The materials, which were used, are first enumerated in the beginning of Terumah
before the subsequent discussion of the various vessels and garments that will be constructed from them: does this textural precedence mean that only these materials can be used and it is not possible to use alternatives? Was kashrus of the vessels of the Mishkan dependent on their shape or dimensions and function or is their chemical composition?
Goldis said to have been created for the Mishkan/Temple. Similarly,Tachashwas created just for the Mishkan (also see Toras Menachem Hisvadus 5752 volume 1, p.157 Week in Review Terumah 5754) to accentuate the singular purpose of the Mishkan. From these two examples, it would appear that there were special materials that are inherently required for each of the parts of the Mishkan/Temple.
If we put aside the view that the Third Temple will descend from Shamayim, the question is whether a whether a different natural, or synthetic substances or a composite can be substituted if man builds the next Beis HaMikdash? One can be sure gold will still be used as it has retained its value over the centuries; however, copper has become too expensive for pennies; perhaps the copper kelim will no longer have the proper relative importance?
Chazal forbid using iron due to its historical association with war, but weapons are no longer exclusively associated with war, so, perhaps stainless steel tools will be as acceptable, and they don't rust. If not, will we have to rediscover the shamir worm to cut stone, or will lasers be acceptable? What about Electrical lighting? Heating by gas furnaces or will the Cohanim still walk on a cold floor?! Would uranium now be the forbidden element?! What about using advanced ceramics and engineering plastics? L'havdil, will the construction crew have to be sold on plastics like the Amish?!
If we err on this issue, will the wrong selection of building materials prevent the proper operation of the mizbayach with Heavenly fire coming down in response to korbanot?
In regard for the blue dye, the Tiferes Yisrael (Introduction to Mishna Shabbas) has concluded that chilazon is not required to make kosher techeles for tzitzis and bigday Kehuna: a spectrally equivalent blue dye that is just as colorfast can be used just as well! Maybe Mishkan can be made from the more easily fashion ready-to-use, more decorative walls from polymer concrete that have many advantages over old-fashioned stone.
Still one can say the timeless fabric of wool endures: it is hard to believe that the Kohen Gadol should dress according to a fad that could become such a fashion nightmare as the polyester leisure suit of the 1970’s !
Many questions! May we soon see the resolution of these questions with the coming of Moshiach Zidkeinu.
Avakesh comments:
One could argue that there can be no deviation whatsoever from the materials that Torah lists, because of the following verse: כְּכֹל, אֲשֶׁר אֲנִי מַרְאֶה אוֹתְךָ, אֵת תַּבְנִית הַמִּשְׁכָּן, וְאֵת תַּבְנִית כָּל-כֵּלָיו; וְכֵן, תַּעֲשׂוּ.
According to all that I show thee, the pattern of the tabernacle, and the pattern of all the furniture thereof, even so shall ye make it.(Shemos 25:9)
Rashi understands this as a commandment to keep the general shape and structure and implies that the metals are not included. This is consistent with his commentary to gemara in Sanhedrin 16b, where he explains that vese as referring solely to the question of whether vessels that are made in the future require annointing or can be sanctified with service alone.
Rashi says:
And so should you make it---
in future generations, in the event that one of the vessels should be lost or when you will make for Me the vessels for the Eternal House (the Beis Hamikdosh), such as the tables, the lamps, the wash basins, and the stands [for the wash basins] which Shlomo made, then make them according to the forms of these.
I note that Chashmonaim when they entered the Temple, first set up a menorah of seven iron spears. "Why do we kindle lights on Hanukah? Because when the sons of the Hasmoneans, the High Priest, defeated the Hellenists, they entered the Temple and found there eight iron spears. They stuck candles on them and lit them." (Pesikta Rabbati ch. 2). This seems to point out that other metals are acceptable.
Netsiv to Shemos 25:9, on the other hand, brings a Tosefta, which he expands to mean that all the particulars of the Mishkan corresponded to the underlying structures of the Creation. Among them, one should surely count the metals of which they were made: gold corresponds to gevurah and silver to malchus etc. The verse not only calls on us to construct a replica of the original Mishkan, it demands that it be built is a way such that Shekhina should dwell within it. It is a Halachic imperative according to Netsiv, not just a nice idea. Rabbi Elie Munk writes in The Call of the Torah: "According to the Kabbalists, the Tabernacle represents a microcosm of the universe [and] reflects the universal source from which life and blessings emanate to all the spheres of creation.") If so, we will need to preserve the metals that Torah listed.
In regard to electricity, it may be different:
In Ner Mitzvah(pp. 13-16), R. Mashash describes the superiority of the electric menorah in even clearer terms.
ועוד אני אומר, דפשוט וברור, שאם היה אור האלקיטריסיטי מצוי בזמן המקדש, ודאי שבו היו מדליקין המנורה, משום שאי אפשר להיות שנמלא בתינו החולין באורים גדולים של אור החשמל היקר הזה, שהוא מעין דוגמא של מעלה, ובבית אלהינו הקדוש נדליק בשמן זית, שאפי[לו] העניים הגרועים מואסים אותו בזה”ז, ופשוט שממנו נדליק בבית האחרון שיבנה בב”א
And I say more, that it is simple and clear, that if the electrical light existed in the time of the Temple, certainly with it they would have lit the menorah, since it is impossible to be that we would fill our everyday homes with these great lights of the precious electrical light, that it is a kind of example from the heavens, and in the House of Our Holy Lord we would light with olive oil, that even the extremely poor are disgusted by it at this time, and it is simple that from it [i.e. electrical light] we will light in the last house [i.e. Temple] that will be built speedily in our days amen. (p. 15)