Scientific explanation for Sotah water

Question

Is there a scientific way to understand the effect that the Sotah water has on a Sotah?

Relevant verses below (Bamidbar chapter 5):

יז: וְלָקַח הַכֹּהֵן מַיִם קְדֹשִׁים, בִּכְלִי-חָרֶשׂ; וּמִן-הֶעָפָר, אֲשֶׁר יִהְיֶה בְּקַרְקַע הַמִּשְׁכָּן, יִקַּח הַכֹּהֵן, וְנָתַן אֶל-הַמָּיִם

17: The kohen shall take holy water in an earthen vessel, and some earth from the Mishkan floor, the kohen shall take and put it into the water.

כז: וְהִשְׁקָהּ אֶת הַמַּיִם וְהָיְתָה אִם נִטְמְאָה וַתִּמְעֹל מַעַל בְּאִישָׁהּ וּבָאוּ בָהּ הַמַּיִם הַמְאָרְרִים לְמָרִים וְצָבְתָה בִטְנָהּ וְנָפְלָה יְרֵכָהּ…‏

22: He shall make her drink the water, and it shall be that, if she had been defiled and was unfaithful to her husband, the curse bearing waters shall enter her to become bitter, and her belly will swell, and her thigh will rupture.…

Answer 1

The most straightforward reading -- I'd say this is based on the Talmud -- is that it's miraculous. And only works if the husband has been behaving himself too, and if this is a rare and shocking event. Hence it stopped working sometime during the Second Temple period.

(In effect, normally if a husband warned his wife not to hang around with Billy Bob, and she spent an hour in a hotel room with Billy Bob anyhow, there's so little trust in this marriage that they'd have to end it. The Torah is doing the odd thing of codifying a miraculous procedure into the law to allow them a chance to reconcile if in fact nothing happened.)

Rabbi Emanuel Rackman is quoted as its being psychosomatic; suffice to say many feel that's not within the framework of Orthodox thought.

Rabbi Aryeh Kaplan notes in his translation that some commentaries say there was an added ingredient beyond simply the dissolved text; but even if it was some medicinal herb, again, how would that only work in cases of guilt? (Could be the herb kills a certain percentage of people, and once there's some natural mechanism, then G-d would rig it based on guilt ... just as the quail in the desert may have suddenly had an unusually high concentration of hemlock in their flesh ... could be.)

Answer 2

It would seem from the Gemara that there is no scientific explanation for the Mei HaMarim of the Sotah.

If there was, it would defeat the stated purpose in the Gemara Sotah 9b:

מנא ה''מ אילימא משום דכתיב {במדבר ה-כא} בתת ה' את יריכך נופלת ואת בטנך צבה והכתיב {במדבר ה-כז} וצבתה בטנה ונפלה ירכה אמר אביי כי לייט לייט תחילה ירך והדר בטן לייט ומיא כי בדקי כי אורחייהו בדקי בטן ברישא והדר ירך בקללה נמי כתיב {במדבר ה-כב} לצבות בטן ולנפיל ירך ההוא דמודע לה כהן דבטן ברישא והדר ירך שלא להוציא לעז על מים המרים

SHE BEGAN THE TRANSGRESSION WITH THE THIGH etc. Whence is this? Shall I say because it is written: When the Lord doth make thy thigh to fall away and thy belly to swell?3 But it is likewise written: Her belly shall swell and her thigh shall fall away!4 — Abaye said: When [the priest] utters the curse, he first curses the thigh and then curses the belly; but when the water produces its effect it does so in its normal order, viz., the belly first and then the thigh. But also in connection with the curse, it is written: Make thy belly to swell and thy thigh to fall away!5 — That is what the priest informs her, viz., that it affects her belly first and then the thigh so as not to discredit the water of bitterness

Rashi says:

שלא להוציא לעז. שיאמרו לא עשו כסדר האלה ואין פורענות זו על יד

That they shall not discredit: for they will say that the water does not work in that order, and the punishment [of death] does not come from their hands.

If there was a scientific explanation for the Mei Marim it would totally discredit the punishment, (or the proof of her not dying from drinking) for the punishment would be caused by natural means and not by "their hands".

However, the Melekhes Machsheves, the 16th century Italian scholar, Rav Moshe Hefetz on explaining the taste of the water as bitter explains them as deriving from the power of the imagination. The kohen wishes to put fear into the woman's heart and prevent the erasure of God's name. He relates to her the powerful nature of the water if she is guilty, as if she were to drink poison. Her sense of imagination fills in the rest – when she drinks, her sense of taste actually relates to her the sensation that she is drinking bitter waters (source note 3).

The Maleches Machsheves:

פעמים רבות יעלה בדמיון האדם דבר שאינו כן ויתחזק שם ויתפעל בו עד כי באמת ישוב הדבר ההוא להיות כמחשבתו מרוב וגדולת כח הדמיון . וזה מאמר הכתוכ שהכהן להביא מורך בלב האשה כדי שתודה ולא ימחה שם ה' על המים אומר אליה שהם מרים מאררים כאלו תשתה סם המות. והיא התפעלה בדמיונה עד כי בשתיתים טעמה בחוש הטעם כאלו הם מרים באמת

According to the Maleches Maschsheves it works similar to the placebo effect.