02 June 2025
Deciphering a 20,000-year-old mystery: An interview with Bennett Bacon
Independent researcher Bennett Bacon used the British Library to make an extraordinary discovery. Examining marks found on cave paintings from the Ice Age, he found what seemed to be a proto-writing system, dating 20,000 years earlier than any other writing ever identified. Bacon collaborated with academics to research and write a paper about his findings.
There are absolutely millions of signs and marks from the Ice Age, and there have been various explanations of them. Some people think they're magical. This project started when I was looking at a painting of an aurochs with four black dots from the Lascaux Cave, and wondering what the dots meant. I noticed that all of the aurochs in the paintings have four dots, and I decided they might be numbers, relating to a lunar calendar. I put the calendar together in about three to four weeks, then contacted a calendar expert: Dr Tony Freeth at University College London.
You have to find a pattern in nature
Four dots appear alongside each auroch and three with each fish. Interval analysis is the only logical way to work it out. The interval between a fish, with three, and an aurochs, with four, is one. The interval between an aurochs, and red deer, who normally have six, is two. You have to find a pattern in nature that matches that pattern. You lay out modern mating intervals and it's a perfect match, across 32 different species.
Tony said, ‘We need a lot more evidence.’ After a couple years’ more research, we took our theory to Paul Pettitt, an archaeology professor at Durham. He offered to give us all the help we needed, and involved his colleague Professor Robert Kentridge, too.
Each one of the lines represents a month
The Upper Paleolithic artefacts are engraved pieces of slate or rock. They are local to the cave where they are found, and it appears that they record information about that cave. The writing system is like this: each one of the lines represents a month, four lunar cycles. The calendar starts when the snow melts and the grass comes back on the mountainsides and the world comes alive. It's spring.
You can show that the animal, chamois, is in the south-east in month one. In month two, it gives birth. In month three, it's leaving the cave.
A sign can go in any one of these positions, but depending where it is, its value is altered. So if we add a sign ‘Y’ in position six, it simply means that an animal, let’s say salmon, gives birth in the sixth month after the start of spring. It's a combination of mathematics, science and metaphor. ‘Y’ means that one animal splits and becomes two animals.
The person who has made this writes it in month two of this year, but it’s about month two of next year. The idea is, ‘Let's be here, because the chamois will be there. They will have given birth to young. The herds are really vulnerable.’ So the group can track the young herds.
Numerosity is an innate human quality
It's like a city guide. Groups go to this cave and discover that, for example, in month seven, the reindeer are migrating, the fish are contra-migrating, the cave is a spawning ground for trout or salmon. So it was a really incredibly useful piece of information, especially when winter was coming. We thought advanced number systems such as a calendar might only belong to urban societies. In fact, numerosity appears to be an innate human quality, provided you have a sufficient mass of individuals.
Survival is about getting food so that you can eat, but it’s also the ability, in a hostile environment, to communicate and pool the resources of the group. You need systems for doing that. We think the cave paintings are one of those systems. You make paintings, in a sense, for everyone. You can't survive as a little group on your own, but if all of you work together, communicating, sharing tools, sharing technology, you increase your chances. We think that these writing systems allowed that to happen.
Most human groups went extinct: Neandertals; Denisovans. We're the only ones that made it, out of maybe three dozen groups, possibly because of our communication skills, and the ability to use more sophisticated language, and conceive of the world in an abstract way.
These people are very easy to connect with
It’s extraordinary how close these people from 20,000 years ago are to humans today. They have personal artefacts – you'd call them jewellery – in which there are marks engraved. One of the things they engraved, most frequently, is the fact that they had a child. They often give the time of birth when that child is born, but they may also indicate the sex of that child. These people are very easy to connect with and I think that's the real value of the work.
I've never been to the caves themselves. I will often look at 2,000 images in a day. I need to process vast amounts, which is why I come here to the Library, and I do a lot of the work on the internet as well. We look at every example of something that we can find, so that we're not making hypotheses based on small amounts of data.
A library preserves the past
The collection at the Library is very comprehensive, containing older books that are very difficult to find. Some of these caves have degraded, so the early photographs are very useful. A lot of the objects have been lost, so the only record is in an old book. It’s a blissful place to work. The staff are really good.
I think this paper probably wouldn't have happened without the Library. I was here yesterday, inspecting a book which I could only access here. It's a really good book but it's from 1920. A library preserves the past. It’s the place where the things that are dead still exist. The internet is wonderful, but a good library does things that the internet can’t.
As told to Lucy Peters