What We're Reading

Over the past decade, two very different ways of calculating the rate at which the universe is expanding have come to be at odds, a disagreement dubbed the Hubble tension, after 20th-century astronomer Edwin Hubble. Experts have speculated that this dispute might be temporary, stemming from subtle shortcomings in observations or analyses that will eventually be corrected rather than from some flawed understanding of the physics of the cosmos. Now, however, a new study that relies on an independent measure of the properties of galaxies has strengthened the case for the tension. Quite possibly, it’s here to stay.

Modern science wouldn’t exist without the online research repository known as arXiv. Three decades in, its creator still can’t let it go.

The oceans teem with photosynthesizing bacteria, tiny-tailed dinoflagellates gobbling other plankton, algae surrounded by intricate glass skeletons. In the 1960s, the ecologist G. Evelyn Hutchinson pointed out something confusing: why do so many kinds of plankton exist?

Penn physicist Randall Kamien, visiting scholar Lauren Niu, and collaborator Geneviève Dion of Drexel bring unprecedented levels of predictability to the ancient practice of knitting by developing a mathematical model that could be used to create a new class of lightweight, ultra-strong materials.

Princeton geoscientists Xinning Zhang and Ashley Maloney have discovered that a geology technique shows promise in detecting cancer-like cells. If their preliminary results bear out, they may have identified a new signature for cancer, which could mean earlier diagnosis and better outcomes.

Renowned cosmologist David Spergel joins Brian Greene to discuss the triumphs and tensions of precision cosmology, exploring remarkable successes as well as persistent discrepancies bedeviling current understanding.

Like Bill Murray in the movie “Groundhog Day,” bacteria species in a Wisconsin lake are in a kind of endless loop that they can’t seem to shake. Except in this case, it’s more like Groundhog Year.

There is no one factor that causes autism — or explains its growing prevalence. Researchers are seeking explanations for the surge. Here are some possibilities.

For the first time, researchers have observed a type of quasiparticle that behaves in an unusual way. In one direction, it acts like it has no mass, zipping around as if it were made of pure energy.

Distant, ancient galaxies are giving scientists more hints that a mysterious force called dark energy may not be what they thought.