Editing 2321: Low-Background Metal

Megan explains that, while delicate equipment is often shielded from radiation by lead, metal produced in modern times is contaminated by {{w|nuclear fallout}} in the atmosphere, which means that the shielding itself has enough radioactivity to interfere with highly delicate equipment.  In order to shield this equipment, "low-background metal" is salvaged from sunken ships.  Lead ingots from Roman cargo have been used in experiments.  The Roman lead was produced before atmospheric nuclear tests occurred{{Citation needed}} and therefore did not have resulting {{w|radionuclides}} in the air used in its manufacture. When it is extracted, lead is naturally contaminated with the radioactive isotope Pb-210, with a 22 year half-life. Because it has spent many centuries continually underwater, it is both shielded from radioactive particles, and has had time for natural radioactivity to fade.

However, while this might be a pragmatic solution, going back in time to sink ships and murder the occupants doesn't seem like a particularly morally acceptable solution,{{Citation needed}} not to mention opening up potential {{w|time travel paradoxes}} such as what if one of the ship occupants killed was an ancestor to one of the protagonists? If this were a real scenario, there would probably be less drastic solutions available, such as purchasing quantities of lead from the time (would need to convincingly impersonate a local and have something that could be used as currency) and dropping them in the ocean from a (rented) non-destroyed ship, which as a bonus eliminates the need to extract it from the charred remains of a ship later.

 

 

The title text refers to {{w|Greek fire}}, which was an incendiary weapon invented and employed by the Byzantine empire. It was a flammable liquid, famously said to burn on water, that was used in naval combat to set fire to enemy ships. As it was a closely-guarded military secret, many of the details have been lost to time, and modern chemists have only been able to develop educated guesses of what it ''probably'' was. Randall proposes a rather outlandish alternative hypothesis: that all records of Greek fire were actually in reference to the modern weapons used by the time travelers. It is also notable that, if the time machine was taken to the time of the classical Roman empire, Greek fire would not yet have been a known term. Perhaps the weapon wielded by the time travelers was later conflated with the Byzantines' weapon, or perhaps the time machine was taken to a period a few centuries later than classical Rome.

:[Black Hat stands behind Megan who addresses Cueball who stands on the other side of a table with a machine. The machine is a rectangular box with a small dome with one large and two small antennas on top. It seems to point in Cueball's direction as it has a broad protrusion at the back and protrusion at the front that gets smaller towards the tip. The word "Time" is written on the side, and below that is possibly more illegible text.]