Ferrara Cathedral

Hexagram on the Romanesque Cathedral of Ferrara, Emilia Romagna, Italy. Built in the 12th century.
Picture is courtesy of "padesig', who published it in Flickr and wrote the caption in Italian, which I don't understand; so I let Alta Vista Babel Fish do the job and here's what came up:

In the facade of the cathedral of Ferrara: what is one senz' other unusual one, but for me also much beautiful one... It seems is "an official" acknowledgment of the job and the contribution offered from the Jewish community of the time to the construction of the cathedral, but also an acknowledgment of the cultural and social importance that had the community in the period extensive

Time

The following paragraph is from a new chapter, The Time Space Correlation, which doesn’t appear on Dr. Asher Eder’s book The Star of David, which was published in 1987 in English in Jerusalem by Rubin Mass Ltd.

a) The peculiarity of time
"What is time?", is an ancient question. The Oxford Dictionary defines time as "duration; continued existence; progress of this viewed as affecting persons or things..., allotted or available portion of time...".We could also say that time is the conception of the changing succession of things one after the other. According to the Dictionary, the word time derives from the root of a Germanic word from which derives also the word tide. Often the words time and tide are interchangeable, while duration and time are not always identical.
How do we know about time, or continued existence? Obviously only if we can relate, or compare, it to something else.
Suppose the universe would consist of the sun and the earth only, and nothing else besides; and the earth would orbit the sun unceasingly in a perfect circle but would not rotate. This process could well be described as duration, continued existence (of sun and earth), but what about time/tide? Suppose, a human being would live on such an earth (if at all something could live there), and would be aware of a duration, but could he develop also a sense of time? Obviously, for doing so he would need a third point, and for that matter a fixed point, to which he could relate. Such a point could be a dark spot in the sun provided it stays always at the same place; or would move, or appear, in regular intervals. If such an earth would not orbit the sun, but would remain unmoving vis-a-vis the sun, or if such a sun and earth would move like a dancing couple, such a dark spot would allow for developing a sense of time only if it would change - or would appear as changing - position or density in regular intervals.
All this means to say that at least three points, or positions, moving in relation to one another, are needed for developing a sense of time, and for measuring it. This holds true in view of chemical and other processes, too, including the vibrations of an atom which provide the base for atom clocks. Also the latter case allows for a time concept only in relation to a third point.
The term developing a sense of time and measuring it, implies the conscious observation (by a human being) of such movements or changes in space. Atoms and minerals may change composition and/or form, each one in its own space, but the duration in which change(s) occur could be conceived by man as time only by putting the change in view in relation to other points or events.
It follows that any measurement of time has to "borrow" its components from spatial measurements. Any length of time can mathematically be rendered as spacial length. Theoretically, space could exist in duration, without time (tide, measurable intervals), but time cannot exist without space.
Sensing time is not given neither to plants nor to animals. In accordance with their inbuilt patterns, they react to changes in temperatures and/or quantities of light (and therefore get out of season in an unusual warm winter, for instance). The feeling of time, the ability to calculate it, and the capability to arrange our lives accordingly, or even independently thereof at least to some degree, are given to men only. This fundamental law is laid down in Gen. 1:14 where we read:
"And God said, Let there be lights in the firmament of the heavens to divide the day from the night; and let them be for signs, and for seasons, and for days, and years".
This whole idea is expressed in the word world. It is composed of two ancient Germanic words, "wer" meaning man, human being; and "aldh" (=old) meaning age, time: it describes our time-relatedness. Each individual is a world of its own ("whosoever has saved a human being from death has saved a whole world", is a famous saying of our sages) with his/her own time, but living in society urges each one to bring his/her time at least to some degree in line with its time table. It is left to us how we cope with it.
Similar the well-known Sanskrit word Maya. Composed of the syllables ma (derived from manu = man; and ya (derived from yuga = age, time, it describes our inclination to take time-bound, passing things for real, instead of yoking us (in yoga) to the eternal.

b) Time conditioned by movement(s(
No time awareness can be developed without movement(s), as we saw. Movement is an operational process the duration of which is conceived as time, namely the time needed for an object moving from place to place or from situation to situation.
While meter, mile, etc, are measurements of distances, we may say that time is a perception and/or measurement of the duration in which the changes in view occur - changes from one position to another due to physical movements as well as through chemical, biological, spiritual, etc processes.

c) Space without time
Time concepts are relevant to man upon earth, that is, upon the surface of our globe.
In coal mines, ore mines, etc several hundred feet below its surface, no time can be perceived (except by looking at a clock which was adjusted to our customary time measurements; or by feeling hungry, or tired, in accordance with the respective intervals our system got accustomed to). There are no changes of light, nor of temperature, nor are there other intervals which would allow for developing a sense of change, or time concept.
Our sun does not "know" time either: It is the source of light and heat, and its orbiting planets cannot provide any lead for time measurements, which would make sense. Each planet has its own specific orbit; its own specific "year" (=the time it needs for one orbit); and even its own speed - which decreases in ratio to its mass density and its distance from the sun. (This example shows, by the way, the inter-relatedness between time and matter; and sequaciously, between time and forces emanating from matter).
The crews in spaceships go either by clocks (similar to the miners), or by instructions sent from their stations upon earth.
There is definitely space in all these cases (mines; sun; spaceship) but they do not allow for developing a time concept.
This shows us that our time concept is ultimately founded upon the perception of intervals (tides, if you want) in light and/or heat intensities pertaining to the surface of our globe. We are children of light, at least in this respect.

d) Since the Creator is omnipresent, and therefore timeless, no measurement whatsoever can be applied to him. Revealingly enough, one of the epithets of God in Hebrew language is המקום, literally The Place but usually rendered as Divine Presence. This concept is one of the main reasons that Judaism does not know "holy places" (except for Mount Moriah), but stresses "holy times", foremost Shabbat. Another characteristic of the Hebrew language is its Wav conversive which changes the future tense of a verb into past, and vice versa the past tense into future. This indicates, amongst others, that there is no past nor future with the Omnipresent. These exist in our perspective only. Heeding the Halahah (Instruction for the Way of Life) entails organization of one's times. Together with the gift of the concept of time to man it is the sanctification of certain times as one of the means by which man raises above animals. All humans are entitled to share in this privilege.
We should note here that the observing the weekly Shabbat is not connected to nature’s seasons (except for the sunsets which mark the beginning and the end of the Shabbat days). It gives us a rhythm congenial to our specific human nature, and is therefore beneficial.
As the notion of a Creator seems incomprehensible to many scientists, let us consider the phenomenon of gravitation for illustration's sake. In contrast to other forces it has no speed and no movement, and therefore has no starting point. In our limited knowledge, we can at present only say that it exists. We feel it in our daily lives, and think we understand it as the force which makes an apple from the tree falling to the ground, and which keeps our solar system in its shape. But at present it is beyond our capacity of understanding to comprehend it as the force (or medium) which keeps huge galaxies with their immense extensions in their spiral forms. The question was put already before Job: "...can you loose the bonds of Orion?" (Job 38:31). Speaking of gravitation as a field, instead of a force, does not explain the phenomenon; it rather sidesteps it. How much less can we dare to comprehend or describe the Creator. One of his epithets is The Omnipresent. Omnipresence needs no movements, and therefore is timeless.
The line a-c in our graph may depict - if we wish to do so - the so-called "absolute" time of creation, including the "age" of the universe as perceived from our perspective, but foremost it depicts the relative times on our globe (see in the following par. 4 & 5) as perceived from our perspective.
Regarding the age of the universe, we would have to clarify first whether we could speak earnestly of some (supposed) gaseous clouds of hydrogen as universe before they (supposedly) condensed to stars and galaxies, etc.
Besides, speculations about the age of the universe are based upon observations which pertain to our relatively young solar system, and which we project to the rest of the much older and infinitely vast universe as we perceive it now. Applying the famous Zen saying: "What looked your face like before your father and mother were born?", we may ask: "What was time before our solar system came into existence"; and: "was time on our globe always the same; or were days, seasons, and years, different due to differences in the earth' rotation speed, tilting, and orbit, which might have occurred during its period of existence?"
While someone would be hard pressed to answer these questions, it is impossible for us to conceive of energy (אל, Power) before anything came into being. Let us mind that waves even in their shortest form are already something, that is, a thing(ness) in its utmost subtlety. What was before the (supposed) Big Bang? What caused the Bang? What banged? Why did it bang, and why did this bang turn out to become the universe? Thinking in theological terms, we would have to ask: What was God (the Creator) before creation came into being?"
Being honest with ourselves we will have to admit that due to ur own limitations we are not able to truly conceive a beginning of the universe; nor its end; nor its eternal existence without any beginning or end, notwithstanding the possibility that within such an absolute eternity it may change its form of appearance. Whatever the case may be, some might like to speak of its eternity (from our point of view) within the eternity of eternities.
Considering that question leads us to the conclusion that creation is as infinite and eternal as the Creator is infinite and eternal. Such a view is indeed held by the Indian cosmology which, accordingly, speaks of an endlessly ongoing process of expansion and contraction of the universe. It portrays it as a inhale-exhale process of Brahm, the absolute power before its manifestation as Brahma, the creative aspect. Our languages seem to support such a view. Both in Hebrew and in English, the word creation (בריאה) denotes even from the point of grammar an (eternally) ongoing process, - The usual translation of the first phrase of the Tanakh, “In the beginning God created the heavens and the earth…” is not quite congenial to the Hebrew text which should rather be understood as “With the beginning…”, this term meaning that with the beginning of time on our earth the heavens and the earth became destined to be partners in the unfolding process of that creation which pertains to man on earth – with the heavens being made manifest as the “Kingdom of Heavens” on earth.
Within this ongoing process many sub-creations so-to-speak, may take place. They range from those of our daily lives we call creations, as e.g. that of creating a book, or a new fashion, up to those recorded in the Tanakh (e..g. Ps.51:12; Jer. 31:21). Interestingly enough, the latter begins with the words: “…"בראשית ברא (“be’reshit bara…”, rendered as “In [or: with] the beginning created God…”). The fact that the Tanakh begins thus with the sign (letter) ב, beth, and not with the first sign (letter) of alphabet(h), א, aleph, is explained that that the latter stands for origin, God, while ב, beth, meaning house, indicates that the Tanakh is given to us for our lives in that “house”, our world, and not for speculations about the infinite creator and the rest of the universe.
Kabbalah, acknowledging our incompetence to answer questions about the eternal and infinite creator, states that beyond creation there was, and is, אין סוף, ain soph (translated as infinity; ∞ in the symbolic language of mathematics); and that everything is part of, and embedded in, אין, ain, a term which means "nothing", "no-thing-ness". We, created as limited beings, can only comprehend thing-ness (to some degree at least), i.e things in their contractions ((צמצום and limitations.
Consequently, those parts of the universe which we can perceive, are depicted in our graph by the sections h-i and k-l, with the resulting calculations shown by g-m. These observations and calculations are inaccurate for several reasons, the main one being due to the fact that the actual positions and movements, and probably also of the brightness of the heavenly bodies -stars and other galaxies- have changed from the moment they emitted thousands and even millions of light years ago the light waves we receive only now. Many of them may meantime even have ceased to exist yet with their light waves still traveling to us! While, on the other hand, new ones may have come into existence with their light waves still being on their way to us!. Moreover, our own position toward these far-away light-emitting bodies, as well as their positions one to the other, have probably changed, and we do not see them where they are now actually positioned.
If it is true that the universe expands, and that everything moves away from everything, we don't know in which direction the stars and galaxies move away (or, in other words, where they have been when they emitted the light we are receiving now).
Nearer to us than these speculations is the known fact that we perceive the rays of the sun which reach us, in a bent, or curved line. When we see the setting sun just touching the horizon, it is in fact already below it. Due to the rays' "travel time" of approximately minutes from there to our globe, our perception of the sun lags behind its real position. In fact, the rays of all the heavenly bodies, although they emit from them in straight lines, reach us in a bent, or curved way.
These facts as well as some others mentioned below may render our calculations rather inaccurate. The differences between the actual situation and our calculations are indicated in our graph by the difference between the straight lines h-i and k-l and the curved lines h'-i' and k'-l' (note: we even don't know the degree of their bend. See also below par. 9)

Cute Little Star of David Lantern

A cute little Magen David lantern at the entrance to a synagogue in Lion, France.
Picture is courtesy of "maria_noland" who published it on Flickr.