Science and Halacha

The biblical signs to distinguish between kosher and non-kosher fish seem exceedingly straightforward: the presence of fins and scales defines a fish as kosher. Despite this seeming simplicity, there have often been difficulties in classifying certain fish. The swordfish (Xiphias gladius) is an example of a fish with an interesting halakhic history. Possibly mentioned as early as the Tosefta, a " fish with a sword " was permitted in the 17th century and repeatedly thereafter. In the 20th century, the kosher status of the swordfish became the subject of an acrimonious debate between the Orthodox and Conservative rabbinate in the United States, and between American Orthodox rabbis and the Israeli rabbinate. This paper traces that history, presents the arguments of the various players, and endeavors to explain why those who prohibited the swordfish seem to have won.

This thesis is a conversation about the hypothetical theological and halakhic challenges the first Jewish settlers on the Moon, Mars, and beyond may face. It is split into two chapters, each with three subsections. The first chapter is entitled “Theological Challenges” and deals with the possible theological issues Jews would have with traveling into space and settling off-planet. The first subsection, entitled “Judaism and Science,” demonstrates that the dichotomy has always
been a positive one, and that one depends on the other. The second subsection, entitled “Astronomy and the Rabbis,” discusses how the rabbis and other Biblical characters struggled to know and understand the cosmos. The third subsection, entitled “Humanity’s Realm, God’s
Realm,” questions whether it is theologically possible for Judaism to exist in space if our realm is on Earth. The second chapter is entitled “Halakhic Challenges” and confronts various challenges following Jewish law on other celestial bodies. The first subsection, entitled
“Rabbinic Sources on the Lunar Calendar,” demonstrates how crucial the Earthly lunar cycle has been to the Jewish calendar and questions if there could even be a Jewish calendar without it. The second subsection, entitled “Can Halakhah Exist Off-Planet?” hits on the fundamental question of whether Earth is needed to observe halakhah, and whether there is an “halakhic bubble” around the Earth. The third and final subsection, entitled “The Jewish Exo-Calendar,” reviews halakhah written for travelers in polar regions, in low Earth orbit, and on the Moon, and applies it to the first settlers off-planet.

The one biblical mitzvah on Rosh Hashanah is the hearing of the shofar. The physical source of the shofar is discussed in various talmudic sources that were later codified. In their codifications, Rabbi Yosef Karo and Rabbi Moses Isserles each include a requirement not mentioned in the Mishnah, Talmud, or Yad Chazakah. Rabbi Yosef Karo invalidates shofarot made from antlers and Rabbi Moses Isserles excludes the use of horns of non-kosher animals. These two laws, in particular the latter, which is difficult both from a halakhic and a practical perspective, are discussed and analyzed and halakhic implications are suggested.

This thought experiment considers whether Siamese (Conjoined) are allowed to marry according to Halacha. It considers various aspects of the Biblical bans on incest and offers a very contemporary discussion about the meaning of personhood. This paper uses medical journals, works on medical history, and various responsa to find a precedent and paradigm by which this question can be considered.

Rabbi Reuven Chaim Klein is the author of God versus Gods: Judaism in the Age of Idolatry (Mosaica Press, 2018) and Lashon HaKodesh: History, Holiness, & Hebrew (Mosaica Press, 2014). He studied in premier Hareidi Yeshivoth including the Mir Yeshiva in Jerusalem and Beth Medrash Govoha in Lakewood. He is currently an RCA Member and lives with his wife and children in Beitar Illit, Israel. ‘Till Death Do Us Part: The Halachic Prospects of Marriage for Conjoined (Siamese) Twins

Social Robots are coming. They are being designed to enter our lives and help in everything from childrearing to elderly care, from household chores to personal therapy, and the list goes on. There is great promise that these machines will further the progress that their predecessors achieved, enhancing our lives and alleviating us of the many tasks with which we would rather not be occupied. But there is a dilemma. On the one hand, these machines are just that, machines. Accordingly, some thinkers propose that we maintain this perspective and relate to Social Robots as "tools". Yet, in treating them as such, it is argued, we deny our own natural empathy, ultimately inculcating vicious as opposed to virtuous dispositions. Many thinkers thus apply Kant's approach to animals-"he who is cruel to animals becomes hard also in his dealings with men"-contending that we must not maltreat robots lest we maltreat humans. On the other hand, because we innately anthropomorphize entities that behave with autonomy and mobility (let alone entities that exhibit beliefs, desires and intentions), we become emotionally entangled with them. Some thinkers actually encourage such relationships. But there are problems here also. For starters, many maintain that it is imprudent to have "empty," unidirectional relationships for we will then fail to appreciate authentic reciprocal relationships. Furthermore, such relationships can lead to our being manipulated, to our shunning of real human interactions as "messy," to our incorrectly allocating resources away from humans, and more. In this article, I review the various positions on this issue and propose an approach that I believe sits in the middle ground between the one extreme of treating Social Robots as mere machines versus the other extreme of accepting Social Robots as having human-like status. I call the approach "The Virtuous Servant Owner" and base it on the virtue ethics of the medieval Jewish philosopher Maimonides.

Star Trek's replicators are perhaps the most intriguing invention in the star trek universe, and also one of the most frequently debated halachic aspects of the show. When seen on screen, the replicators have the ability to seemingly create any object out of thin air. The exact method of operation of the replicators is unfortunately a matter of some disagreement. The Star Trek technical manual describes one method of operation, while their operation on screen is different. The technical manual explains that the replicators disassemble matter into a matter stream, move it to a new location, and reassemble the matter as a new object. In this conception, the object never exists as pure energy. It is stored and transported as matter. In the TV series however the transporters and replicators are shown to operate as if they were assembling objects from pure energy and not matter. In The Original Series episode The Enemy Within, the transporter duplicates captain Kirk, an alien dog-like animal, and some industrial heaters. In Second Chances Riker is duplicated when a second transporter beam reflects off of the first. In both of these instances if the transporter was sending matter in addition to energy then it would have no way to duplicate the matter present. Only by transporting pure energy could it hope to duplicate the amount of matter present. If that wasn't enough, in the Next Generation episode Lonely Among Us captain Picard is reassembled from pure energy by the transporter. No matter exists when the process begins, but by the end captain Picard is standing on the ship-clearly the product of a process which converted pure energy into matter. (Physicist Lawrence Krauss describes in detail how the depiction in the show and the description in the technical manual are incompatible in his book, The Physics of Star Trek). Like any good machloket, we will have to analyze the issue from both perspectives, however for this blog post we're just going to analyze the replicators from the show's