So there’s a new radiation warning symbol. (See also here; previous link is non-specific.) It’s this thing:

Why do we need a new radiation warning symbol?

The trefoil symbol has no inherent meaning and only those people that have been educated in its meaning have knowledge that it represents the presence of ionizing radiation. The new symbol is the completion of a multi-year effort by the IAEA to develop a universal radiation warning symbol that anyone anywhere will understand the message of “Danger- Stay Away”.

And this brings up an interesting point about symbols — they have no intrinsic meaning in and of themselves. Even the skull and crossbones doesn’t really mean anything; we assume that it is a good representation of death and destruction, but anyone who’s done poison education can tell you that some kids will see it and think, “Oooh, pirates!” (To be fair, I know some adults who will think the same thing, too.) Hence, Mr. Yuk comes into existence (deeply messed-up video also available). It’s debatable whether Mr. Yuk works better than the skull and crossbones, but he was designed by committee, so you tell me.

It’s worth taking a peek at this discussion of the development of the biohazard warning symbol. The creators wanted something memorable, yet totally meaningless in and of itself, so as to be able to educate people in its meaning later. Educated, the biohazard symbol manages to convey the idea that “something nearby will fuck you and/or your offspring up in a disturbingly organic manner,” and that’s probably a good thing. But would it carry the same message to someone who had never seen it before? I doubt it.

The trefoil has been around since 1946. Some of the design considerations were pretty interesting:

The first signs printed at Berkeley had a magenta (Martin Senour Roman Violet No. 2225) symbol on a blue background. In an earlier letter written in 1948, Garden explained why this particular shade of magenta color was selected: “it was distinctive and did not conflict with any color code that we were familiar with. Another factor in its favor was its cost. . . The high cost will deter others from using this color promiscuously.” Explaining the blue background, he said, “The use of a blue background was selected because there is very little blue color used in most of the areas where radioactive work would be carried out.”

Garden did not like yellow as a background: “the very fact that . . . the high visibility yellow stands out most prominently has led to extensive use of this color and it is very common.” To compensate for the lower visibility of the blue, Garden even toyed with the idea of including diagonal white stripes across the sign.

Despite Garden’s view to the contrary, most workers felt that a blue background was a poor choice. Blue was not supposed to be used on warning signs, and it faded, especially outdoors. The use of yellow was standardized at Oak Ridge National Lab in early 1948. At that time, Bill Ray and George Warlick, both working for K.Z. Morgan, were given the task of coming up with a more suitable warning sign, a blue background being too unacceptable. Ray traveled to Berkeley and picked up a set of their signs. Back in Oak Ridge, Ray and Warlick had their graphics people cut out the magenta symbols and staple them on cards of different colors. Outdoors, and at a distance of 20 feet, a committee selected the magenta on yellow as the best combination.

Maybe it’s just me, but there’s something funny about physicists arguing about color choices.

Note that in both cases, the guys designing the symbols were not trying to make something that would be intuitively obvious to someone who had never seen it before — they were counting on the ability to education potential warnees about the dangers posted, either from radiation or biological activity. With education you can do more or less whatever you want (consider the European hazard symbols, some of which aren’t terribly helpful unless you know what’s going on). A vastly different problem occurs when you’re trying to warn naive people away from stuff, and that’s where the new symbol comes into play.

The intention is to put this symbol on equipment (sources, generating devices, etc) such that it only becomes obvious when the equipment is disassembled — it’s not a general purpose warning (and, indeed, it would fail miserably at that task since it seems to imply not just that there’s danger, but that there’s danger and that you should leave, now). The goal would be to prevent a repeat of something like the Goiania accident, where naive individuals inadvertently contaminated themselves with Cs-137. (Incidentally, the IAEA’s report into Goiania should be mandatory reading to anyone who wants to talk seriously about radiological terrorism, but that’s another post for another day.) What’s interesting about the new symbol is that I don’t have that visceral reaction to seeing it that I think the IAEA thinks I should — although I understand its message perfectly and know exactly what it means. That said, they’ve apparently tested the snot out of it, and are apparently happy with the message it communicates, and they’re smarter than I am, so I defer to their expert judgment.

No discussion about naive warnings in this journal would be complete without me bringing up what has become quite possibly my favorite long-term problem: Marking the Waste Isolation Pilot Plant so that humans from the future stay the hell out:

* This place is a message… and part of a system of messages… pay attention to it!
* Sending this message was impotant to us. We considered ourselves to be a powerful culture.
* This place is not a place of honor…no highly esteemed deed is commemorated here… nothing valued is here.
* What is here is dangerous and repulsive to us. This message is a warning about danger.
* The danger is in a particular location… it increases toward a center… the center of danger is here… of a particular size and shape, and below us.
* The danger is still present, in your time, as it was in ours.
* The danger is to the body, and it can kill.
* The form of the danger is an emanation of energy.
* The danger is unleashed only if you substantially disturb this place physically. This place is best shunned and left uninhabited.

The excerpts capture the spirit well, but if you’re truly interested in the topic and have some time to kill, the full 351 page report from Sandia is worth a read too. I find the whole thing to be deeply fascinating: How do you communicate with your own species across time? How to you ensure understanding? How do you ensure survival? The fact that we’re even thinking about it makes me proud as a human.

I check back on this every year or so, to see if there are new developments or changes to the plan as written. The last new thing I saw was the implementation plan for the permanent markers, which sets up a bunch of timetables and discusses where they’re at in terms of preparing to mark the site. I hope they finish it, and that I live long enough to see what they’ve done.