« on: 20/05/2022 04:48:20 »

my layman level logic tells me that you can't get "something" from "nothing"

With that I will agree.

I maintain that though empty space can be thought of as "nothingness"

Empty space might be indistinguishable from not-space, but I'd not say that it would be nothingness. Time implies a change in state, so time without this change would be equally meaningless. So I'm still agreeing with you here.

unless space has always contained matter and energy

And that too. I'm not saying otherwise. But that statement isn't inconsistent with one big bang. The logic is similar to what holds me up: The floor does, and the ground holds that up, and by the logic you seem to be implying, it must be turtles all the way down, but instead there's a limit to how deep you can dig a hole to find out what holds me up. It isn't 'nothing' holding me up. There is a bottom and it isn't inconsistent to not have that in turn supported from below.

then in order for the universe to be as it is today, you would have to invoke "something from nothing".

But nobody seems to invoke that. It's pretty easily torn apart.