Then jump to 1439 when Johannes Gutenberg invented the printing press or consider more modern inventions such as light bulbs and telephones and vaccines and ... well, name your favourite invention or discovery. The list is extensive.

It is obvious to all and sundry (apart from our government) that we need to come up with alternative fuel sources for transportation. Electric vehicles are making slow inroads (pun out of the way for this week) and even electric planes are being trialled for short flights.

An alternative fuel source that is often discussed is hydrogen. Some car companies are basing a large part of their future strategy on hydrogen rather than electricity but hydrogen also has the potential to power aircraft.

Now when I mention hydrogen and flying the first image that comes to mind is the horrific image of the Hindenburg and the 36 people that died when the airship went up in flames.

One of the issues with using hydrogen is storage.

Strong and large tanks are required that can withstand extremely high pressure. Usually in the order of 700 atmospheres. This creates a whole range of problems.

And then comes along human ingenuity.

Instead of storing the hydrogen as a gas under extreme pressure, could it be stored as a solid without the high levels of compression?

Well one company thinks so. Trials are already underway with drones powered by solid state hydrogen.

The hydrogen is mixed with oxygen in the reactor to produce power with a waste product of H2O - good old-fashioned water.

While fuels based on oil have been the dominant source for over a century it is almost surprising we haven't worked on hydrogen previously with the superior fuel capacity of hydrogen.

While it is obviously the climate that is driving the change now, the numbers look good.

Hydrogen can generate approximately 39kWh from one kilogram compared to 13kWh for petrol and only 0.2kWh for batteries.

This superior fuel capacity by weight is particularly important in aircraft where every kilogram is important.

While the main focus of current development is the storage of hydrogen while waiting to be utilised, another major hurdle has already been largely addressed.

Producing the initial hydrogen (typically by splitting water molecules) used a lot of energy which usually came from fossil fuels. This defeated the purpose of developing a clean energy source and also incurred significant costs. However, the improvements in electrolysis and the widespread availability of renewable energy have brought down the environmental and financial costs of producing hydrogen as a fuel source.

As solid state hydrogen is further developed, I can see other uses for it as well.

We know that large scale batteries lose charge over time while sitting idle waiting to be used. Solid state hydrogen has no such problem so it could be used for backup power storage facilities.

Other transportation is also an obvious target market. Imagine a truck or train with the capability to travel three times the distance on the same weight of hydrogen fuel compared to the petrol equivalent.

There is no doubt in my mind that we have some significant technical challenges facing us in the immediate future - perhaps some of our biggest ever. But I have faith in human ingenuity to solve these problems for all mankind. Tell me what you believe man's greatest invention is at ask@techtalk.digital.