Assignment, for Science / Law Geeks:

We hear much about litmus tests for Supreme Court candidates.

(1) Red, the Republican color, is acidic. Blue, the Democratic color, is alkaline. Discuss.

(2) Litmus paper apparently turns red for pH < 4.5, which is to say 2.5 away from the moderate 7, but blue for pH > 8.3, which is only 1.3 away. Do litmus tests identify slight deviations from center to the left more than they do slight deviations to the right?

(3) Determine the pHs of the potential judicial nominees, from Gonzales (3.2) to Jones (-4).

Universal Acid (mail) (www):
I think pH = -4 is physically impossible... that would require 180 H+ ions per water molecule! (if my calculations are correct... pH -4 --> [H+] = 10^4 mol/L, whereas [H2O] = 1000 g/L = 55.6 mol/L)
7.6.2005 2:01pm
myalterego (mail):
Aha, I knew that I would still get to use my chemistry degree even after law school! The pH scale is logarithmic (base 10), not linear. Thus, a PH of 4 is ten times more acidic than a pH of 5. The range where litmus paper doesn't change is in a buffer zone where the litmus paper itself just isn't a very good indicator (sensitivity is too low). As an aside, there are plenty of other pH indicators that turn colors at various pH's. In any event, as you point out, the range of deviation in reaction close to the center is pretty broad, so perhaps describing "litmus tests" in judicial confirmation hearings is appropriately reserved for issues where people (usually the loudest of the warring factions on both sides) see very little gray/neutral area.

Just out of curiousity, where did 3.2 for Gonzalez and -4 for Jones come from?
7.6.2005 2:03pm
Buck Turgidson (mail):
Er... it's only the short memory of the press that has assigned red to be a "Republican" color. If the journalistic convention that has been used for the past three plus decades prevails, in 2008 red will be the Democratic color. People seem to have forgotten that the convention is that the incumbent color alternates irrespectively of the party affiliation. Because of the way the election process has worked out since 1980, Republicans got most of the red. However, as it happens, they are the incumbent party in 2008 and they had red last time, so they are supposed to be assigned blue. It remains to be seen if newsrooms will follow the professional convention or choose the Bubba factor. The original intent of the color coding was precisely to prevent the kind of color-based rhetoric that has prevailed in since 2004.
7.6.2005 2:21pm
Keith Hilzendeger:
A pH value of -4 strikes me as odd. pH is calculated logarithmically, which means it can't be negative. Can it?
7.6.2005 2:30pm
Universal Acid (mail) (www):
"A pH value of -4 strikes me as odd. pH is calculated logarithmically, which means it can't be negative. Can it?"

It can in theory, but probably not much in practice. pH = -log [H+]. So if you had 2 M HCl, theoretically the concentration of H+ would be 2 M, mean that log [H+] = log 2 = 0.3, thus pH = -0.3. But in practice it would be rare to have [H+] go about 1 M, so that's why you hardly ever see negative pH.

(Logs can be both negative and positive. Log x < 0 if 0 0 if x>1. usually [H+] is between 0 and 1 M, so log [H+] is negative, so pH is positive.)
7.6.2005 2:36pm
Universal Acid (mail) (www):
Um, sorry about the typos. That's "meaning," not "mean," and "above," not "about."
7.6.2005 2:38pm
EBuz (mail) (www):
Thanks, Buck, for that explanation. I thought my memory of being 8 years old watching the Reagan states appear in blue in 1984 was a false one, but by the incumbent/nonincumbent formula, it is correct. Do you know if 2004 is the first year that the media did not employ this formula? If so, I wonder if that is a *result of* or the *cause for* the red state/blue state rhetoric catching on?
7.6.2005 2:58pm
Eugene Volokh (www):
Jones's pH of -4 was a little joke -- kind of like the rest of the post.
7.6.2005 3:37pm
NickM (mail) (www):
It wasn't a very good joke. Jones would be about a pH of 2. To get a pH of -4, you would need Randy Barnett or Richard Epstein. :-)
Of course, you can't do a litmus test on someone of that pH, because the litmus paper will dissolve.

7.6.2005 4:35pm
Eugene Volokh (www):
Follow-up question: What color would libertarians produce? Barnett and Epstein are certainly not very conservative generally, though they agree with conservatives on many economic questions.
7.6.2005 5:23pm
Captain Holly (mail) (www):
Libertarians are like oxidizing solutions such as hypochlorite (ClO-), which are difficult to detect with pH paper as the oxidizer destroys the dye upon contact.

How this is symbolic, I do not know.
7.6.2005 6:48pm
Buck Turgidson (mail):
In response to EBuz:

In 2000, the incumbent party was Democrats and they were blue. In 2004, the incumbent party was Republicans and they were red. There is no break in the convention in 2004. But for 2008, the incumbent--Republican--should be blue again. I would expect Fox to go with red for Republicans and at least some of the traditional networks to restore the convention. Should make for interesting watching if colors are split among the networks.
7.7.2005 2:33am
On the other hand, if you use phenolphthalein as an indicator, as one often does in undergraduate titrations, then on reaching Democratic nature you turn pink.

Now where's J. Edgar when you need him?
7.7.2005 7:35am
EBuz (mail) (www):
Thanks Buck. Now that I reread your first post I see that I missed the key word "alternates." I think our current red/blue paradigm is too entrenched for even the more traditional media to try to reclaim the former convention. Maybe they should start over with new colors. Gold and Silver. Taupe and Mauve. Coral and Seafoam.
7.7.2005 1:41pm