Must children wear Techeiles?

[Doorknob]

1. I've read tens of articles about techeiles, and this is what it all boils down to. Some also mention the fact that no other snail is recorded in ancient history books. But that is not much of a proof on its own merit, since there is so little written about mollusk dyeing to begin with. The other "proofs", such as from the Tosefta, are easily refutable, and indeed not mentioned by any academics.
2. I don't have a specific source, but I think it's quite logical. I dont think any Rov would give such a type of proof any weight. Rav Herzog already wrote that the shells are a good proof, but not conclusive. It is taking numerous assumptions for granted.
A. The chilazon of techeiles is a snail
B. It has a THICK shell which would last over thousands of years
C. It was very popuar by the gentiles as well, and we therefore should see lots of shells 
D. It is a relatively small snail similar to the murex with each one not producing that much dye. 
E. The ancients had no other uses for their shells (Rav Herzog points this out)
F. Archeologists have already discovered everything there is

3. Professor Koren makes a very good case against pure blue techeiles. It is highly unlikely that it was possible to dye blue in the olden days with the murex. All "blue" textiles that were found contained a nice amount of monobromo-indigo, which makes it highly unlikely that photo-debromination (exposure to sunlight to remove bromine) was ever used in the past.
I understand that many Rabbonim are convinced about the murex, but I believe that they were all fed false information. I don't think any of them researched it like i did. How many of them know that on ptils website they say that you can make blue out of the other 2 Mediterranean snails as well?
 

[rhecht]

1. I've read tens of articles about techeiles, and this is what it all boils down to. Some also mention the fact that no other snail is recorded in ancient history books. But that is not much of a proof on its own merit, since there is so little written about mollusk dyeing to begin with. The other "proofs", such as from the Tosefta, are easily refutable, and indeed not mentioned by any academics.
2. I don't have a specific source, but I think it's quite logical. I dont think any Rov would give such a type of proof any weight. Rav Herzog already wrote that the shells are a good proof, but not conclusive. It is taking numerous assumptions for granted.
A. The chilazon of techeiles is a snail
B. It has a THICK shell which would last over thousands of years
C. It was very popuar by the gentiles as well, and we therefore should see lots of shells 
D. It is a relatively small snail similar to the murex with each one not producing that much dye. 
E. The ancients had no other uses for their shells (Rav Herzog points this out)
F. Archeologists have already discovered everything there is

3. Professor Koren makes a very good case against pure blue techeiles. It is highly unlikely that it was possible to dye blue in the olden days with the murex. All "blue" textiles that were found contained a nice amount of monobromo-indigo, which makes it highly unlikely that photo-debromination (exposure to sunlight to remove bromine) was ever used in the past.
I understand that many Rabbonim are convinced about the murex, but I believe that they were all fed false information. I don't think any of them researched it like i did. How many of them know that on ptils website they say that you can make blue out of the other 2 Mediterranean snails as well?
 


 

I love Dr. Koren for the research he's done but his last piece had more holes than can be mentioned in one comment here. Suffice it to say he's inaccurate in that people could have never dyed pure blue in ancient times, that it was "bluish." Besides sunlight at a specific stage, there are at least 7 other ways to get pure blue (https://www.mywesternwall.net/2020/05/1 ... color.html), 6 coming from the murex trunculus. Also, one of the methods mentioned is what Baruch Sterman quoted Dr. Koren as saying, that there might have been a subspecies of murex to make pure blue, which contradicts his thesis that this couldn't have been produced in ancient times.

Anyway, the two main methods to get pure blue are simple: sunlight and boiling. Both were 100% available in ancient times, with or without clay jars. I'd also argue that blue purple AND pure blue AND blue-green, as long as they're from the MT, are kosher as the base color is blue. The hue isn't argued in the Gemara as Dam Nidda is.

Full disclosure: I'm not a professional dyer, but recently did the "dye in a box" with one of my kids. The dye didn't go through all the way, which explains the white-brown spots, but I boiled the tuft of wool on the right, using 3 rounds of plain urn water which reaches a max temperature of 95C before being poured into a paper cup. This turned pretty blue. I would think that professional dyers were able to boil it at more consistent temperatures.

Now the Romans didn't prize pure blue because it was deemed to be melancholy, and this probably is the main reason why they wrote on purple being produced (with blue being one of those unfortunate shades), but Jews never had that issue. And as we see today, if anything it's "too easy" to get pure blue from the Murex Trunculus with the above methods. If it's "too easy" how can we say that it wasn't done in ancient times?

333837264_526455326270921_3646127020466322537_n.jpg

 

[Doorknob]

Professor Koren discusses all the points you mentioned. It was impossible to get blue with exposure to sunlight, as he explains in great detail in his article. 
additionally, i dont believe he ever mentioned that there was a different undiscovered species of murex that dyed blue.
it is clear from the gemara that they did not get blue via boiling the garment itself, so that is not really relevant 

[rhecht]

Professor Koren discusses all the points you mentioned. It was impossible to get blue with exposure to sunlight, as he explains in great detail in his article. 
additionally, i dont believe he ever mentioned that there was a different undiscovered species of murex that dyed blue.
it is clear from the gemara that they did not get blue via boiling the garment itself, so that is not really relevant 

 

R' Aryeh Levanon (https://thelibrary.tekhelet.com/uploads ... ra2022.pdf) already did the test based on Prof. Koren's guidelines and he was able to get blue, not "bluish."

Rambam writes about boiling, and in the end of the day he still writes that it's sky blue even with one word missing from the original text. 

[Mr. Genugshoin]

Rabbi Levanon did NOT succeed at dyeing blue with Toporovitz snails, read his recent article