Against the wall is a huge, 20-ton double column of steel, misshapen and mangled like a dry stick thrown casually into a fire. It was part of the perimeter wall of floors 71 to 74 of the north face of the north tower of the World Trade Centre.
Beside it is a damaged sign for a bicycle rack near the base of the towers, warning evil-doers not to park their bikes elsewhere: "Violation will result in removal of equipment and a $30 fee." The sense of lost innocence is heartbreaking.
Opposite is what's left of a fire engine that was hooked to a hydrant under a footbridge, when the north tower fell on the bridge. More moving still are the odds and ends of human detritus: the half-crushed remnant of a payphone, the twisted stub of a red umbrella carrying the logo of an investment company, the floor number signs from the elevators, the broken-off head of somebody's golf club. And, almost unbearable to contemplate, stray pieces of the fuselage and engine of a Boeing 707.
Looking at all of this you get a weird sense of archaeology as current affairs. These relics - and that is exactly the right word - of September 11th on display at the New York State Museum in Albany were excavated from the now gaping site of the atrocity and from the hauntingly-named Freshkills dump on Staten Island to which the rubble was removed. In a country with a thin layer of historical memory, they are sacred objects, radiating the mystery and solemnity of the recovered remnants of a lost civilisation. Yet they are also today's news, exhibits in a sensational trial still in progress.
You can't look at an exhibition like that or visit the bleak, awful absence of Ground Zero without understanding how copiously the wounds of September 11th still bleed. And even if you could, many Irish-Americans, especially those who were in New York on that day, are all too anxious to remind you of their hurt. A hurt, they will tell you, that has been compounded by the incomprehension of the Irish.
Some, including some of the wealthy and influential businessmen who put their money and their energy into the peace process and Irish charities, go so far as to say that they are finished with Ireland now. The demonstrations against the Iraqi war and the wave of media criticism seem to them an unforgivable betrayal. And yet the other thing that is inescapable in the US now is a sense of just how useless the war has been, even as a poultice to draw out the poison of September 11th. The day before I saw the exhibition in Albany last week, there was a big Support the Troops rally in a 5,000-seater stadium on the edge of the city.
Or at least it was it meant to be big; the turnout was pathetic. About 200 people, almost all of them the wives, children and elderly parents of soldiers, waved their flags while the patriotic music echoed off the empty seats. Apparently nobody else was in the mood to celebrate a triumph.
This was a few days before the horrific wave of car-bombs in Saudi Arabia and Morocco reminded everyone that Osama bin Laden is in his element again.
Even without such grotesque evidence that there are no simple military solutions to terrorism, the feeling of anti-climax in the US is palpable. The flames of euphoria that were sparked by the successful occupation of Baghdad have been doused by the realisation that the US is now mired in an Iraqi landscape it barely recognises, a tempting and vulnerable target to its enemies, and that it has no exit strategy.
The home front doesn't feel exactly triumphant either. The trouble in the economy runs very deep. The daily headlines are about cutbacks in public services, including not just schools but the venerated police and fire departments. In New York even the Republican Party is in outraged revolt against the savage budget cutbacks proposed by the Republican governor, George Pataki. The state that acts like a hyper-power on the world stage feels like a seven-stone weakling at home, unable to guarantee even basic education and healthcare for its citizens.
The largely gung-ho media coverage, the deep well-spring of patriotism and the lingering hurt of September 11th can't obscure the reality for ever. Americans know that Afghanistan remains in the grip of the warlords, that al-Qaeda is still very much in business and that, if the aim of the war in Iraq was to establish a stable, democratic pro-Western government, that war is being lost. Sooner or later that knowledge will lead to a reassessment of the dominant neo-conservative agenda.
When it does, those Irish-Americans who now feel betrayed by the old country may also come to see that Irish popular opposition was not anti-American but simply evidence of a hard lesson well learned. We got the message that many of those same Irish-Americans wanted to give us: that there are no military solutions to political problems and that the politics of revenge ultimately satisfy nobody. The instinctive reluctance to celebrate victory in Iraq suggests that Americans themselves are gradually getting the same message.