It's all in the timing: a tale of two detonations

Athens Double-Barrelled Cannon

You might think that this double-barrelled cannon sitting next to City Hall in Athens, Georgia could be prop in some sort of misguided Civil War comedy. And, if you did, you wouldn’t be far from right. According to a plaque nearby, the cannon, the only one of its kind, was the brainchild of a Mr. John Gilleland, a private in the “Mitchell Thunderbolts,” an elite “home guard” unit of business and professional men ineligible because of age or disability for service in the Confederate army. Here I use the the words “brainchild” and “elite” quite loosely.

The double-barrel design was intended to fire simultaneously two balls connected by a chain which would “mow down the enemy somewhat as a scythe cuts wheat.” It failed for lack of a means of firing both barrels at the exact same instant. Apparently, “the lack of precise simultaneity caused uneven explosion of the propelling charges, which snapped the chain and gave each ball an erratic and unpredictable trajectory.”

My first reaction to reading this story of this unusual weapon was, “well, duh!” I ran the numbers in my head, first estimating that the velocity of a ball leaving the muzzle of a cannon was on the order of a a thousand feet per second. This meant that if the two detonations occurred even a millisecond apart, the balls would be separated by a foot when exiting the mouth of the cannon, and that separation would increase by an additional foot for each additional millisecond difference in the timing of the detonations. It’s no wonder the chain broke

It’s hard to imagine how 1860s technology, utilizing sputtering fuses and hand-packed gun power, could achieve such precise simultaneous detonations. It’s also hard for me to imagine how the “elite” men of the Mitchell Thunderbolts failed to do the simple arithmetic required to determine the feasibility of their ambitious Yankee-killer.

Oddly enough, this misadventure in weapons development brought to mind a more recent development in military technology that faced a timing challenge far more daunting than the one that faced the Mitchell Thunderbolts. Fast forward only eighty years, and a genuinely elite international team of scientists and engineers found themselves engaged in the development of the first atomic bombs as part of the American Manhattan Project.

Most popular discussion of the technological hurdles faced by J. Robert Oppenheimer and his crew based at Los Alamos centers on the difficulties in creating the necessary amounts of enriched uranium and plutonium to serve as the cores of the fission bombs they wanted to build. But there were other formidable problems, including some having to do with then as yet uninvented electronics.

In particular, design for one of the first two bombs, dubbed Fatman, employed a spherical plutonium core and required that it be compressed by an implosion that would squeeze that core to the critical density needed to initiate the sustained chain reaction that would result in the desired nuclear detonation. To accomplish this, the small plutonium core was nestled in a spherical structure whose outer layer was formed of facets of very powerful chemical explosives. For this arrangement to work, these facets — or lenses as they were called — had themselves to be detonated within a microsecond of each other.

Failure to achieve this kind of “precise simultaneity,” to borrow words from the Athens double-barreled cannon plaque, would lead to an “uneven explosion of the propelling charges.” In the case of Fatman, this would mean that the plutonium core would not be compressed uniformly to the required density and, as a result, the necessary chain reaction would be muted or, perhaps, not occur at all.

As we know from history, whether for good or ill is a matter still hotly disputed in some quarters, the Manhattan Project team succeeded in achieving the exquisite timing required for an implosion bomb.The 40,000–80,000 deaths in 1945 resulting from the detonation of such a device above the city of Nagasaki, Japan on August 9 of that year serve as lasting reminder of their tragic success.

In closing, it is interesting to note that the Athens-area Confederates failed attempt at constructing a weapon of enhanced destruction resulted in a public “object of curiosity.” More telling, as it says on the plaque, the double-barrelled cannon “performed sturdy service for many years in celebrating political victories.” Somehow the cruel madness of the Jim Crow South saw this ill-conceived cannon as something to be proud of. Go figure.

I can only hope that one day our own more successful weapons of mass destruction will be stripped on their nuclear cores and their husks distributed to city halls far and wide as objects of curiosity where they can perform sturdy service celebrating the victory of those fighting for complete nuclear disarmament.

The peace monument in Atlanta's Piedmont Park: four dates and a funeral for racial justice

"Cease Firing - Peace Proclaimed"
monument at the 14th Street entrance
of Atlanta's Piedmont Park

Until recently, I had never paid much attention to this monument at the 14th Street entrance to Atlanta’s Piedmont Park. It is a larger-than-life sculpture that portrays an Angel of Peace stilling the hand of a Confederate soldier about to fire his rifle. It bears the title “Cease Firing - Peace Proclaimed.”

I had always assumed that it was not much more than a conventional memorial to the end of the Civil War, that was until I took a closer look at the plaque on its side. Depending upon your point of view, either God or the Devil lives in the details. In the case of this monument, I think that a convincing argument can be made for the latter.

Four dates are involved in telling the tale of this peace monument.

The earliest date is April 30, 1861, which marks the incorporation of Atlanta’s Gate City Guard into the Confederate Army, little more than two weeks after the firing on Fort Sumter lead to the outbreak of the Civil War. According to the plaque, they did this “in the conscientious conviction of their duty to uphold the Cause of the Southern Confederacy.” This so-called “Lost Cause” rationale was the Confederate retelling of history that transformed their shameful fight to uphold the institution of slavery into a noble struggle in defense of states rights.

A second date is that of a ceasefire somewhat disingenuously alluded to in the monument’s title. As far as I can tell, there was no formal declaration of “cease firing” that marked the end of hostilities of the Civil War. While it is true that Robert E. Lee surrendered the Army of Northern Virginia to Ulysses S. Grant at Appomattox on April 9, 1865, not everyone got the memo. And many of those that did get the memo ignored it. There was no shortage of Confederate dead-enders, as Donald Rumsfeld would have called them. Fighting continued sporadically for months. And a formal end of the war was only declared by President Andrew Johnson on August 20, 1866.

October 6, 1879 is the third date commemorated on the memorial. That was the date that the very same Gate City Guard “went forth to greet their former adversaries in the Northeastern and Eastern States, inviting them to unite with the people of the South to heal the Nation's wounds in a peaceful and prosperous reunion of the States.” Sick and tired of the bloody opposition to Reconstruction in the South, by 1876 the nation had decided to abandon its commitment to transform the political landscape of the former Confederate States. Although the Gate City Guard’s mission was, on its surface, a mission of reconciliation, it was, in many respects, a celebration of the Confederate triumph when it came to matters of race.

The fourth and final date associated with the memorial is October 10th 1911, the date of its dedication. Almost thirty-five years after the end of Reconstruction, a prosperous and resurgent South had been brought back into the Union.

Georgia Governor Hoke Smith attended the dedication. Although Smith was a member of the national Progressive Party formed by Theodore Roosevelt, fulfilling a campaign promise, he led the adoption of a constitutional amendment that effectively disenfranchised black Georgians. This revision marked the final nail in the coffin of any hope for racial justice that had propelled the Union during the Civil War and postwar Reconstruction. All gains that had been made in that regard had been turned back. Jim Crow reigned supreme.

The TV Tower that Saved Atlanta's Freedom Park

This bit of Atlanta history is a departure from my usual blog posts about movies, politics or science.

Building at the base of the WSB-TV Tower (Marc Merlin)

Ever wonder what's at the base of the broadcast tower that looms over Freedom Parkway near the Carter Center? Well wonder no more.

Many Atlanta residents who arrived here in the last twenty years or so may not be aware of the critical role that the WSB-TV Tower played in keeping a stretch of interstate highway from taking over the land that The Path and Freedom Park occupy today.

Original plans had called for the complex that includes the Jimmy Carter Library and Museum and the Carter Center (completed in 1986) to connect with the rest of Atlanta by an interstate spur, in part elevated, which was to run to the downtown connector in one direction and to Ponce de Leon Avenue near its intersection with Clifton Road in the other.

WSB TV tower with guy wires (Marc Merlin)

Opposition to the project was fierce - the powers that be wanted to put a freeway through a white neighborhood for a change - but supporters of the Ex-Pres-way, as it came to be called, included both President Carter and his one-time UN-ambassador, Andrew Young, who had served a term as mayor of Atlanta after leaving the Carter administration and was a force in local politics to be reckoned with. After several years of protests and legal challenges, the tide seemed to be turning in favor of the interstate proponents.

Then it occurred to some clever adversary that the guy wires from the WSB-TV broadcast tower would cross over the proposed roadway and that any ice falling from them as a result of winter storms would pose a hazard to the traffic passing below. Addressing this problem frustrated progress on the interstate plan, adding another considerable delay.

By the early 1990s most of the legal obstacles to the original project had been cleared, but its backers realized that time was running short if the city was to be fully prepared to handle the crowds expected for the 1996 Olympic Games. So, believing that any sort of road was better than none, they relented and agreed to an alternate plan, the shorter, street-grade parkway that, along with The Path and Freedom Park, we use and enjoy today.

The seemingly pointless tunnel that bestrides the parkway just south of the Carter Center stands as a reminder of this, the best-known of Atlanta's "freeway revolts," and as an ever-present defender against winter ice falling from the guy wires of the WSB-TV Tower above.