The anthropic principle is a theory that focuses on human life as the main drive behind the existence of the universe, a suggestion that scientists could use as the starting point to study how properties of the universe exist to accommodate human life. It is regarded as a cosmological theory, as it attempts to explain the seemingly perfect balance of the universe.
The History of the Anthropic Principle
The anthropic principle term was first coined by physicist Brandon Carter in 1973, which was a response to Nicolaus Copernicus’ principle that rid humanity of any significant role in the universe.
Contrary to popular belief, Carter didn’t think that humans formed a vital part of the universe, so he did somewhat follow Copernicus’ lead. The way his theory differs slightly is that Carter viewed human life as a fact that cannot be completely ignored. In this case, Carter proposed a re-examination of the Copernican principle.
Before the Copernican principle, it was widely accepted that the Earth’s physical laws differed to those of other parts of the universe, including the stars and other planets. The hypothesis that the Earth is not that different from the rest of the rest of the universe indicates that all parts of the universe are the same.
The Branches of The Anthropic Principle
In 1930, F. R. Tennant came up with three main forms to the anthropic principle:
- The Strong Anthropic Principle – The hypothesis that the universe has been created to accommodate human life, signifying that since the moment of the Big Bang, the conditions were designed so that 15 billion years later, the human species would evolve on Earth.
- The Aesthetic Anthropic Principle – The notion that human beings can appreciate and enjoy beauty, music, art, literature; qualities which aren’t necessary for survival, but are there to develop aspects of beauty and love, which raises the question of whether beauty is a product of a grand universal design.
- The Weak Anthropic Principle – The idea that the current Universe has a form that causes intelligent beings to observe it. In other words, it assumes that the universe has a perfect balance of space and time that fosters the evolution of intelligence, a statement which is widely agreed upon.
There are many factors that led to the Strong Anthropic Principle, in particular. The Earth is 93 million miles away from the sun, in an area that contains just the right temperature for it. In addition, there is the presence of the ozone layer that projects disruptive ultraviolet rays away from the Earth, and the moon balances the Earth’s rotation that gives us regular seasons and creates tides that allow creatures in the sea to evolve on land. There is also the fact that Jupiter and Saturn have powerful gravity that catch asteroids and meteors that could reach Earth and eliminate life.
Criticisms of the Strong Anthropic Principle
The Strong Anthropic Principle tends to be viewed as too simplistic, with a number of factors that challenge the entire universe to be determined by the starting conditions of the Big Bang.Additionally, it raises a question as to why the universe is so infinite if we only pay the most attention to the Earth.
The principle is also seen as anthropocentric, as it views human beings as the center of the stage. In fact, the main Greek, Roman and Medieval scientists believed that the planet was located at the center of the cosmos, even though the scientist Galileo proved the theory wrong, indicating that the Strong Anthropic Principle is a reflection of that prediction proven wrong.
In addition, the Strong Anthropic Principle falsely claims that the universe’s laws exist because of us, but there is a possibility that we exist because of the universe’s laws. The idea is that since we have evolved to live in the universe, we will be inclined to find it suitable to live in.
Criticisms of the Aesthetic Anthropic Principle
The author Douglas Adams attempted to critique the Aesthetic Anthropic Principle by understanding how a puddle that was intelligent would feel about the hole that surrounds it. In this case, the puddle represents humanity while the hole represents the universe. The puddle sees that the hole matches its own shape and decides to conclude that the hole was only made for it to be filled.
However, since we are able to register beauty, there would be no need for the universe to be beautiful and no need for human beings to appreciate it, since it wouldn’t bring about our survival. Given that there is beauty and we perceive it may indicate that it has been purposefully arranged so that its beauty is noticed by us.
The Usefulness of the Anthropic Principle
As unfounded as the anthropic principle may appear, it can be still useful for eliminating the importance of specific parameters, such as the cosmological constant which wouldn’t let the creation of structures to be big enough to support life.
The anthropic principle is a constraint on the parameters appearing in our theories, and we could derive from it certain assumptions of potential combinations of parameters, but given that they have already been measured, they are seen as retro-active predictions.
One successful Anthropic Principle application is Fred Hoyle’s prediction of properties of the carbon nucleus that deem the merging of carbon in stellar interiors possible – a theory which was proven correct. It’s a successful example of the principle since Hoyle believed that carbon is central to life on Earth. While a few historians do challenge the fact that this was Hoyle’s mode of thinking, simply the fact that it could have been indicates that the anthropic principle can be a useful tool of observation, in Hoyle’s case being the presence of carbon on our planet.
The Anthropic Principle in Practice
The main purpose of the Anthropic Principle is to help give an explanation as to why our universe has a specific set of properties. There are a number of values of properties in the universe that appear to need a very specific range for our universe to work in the way it does, forming the fine-tuning problem which tries to explain how these values are so well-crafted for life on the planet.
The principle opens the path for a wide range of potential universes, each of them making use of various physical properties, with our one belonging to what is thought to be a small set of universes that are capable of sustaining life. This idea goes hand in hand with the multiverse theory.
String theory physicists suggest that there is a very large amount of forms that string theory takes, leading to some of them to begin adopting the viewpoint that the string theory is so wide that it could signify the presence of multiple universes, with anthropic reasoning acting as an evaluative factor within theories that try to distinguish our place in this universe.
The Participatory Anthropic Principle
The physicist John Archibald Wheeler once said that we exist in a participatory universe, suggesting that in order for the wavefunction to be set apart, there needs to be an observer, rather than viewing it as bits and pieces that clash with each other.
This would imply that the universe as a whole exists only if one is there to observe it, raising the fact that it requires some form of life to exist in order for the wavefunction to collapse in the first place, so the universe could not exist without it sustaining life.
Ultimately, the Anthropic Principle indicates that the universe has a set of fundamental laws that we tend to observe. The fact that we exist and are made of certain properties that follow those same fundamental laws, means that one can come up with certain facts that are difficult to dispute.
Our location in the Universe is particularly interesting, so much so that it perfectly aligns with our existence as observers. The Universe and the parameters it is built on include the creation of its observers.
Despite a few physicists challenging the anthropic principle, even they have resorted to subtly making use of it in order to facilitate predictions from the huge amount of string theory possibilities.
The anthropic principle tends to make humans a vital part of the universe, which gives us a reason to give meaning to our existence, the fact that it’s not pure coincidence.