Trying to predict the future is fairly hit and miss.
General trends you may get right, but individual gadgets and inventions, however, are very hard to foresee. Futurologist Ian Pearson and technology journalist Tim Phillips look back at inventions that never made it.
Ian Pearson asks: Whatever happened...to Virtual Reality?
VR: The dream did not live up to the reality
When Virtual Reality came out it was really, really crude. You could not do much with it and you had this enormous great heavy headset
But we were looking ahead ten years to when this was obviously going to be dirt cheap to make, and have really, really good games.
So we were really convinced that it was going to take off around the end of the millennium.
And it did not.
We got it really quite wrong.
One of the big problems is the headset.
On some of the early headsets coming out in the early 1990s they found that kids were getting eyestrain when they were using it.
So you can imagine the lawyers in the companies that might have been making them thinking: "Well we could make this and we could make a few million pounds from selling the headsets.
"On the other hand, every single teenager that gets a squint for the next 10 years is going to sue us for damages."
Tim Phillips asks: Whatever happened to...the paperless office?
It seems people often prefer paper to computer screens
The paperless office was the big idea coming out of the Xerox PARC in 1973.
'The idea is that if we have enough computers and we link them all together, then nobody will need paper'.
But what happened is during the 1980s, we needed 40% more paper to print out all the information we were generating.
Futurologists did not factor in the fact that paper is a really good invention. It is cheap, it is convenient, you do not need an instruction manual to use it.
People liked paper.
Tim Phillips asks: Whatever happened to...homes delivered by airship?
Would using airships really make house moving easier?
My favourite futurologist moment was about ten years ago, when I saw a guy making a speech, and he was talking about how we would live in the future.
And he said "within 10 years we would all order our houses on the internet and they would be delivered to where we wanted them by airship and dropped from the airship."
And I am in the audience thinking "has he gone mad?"
I think what happens is people say 'here is a great idea, here is the internet.
Here is an idea, you can use the internet to maybe order something big like a house in exactly the way you want it .
And oh look, here is a company that can make airships."