The ultimate age

How old can we eventually get? What is the real maximum age limit? What do we need to do to reach that age? To answer these questions (yes, I am ambitious this week) we first need to dive into some fundamental science.

This week I visited with my family the European Organisation for Nuclear Research, better known as CERN, in Geneva. CERN is home to the world’s biggest and most powerful particle accelerator, the 27km Large Hadron Collider (LHC). This is a machine to accelerate two beams of particles in opposite directions. When particles collide, the energy released produces many new particles, as energy turns into matter in accordance with the equation by Einstein E=MC² .

The interesting thing is that many of these new particles age extremely fast. They were there during the very beginning of the universe, but then decayed in a split second and were never seen again. The LHC simulates the conditions directly after the big bang and detects these very old particles before they decay again. What we learn is a deeper understanding of these particles and of the beginning of the universe.

On the other hand, there are particles that are extremely stable. The protons and neutrons that form the core of our atoms decay very slowly, if ever. Protons may have a half-life of 10³⁴ years which is a long, very long time. That means that they have virtually disappeared after about 1000 half lives when the universe is 10⁴⁰ years old. The bigger stuff, the different atoms we are made of (and which were mainly created when stars collapsed) will of course also have vanished by then.

So the simple answer to the question how old we can get is when all protons have disappeared, say after 10⁴⁰ years. Of course we will have to overcome some other obstacles, for example that star formation will cease after 100 trillion years (10¹⁴ ) and that planets will be out of orbit after 10¹⁵ years, but there is enough time to solve that.

Of course it is highly unlikely that we will ever achieve that. There are other physical laws that facilitate our decline. The extremely weak force of gravity (compared to other fundamental forces) has a significant impact on us, at least on the surface of the planet we are now living on. Sagging breasts, hunchbacks and weaker muscles are all preys of the force of gravity.

We also have to find a solution to the limited replacement of the giant particles in our body that are known as cells. Between 50 and 70 billion cells die every day in the average human being due to apoptosis (programmed cell death in multi cellular organisms, derived from Greek - meaning falling leaves from trees). How often each cell in your body is replaced depends very much on what type of cell it is. Anyhow, the process is vulnerable to ageing and is at present an important determinant of our maximum age.

Whatever the precise maximum age will be that we can eventually achieve, immortality is not something to aim for. In 10¹⁰⁰ years from now, the universe will be a very cold, empty and dark place. Even black holes will have evaporated by then. But maybe even this can be seen as a challenge.

As is written on the Lutheran church in Geneva: “To venture the unlimited you have to leave behind your limits”.