[RascalPuff]

Dear Hearts:
There seems to be a lot of confusion and misunderstandings concerning the nature, meaning and/or import of what is known as the 'event horizon' (sometimes called the 'optical horizon').

I include myself among those who are confused regarding this issue.
As I learned it many years ago, the 'event horizon' is the parameter surrounding a point of observation, where the 'expanding universe' (based on Hubble's constant) overtakes the speed of light. The distance where the relative velocity of light is exceeded, in accordance with the speed of the (spatial) expansion increasing with distance. (This puts a limitation on how far one may proceed with observing the universe - all stations of observation are likewise handicapped with the same limitation: light signals from beyond and outside a given event horizon's boundary no longer reach the observer. With increasing distance, events increasingly slow down, the closer a given light source is to the event horizon; at the parameter there is the same constant signal, and beyond that parameter - event horizon - the light source 'goes out' - there are no signals reaching the observer. Personally, I have no contest with this definition.)

Among the confusions on this issue: is generally founded on the axiom that the speed of light cannot be exceeded.

Whereas, the special theory - to the best of my perhaps out dated knowledge - allows the premise that * the speed of light is constant relative to the source from which it originates.

As far as that goes, allowing that the above *information is correct, I see no contradictiion of the Special Theory with regard to the 'event horizon'. Whereas, there is no small amount of confusion - and related misunderstandings and arguments - surrounding this premise.

Now, when I google 'event horizon' there is much information about black holes and the Schwartzchild radius. 'Dark matter' and 'Dark Energy' has also entered the discussion.

Someone please correct me if I'm wrong, but it is my understanding that the existence of black holes is not a certainty, and, until the '70's, black holes were not even a consideration or controversy and dark matter and dark energy are relative newcomers also; while the 'event horizon' has accompanied the introduction of Hubble's constant since the early 1930's.

Moreover: There seem to be arguments for and against the meaning of Silpher's red shift findings.

Arguments pro and con, whether the (spatial) universe is actually expanding, or whether the red shift is caused by something other than the recession of stellar light sources and galactic systems and clusters of same (quasars).


The only thing I'm sure of is there seems to be a lot of confusion about the mentioned issues and many other considerations contingent to them.

As I understand it, the apparently convuluted (high profile) ensemble of subjects include the works of Silpher, Hubble, Eddington, Lemaitre, de Sitter and Einstein; more recently including Hawking (Certainly there are many other cogent issues - Big Bang, Steady State, Cosmological Constant, hot and cold running dark matter and energy - with as many representatives).

Is there a particular source of information which specifically addresses - the apparently characteristic disparity of - these seemingly entangled issues? Or, is the controversy still embroiled in points and counterpoints (which I tend to think is the case - refer, 'A Can of Wormholes')?

Thank you for reading this missive.

Best regards,
- RP

[neutralino]

The short answer is that an event horizon can crop up in various places in cosmology and astrophysics. The general definition is that an event horizon is a boundary beyond which and event cannot affect an observer. I'll write some more about this tomorrow when I've got more time.

[mkirkpatrick]

Thanks Rascal,is not the event horizon the point where the accepted understanding of
universal laws become "some what hazy?"And possibly the entrance into an alternative
universe/anti/matter!


regards michael.

[everymansmedium]

Hello:
I understand the event horizon in the same way as Neutralino. It is a point beyond which we have no way to attain information. The ones that I know are the macro limit as indicated by the Red Shift, The micro limit as indicated by the Uncertainty Principal. Recently this term is applied to the point of no return as found when approaching a black hole. Still this point is the point beyond which we can achieve no information. RP you are correct this term was initially applied to the red shift, but only because it fit the pattern concept of a horizon.

I see the micro and macro EH as a point where time and space become non linear. I agree that the EH associated with a black hole is also a horizon. I, like many others, am not sure how to categorize this horizon, but only to presently in my own mind to keep this as a separate issue under the same heading.

I will also indicate that what is beyond an EH is only speculative. Michael I agree also with you but it seems that when I speculate these concepts that go beyond the EH they tend to generate nothing but silence.
I wonder if I might have spent to much time mapping the land of maybe. It is not easy to back away from this place when it keeps returning all these coincidences. Each new turn results with more concepts that seem to have been documented by only faith before. Is the picture that I show a personal excuse to explain what I have experienced in my life, or is my life a manifestation of the picture I find.
More silence?
Did I offend anybody?
John.

[mkirkpatrick]

Originally Posted by everymansmedium Hello: I understand the event horizon in the same way as Neutralino. It is a point beyond which we have no way to attain information. The ones that I know are the macro limit as indicated by the Red Shift, The micro limit as indicated by the Uncertainty Principal. Recently this term is applied to the point of no return as found when approaching a black hole. Still this point is the point beyond which we can achieve no information. RP you are correct this term was initially applied to the red shift, but only because it fit the pattern concept of a horizon. I see the micro and macro EH as a point where time and space become non linear. I agree that the EH associated with a black hole is also a horizon. I, like many others, am not sure how to categorize this horizon, but only to presently in my own mind to keep this as a separate issue under the same heading. I will also indicate that what is beyond an EH is only speculative. Michael I agree also with you but it seems that when I speculate these concepts that go beyond the EH they tend to generate nothing but silence. I wonder if I might have spent to much time mapping the land of maybe. It is not easy to back away from this place when it keeps returning all these coincidences. Each new turn results with more concepts that seem to have been documented by only faith before. Is the picture that I show a personal excuse to explain what I have experienced in my life, or is my life a manifestation of the picture I find. More silence? Did I offend anybody? John.

Cheers John,silence is good John,as with darkness,both are needed for growth?Let your
heart and conscience be your guide.

regards michael.

[MJA]

Thanks RP for the stimulating thoughts.

Basically, and obviously there is light in the distant universe that has not reached us yet. Do you agree?
And that light can be considered as beyond our horizon of sight or even beyond our thoughts.
Do you agree with that too?
Beyond our horizon is what?
Will we fall off the edge if we go there?
I'll skipper the boat and call it the Santa Maria II.
Anybody wonna go?

=
MJA

[RascalPuff]

Originally Posted by MJA Thanks RP for the stimulating thoughts. Basically, and obviously there is light in the distant universe that has not reached us yet. Do you agree? And that light can be considered as beyond our horizon of sight or even beyond our thoughts. Do you agree with that too? Beyond our horizon is what? Will we fall off the edge if we go there? I'll skipper the boat and call it the Santa Maria II. Anybody wonna go? = MJA

Agreed, MJA, although maybe you can give me a rain check on your proposed voyage.

It seems there are as many event horizons (parameters and radii) as there are locations in (macrocosmic outer - or microcosmic inner - ) space, squared?
(Inner space may be just as endless as outer space, on this note.)

Agreed. In the provided, original (Hubble constant) setting, observers beyond our event horizon parameter are as blind to us as we are to them.

How extensive this consideration is, may depend on the various schools of thought regarding, open, closed, flat or spheroidal - expanding or static - universe(s).

Best regards,
- RP

[neutralino]

Ok, so now for a more thorough post on the topic that I promised yesterday.

As I said above, there are various event horizons that arise in cosmology. The most "famous" event horizon (that is, the one that is most likely to be called an event horizon) is the one associated with a black hole. A black hole event horizon can be very loosely described as the "boundary" of a black hole-- anything (light, or any other particle) at a radius smaller than the event horizon will not be able to escape into the rest of the universe and all possible worldlines of the particle will end up at the singularity. For the most simple black hole (a spherically symmetric, non-rotating black hole) the event horizon coincides with the Schwarzschild radius [1], but for others it does not.

Another interesting horizon in cosmology is the particle horizon. This is defined as the maximum distance from us that light can have possible travelled since the beginning of the universe. Sometimes this is called the "observable universe."

A final horizon that is often discussed is normally just called the "event horizon." This is defined as the current boundary, beyond which objects' light will never reach us in the future.

[MJA]

Thanks again RP,

I find this line of thought wonderful!

I am somewhat well read in the thought processes of A Einstein, but have never grasped with simplicity the purpose of squared in the equations of physics. Would you do me a great favor and try to explain C squared.
I know you know.

Thanks,

=
MJA

[RascalPuff]

Originally Posted by MJA Thanks again RP, I find this line of thought wonderful! I am somewhat well read in the thought processes of A Einstein, but have never grasped with simplicity the purpose of squared in the equations of physics. Would you do me a great favor and try to explain C squared. I know you know. Thanks, = MJA

Think of the inverse square law (the rate at which concentrically arranged expanding energy increasingly distributes itself over a greater area) and you fairly well have it.

The following is a cogent excerpt from my forum:

The formula is E=MC2. The direct non-mathematical translation of which is: 'Energy equals Matter times the speed of light, squared'.

In grade school as well as jr. high school, I would hear other students ask a question which I have since then learned is also familiar to many others; that question being: "In the formula 'E=MC2', why is C (light; field energy) squared (Out of M < Mass/Matter/ Particle>; which is perceived as a static, non-expanding, non-field)?"

I may have asked the question myself, but I knew less of mathematics than I do now. But others did ask that question, and that is understandable enough. The teacher's (ubiquitous) answer, which I have also learned since then is familiar to many others, was not so understandable. That (alleged) 'answer' being:
'It (C squared) actually isn't necessary'.

This answer, it will not surprise some of you to know, is quite standardized as a response to the question, 'Why is C squared, in the formula E=MC2?'

All are implored not to take my word for this. Simply ask the next physicist or mathematician you happen in to. If you pursue this question, you will get that answer or its equivalent. I had no understanding of mathematics whatsoever, and yet it still left me and many others wondering:
'If in fact it isn't necessary, then why did Einstein include it in the formula?'
If it isn't necessary, why is pi r squared? To find the volume of a circle why square pi r? (Answer: because the circle is 4-Dimensionally expanding, squared. Exactly why you can spend forever carrying pi out to it's 'last' decimal point... Refer, the Golden Rectangle, also known as the Golden Spiral, and 'Phi'.)


One may again reasonably ask, 'What is the speed of light squared from?' Of course the only answer is, 'The speed of light (C - celeritas constant) is squared from (out of) Matter'.
Smoke On The Perrier:
Affixed to that familiar explicit statement made by Einstein, is the familiar implicit statement - 'but it isn't necessary'.
Light energy is acknowledged to be, to say the least, expanding. Specifically, it is very accurately measured, originally in 1887 by Michelson & Morley, to do so at 186,282 miles-per-second.
*Light energy is also acknowledged to be qualitatively identical to *Matter energy; *their differences being only their densities. Light being much more thinly distributed and tenuous than matter. This is proven in the statement 'E=M' of the formula 'E=MC2. Originally published by Einstein in 1906. Light energy or electromagnetism is furthermore acknowledged to invariably originate within and expand-out-of *MatterEnergy - *generator of all spaces and times.


On the other hand, MatterEnergy is not acknowledged to be expanding.
Quite the contrary. Matter is unanimously agreed to be static and non-expanding.


Digressing To Reality, Geometric & Algebraic Law:
In the formula E=MC2 we have the acknowledged dynamical omni-directional expansion of electromagnetic or light energy, squared from presumably static/non-expanding MatterEnergy.

As long as there are those who demand and deny proof of the 4-Dimensional MassField, there will also be those who fail or refuse to recognize the accumulative achievements of historical and contemporary Academic Physical Science - and, the lessons of Algebra 101.

If all the Nobel laureates in the world gather together to agree that any entity acknowledged and agreed to be dynamically expanding, can be algebraically squared from any other entity which is agreed to be static and non-expanding (exactly such a gathering exists, and has existed since 1906):
what is established in such an assemblage of authority is that, none among these mortar-boarded multitudes has possession of the mathematical ability required to pass the seventh grade.

___________________

Any further thoughts on this?

Best regards,
- RP