NASA, ESA, CFHT, CXO, MJ Jee (University of California, Davis) and A. Mahdavi (San Francisco State University)
A few years ago, the internet started talking about a “vibe shift” in what counts as cool. Skinny jeans and minimalism were out; baggy pants and messy hair were in. Cue a little panic for aging millennials everywhere as they realized they were suddenly out of touch.
Now something similar is happening in cosmology. For years, physicists thought they had a good understanding of how the universe works, a simple and elegant framework called the Standard Model of Cosmology that provided an excellent description of how it began and evolved. At the heart of the model is dark energy, a force we cannot identify, but which behaves predictably to force the universe to expand.
Then, last year, explosive results from a telescope survey seemed to show the unthinkable: dark energy has weakened over the course of the universe’s history. If true, the Standard Model of cosmology needs to be rewritten. In a package of three special features, we delve into the beauty of the standard model, reveal how endangered 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, it does not hold
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However, it must be said that many physicists are still reluctant to abandon their beloved model. To some extent this is fine enough. As with so many seemingly convincing results in modern physics, the discoveries of dark energy may not stand the test of time. But where attachment to the old model is motivated by fear of the unknown or nostalgia for simpler times, it does not hold.
Researchers tend not to talk about mood shifts, but about paradigm shifts – periods when our lens of understanding fundamentally changes. History teaches us that paradigm shifts are a good thing. They are discombobulating, no doubt, but allow us to see reality more clearly. We are not yet sure whether the challenge of dark energy will truly constitute a paradigm shift akin to quantum or Copernican revolutions – but if it does, we will look back on this period of cosmology as an exciting time to be alive. Get the new vibe.
