One could also ask the question about Aveilus concerning the other part of the year when we are in mourning, the Three Weeks and the Nine Days. However, we can find it much simpler to understand there. When we go to the Kotel, when we daven and remember the glory of the Bais HaMikdosh, when we see that ‘foxes are frolicking on Har Tzion’ and we cannot go up to serve HaShem there; we understand that it is not just a commemoration of something that happened 2,000 years ago, but an ongoing tragedy, that we are still mourning. There is even a parallel Halacha in the Laws of Aveilus. Even though there is no Aveilus after the year is over, if the body is exhumed then the laws of Aveilus return till it is reburied. So too, for us the Bais HaMikdosh is as if the corpse is in front of us. Actually, we should be in Aveilus at all times for the Churban, and in the time immediately following the Churban there were such people, but Chazal realized that we could not live in such a state and delineated the times and methods for mourning to the laws of Zecher LAcChurban, and the days between 17 b’Tamuz and Tisha b’Av. But that just returns us to our question about Sefirah!
To understand this we need to return to the time of Matan Torah. After HaShem came down to Har Sinai and gave the Aseret HaDibrot, Moshe goes up to Heaven to receive the Luchos and rest of the Torah. Says the Gemarra in Menachos, “When Moshe arrives in heaven he sees HaShem with a completed Torah and tying crowns onto the letters”. [Of the 22 letters of the Hebrew alphabet seven of them have a crown on the top. These are the letters שעטנ”ז ג”ץ.] Says Moshe to HaShem, for whom are you tying these letter?
Answers HaShem, there will be a person born in a number of generations whose name is Akiva ben Yosef who will derive from each crown heaps upon heaps of Halachos. Says Moshe, let me see him, and he is transported to the Bais Midrash of Rabbi Akiva. In the give and take of Halacha in that Bais Midrash, Moshe does not ‘understand’ what is being said and is ‘upset’, till when Rabbi Akiva is asked about one particular Halacha, he responds that is a Halacha that was transmitted to Moshe at Sinai. Moshe ‘returns’ to HaShem and questions why the Torah is being given through him, when there is a Rabbi Akiva in the world. HaShem responds, “Silence, this is my thought!” 
Obviously there are many parts of this Gemarra which require clarification, but there are two points needed for our discussion. One is the number of Halachos that are in the crowns. Since there are 304,805 letters in the Torah, and approximately a quarter of the letters of the Aleph Bet have crowns, there should be millions of Halachos derived from these crowns, and all of Talmudic literature should be replete with references to the crowns. However, in all of the Bavli, Yerushalmi, and Midrash there is not a single reference to these Halachos. Where did they disappear to?
Secondly, when Moshe questions why is he the one to give the Torah, is not Rabbi Akiva more qualified, HaShem does not disagree or tell him he is incorrect. The response is, ‘Silence!’ Why is that the response?
The answer is found in another well known incident in the life of Rabbi Akiva. The Gemarra brings a Pasuk, that if one planted in the morning he should also plant in the evening, since one does not know which one will ultimately be successful. Rabbi Akiva himself learns from that Pasuk that if you had students as a young man, you should strive to teach even when you are older, since you do not know which group of students will transmit your legacy. The Gemarra then relates this concept to the story of Rabbi Akiva’s life. He had 12,000 pairs of students throughout the land of Israel, and they all died in the time of Sefirah since they did not treat one another with honor, and the world was desolate till he found five students to whom he taught the Torah, and from them the world was reestablished. Adds the Gemarra in another place, that all of the Oral Law as we have it is from this group of students. Therefore one should never lose hope, but always continue to strive.
Therefore, it would seem that the Halachos derived from the crowns were lost with the passing of the first group of Rabbi Akiva’s students. That is what the Gemarra is referring to in the words ‘that the world was desolate’. But that then just leads to another question, why did he not teach his second group of students the Halachos of the crowns? To answer that we need the second insight into the Gemarra about HaShem’s response to Moshe’s request to allow the Torah to be given through Rabbi Akiva.
The Torah comes in two methods of transmission and teaching; Written Law and Oral Law. A close examination will show a direct parallel between the events of the giving of these two aspects of the Torah.
- The master of the transmission of the Written Law was Moshe and the place of transmission was Har Sinai. The Oral Law was transmitted through Rabbi Akiva and his students, as we saw that all of the Oral Law that we have is through his teaching. Therefore the place of transmission was his Bais Midrash. And that is why HaShem does not disagree with Moshe’s amazement, since Moshe is correct. Rabbi Akiva will be one to give the Torah, only a different aspect of it.
- The perquisite for the acceptance of the Written Law is as stated in the Pasuk in Yisro, that they all encamped as one, the unity of the nation. That is required since the Torah is given to the nation as a whole. The time when the Jewish people prepared for that was from the Exodus till Rosh Chodesh Sivan, the time of Sefirah. Thus we see that this preparation should be incumbent on the students of Rabbi Akiva also.
- The first version of the Written Law was the first Luchos. They were prepared by HaShem himself, and the Torah that was studied from them was on a higher level. This can be seen by comparing the first place they are taught in Yisro with the second place in Va’Etchonon, as clarified by the Ramban and the Maharal. Parallel to this is the first iteration of the Oral Law taught by Rabbi Akiva, which included the understanding of the crowns of the letters. This is obviously a reference to the highest level of Torah.
- But after this tremendous height there is a fall. There is the sin of the Golden Calf by the written Law and the sin of the lack of honor among the students by the Oral Law. (We will clarify further on why that was such a tremendous failing that it is comparable to the sin of the Golden Calf.) And even though there is repentance, the world is changed and we do not go back to the original state which it was prior to the sin.
- There are the second Luchos which are a version of the original, but on a lower ‘octave’. So too, the five students are the second teaching of the Oral Law, but once again on lower level. And just as the repentance of the sin of the Calf gives us back the broken Luchos but on a lower level, the sin of the 24,000 students is rectified, but the Torah remains on a lower level, without the crowns. Even more, the consequence of the sin of the Golden Calf was that the Jews removed their crowns, as it says: ועתה הורד עדיך, and so too the students of Rabbi Akiva lost the crowns of the letters.
- Lastly, the Torah is given with a warning, that if you do not accept it, here is where you will be buried. That was true by Har Sinai with the written Law, and there the Jews did accept it. By the Oral Law since the students did not accept it correctly that same principle came into play and the mountain did come crashing down on them.
This is why we mourn the students of Rabbi Akiva to this day. It is not only the loss of such great scholars, and the interpersonal failings that they had, but there is an ongoing everyday lack that we feel. Every time we learn the Torah and we get to one of the seven letters with a crown, we are reminded that there are tremendous deep and involved ideas of Torah that are there, but we cannot access that. Just as whenever we see the Kotel, we also feel the incompleteness that we cannot go further and are unable to actually go to the Bais HaMikdosh; so too every time we learn we see the tremendous depth of the Torah, but we also realize that the secrets of the crowns remain beyond us. Therefore this too is an Aveilus of the corpse being before us at every moment.
Where is this idea reflected in the statement of the Gemarra that ‘they did not honor each other’? I would like to present two approaches.
One is that the need for unity in receiving the Torah is found in the following idea. It is well known that Chazal reveal that there are 600,000 letters in the Torah; one for each of the Jewish people. However, a jumble of individual letters does not make a Sefer Torah. If I have the four letters which make up the name of HaShem on four separate pieces of paper, which does not make a name of G-d. They need to be attached in the proper way. In order that the Torah is received into the Jewish people we need to be a unified Sefer Torah rather than a random collection of letters. Thus, the “one man with one heart” is the parchment upon which the Torah is written. Similarly the Oral Law needs to be accepted in the same way and if the different ideas of the Oral Law are not unified in the students who are studying them then the Torah cannot be transmitted through them.
The other approach is that Oral Law by definition has disagreement and different approaches. Therefore the requirement to honor your intellectual opponent and respect his approach is the key to the transmission of the Oral Law. When they denigrated their colleague’s approach they were all deemed unworthy of being the link in the chain of transmission and their responsibility was transferred to others.
When we contemplate these ideas we can now understand the sorrow and Aveilus of Sefirah, not as a commemoration of something that took place 1,800 years ago, but a lack that is to be keenly felt to this day, every time we study the Torah.
 מנחות דף כט/ב – אמר רב יהודה אמר רב בשעה שעלה משה למרום מצאו להקב”ה שיושב וקושר כתרים לאותיות אמר לפניו רבש”ע מי מעכב על ידך אמר לו אדם אחד יש שעתיד להיות בסוף כמה דורות ועקיבא בן יוסף שמו שעתיד לדרוש על כל קוץ וקוץ תילין תילין של הלכות אמר לפניו רבש”ע הראהו לי אמר לו חזור לאחורך הלך וישב בסוף שמונה שורות ולא היה יודע מה הן אומרים תשש כחו כיון שהגיע לדבר אחד אמרו לו תלמידיו רבי מנין לך אמר להן הלכה למשה מסיני נתיישבה דעתו חזר ובא לפני הקב”ה אמר לפניו רבונו של עולם יש לך אדם כזה ואתה נותן תורה ע”י אמר לו שתוק כך עלה במחשבה לפני אמר לפניו רבונו של עולם הראיתני תורתו הראני שכרו אמר לו חזור [לאחורך] חזר לאחוריו ראה ששוקלין בשרו במקולין אמר לפניו רבש”ע זו תורה וזו שכרה א”ל שתוק כך עלה במחשבה לפני
 There is an interesting point that can be seen in this Gemarra. It says that Rabbi Akiva’s students asked him a question which the only way he could answer was by saying it is a הלכה למשה מסיני- a Halacha which a tradition from Moshe at Sinai. What Halacha was it? The Gemarra does not say. There are various readings of the text, but one of them says: כיון שהגיע לדבר אחד- When he reached one matter. What was that דבר אחד? I would like to suggest that maybe it was Rabbi Akiva spent his life trying to reach. This is what the Gemarra in Berachos says that as he was being tortured to death, he expired as he said אחד- One, which was the desire his entire life. That is the One matter which they had asked him.
 יבמות דף סב/ב – דתניא רבי יהושע אומר נשא אדם אשה בילדותו ישא אשה בזקנותו היו לו בנים בילדותו יהיו לו בנים בזקנותו שנאמר בבקר זרע את זרעך ולערב אל תנח ידך כי אינך יודע אי זה יכשר הזה או זה ואם שניהם כאחד טובים ר”ע אומר למד תורה בילדותו ילמוד תורה בזקנותו היו לו תלמידים בילדותו יהיו לו תלמידים בזקנותו שנאמר בבקר זרע את זרעך וגו’ אמרו שנים עשר אלף זוגים תלמידים היו לו לרבי עקיבא מגבת עד אנטיפרס וכולן מתו בפרק אחד מפני שלא נהגו כבוד זה לזה והיה העולם שמם עד שבא ר”ע אצל רבותינו שבדרום ושנאה להם ר”מ ור’ יהודה ור’ יוסי ורבי שמעון ורבי אלעזר בן שמוע והם הם העמידו תורה אותה שעה תנא כולם מתו מפסח ועד עצרת
 סנהדרין דף פו/א – דאמר רבי יוחנן סתם מתניתין רבי מאיר סתם תוספתא רבי נחמיה סתם ספרא רבי יהודה סתם ספרי רבי שמעון וכולהו אליבא דרבי עקיבא:
 ספר פוקד עקרים – אות ו – וכן במשה רבינו ע”ה שהוא שורש התורה שבכתב דבר זה אי אפשר להיות נשאר בלבבות בני ישראל כי מה שהוא בלבב חכמה של חכמי ישראל שהוא חכם דעדיף מנביא זהו חכמת תורה שבעל פה, אבל תורה שבכתב שהיא חכמת הקב”ה ונובלות מחכמה העליונה שבא משה והורידה לארץ משמת משה רבינו ע”ה נגנזו מעיינות חכמתו: ועל זה שמח משה רבינו ע”ה כששמע ששאלו לרבי עקיבא זו מנא להו ואמר להם הלכה למשה מסיני (מנחות כ”ט ע”ב) כי כל יקר שראתה עינו של רבי עקיבא מה שלא ראה משה רבינו ע”ה הוא חכמת תורה שבעל פה שרבי עקיבא היה שורש לה כמשה רבינו ע”ה לתורה שבכתב כידוע וחכם עדיף מנביא דבחכמת התורה שבעל פה יכולים להשיג כל יקר אבל הכל בהסתכלות דרך אספקלריא שאין מאירה שאינה אלא מהשגת לבו ויוכל השואל לשאול זו מנלך ושמא אתה טועה:
 רש”י על שמות יט,ב – ויחן שם ישראל – כאיש אחד בלב אחד אבל שאר כל החניות בתרעומות ובמחלוקת:
 מפרק מ”ג והלאה בתפארת ישראל
 שמות פרק יט – (יז) ויוצא משה את העם לקראת האלהים מן המחנה ויתיצבו בתחתית ההר: (יח) והר סיני עשן כלו מפני אשר ירד עליו יהוה באש ויעל עשנו כעשן הכבשן ויחרד כל ההר מאד:
עבודה זרה דף ב/ב – דכתיב ויתיצבו בתחתית ההר ואמר רב דימי בר חמא מלמד שכפה הקדוש ברוך הוא הר כגיגית על ישראל ואמר להם אם אתם מקבלין את התורה מוטב ואם לאו שם תהא קבורתכם
 השל”ה הקדוש – מסכת פסחים – מצה עשירה (כה) – ר, כי יש ששים רבוא אותיות התורה, והם ששים רבוא נשמות של ישראל