Key Takeaways:
- Scientists may have misunderstood the expansion of the universe.
- Stretching of light waves (redshift) could be due to changing particle mass, not universal expansion.
- The theory suggests these concepts might not be necessary.
- A new perspective on physics explains observations without dark matter or energy.
- While promising, the theory needs further exploration to be validated.
A potentially controversial new study suggests that the universe’s expansion may be a mirage.
This new perspective on the universe may also provide answers to the mysteries surrounding dark energy and dark matter, which scientists estimate make up about 95% of all the energy and matter in the universe but are still poorly understood.
The innovative new method is described in detail in a paper by University of Geneva theoretical physics professor Lucas Lombriser, which was published in the journal Classical and Quantum Gravity.
Redshift, or the stretching of light’s wavelength towards the redder end of the spectrum as the source of the light moves away from us, is how scientists know the universe is expanding. The redshift of distant galaxies is higher than that of nearby galaxies, indicating that the latter are moving away from Earth.
In more recent times, scientists have discovered evidence that the expansion of the universe is not static, but rather is speeding up exponentially. The cosmological constant, or lambda, is a term used to describe this accelerating expansion.
Cosmologists have struggled with the cosmological constant because particle physics predictions of its value are 120 orders of magnitude off from actual observations. Thus, it has been said that the cosmological constant is “the worst prediction in the history of physics.”
By reconsidering what already exists, Lombriser addresses the difference between the various values of lambda, a problem that cosmologists frequently attempt to solve by suggesting new particles or physical forces.
“In this work, we put on a new pair of glasses to look at the cosmos and its unsolved puzzles by performing a mathematical transformation of the physical laws that govern it,” Lombriser said in an email to Live Science.
According to Lombriser’s mathematical interpretation, the universe is flat and static rather than expanding, as Einstein previously postulated. Rather, the effects we see that suggest expansion can be explained by the way particle masses, like those of protons and electrons, change over time.
These particles in this image originate from a field that permeates space-time. The mass of the field determines the cosmological constant, and as the field fluctuates, so do the masses of the particles it gives birth to. Even in this model, the variation in the cosmological constant with time is not caused by the expansion of the universe but rather by changes in particle mass over time.
Larger redshifts for distant galaxy clusters are predicted by the model as a result of these field fluctuations than by conventional cosmological models. Thus, the cosmological constant continues to agree with the predictions of the model.
“I was surprised that the cosmological constant problem simply seems to disappear in this new perspective on the cosmos,” said Lombriser.
A recipe for the dark universe
Lombriser’s new framework also tackles some of cosmology’s other pressing problems, including the nature of dark matter. This invisible material outnumbers ordinary matter particles by a ratio of 5 to 1, but remains mysterious because it doesn’t interact with light.
According to Lombriser, the field’s fluctuations might also exhibit characteristics of an axion field—a hypothetical particle that is one of the proposed candidates for dark matter.
These fluctuations could also do away with dark energy, the hypothetical force stretching the fabric of space and thus driving galaxies apart faster and faster. In this model, the effect of dark energy, according to Lombriser, would be explained by particle masses taking a different evolutionary path at later times in the universe.
In this picture “there is, in principle, no need for dark energy,” Lombriser added.
Luz Ángela García, a post-doctoral researcher at the Universidad ECCI in Bogotá, Colombia, expressed her admiration for Lombriser’s new interpretation and the number of issues it fixes.
Unrelated to the research, García told Live Science, “The paper is pretty interesting, and it provides an unusual outcome for multiple problems in cosmology.” “The theory provides an outlet for the current tensions in cosmology.”
However, García urged caution in assessing the paper’s findings, saying it contains elements in its theoretical model that likely can’t be tested observationally, at least in the near future.
