It’s just gotta be out there. To get rid of the evidence for fine-tuning of our universe.
Seldom is this stuff ever challenged:
The notion that our universe is just one of many other universes existing together has given birth to the idea of a “multiverse”, a uber-universe that contains a sea of individual universes The mere mention of this word can raise the hackles on a lot of physicists, so it is important to note that the concept of a multiverse is not a single idea, but more of a grab-bag of thoughts — from causally disconnected regions within a single overall-universe, to distinct individual universes floating like jellyfish in some higher-dimensional structure.
In justifying the idea of a multiverse, some physicists have noted that it might be a solution to some peculiarities of our universe, namely the question of cosmic fine-tuning. To understand fine-tuning, we have to imagine how the universe could have been different, not just different in a rearrangement of the stars and galaxies, but different in its physical properties, such as the strength of fundamental forces, the masses of subatomic particles, the rate of cosmic expansion, and the initial conditions at cosmic birth.
Let’s take an example. Hydrogen is the most common element in the universe, providing the raw materials for stars. It is a simple atom, consisting of a single proton coupled with an orbiting electron. The other particle found in atomic nuclei is the neutron, which is 0.14% more massive than the proton. This tiny mass difference is due to the properties of the fundamental quarks that make up these particles, and if these were slightly different the neutron would be lighter. This would radically change the make-up of the universe, with the neutron being the dominant particle, leaving it inert with no atoms.
Geraint F. Lewis, “Searching for the multiverse” at IAI News
Let’s be clear here. We have evidence for fine-tuning in the only universe we know to exist. To argue against it, we must posit universes for which we have no evidence and maybe cannot ever have any evidence. This makes sense, why again? Lewis is undeterred:
The multiverse, the critics tell us, will never yield to experimentation because it cannot.
But in reality, it is far too soon to say this is truly the case. We simply lack the theoretical tools to construct meaningful multiverse models, and we will potentially need the sought-after Theory of Everything to do so. However, once we do, not only will this open the door back through the beginning of the Big Bang but could also provide us with new observational tests of our universe’s relation to any multiverse. Maybe something will be written into the cosmic microwave background or the fundamental physical properties of the cosmos, revealing whether our universe is just one in a crowded multiverse or is truly alone. Either outcome will be cosmically mind-bending.
Geraint F. Lewis, “Searching for the multiverse” at IAI News
Actually, we have no basis for believing that a multiverse exists except an unwillingness to accept the implications of fine-tuning of the universe we do know about. There’s something faintly scandalous about cosmologists keeping the nonsense going to the extent that they do.
See also: The multiverse is science’s assisted suicide