Chain reactions

Play & Fun with chain reactions

Funny Reactions

Discover exciting chain reactions with the new Funny Reactions construction kit!
To the Funny Reactions explanation

Funny Machines

Funny chain reactions for young designers and tinkerers!
To the Funny Machines explanation

What is a chain reaction? What are the physics behind a chain reaction?

Everyone has seen one: A long chain of dominoes falling one by one after the first one tips over.

These different sequences of reactions are called a chain reaction.  
Chain reactions are processes in which the energy of a previous action (such as the first domino falling) releases a force that moves subsequent objects (such as the second domino).
Every chain reaction has to have starting momentum to initiate the following physical reactions, which continue to transmit the energy.
When a starting force triggers subsequent forces, setting the chain reaction in motion, this is also called a domino effect.
In physics, we speak of potential energy. This term describes the ability of an object to carry out mechanical work, for instance, due to its position. This energy can even be calculated using different physics formulas. In some cases, such as in chain reactions, potential energy is converted into kinetic energy. This energy corresponds to the work that must be performed to set the object into its current movement from rest. It depends on the mass and speed of the moved body. The joule is the unit of measure for kinetic energy. The concept of kinetic energy was introduced by Émilie du Châtelet in the 18th century, building on the work of Gottfried Wilhelm Leibniz. There are also chain reactions between particles that we cannot see - such as in a nuclear reactor.

But how long does such a chain last?

From the viewpoint of physics, there are no limits to a chain reaction. There is just one requirement: The previous process must generate sufficient energy to set the subsequent movements in motion.
If the energy is not sufficient (for instance, a normal domino cannot knock over a glass), the chain reaction stops.
From a practical standpoint, the chain reaction also ends when there are no more dominoes or no more objects.
If there is always another object and the previous object applies sufficient force to it, theoretically a chain reaction could continue indefinitely.

But how long does such a chain last?

From the viewpoint of physics, there are no limits to a chain reaction. There is just one requirement: The previous process must generate sufficient energy to set the subsequent movements in motion.
If the energy is not sufficient (for instance, a normal domino cannot knock over a glass), the chain reaction stops.
From a practical standpoint, the chain reaction also ends when there are no more dominoes or no more objects.
If there is always another object and the previous object applies sufficient force to it, theoretically a chain reaction could continue indefinitely.

Brilliant: What is a Gauss rifle?

A ball runs smoothly along, hitting another ball, which accelerates suddenly, like a rollercoaster - this is called a Gauss rifle. It takes its name from mathematician and physicist Carl Friedrich Gauß. He worked on magnetism. How is it possible for the magnetic sphere to shoot off like it does?
It’s simple: The Gauss rifle works using magnetism. There are two spheres on one side of the magnet. If a sphere is rolled towards them from the other side, it is accelerated more and more by kinetic energy the closer it rolls to the magnet (attracted by the magnet). When it hits the magnet, the kinetic energy is transferred to the right metal sphere, which speeds off. The sphere on the other side, however, does not need as much energy as the oncoming sphere to break free from the magnet in the center. It is farther away from the magnet because there is another sphere between them.
 
This difference in energy causes the right sphere to speed off much faster than the oncoming sphere, shooting off. Brilliant – don’t you think?  
And it's all done with magnetism!

sc93-delivery-1