Pirkei Avot (Chap. 5, Mishna 8 — h/t Lise):
Ten things were created at twilight on the eve of the first Sabbath:
the mouth of the earth (Numbers 16:32);
the mouth of the well (Numbers 21:16);
the mouth of the ass (Numbers 22:28);
the Shamir, writing;
the inscription on the tablets of the Ten Commandments;
and the tablets themselves.
Some also include the evil spirits, the grave of Moses, the ram of Abraham; and others add the original tongs, for tongs must be made with tongs.
So what is the Shamir? Rabbi Dovid Rosenfeld explains,
The shamir was a type of worm which produced a highly corrosive substance. The Talmud writes that it was used to hew stones for the Temple’s construction or engrave inscriptions on the stones of the High Priest’s garments (Sotah 48b). It used a force which emanated directly from G-d, and was used in the construction of the Temple — the structure which enabled G-d’s Divine Presence to dwell in the physical world.
Wikipedia provides this additional speculation:
For storage, the Shamir was always wrapped in wool and stored in a container made of lead; any other vessel would burst and disintegrate under the Shamir’s gaze.
The Shamir was either lost or had lost its potency (along with the “dripping of the honeycomb”) by the time of the destruction of the First Temple at the hands of Nebuchadnezzar in 586 B.C.
Noting the conditions under which the Shamir was stored when not in use, controversial theorist Immanuel Velikovsky posited that the Shamir’s true nature was radioactive. Velikovsky hypothesized that the Shamir was a small sample of a naturally occurring radioactive isotope, possibly radium, though he fails to explain how this would cut material.
Worms are in the news today
Iran’s nuclear project is suffering serious technical problems, evidenced by the recent shutdown of hundreds or even thousands of its uranium-enrichment centrifuges. Analysts suggest that the Stuxnet computer worm is the cause. Stuxnet has turned out to be far more sophisticated and targeted than heretofore thought:
Technical analysis shows that Stuxnet contains two different digital warheads that are obviously unrelated. The warheads are considerably different in structure and run on different platforms…
It appears that warhead one and warhead two were deployed in combination as an all-out cyber strike against the Iranian nuclear program. None of the targets, which are detailed below, can be categorized as critical infrastructure; both are dedicated military targets.
Warhead one is running on Siemens S7-315 controllers. It contains the much-quoted DEADFOOT sequence, first discovered by us on Sep 16 2010, where control is temporarily taken away from the legitimate program. Code analysis shows that warhead one manipulates an array of up to 186 high-speed drives attached to up to six Profibus segments. In essence, the manipulation is cycling drive speeds (RPM) between low values and high values. For a gas centrifuge, this will sooner or later result in cracking the rotor, thereby destroying the centrifuge…
Warhead two is running on a Siemens S7-417 controller. It has no obvious relation to warhead one in structure, configuration and timing. The configuration that warhead two is looking for matches that of a steam turbine controller as it is used in power plants, such as the Bushehr nuclear power plant. — Ralph Langner, German software engineer (h/t,Yochanan Visser)