Is Hyperloop the future of travel?
There was a moment, an hour before an event last week, when 30 or so young fresh-faced people stood around their creation and posed for a group photo.
They were in the Massachusetts Institute of Technology (MIT) museum in Cambridge, Massachusetts. All around them, reminders of historic innovations that began with research at this legendary college.
As the photographer clicked away, I wondered - what place in history would this photograph have? Will we look back at these 30 smiles and say, "That was the team that changed the world!"?
If that is to be the case, there is a long road ahead. And indeed, it is long roads that are the motivation for this project. The MIT team is one of several working on Hyperloop, a vision for rapid travel put forth by Silicon Valley's most interesting man, Elon Musk.
He says the commute from San Francisco to Los Angeles - currently a five-hour drive or an hour of flying - could be cut to 30 minutes.
What is Hyperloop?
Hyperloop is a conceptual transport system in which passengers are loaded into pods and fired through vacuum tubes at more than 600mph (1,000km/h).
Prototype pods have been tested running along magnetic tracks, much like the maglev trains used in countries such as Japan today.
Pumping the air out of the tubes reduces resistance, allowing high speeds to be achieved, potentially using less energy than a train.
The idea could reduce journey times over long distances, but there are many challenges for the rival developers to overcome before any such project can become a reality.
Mr Musk is the boss of Tesla and founder of SpaceX, and when he published in 2013 a white paper outlining a way to use airtight tubes to propel pods at speeds of up to 700mph (1130km/h), he set a challenge to anyone and everyone who wanted to try and build the technology.
Mr Musk isn't paying the firms, but he has committed to funding a series of tests. The hope is that these will happen in August this year. The target is that by 2021 humans will be travelling on Hyperloops around the world.
The MIT team is one of more than 20 non-commercial groups also designing a Hyperloop pod - with money coming from SpaceX in the form of a competition.
That was split over two phases - a design contest, which MIT won in January, and an on-track test coming up in the summer.
But it all could be a colossal waste of time. The barriers to Hyperloop becoming a reality are enormous - and it's not just about technology.
Straight and narrow
Part of any visionary's CV is the ability to ignore the naysayers and focus on your vision. If and when you succeed, everyone backtracks and says they knew you were a genius all along.
Elon Musk is the sort of chap that is used to people telling him he's wrong. When he set out to make electric cars appeal to petrolheads, he had a lot of people to convince - but somehow, and on the brink of bankruptcy, he got some investors on board.
Yet an awful lot stands in Hyperloop's way. Literally.
Christopher Merian, chief engineer on MIT's effort, told me that the key problem with his pod - and the Hyperloop concept in general - is that it can't handle corners.
So the Hyperloop tube would need to take a rather Roman approach, and go in an almost complete straight line from A to B.
If the proposed route of San Francisco to Los Angeles is to be realised, you're looking at slicing through some of the most beautiful sights the natural world has to offer, not to mention acre after acre of land belonging to people who may not be too keen on a big fat tube being plonked outside their front door.
Philippe Kirschen, MIT's team captain, told me he thinks this will lead to Hyperloop being built in a different part of the world with a less strenuous regulatory environment.
Indeed it's hard to imagine anywhere in the US that would be suitable for Hyperloop, short of shelling out monstrous payouts and a free Tesla or two to people whose lives have been uprooted.
But let's put that aside and, for the sake of argument, say an agreement has been made and a route between San Francisco and Los Angeles is built. It works, it's safe and it's pretty darn marvellous, all told.
Except it is really, really expensive.
Mr Musk says the cost of building the route would be in the region of $6bn (£4.1bn), an estimate most agree is extremely conservative.
Some are calling Hyperloop the new Concorde which, despite being a glorious piece of innovation, ultimately failed due to regulations - it wasn't allowed to fly at supersonic speeds over land - and a lack of profitability.
A return ticket on Concorde would see you part with several thousand pounds or dollars. Which over time was not considered to be worthwhile trade to save a few hours.
How much will a ticket for Hyperloop cost?
MIT's pod design - which they said can be scaled up - will likely be able to carry around 20 people at once.
Unless the Hyperloop system can handle a great number of pods leaving a station in very quick succession, tickets for those pods will need to be extremely high in order to make the system economically viable.
Furthermore, if Hyperloop runs from San Francisco to Los Angeles, it will be competing with the currently under-construction California High Speed Rail. The network - due to open in 2025 - promises a journey time of two hours and 40 minutes. Each train will be able to carry well over a thousand people. Tickets, surely, will be a lot cheaper than Hyperloop.
It would leave Hyperloop as an option only for the rich. Public support no doubt would evaporate.
I was something of a partypooper at MIT's event, I'll admit - putting all these points to the team on a night designed to celebrate their outstanding efforts thus far.
The math(s) not adding up was a concern, they said - but at the very least, the hope is that developing Hyperloop will create something, even if it's not the transportation of the future.
There could be many industrial uses for an environmentally friendly Hyperloop-style system.
In 50 years, when we look back at the hopeful, expectant faces in that photograph, it seems unlikely that we'll see them as the team that changed the way we travel.
But that's not to say developing Hyperloop - a clean, perhaps revolutionary technology - won't have been worth it.