This chapter is concerned with the method by which the court examined the witnesses and the how the news regarding Rosh Chodesh was disseminated to the diaspora in Babylon. We can see that the Sages, especially Rabban Gamliel and Rabbi Yehoshua ben Chananya, possessed a tremendous understanding of Astronomical knowledge even if it was for practical and not theoretical purposes.

Mishnah 1:

If they (the court) did not know him, they sent another with him to vouch for him. Before, they used to accept evidence about the new moon from any man, but after the heretics caused great harm (by hiring false witnesses), the Sages enacted a rule that evidence may be admitted only from those whom they knew.

Mishnah 2:

Before, they used to light beacons, but after the Samaritans caused great harm (by lighting false fires), they enacted that messengers should be sent.

Mishnah 3:

In what manner did they light the beacons? They used to bring long poles of cedar wood, rushes, pine wood, and tow flax. A man tied it together with twine. He went up to the top of the hill and set them on fire and waved them to and fro and moved them up and down until he saw his fellow on the next hill doing the same thing. And similarly on the top of the third hill.

Mishnah 4:

And from where did they kindle the beacons? From the Mount of Olives to Sarbata. from Sarbata to Agrappina. From Agrappina to Hauran. From Hauran to Bet Baltin And from bet Baltin they did not go, but waved to and fro and moved up and down until he could see the whole of the diaspora before him like a mass of fire.

Commentary:

To better understand mishnah 1, we look at the Rambam's commentary:

"Two trustworthy men only are qualified to testify concerning the new moon. These are men that are fit to bear witness in any legal case...According to Biblical law, the court is not required to be too strict in accepting evidence concerning the new moon. If the court sanctified the new moon on the evidence of two witnesses, who were later found to have given false testimony, the new month remains sanctified."

"Originally, the court used to accept evidence concerning the new moon from any Jewish man, proceeding upon the assumption that each Israelite is qualified as a witness unless he is known to be disqualified. However, after the evil doings of the heretics, who would hire false witnesses to testify before the court, the Sages enacted the rule that evidence concerning the new moon can only be given by men the court knew to be trustworthy and that witnesses should nevertheless be thoroughly examined and tested. For this reason, if the court does not know the men who saw the new moon, the people of the town should send along with the witnesses, other witnesses to certify them before the court, vouching for their being trustworthy men; only then is their evidence accepted."

The beacons were lit from the Mount of Olives in Jerusalem. From there, the chain went northward across the Dead Sea then in an arc through Syria and then into Mesopotamia. The area between the Tigris and Euphrates Rivers, in modern Northwestern Iraq, represented the nearest settlements of the Jews in the Babylonian Diaspora. On the map below, you can see the proximity and general direction of the signal fires. When the messengers were sent, the went through Syria and then into "Babylonia". The confusion with the Samaritans involved differences in calculations. They would therefore light their own fires on the days that they believed the new month began, and this would confuse the people in the diaspora. You have to remeber, that at hat time, with no light pollution and massive buildings, nights were pitch black and a signal fire, from a mountaintop, could be seen over thirty miles away!

Mishnah 5:

There was a large courtyard in Jerusalem which was called Bet Yaazek, and there all the witnesses used to assemble. And there the court examined them. And they prepared big meals for them so that they should acquire the habit of coming. Before, they might not move away from there all day (on the Sabbath), then Rabban Gamliel the Elder ordained that they might go two thousand cubits in any direction. And not only these, but also a midwife who comes to a delivery, and one who comes to save one from a fire, or from robbers, or from a river, or from a collapsed building, as are the other inhabitants of the city and may walk two thousand cubits in any direction.

Mishnah 6:

How did they examine the witnesses? The pair that arrived first, they examined first. And they brought in the elder of the two and said to him, "Relate how you saw the moon? In front of the sun or behind it? To the north of it or to the south of it? How high was it in the sky? How wide was it? In what direction was it leaning?" And if he said, "in front of the sun", he has said nothing. And then they brought in the second one and examined him. If their statements agree, their evidence stood. And as for all the other pairs, they asked them the important points, not because they required them, but in order that they should not depart disappointed and that they should acquire the habit of coming.

Mishnah 7:

The head of the court said, "It is sanctified! It is sanctified!" and all the people answered after him "It is sanctified! It is sanctified!" Whetehr it was seen at its proper time, or whether it was not observed at its due time, they proclaimed and hallowed it. Rabbi Eliezer ben Zadok says, "If it has not been seen at its appointed time, they do not acclaim it as sanctified, since heaven has already sanctified it."

Commentary:

There seems to have been a festival atmosphere surrounding the witnesses and their examination. If they arrived on Shabbos, they were originally apprehensive about traveling around the city ,even if the local inhabitants were permitted. Rabban Gamliel seemes to have remedied that situation with his ruling. It is also interesting that the court maintained a sensitivity to people who may have traveled many miles to reach the location of the court. Thus, even though only two people are necessary to sanctify the new moon, the court still examined the remaining witnesses so that they should not feel disappointed.

We can now spend some more time on the nature of the Jewish calendar. As we said, the cycle of lunar phases (the synodic period) is approximately 29.5 days in duration. If the year is to contain twelve months, then they cannot all have either 29 or 30 days each. One method that wroks is to have months that alternate between 29 and 30 days. Still, the time runs short; such a scheme has 354 days, 8 hours, 48 minutes and 34 seconds to its year (using more precise numbers than I have given). The actual duration of a solar year is 365 days, 5 hours, 48 minutes and 45 seconds. Clearly these two sets of numbers do not reconcile each other. The Rambam writes about this in his "Mishnah Torah":

"The solar year exceeds the lunar year by approximately eleven days. hence, whenever this excess accumulates to about 30 days, somewhat more or less, one month is added and the year is made up of thirteen months (called a "leap" year). The year cannot be made up of 12 months and a few days because it is written in the Torah 'Months of the year', implying that the year should be reckoned by a whole number of months."

"The moon is invisible for about two days each month, or somewhat more or less. About one day at the end of the old month before it is close to the sun and about one day after its conjunction with the sun, when it reappears in the evening in the west..."

"A leap year is a year in which an extra month is added. Only Adar is the month that is ever added so that a leap year has two months of Adar...Why is just this month added? Because of the spring season, so that pesach should be observed during the barley season as it is written (Devarim 16:1):'observe the month of Aviv, and keep the passover...' "

The difference between 12 lunar months and the solar year can be reconciled every nineteen years. This is called the "metonic cycle" and named after the ancient Greek Astronomer Meton who worked on this problem more than 2500 years ago. The Rambam uses the word "machzor", which means "cycle". The intercalation of leap years occurs during the years 3,6,8,11,14,17, and 19 in a given nineteen year cycle (the year 5760, for example will be a leap year). There are 235 lunar months in a metonic cycle and one year is defined in the Talmud to be 1/19 of a metonic cycle.

It is interesting that the Sages did not use the "second" as small division of time. The Rambam writes that the Sages divided the hour into 1080 parts since that number is divisible by the numbers 2,3,4,5,6,8, and 10. Thus, according to the Rambam, a cycle of lunar phases is 29 days, 12 hours, 793 parts of an hour (known as "chelakim").

The crescent moon, as we have said, can be seen starting at about 21 hours after "new". The horns of the crescent always point away from the sun and in the waxing phases, the moon is always east of the sun. The apparent path of the sun in the sky is called the "ecliptic". The moon, planets, and the twelve constellations of the zodiac also appear to follow the ecliptic. Remember, from the earth's frame of reference, it appears as all of these objects revolve around the fixed earth! This was the frame of refernce used by the Sages and all adherents to the geocentric model of the solar system (until Copernicus published his treatise in 1543 CE). The sages, therefore, needed to understand precisely the decsriptions being given by the witnesses in order to ascertain if in fact it was the moon that they observed.

To these events the Rambam writes:

"The court would make calculations in a manner resembling the calculations of the astronomers, and would know whether the position of the moon, if it could be sighted, would be to the north of the sun or to the south of it; if its crescent would be wide or narrow, and which direction its corners pointed..."

"If the witnesses say, 'we saw the reflection of the moon in water', or 'we saw its form behind the clouds', or 'we saw its reflection in a mirror', what they saw was of no consequence, and these sightings could not be used as the basis for sanctifying the new moon. The same law applies if the witnesses say, 'we saw a portion of the moon in the sky and a portion behind it in the clouds'..."

"If one potential witness says, 'I saw it and it appeared to be two stories high', and another witness says, 'it was three stories high', their testimonies may be combined and the moon sanctified on this basis. If one witness says, 'it was approximately three stories high', and another witness says, 'it was five stories high', their testimonies cannot be combined together..."

If witnesses say, 'we saw the moon without concentrating our attention, and afterwords, when we concentrated our attention, with the intention of sighting it and reporting it, we did not see it', this is not considered valid testimony... Perhaps clouds came together, appeared like the moon, and then dispersed."

"If witnesses say, 'we saw the moon on the twenty-ninth day in the morning, in the east before sunrise, and afterwords in the evening we saw it in the west on the thirtieth night', their testimony is believed...since it is obvious that what they saw in the morning was not the moon, but clouds and that testimony is disregarded... but their second observation is accepted..."

" A minimum of three judges is required to sanctify the new moon. Similarly, the calculations must be made by three judges...The new moon is only sanctified during the day. If it was sanctified a night, the sanctification is of no consequence. The new moon is not sanctified by observation, but by the authority of the court that declares, 'It has been sanctified!'..."

Mishnah 8:

Rabban Gamliel had diagrams of the shapes of the moon on a tablet and on the wall of the upper chamber. These he sued to show the ordinary people asking, "Did you see the moon like this or like that?" It once happened that two came and said, "We saw it in the east in the morning and in the west in the evening". Rabbi Yochannen ben Nuri said, "they are false witnesses." But, when they arrived in Yavneh, Rabban Gamliel accepted them. And on another occasion, two came and said, "We saw it at its proper time, but on the following night, we did not see it"; and Rabban Gamliel accepted them. Rabbi Dose ben Hyrcanus said, "They are false witnesses", and Rabbi Yehoshua ben Chananya replied, "I agree with you."

Mishnah 9:

Rabban Gamliel sent to him (Rabbi Yehoshua), "I order you to come before me with you staff and your money on the day you calculate to be the Day of Atonement." Rabbi Akiva went and found him looking troubled. He said to him, "I can prove that whatever rabban Gamliel has done is decisive, for it is said, 'These are the appointed seasons of the Lord, Holy convocations, which you shall proclaim'. Whether at their proper time or not, I have no other festivals than these." Rabbi Yehoshua came to Rabbi Dosa who said to him, "If we desire to argue against the court of Rabban Gamliel, we must argue against every court that has arisen from the days of Moshe until now, as it is said, 'Then went up Moshe and Aharon, Nadab and Abihu, and sevnty of the Elders of Israel...' Why were not the names of the elders expressly mentioned? To teach us that any three persons who have risen up as a court over Israel, are like the court of Moshe." Rabbi Yehoshua took his staff and his money in his hand and went to Yavneh on the day the he calculated to be the Day of Atonement. Rabban Gamliel stood up and kissed him and said,

"Come in peace my master and my disciple; my master in wisdom and my disciple because you have accepted my words."

Commentary:

In these mishnayot, we see that RabbanGamliel was an accomplished Astronomer. As head of the court, he had the responsibility to make sure that the wirnesses saw the new crescent not only in its proper time but also in the correct location. As head of the court, it was also Rabban Gamliel's authority to decide matters of Jewish law. Thus, even if Rabbi Yehoshua ben Chananya's calculations were correct, he could not go against the standing of the court. This was derived by Rabbi Akiva using the Torah's phrase " to you" meaning the designated authoirty (in this case Rabban Gamliel).

There is an interesting ancedote about Rabban Gamliel from the Talmud in Tractate Eruvin 43b:

"A Tanna taught: Rabban Gamliel had a tube through which he could see at a distance of two thousand cubits across the land and a corresponding distance across the sea. If a man desires to ascertain the depth of a ravine, let him use a tube and by looking through it, be in a position to ascertain the depth of the ravine. And if he wishes to ascertain the height of a palm tree, let him measure his own height and the length of his shadow, as well as the shadow of the tree, and he will know the height of the tree..."

This description may sound like a telescope, but on closer examination, it seems that the "tube" is using angles and trigonometry and is therefore more likely an "astrolabe". We cannot interpret the word "see" literally. Rashi comments on this verse in the Talmud:

"It is a hollow tube which, when it is long, enables one to see a short distance, and when it is short, enables one to see a long distance. Rabban Gamliel's tube was adjusted to give vision for two thousand cubits on land or sea...The observer should measure first for what distance the tube is adjusted. Then let him go to the edge of the valley and look down into it. Let him walk back until he finds that the bottom of the valley is just visible in the tube so that if he walked back any further, he would not be able to see the bottom of the valley. He will know the depth of the valley since he knows how far he has walked back from the edge of the valley..."

Rabbi Yehoshua ben Chananya was also an astronomer as can be seen from the following anecdote (Tractate Horayot 10a):

"Rabban Gamliel and Rabbi Yehoshua ben Chananya were traveling by sea. The former took with him a supply of bread for the voyage, but the latter also took along some flour. When Rabban Gamliel had eaten his bread, he also had to use some of Rabbi Yehoshua's flour. He asked Rabbi Yehoshua, ' How did you know that the voyage was going to take so long that you brought flour with you?' Rabbi Yehoshua replied, 'There is a star which appears every seventy years and leads sailors astray. I thought that it might appear during our voyage and lead us astray.' "

From the description, it sounds like Rabbi Yehoshua is describing the periodic return of a comet (such as Halley's comet which returns every 76 years). Modern studies of cometary orbits, using Kepler's Laws and Isaac Newton's Laws of Physics would not begin until Edmund Halley's famous work in the early eighteenth century!