Why can't food chains go on forever?

Since entropy, or disorder, is always increasing according to the Second Law of Thermodynamics, the "peak" cannot go on forever or get "taller" without increasing the size of the entire pyramid, which is also constrained by the amount of energy that is available.

The process through which higher-order organisms develop and persist is known as a "food chain" and involves the breakdown and digestion of other organisms in order to produce more disorder.

The lowest organism forms are at the beginning of the "Chain," which can be extended to include solar energy and end with the highest organic forms found in humans and other animals.

As simple plant life is the closest an organism can get to the original energy, the chain currently has "ends" because there aren't any consumers at a "higher" level than humans at this time.

Theoretically, the chain cannot continue indefinitely because, at each higher level, the disorder in the lower level must be increased by orders of magnitude; eventually, the universe's total energy would have reached maximum entropy and the chain would come to an end.

Energy is lost as it moves up the food chain, resulting in reduced biomass and efficiency.