Multiple Universes and the Anthropic Principle
Lead: Jacob Day

3/25/2008

Summary by Rachel Ripperger

An answer for us being here?

Tonight’s presentation, led by Jacob Day, set out to discuss two theories that might hold answers to the question how our universe has become hospitable to life and to us. The class started out with an audio clip of Paul Davies being interviewed. During this clip Davies discussed his thoughts that the laws of physics on earth created an environment for life not by luck, but rather for a rational reason. He states that most scientists believe that it was luck that the laws of physics created an environment suited for life and that they fail to question why. Davies said that it is important to seek out how the laws of physics became perfect to support life. In the interview Davies discusses two versions of the so-called anthropic principle, which is used in attempts to explain how the {physical or natural} laws became suited for living creatures. The first version is the weak anthropic principle, which he says is easy for everyone to agree on. It merely states that the physical laws in our universe are consistent with life. This means nothing unless it is paired with a multiverse theory, according to Davies. The multiverse theory suggests that there are many universes which each has its own set of laws, also termed as by-laws. Out of these universes, only a small fraction is good for supporting life. The second version is the strong anthropic principle. In this idea the universe must bring forth life. Some forms of life have an observing mind and consciousness. Davies also talked about how these ideas could lead to both a religious and anti-religious reason to why the earth was created. The earth could have been created by a God or from the emergence of life.

Davies also discussed the participatory anthropic principle. He wanted to find out how life affected the laws of physics at the time of the big bang. According to quantum physics, the laws can be applied to both the future and the past. Therefore, what we observe today can help us figure out what the laws will be like in the future and what they were like in the past even though there is some uncertainty. This is considered Davies’ radical thought.

After the audio clip, Jacob proceeded with his power point presentation. First, he recapped the anthropic principle which was discussed in the audio clip. This was followed by the topic of our universe’s laws of physics being “fine tuned” for the existence of life. For example, if gravity were weaker or stronger than it is, life would not be able to exist. One subtopic brought up was Fred Hoyle’s triple-alpha process. This is important because it explains how Carbon forms in a star. Professor Möbius explained this process to us. The main point of the triple-alpha process is as follows: First, helium comes from hydrogen. When the energy runs out from these reactions, two helium molecules come together to create beryllium. However, this is uncommon, because energy must be added to complete the reaction. Therefore, it is more likely that three alpha particles are combined to form Carbon. Based on this, Hoyle predicted that there must be a very specific resonance in the Carbon nucleus in order to allow the fusion with high enough probability. When Carbon is in this state it allows three helium nuclei to come together efficiently. Normally, two helium nuclei would come together to create beryllium and then come together with another helium nucleus to form carbon, but this would be way too slow, and almost no Carbon and thus other heavy elements could be formed.

The theory of the multiverse was the next topic to be discussed. This theory states that there are pocket universes, and life only exists in a universe when the conditions are perfect. Only the universes which contain life are observed. A subtopic which was talked about was the goldilocks enigma. This states that if the big bang could not spread out the space would be filled with black holes. On the opposite side, if the big bang spread out too far, no stars could form.
Another subtopic brought up was symmetry breaking. This is when there is a point in time when an object must choose which side to lean to. The decision made helps to move the universe from a state of disorder, where there is more symmetry, to a state of order. This topic sparked Jacob to ask professor Möbius is this what was pushing space outwards? His response was that the physics fault vacuum requires a higher energy for symmetry breaking. This energy produces matter while there is still enough pressure left which leads to further expansion. An analogy for this can be seen with the transition of phases with water. At zero degrees Celsius water can exist as either ice or liquid water. When water is ice its symmetry is broken. Energy must be added in order to melt the ice. Once that occurs the water flows aside and symmetry is restored.

Another subtopic of the multiverse theory is bylaws. Bylaws are different laws which exist in each universe. At this point Professor Möbius discussed the “fine tuning” concept in coexistence with two steps in different laws. The first step is the relative quantity in each constant. The constants determine the strength of each of the different forces. The second step is when one imagines that the laws of physics attain a different mathematical form. During this point it was also stated that if there were no stable planet orbits there would be no planets. An example of this is the law of gravity might be different. Gravitational force in our universe decreases with the inverse square of the distance from the center mass. If this were just distance or distance cubed, the planet orbits could not be stable.

There were three other subtopics which were discussed under the multiverse theory. The first was chaotic inflation. Chaotic inflation has two important points to it. One, it mandates the existence of universes precedent to our own (if a multiverse theory holds true) and two; it implies the existence of other universes. Following this concept was the role of string theory in which the laws of physics are dependent on the shape created by the strings. The last subtopic which sparked a class discussion was that of Bostrom’s question: is the universe real? He believed that creating a simulation of a universe would be cheaper than a real universe. Discussion followed when Jacob asked Professor DeVries what his thoughts were.

Discussion:

DeVries: States that he did not buy the idea of creating a simulation universe because a fake universe is not cheaper than a real one. He believes that it takes a lot more matter to make a simulation.

Student #1: How is creating a fake universe different from God creating a universe?

Student #2: The high quality technology is not different from magic. The two are indistinguishable

Student #2: Do math principles hold true for other universes?

DeVries: The number and size of calculations are too much for the computers we have now. They are not fast enough.

Jacob: Could we develop the needed technology? After all we have an Ipod the size of a credit card playing music.

DeVries: No, we cannot develop the needed technology. The greatest chess player is a machine. It is possible using an algorithm to play a perfect chess game or at least one where you cannot lose. However, this is physically impossible because it requires a faster and more powerful computer than could be built using the entire resources of our universe. That’s not going to happen. The principle is possible, but realistically it is not possible because it would be too slow and the possibilities are too big to search all the given information. The reality of a simulation universe is that there are aspects which are undiscoverable. The simulation would have to contain enough detail that we could never uncover all the answers. The notion of the real is the notion of the inexhaustibly determinate. No simulated object is inexhaustibly determinate. So reality is not a simulation.

Austin: Can you simulate an atom with something simpler? Is it cheaper than just producing an atom?

DeVries: A simulation is an abstraction. Simulations can occur at different levels. For example, a water bottle used to illustrate the ocean. We can learn some things but not everything.

Austin: There are discoverable and undiscoverable simulations. Are undiscoverable simulations as complicated as the real things?

Student #3: What about random information?

DeVries: Random information cannot be compressed.

Möbius: Random generators are used in simulations.

Austin: Even if a fake universe is cheaper, is it justified to create one?

Jacob: It would be easier if we could develop the necessary technology.

Möbius: We should question it. There is no real justification. Davies was unable to work the concept out. A simulation has its limitations.

Abbie: Did Davies count on a perfect simulation not being detectable as such by the sentient beings in the simulation?

Möbius: That’s the idea behind it. People go into a simulation and they do not know it is a simulation. Discussion about a German three part show where the simulation beings realize they are living in a simulated world. The plot of the series suggested that we might live in a simulation ourselves.

DeVries: We could not be a simulation. The world is infinitely detailed as far as we can see.

Student #4: Bostrom views a simulation as having a consciousness. Most people look at the outside in. A digital brain can process a stimulus and draw conclusions.

Student #2: But the brain is not making a stimulus. Can one brain process a stimulus?

Student #4: Yes, it can. One brain can be flooded with stimuli.

DeVries: Is anything going on in this brain besides interpreting patterns?

Student #4: Chemical reactions are occurring.

DeVries: Chemical reactions are not the same as thinking. Terms need to be defined. There is a causal connection between the inside and the outside, which Bostrom does not address. How does the brain connect with the mind?

Student #4: If it has no senses, how is it able to perceive information?

DeVries: It is able to gather and use information unconsciously. (Example: Blind spot)

Möbius: Redirects topic. A fake universe to say multiverse leads to a corner which is not a good idea.

Jacob: A multiverse is a real explanation to how our universe is so fine-tuned.

Möbius: Discussion topic: Multiverse vs. The Cosmic Jackpot
The consequence of eternal inflation would be that we get an infinite amount of universes in a multiverse. Are there similar universes far away? What are the consequences of having identical universes far away with beings like us in them?

Student #5: The concept of an infinite number of universes has to be questioned.

Möbius: Agrees with the statement above.

Student #6: There are different orders of infinity not infinite universes like us.

DeVries: Why are there other universes like us with so many variants? Can someone prove it?

Student #7: Probability.

DeVries: Is an infinite number required?

Austin: There does not have to be.

Student #3: It’s “Life, as we know it.” What happens when the knobs are turned?

Jacob: Not testable.

Austin: Are there verifiable experiments we can perform?

Student #1: We have to observe interactions between universes.

DeVries: The universe is causally affected.

Austin: Is our universe in a region considered as a good place for life?

Jeff: Is our universe in a specific time which is suitable for life?

DeVries: Is the universe causally affected in a way which changes laws?

Austin: No.

Möbius: Different laws Vs. Strengths of constants
Universes can have different laws and same constants or vice versa.

Austin: In regions where bylaws differ is it causally verified? Do we know for sure we are causally closed?

Möbius: There are vast, observable regions, which are smaller than our entire universe, that have been causally affected at the beginning. We may be able to see gradual, very small variations in forces over space and/or time. An example is possible variations in the strength of gravity across our observable universe. If we find them, this might signal that we live close to the edge of a universe, beyond which everything might look different. This would be an indication for a multiverse model. What can we predict?

End of Class.