Does the Uncertainty Principle imply a linear cosmology?

In summary: Also, the uncertainty principle only applies to measurements on observables, not the universe as a whole.
  • #1
jcap
170
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If the uncertainty in the age of the Universe is ##\Delta t## then the Uncertainty Principle implies that it has an uncertainty in its energy ##\Delta E## given by
$$\Delta E \ \Delta t \sim h.\tag{1}$$
If this energy fluctuation excites the zero-point electromagnetic field of the vacuum then a photon is created with energy ##\Delta E## and wavelength ##\lambda## given by
$$\Delta E \sim h \frac{c}{\lambda}.\tag{2}$$
Combining Equations ##(1)## and ##(2)## we find that
$$\lambda \sim c\ \Delta t.\tag{3}$$
Now as this characteristic length ##\lambda## is the wavelength of a photon it is a proper length that expands with the Universal scale factor ##a(t)## so that
$$\lambda \sim a(t).\tag{4}$$
Combining Equations ##(3)## and ##(4)##, and taking ##\Delta t \sim t##, we arrive at a unique linear cosmology with the normalized scale factor ##a## given by
$$a(t) = \frac{t}{t_0}.$$
where ##t_0## is the current age of the Universe.
 
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  • #2
I'll leave it to more knowledgeable folks to weight in, but what I think is that you have extrapolated the HUP to WAY outside of it's domain of relevance.
 
  • #3
jcap said:
If the uncertainty in the age of the Universe is ##\Delta t## then the Uncertainty Principle implies that it has an uncertainty in its energy

You can't apply the uncertainty principle to the universe as a whole since there is no way to make an external measurement on it, and the uncertainty principle applies to external measurements.

Also, there is no "energy-time" uncertainty principle as you are using it. See, for example, here:

http://math.ucr.edu/home/baez/uncertainty.html

So your post is based on at least two incorrect premises.
 
  • #4
jcap said:
If this energy fluctuation excites the zero-point electromagnetic field of the vacuum

Correction, three incorrect premises. The universe as a whole doesn't have "energy fluctuations" in this sense.
 

1. What is the Uncertainty Principle?

The Uncertainty Principle is a fundamental principle in quantum mechanics that states that the more precisely the position of a particle is known, the less precisely its momentum can be known, and vice versa.

2. How does the Uncertainty Principle relate to cosmology?

The Uncertainty Principle has implications for the study of the early universe, as it limits our ability to precisely measure certain properties of particles and their interactions. This can affect our understanding of the dynamics of the universe and the accuracy of cosmological models.

3. What is a linear cosmology?

A linear cosmology is a model of the universe in which the expansion of the universe is described by a linear function. This means that the rate of expansion is constant over time and does not accelerate or decelerate.

4. How does the Uncertainty Principle imply a linear cosmology?

Some theories suggest that the Uncertainty Principle may lead to a linear expansion of the universe, as it introduces a level of unpredictability in the dynamics of particles and their interactions. This can potentially affect the overall expansion rate of the universe.

5. Is a linear cosmology the only possible implication of the Uncertainty Principle?

No, there are various theories and models that incorporate the Uncertainty Principle in different ways and can lead to different implications for the evolution of the universe. A linear cosmology is just one possible interpretation.

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