THE job of the professional astrophysicist is to contemplate the music of the spheres. Given the global nature of modern science, however, today's astrophysicists often spend just as much time confronting the cacophony of the airport. Now, one of them has devised a way to make that experience a little less tedious. Jason Steffen, from Fermilab, near Chicago, has designed and experimentally tested a faster method of boarding aeroplanes. By his calculation, it could save airlines hundreds of millions of dollars a year.

Dr Steffen spends his time thinking about such things as extrasolar planets, dark matter and cosmology. After waiting in a particularly long queue to board a flight, though, he began to harbour an interest in the mechanics of getting people on to planes. In 2008 he wrote a computer simulation to test different methods. Using a numerical technique familiar to him from his day job, he was able to find what looked like the best. He has put his answer to the test, and the results have just been submitted for publication to the Journal of Air Transport Management.

According to Dr Steffen, two things bog down the boarding process. The first is that passengers are often forced to wait in the aisle while those ahead of them stow their luggage and then get out of the way. The second is that passengers already seated in aisle or middle seats often have to get up and move into the aisle to let others take seats nearer the window. Dr Steffen's proposal minimises the former type of disturbance and eliminates the latter.

In the Steffen method, passengers are boarded by seat type (ie, window, middle or aisle) while also ensuring that neighbours in the boarding queue are seated in alternating rows. First, the window seats for every other row on one side of the plane are boarded. Next, alternate rows of window seats on the opposite side are boarded. Then, the window seats in the skipped rows are filled in on each side. The procedure then repeats with the middle seats and the aisles.

By boarding alternate rows in this way, passengers are spaced far enough apart along the aisle to stow their luggage in parallel, all at the same time. Because passengers in the same seat types board together, they do not have to step over each other to swap seats.

To test the idea, Dr Steffen conducted a test using passengers and a mock Boeing 757 fuselage. The fuselage had a single aisle and 12 rows. Seventy-two passengers (including families with children) boarded, towing their bags and roll-aboard suitcases. In addition to the Steffen method, the team tried boarding in a strict back-to-front order, block boarding (the system now used by most airlines, with passengers assigned to groups within the cabin) and boarding in random order (which made its debut at American Airlines earlier this summer).

Standard block boarding turned out to be the slowest way to do things, taking almost seven minutes to fill the 12 rows. Dr Steffen's system took half that time. Indeed, it was the fastest performing of the methods tested. With full-sized planes, the benefit should increase, as more people can stow their luggage simultaneously along the longer aisles.

Although Dr Steffen admits that the airline industry has shown no interest in his method so far, he points out that, in principle, there should be no barriers to its adoption. Though directing airline passengers on to a plane is a little like herding cats some airlines, such as Southwest, already try to get their passengers to line up in a certain order before boarding. If travellers believed that complying with the new arrangements really would make their lives easier, they would probably do so. And by Dr Steffen's calculations, airlines have a pretty strong incentive to persuade them. Previous work has shown that every minute a plane spends at the terminal costs $30. Assuming the average carrier runs 1,500 flights a day, saving as little as six minutes per flight would add up to $100m a year. For hard-pressed airlines running on razor-thin margins, that really would be astronomical.