Is the cosmological constant fine-tuned to 120 decimal places just by accident?

[Boojatta]

What We Still Don't Know, Episode 3, Part 2 of 5

[Azathoth]

1. The fine-tuning argument suffers from a fundamental logical fallacy

A simpler argument employing the same reasoning might be:

Humans require an atmosphere that is roughly four parts nitrogen and one part oxygen in order to breathe.
The Earth's atmosphere is exactly 80% nitrogen and 20% oxygen.
Therefore the Earth must have been specifically fine-tuned to support human life.

We define "life" to be a collection of processes that happened to emerge in a universe with a particular cosmological constant. Thus, whenever we talk about the possibilities of "life" existing somewhere, our definition implies that we are dealing with a universe very much like our own. A universe with different quantum laws and mathematical constants would be utterly alien and incomprehensible to us. Life as we understand it obviously would not exist in such a universe, but it does not follow that such a universe necessarily would be empty. In fact, that universe would define "life" (assuming such a term could even be meaningfully translated to a state of existence so utterly dissimilar from our own) according to whatever processes were permitted by its own laws and constants.

[Boojatta]

2. "utterly alien and incomprehensible to us"

By using computer simulations, it's possible to consider the effect of varying the values of physical constants.

Life as we understand it obviously would not exist in such a universe,

Instead of running computer simulations, researchers could simply ask you what the results would be. However, anybody can wait for results to be reported and then claim that they are "obvious." Perhaps it would be wise for researchers to test you to see whether or not you can predict results that have not yet been reported to you.

whenever we talk about the possibilities of "life" existing somewhere, our definition implies that we are dealing with a universe very much like our own

How much is "very much"?

[tiny elvis]

3. yes. 'very much' is how much

that was too cute how you were rude to a scarce reply

[toddaa]

4. Accident implies that a mistake was made

What's the correct cosmological constant?

[Jim__]

5. There are some theoretical problems with the computed size of the cosmological constant.

From wiki:

A major outstanding problem is that most quantum field theories predict a huge value for the quantum vacuum. A common assumption is that the quantum vacuum is equivalent to the cosmological constant. Although no theory exists that supports this assumption arguments can be made in its favor <7>

Arguments for this assumption are usually based on dimensional analysis and effective field theory. If the universe is described by an effective local quantum field theory down to the Planck scale, then we would expect a cosmological constant of the order of M⁴_pl. As noted above, the measured cosmological constant is smaller than this by a factor of 10⁻¹²⁰. This discrepancy has been called "the worst theoretical prediction in the history of physics!"<8>.

Some supersymmetric theories require a cosmological constant that is exactly zero, which further complicates things. This is the cosmological constant problem, the worst problem of fine-tuning in physics: there is no known natural way to derive the tiny cosmological constant used in cosmology from particle physics.

I'm not sure how reliable the cosmological constant is in telling us about the actual nature of the universe.