As for the pyramid, I don’t know, I think it’s from the field of philosophy. And regarding the largest source of energy for the earth's biosphere, this is the Sun

Dr V.N. Bublias Bublias thank you for your contribution to the discussion

The pyramid of energy is always upright as the energy flow in a food chain is always unidirectional. In the pyramid of energy, the energy flow is always unidirectional. Pyramid of energy is always upright. As energy flows from one trophic level to the next trophic level some amount of energy is lost in each trophic level in the form of heat. Therefore, the pyramid of energy is always upright and can never be inverted. The pyramid of energy is always upright because when the energy flows from one trophic level to another, some energy is always lost as heat in each step. This heat is lost to the atmosphere and never goes back to the sun. Most pyramids are larger at the bottom, but marine biomass pyramids are often inverted. This is because the producers are very small and have limited mass. They also reproduce and die quickly, so there is less biomass at any given time compared to consumers. The flow of energy in an ecosystem is said to be unidirectional because some energy is lost in form of heat when moving from one trophic level to next for the maintenance of homeostasis of an organism thus each successive trophic level receive a less amount of energy as compared to the preceding trophic level. The pyramid is not necessarily upright. For example, it'll be inverted if beetles are feeding on the output of forest trees, or parasites are feeding on large host animals. So, the correct answer is 'Either upright or inverted'. The ultimate origin of energy for the biosphere is Sunlight. Sunlight is used by the organisms of the first trophic level,i.e., the producers, and the green plants for producing their own food. Sun (solar radiation) is the biggest source of energy on Earth's surface. It is also known as the ultimate source of energy on Earth's surface because we know that green plants use sunlight for photosynthesis, which is the process by which they make food for their growth. The largest ecosystem still in existence on Earth is the World's Oceans. With more than 71 percent of the Earth's surface under it, it provides a living for more than 3 billion species. Nearly all of the earth's energy comes from the sun. Some of this radiant energy is reflected by water droplets and dust particles in the atmosphere and bounced back into space or scattered throughout the atmosphere; some is absorbed by clouds or ozone.The bottom and largest level of the pyramid is the producers and contains the largest amount of energy. As you move up the pyramid, through the trophic levels to primary, secondary and tertiary consumers, the amount of energy decreases and the levels become smaller.