Like the Universe, the travel industry constantly expands. A key duty of The Independent Traveller is to keep you abreast of the increasing range of possibilities: hotel openings, fresh adventures and new airline routes such as Belfast-Katowice – the latest improbable link to be revealed by Wizz Air.
The converse is that individual elements can disappear. Some collapse spectacularly, in a financial supernova, such as befell XL Airways six summers ago. But most exit quietly, with whispered announcements – death notices, if you like – that a particular route is no longer viable.
You might imagine that Britain is far better connected with the rest of the world than it was two decades ago. Certainly, the network of European flights has vastly expanded, embracing a constellation of places that you cannot pronounce and did not know you wanted to see.
Yet long-haul, the picture is very different. I have compared the summer timetable schedule of British Airways from 1994 with the present network.
The losses are dramatic, leaving a wide scattering of places no longer accessible direct from the UK on any airline at all. Africa is particularly badly affected, with the old "Empire" routes to Dar es Salaam, Gaborone, Harare, Lilongwe and Lusaka all disappearing.
Emirates and Turkish Airlines are in a race to conquer Africa from an aviation perspective, nibbling away at non-stop traffic from Heathrow. The airport authorities in Entebbe are presumably fretting about BA deciding to deploy its valuable Boeing 767s and even more precious Heathrow slots somewhere less lovely but more lucrative than Uganda.
Given that Asia is leading the world in 21st-century economic growth, I was surprised to discern no net gain of destinations served by BA. In the Indian subcontinent, Dhaka and Calcutta have been supplanted by Hyderabad and Bangalore. In the Far East, while China has gained BA non-stops to Shanghai and Chengdu, the airline bid sayonara to Nagoya and Osaka in Japan.
Australasia was once an extremely important part of BA's long-haul network. Boeing 747s flew via various circuitous and exotic routes to all the mainland Australian state capitals, as well as New Zealand's largest city, Auckland.
Twenty years on, almost all the airline's Antipodean destinations have been deleted, leaving a single service to Sydney via Singapore using a 777 – smaller than a Jumbo. Having planes "down route" for days and crews gone for a couple of weeks is no longer viable for BA, and Australia has become an outlier.
Yet even though Adelaide, Brisbane, Melbourne and Perth no longer have direct services, they are actually far more accessible from Britain thanks to multiple one-stop options daily on a range of airlines via the Gulf, Hong Kong and Singapore. The intense competition keeps fares almost as low as they were 20 years ago. Auckland departed BA's schedules in 1995, but is accessible via the same hubs as well as Air New Zealand's daily link via Los Angeles. Talking of LA: no one has seen fit to take over BA's old non-stop from Manchester, but other axed routes between UK regional airports and the US have been taken up by other operators. United now flies from Birmingham, Manchester and Glasgow to New York.
Heathrow's first departure, in 1946, was a proving flight for British South American Airways. Yet these days the continent scarcely features on the airline route map from Britain. Santiago de Chile followed Lima and Montevideo into oblivion. For a time, so did Bogota. Thankfully, Avianca last month revived the link from Heathrow to the Colombian capital.
The most glaring omission is Caracas – the nearest big South American city to the UK. Venezuela's capital used to be the ideal gateway to the continent. Two decades ago, the now-defunct national airline, Viasa, offered excellent fares via its hub to all the key Latin American destinations, from Havana to Buenos Aires. It also allowed stopovers at no extra charge. You could grab some cheap Caribbean sun (from the arrivals hall at Caracas airport to the nearest pristine beach takes 10 minutes), then explore the capital and its high-altitude hinterland, or fly off to the spectacular east of the country and track down the Angel Falls.
The root cause of the routelessness? Official incompetence, squandering Venezuela's oil wealth. The currency, the bolivar, is in such a dreadful state that some locals buy international air tickets with no intention of travelling. Having a ticket out of the country entitles them to buy dollars at the official rate, and promptly resell them for a massive profit on the black market.
You might imagine that the airlines would be delighted by passengers who buy but don't fly. Yet foreign carriers have had a dreadful time trying to get their earnings out of the country. At present £2.5bn of ticket revenue is being withheld by the government and, as a result, flights to the country have been halved since January. A fortnight ago, the nation's top football team, Caracas FC, could reach a key fixture in Lima only by crossing the border to Colombia by bus before flying on to the Peruvian capital.
Venezuela has become isolated – a vast nation connected to North America by fewer flights than the average Caribbean island.
New York to Nevada
Twenty years ago, British Airways considered only one long-haul destination deserving of a link from both its main UK bases, Heathrow and Gatwick. Today, the same accolade is still ascribed only to one city. It is also in the US. But the hub of human happiness has apparently shifted 2,000 miles south-west: farewell, New York, viva Las Vegas.