I have added a short video presentation called How Far Away which helps with this question:

Data How Far Away

Richard

I am only a Master's student, but here are my insights on the question: For the original departure point light year distance, we need to incorporate cosmological evolution and expansion in a model that would predict or 'best construct' the history of present-day universe, complying with observations. The accuracy of the parameters used to build the model determines the accuracy of our estimated distance. In the article link I'm attaching to answer your question (with uncertainty due to observation-based constraints and model accuracy, of course), there are several internal links which exemplify our understanding : https://imagine.gsfc.nasa.gov/features/cosmic/farthest_info.html

Surely with the advancement of technology, our models will improve and better estimates can be made for the original departure point of the farthest known stellar object (which is also expected to change), but the current estimates are important scientific accomplishments in themselves. They are also valuable in the sense of building a foundation for future observations with the then improved performance of our models. An intriguing study that comes to mind when outlining the importance of our current estimates is of the first predicted supernova, Refsdal ( References: DEJA VU ALL OVER AGAIN: THE REAPPEARANCE OF SUPERNOVA REFSDAL: https://arxiv.org/abs/1512.04654 and “REFSDAL” MEETS POPPER: COMPARING PREDICTIONS OF THE RE-APPEARANCE OF THE MULTIPLY IMAGED SUPERNOVA BEHIND MACSJ1149.5+2223 : https://arxiv.org/abs/1510.05750).

I hope I understood your question correctly and answered it adequately, but please do let me know if I missed something.

Note: the answer is given assuming that in your question, 'visible' meant observable, and not the visible part of the electromagnetic spectrum.

Thank you Pratishtha,

i happen to be working on the cosmic distance ladder and

J1149 is one issue we are looking at. so the links do help.

i have been basing my work on x = 4B LY, as the cap of the departure point of the light reaching us here and now, from the most distant visible stellar object/s.

so any refinement of that cap is appreciated.

all the best, rm

The light radiated by stars is created by impulses: it is not some light medium which moves with the light velocity. Therefore we see stars as points but not as expanding spheres. We percept the world in the form of impulses. The light year is the interval of the time, during it we percept the impulse which was radiated at the moment corresponding to position of observer in the Galaxy at the corresponding to the moment of the time which equals to celestial year.

Ok on the nature of light, but what is your understanding of the most distant departure point distance of any light visible here and now?

assuming the current consensus SCM-LCDM?

4B LY?

how much less could it be? 2B? 400M? 40M? LY.

(as one needs to take into account consensus Hubble expansion assumption).

so, far below 13B LY.

Photons travel in the 3-space with the light velocity, but they spread instantly in the space-time. It follows from GR, the mathematical basis of which is Riemannian geometry. Light spreads along trajectories, the 4-dimensional length of which is zero: ds^2 = 0. Any physical observer possesses his own material body. All material bodies move with velocities v 0. In other words, photons and physical bodies are located in different spaces, but light spreads in 3-space with v = c. Therefore the material observer perceives photons as particles traveling with v = c from the star to the observer. Really we perceive photons instantly, but our consciousness is a result of activity our material brain (the past of our body). Just the brain districts our perception only 3-space. If we will ready perceive the idea of instantly interactions between all objects we will understand that we are linked instantly with all structures of the Universe. In this case we do not think, what photon was radiated in the last year: we will know that we perceive impulses from the world and all they reach us momentary. Bt our brain will perceive only the impulses which correspond to given moment, because the time is not homogeneous. We are not until to be oriented in such world, therefore our brain creates the given model of the world, where instant connections All with All are impossible.

OK i hold by, and assume, a light speed limit of 'c' standard light speed.

Is your answer we see light departing from the most distant stellar objects departing now 46.5B LY distance instantly?

My q. is assuming the current consensus.

so even if you have an alt. hypothesis that is valid, i am trying to pin down the current consensus, for comparison purposes.

assume a hyper-dense start

assume subsequent cosmic expansion.

assume the current visible universe at any size you want, probably 46.5 B LY for the purposes of this question.

Now what was the departure point of the light we see here and now, from the most distant stellar objects in the visible universe?

Your question is very interesting and important. But it is related to problem, which is refused by contemporary scientists. It is long-far-action as manifestation of instant interactions between all objects of the Universe. The existing of long-far-action is proved experimentally by astronomer Kozyrev: see my book about these studies) on my site, where these results and theory are represented in detail.

http://geocities.ws/borissova/ These studies show that the observer can obtain momentary signals from the Sun, stars of Milky Way and Andromeda Nebula. There exist also the problem: how we must register visible position of stars in Galaxy, knowing that the Sun together with the Earth flies in the Local star cluster with the velocity 250 km/sec. This fact we must take into account by determination distances of stars. These results are represented in partial on my site in the book Spectralcolour flows of time. More in detail this problem will be showed later: it is necessary to introduce such notions as the Sun's parsec. It takes into consideration the fact: until the photon travels to the observer, the Earth together with the Sun flies in the Galaxy, therefore the Sun's parsec distinguishes frof accepted in astronomy.

If you hold we see all line of sight objects instantaneously, regardless of distance, why are the distant objects increase of cosmological redshift with distance?

why the 8 minute delay on seeing the sun once it has just risen but light not yet reached us and why the 8 minutes of light after it has gone down but we still see from where it was?

why would any stellar objects be outside the visible universe?

You might be interested in this way of calculating the distance of an object at the time that the light was emitted when the travel time is T.

The formula is X = (1/K) (1 - exp(-KT)) where X is in light years, T is in years and K is based on Hubble constant and is 1 / (14 billion) light years per year per light year. (corresponds to around 69.84 km/s per Mpc).

See also video explanation here:

https://www.academia.edu/video/KjKORj

Interestingly this gives the result when T = 13.8 billion years of around 8.77 billion light years.

Richard

Hi Richard, TY.

OK so if the most distant stellar objects we see here and now we see from 13B +/- LY travel distance and years ago, where were they, or how much closer were they, when that light departed them 13B years ago? As a lot closer than the 13 B years the light had to travel due to the Hybble ongoing cmic expansion factor. I hope to check the link but if anyone has,done or can do, and post the calculations, TY in advance.

also:

So where does 'K' Hubble variable start to kick in?

for example i suspect for sure not a factor under 5K LY and Years,

but how about 30K? or 100k?

that minimum would help with another question of mine, LY distance to nearest departure point of light visi=ble here and now ever subjected to cosmic expansion.

be well,

roger m.

I have done the calculation for 13.8 billion years of light travel time and it comes from a distance of 8.77 billion light years. The formula using a constant K expansion of space at 1/(14 billion) light years per year per light year (= 69.84 km/s per Mpc). The formula is (1/K) (1 - exp(-KT)). The expansion of space is uniform everywhere including the local region of the galaxy. Richard

OK but even taking into account cosmic expanssion, how did the matter that comprise the stellar objects get to 8.77B LY distance from us, formed/start emitting light within even 800k years?

How could the most distant visible stellar objects whose light had traversed 13B LY (after factoring in cosmic expansion) and years, have departed from a max of 4B LY? prehaps far fewer. So maybe something is wrong with the Hubble factor.

I have added a short video presentation called How Far Away which helps with this question:

Data How Far Away

Richard