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10
votes
2answers
359 views

Kosherizing Water using Distillation

Suppose I have water that was cooked with non-kosher food. I then take the water and distill it. Would this water be considered permissible to drink?
18
votes
1answer
389 views

Mushrooms in a Vineyard

The bracha on a mushroom is "shehakol" because the Talmud (Berachot 40b) correctly (I think) states that mushrooms do not derive their nutrients from the ground. If a mushroom is growing in a ...
12
votes
1answer
169 views

In what way are mushrooms considered “non-nutritive”?

The Mishnah (Eruvin 26b) states that water and salt can't be used as the food for eruv chatzeiros or eruv techumin (thus Rashi; according to Tosafos only the latter). Rashi explains that this is ...
4
votes
1answer
158 views

How is Hagalah done on glass?

With regards to using glass vessels on Pesach that were used year round, The Shulchan Aruch HaRav (Orach Chaim 451:63) says that, for Ashkenazim, if the glass vessel was used multiple times during the ...
4
votes
5answers
165 views

The Plague of Darkness

This is a two fold question 1)The plaque of darkness has considerable commentary, however I have yet to find a rabbi who speaks about what created the darkness. Therefore, What created the darkness ...
2
votes
1answer
157 views

Archaeology and תחיית המתים

A few minutes ago, while standing in the rain and seeing some people passing out some pamphlets an idea occurred to me. Are there any papers, books, dvar torahs etc, which links the traditional ...
7
votes
3answers
351 views

Is olive oil unhealthy?

The Gemara in Brachot 35b says that the proper bracha on pure olive oil is "Borei Peri HaEtz". However, it says that this refers to when you mixed the oil with some אניגרון which Prof Marcus Jastrow ...
10
votes
5answers
309 views

Does the colouring of animals depend on what the mother sees before conception?

What is the meaning of the hishtadlus that Yaakov made with the conception of the animals starting at 30 (37)? Is it or was it a natural thing that the colouring of animals depends on what their ...
8
votes
1answer
430 views

Retention of urine causing infertility?

In several places in the Gemara (Yevamos 64b, Bechoros 44b) it is stated that holding back urine for an extended period can cause a man to become infertile. In the latter place the Gemara gives a ...
8
votes
3answers
711 views

Why does the Talmud assume a woman cannot get pregnant on the first act of intercourse?

There is a rule in the Gemara (Yevamot 34a) that אין אשה מתעברת בביאה ראשונה. The question is why the Talmud assumes that a virgin cannot conceive on her first act of sexual intercourse if the hymen ...
23
votes
4answers
967 views

Does artificial meat grown in a petri dish have the halachic status of meat?

Scientists are developing means of growing artificial meat in a petri dish. Does such 'meat' have the halachic status of meat? Source: ...
5
votes
2answers
2k views

how old is Judaism?

How old is Judaism - not legendary, but indicated by science? What are the oldest scriptures found of the story of Moses, for example? Or are the scriptures imported from very different cultures so ...
14
votes
11answers
761 views

Reconciling the evidence for the Uncertainty Principle with belief in an omniscient G-d

One of the foundations of modern quantum mechanics is the Uncertainty Principle. This principle is not an assumption, but rather is derived from assumptions made with regard to the structure of ...
7
votes
4answers
372 views

How does salt “add heat” (mishna in Shabbos 4(1))

The mishna in Shabbos 4(1) tells us which materials may not be used to insulate foods for Shabbos because they "add heat". One of these materials is salt. Can anyone explain how salt can add heat ...
14
votes
4answers
1k views

Time Travel and Judaism

Has time travel ever been discussed before in terms of Judaism? According to Judaism would (should) it be possible to travel through time?
10
votes
1answer
204 views

What is the “Kos Shel Ikrin,” a potion that renders one infertile?

The Talmud discusses the "Kos Shel Ikrin" (Cup of the Barren, or Cup of Roots), a potion that rendered a woman or man infertile. The recipe for this potion is on record in tractate Shabbos and there ...
16
votes
7answers
492 views

why half-believe the Torah?

(I'm not sure this is on-topic, and feel free to close it if it's not, of course.) I understand some who study the Bible claim natural reasons for things we recognize as miracles, from the plagues of ...
5
votes
2answers
210 views

Science of the Rishonim on “celestial spheres”

In the writings of the Rishonim, it is not uncommon to see explanations of pesukim or of aggadic concepts using the "celestial spheres" model of the universe. The Rambam in particular uses the idea ...
8
votes
6answers
604 views

Rationalist Position on Bible Ancients' Long Lives

How would a rationalist interpret the long lives of the ancient people enumerated in the Bible, from Methuselah on down? Virtually no person lives more than 120 years today, even with the assistance ...
14
votes
3answers
394 views

Let there be light! But from where?

According to Genesis 1:3, "And G-d said, Let there be light; and there was light." What light is the Torah referring to if the sun which produces light by day was created only on the 4th day of ...
41
votes
5answers
2k views

Are sea sponges kosher?

The sea sponge is scientifically classified as an animal, therefore maybe it would be considered unkosher, as seafood. On the other hand, it seems much more similar to a vegetable of some kind, so ...
9
votes
3answers
267 views

How do scientists such as Natan Aviezer and Gerald Schroeder understand the fourth day of creation?

If I understand correctly, scientists such as Natan Aviezer and Gerald Schroeder have readings of Genesis Chapter 1 that fit with the current scientific understanding of how the universe/planet/life ...
21
votes
7answers
1k views

Why the vast difference of opinion about the age of the Universe?

5770 and 13,000,000,000 is a big difference! I am looking for a good explanation to the difference opinion of the age of the universe. Please help me out!
26
votes
9answers
2k views

Bereishit vs. science

How does Judaism deal with the differences between scientific evidence of the beginning of the world and the account(s) in Bereishit?