Why cosmology seems to be caught in a vibe shift
NASA, ESA, CFHT, CXO, MJ Jee (University of California, Davis) and A. Mahdavi (San Francisco State University)
A few years ago, the Internet was abuzz with talk of a “vibe shift” in what is considered cool. Skinny jeans and minimalism were over; baggy pants and messy hair were in fashion. This caused a slight panic among aging millennials around the world, as they realized they were suddenly disconnected.
Today, something similar is happening in cosmology. For years, physicists thought they had a deep understanding of how the universe worked, a simple and elegant framework called the Standard Model of cosmology that perfectly accounted for how it began and evolved. At the heart of the model is dark energy, a force that we certainly cannot identify but which behaves in predictable ways to force the expansion of the universe.
Then, last year, explosive results from a telescope study seemed to show the unthinkable: Dark energy has been weakening over the history of the universe. If this is true, then the standard model of cosmology will need to be rewritten. In a set of three special features, we explore the beauty of the standard model, reveal how threatened it really is, and explore what could replace it.
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Where attachment to the old model is motivated by fear or nostalgia, this is not enough
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However, it must be admitted that many physicists are still hesitant to abandon their beloved model. To a certain extent, that’s fair enough. As is the case with so many seemingly compelling results in modern physics, the findings about dark energy may not stand the test of time. But where attachment to the old model is driven by fear of the unknown or nostalgia for simpler times, that is not enough.
Scientists tend to talk not about mood shifts, but about paradigm shifts – periods in which our view of understanding fundamentally changes. History teaches us that paradigm shifts are a good thing. They are certainly disconcerting, but allow us to see reality more clearly. We don’t yet know whether the challenge to dark energy will actually amount to a paradigm shift akin to the quantum or Copernican revolutions – but if it does, we will view this period in cosmology as an exciting time to be alive. Bring on the new vibe.
