Lifelong Learning
Is There a Solution for the Half-Life of Knowledge?
4 min read

I’ve always been impressed by the encyclopedic minds of the past- people who had a vast knowledge of diverse subjects. 

For example, “the renaissance man” Leonardo Da Vinci was not only interested in painting, but also in sculpting, engineering, architecture, anatomy… 

In the Islamic Golden Age, Al-Biruni was well versed in physics, mathematics, natural sciences, history, and linguistic. 

I don’t know if such polymaths could exist today. 

The exponential growth of knowledge is just crazy. 

In 1982, the inventor and futurist, Buckminster Fuller created the ‘knowledge doubling curve’.  

He noticed that:  

  • Before 1900, human knowledge doubled approximately every century.  
  • 1900- 1945: every 25 years  
  • 1945-1982: every year on average  
  • 1982-2020: IBM added the predication that knowledge will double every 12 hours! 

This will depend on the field of knowledge. Not all of them are growing at the same rate. For example, engineering knowledge is growing slower than the psychological one. 

Regardless of how accurate is this prediction, we can all agree that human knowledge is increasing at an extraordinary rate. 

Information overload

The exponential growth of knowledge raises 2 challenges:  

  • How to handle it  
  • What to do about the obsolescence of knowledge 

The Half-life of knowledge 


Measuring half-life knowledge is knowing how long it takes for knowledge to lose half of its value.  

What before was relevant for years might be now valuable only for months. It is especially true for fields like science, technology, R&D, marketing, and finance. 

Remember when the Earth was flat, when doctors used to recommend smoking, and when our brain neurons were a fixed number? 

People who believed in these facts weren’t stupid. They believed in available knowledge that is now outdated. 

Most likely, we are not different from them. Tomorrow, we’ll discover something new that disapproves of what we know. 

In 1970, the futurist and author Alvin Toffler suggested what would be the skill of the future:  

“The illiterate of the 21st century will not be those who cannot read and write, but those who cannot learn, unlearn, and relearn.”  

If knowledge is outdated at such a rapid pace, being able to replace the incorrect and irrelevant with the new and more accurate is a powerful skill. 

What’s the solution? 


In the book “The Half-Life of Facts: Why Everything We Know Has an Expiration Date”, Samuel Arbesman points out that facts have a predictable half-life.  

But how can we learn confidently if knowledge is changing constantly? 

Samuel gives the example of the medical field. He says that doctors have the right attitude towards the rapid change of knowledge. They are taught from school that what they’re learning will be obsolete so they need to keep updating their knowledge.  

Samuel’s goal is to teach us how to learn. So he offers some solutions to the half-life of knowledge. 

1- Learning general information

Learning the fundamentals

General information gives you a starting point to ask the right questions. 

It’s your reference; the foundation that will support your learning process. 

The mathematician and computer engineer Richard Hamming was conscious of the half-life knowledge. His solution is to cling the fundamentals. 

For Hamming, the fundamentals have 2 criteria:  

  • You can derive from them the rest of the field  
  • They’ve been around for some time. 

The fundamentals stand the test of time. They are the support that helps you know the rest of a field. 

David Henry Thoreau expressed the same idea when he said:  

“If you understand the general principle, you don’t need to see every one of its illustrations”.  

2- How to find this new knowledge

Learning how to use search engines is a skill

Learning how to use search engines is a skill by itself.  

A piece of new information can be available out there, but you’ll never come across it because of the keywords you’re using.  

Knowledge is a homogeneous body divided by specialties. 

Each specialty uses its own phrases, jargon, and keywords for the same subject. 

Learning how to use the search engines gives you access to insights from various fields that you won’t have otherwise. 

3- Look for credible sources

Credible sources of knowledge are not only online

Teachers, scholars, experts, and any knowledgeable person can play a crucial role here. 

They can direct students and learners towards serious sources of knowledge. 

Today more than ever, it’s critical to be selective with our sources. 

In a world of an uninterrupted flow of information, practicing selective ignorance is a rare skill.  

We don’t need to know everything. Only important knowledge coming from trusted sources. 

We find them online but not only. We can get off the internet and head to the library to find more credible sources (like we used to do in the old good times!) 

The key here is credibility.  

Final thoughts 


Half-life knowledge

We might think: what’s the point to learn something new if it will be outdated after a certain time. 

And the best answer I found comes from Isaac Asimov:  

“When people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together”. 

The Earth is an irregular-shaped ellipsoid.  

So even if we use to think the Earth is spherical and it’s not, it is still a big progress compared to thinking the Earth is flat. 

We don’t need to be discouraged by the half-life knowledge. Because in the end, we’re still improving. We are less ‘wronger’ than yesterday! 

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