[Avodah] [Areivim] Are there any chemists on Areivim? (to

[Hankman]

Rn'SLB wrote:

 I realize that the translation to English of Zevachim 54a is such, but I couldn't find an online resource in Hebrew that translated any of the materials listed as "lead". 

CM responds:

Why do you not accept the Artscroll translation (of lead)?

Rn'SLB wrote:

 Pitch hardens after being heated (which is what I intended to say in the previous post).

CM responds:

I believe you have this wrong. Pitch does not harden with the application of heat, it softens with the addition of heat. I believe what you are erroneously referring to is the curing of asphalt concrete. Cooling of the asphalt results in the hardening of it. However, in the curing process, the heat is prolonged (to counteract the heat loss) somewhat, so the temperature does not drop too rapidly but in a controlled manner and not too rapidly and is reasonably uniform throughout the volume as the asphalt loses heat through its surface to the environment. In this manner (curing process) the cooling takes place in a fashion conducive to obtaining optimum hardness of the asphalt. But heating asphalt will soften it, not harden it. I think I have it right. 

How do you think they got the liquid tar they pour in the youtube video you cited, by putting it in the freezer?

Kol tuv

Chaim Manaster
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.aishdas.org/pipermail/avodah-aishdas.org/attachments/20110111/f8a60fb8/attachment.htm>