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No one looks forward to that first colonoscopy, but this glimpse into the gut is one of the most powerful existing weapons against colon cancer. Yet current protocol for when to start checking for the disease may be too late for many men and may put many women through an expensive and unnecessary ordeal, a new study suggests. Doctors currently advise men and women with no family history of colon cancer or other risk factors to start undergoing screening at age 50, and sooner for those deemed more at risk....

Cancer travels. Large tumors shed cells that move through the body and seed new malignancies. Now scientists are tinkering on the nanoscale to build unusual spheres made of DNA—a molecule that became famous as another shape, the double helix—that can find, tag and potentially kill off these tumor cells. The spheres look a bit like toothpicks stuck in a small Styrofoam ball. The toothpicks are really a dense crowd of single DNA strands jutting out from a central core....

Natural selection is not natural perfection. Living creatures have evolved some remarkably complex adaptations, but we are still very vulnerable to disease. Among the most tragic of those ills–and perhaps most enigmatic–is cancer. A cancerous tumor is exquisitely well adapted for survival in its own grotesque way. Its cells continue to divide long after ordinary cells would stop. They destroy surrounding tissues to make room for themselves, and they trick the body into supplying them with energy to grow even larger....

Premium gasoline must be called “premium” because it is better for your automobile. After all, one of that adjective’s definitions is “a high value or a value in excess of that normally or usually expected,” according to Merriam-Webster’s Collegiate Dictionary. But is that common assumption safe? The answer to this question lies in the process of refining gasoline from oil, the dynamics of the typical internal-combustion engine and another definition of “premium”—this one from its noun form: “a sum over and above a regular price paid chiefly as an inducement or incentive....

The following essay is reprinted with permission from The Conversation, an online publication covering the latest research. Parents often receive books at pediatric checkups via programs like Reach Out and Read and hear from a variety of health professionals and educators that reading to their kids is critical for supporting development. The pro-reading message is getting through to parents, who recognize that it’s an important habit. A summary report by Child Trends, for instance, suggests 55 percent of three- to five-year-old children were read to every day in 2007....

Most of the universe is rushing away from us. It’s not that we’re particularly repellent; it’s just that the universe is expanding, pushing most other galaxies away. Light from distant galaxies travels toward us through this expanding space, which stretches their light to longer, or redder, wavelengths. As a result, the spectra of most galaxies exhibit redshifts. Now astronomers have accidentally discovered the greatest blueshift ever seen, in a star cluster that a giant black hole may have catapulted our way....

During a 2017 casino tournament, a poker-playing program called Libratus deftly defeated four professional players in 120,000 hands of two-player poker. But the program’s co-creator, Tuomas Sandholm, did not believe artificial intelligence could achieve a similar performance against a greater number of players. Two years later, he has proved himself wrong. Sandholm has co-created an AI program called Pluribus, which can consistently defeat human experts in six-player matches of no-limit Texas Hold’em poker....

Where most spiral galaxies have two twisting arms, a neighbor of the Milky Way is a four-armed monster. A new photo snapped by the Hubble Space Telescope, combined with observations by amateur astronomers, reveals these arms in stunning detail. The galaxy Messier 106 lies about 20 million light-years from Earth in the constellation Ursa Major (the Great Bear). Hubble scientists released a video of the four-armed galaxy in addition to the new photo....

Sea-level rise threatens California’s economy 10 times more than recent extreme wildfires or severe earthquakes, according to a major new study. U.S. Geological Survey researchers and other scientists found that rising seas, combined with storms, will wallop California by the turn of the century, with impacts occurring as early as 2040. The study published in the journal Nature translated physical impacts into socio-economic ones, finding that both the coast and inland areas will face major financial losses....

“Where are the Native Americans now?” asked fifth grade students in an Iowa City classroom last year. There are many ways their teacher, Melanie Hester, might have answered. She could have pointed out that today Native Americans live in cities and towns across the U.S. About 20 percent live on reservations, and Hester could have used that to open a discussion of the U.S. government’s forcible movement and isolation of tribes....

This week fissure number 18 opened on the east flank of Hawaii’s rumbling Kilauea Volcano, another in the set of rift-zone fractures advancing toward the Pacific coast. Several miles westward, nestled in Kilauea’s summit caldera, Halema‘uma‘u pit crater is evolving toward a hazardous scenario that reminds volcanologists like myself of a giant blowout that happened there in 1924. That year a long-lived deep lake of bubbling molten basalt lava, a very popular tourist attraction, unexpectedly began to drop downward until it was no longer visible....

Stress can help or hurt learning depending on when the stressor hits. As psychologists well know, exposure to brief stress just before an event can enhance long-term memory of that occurrence. Had the stressful experience descended 30 minutes prior, learning would instead have been impaired. A new study published in the February Neurobiology of Learning and Memory now finds that the effect is sex-dependent. Male and female participants were randomly assigned to one of two groups: For three minutes, one group submerged a hand in ice-cold water, while the control subjects placed their hand in warm water....

Key concepts Physics Wavelength Refraction Reflection Introduction Did you know that in the U.S. we generally count seven colors in a rainbow whereas elsewhere in the world people only count five? We all see the same rainbows but it can be tricky to count the colors because they all blend together so seamlessly. So next time you see a rainbow in the sky try to count how many distinct colors you see!...

A large amount of methane is bubbling up from the ocean floor east of Siberia at a surprising rate and could accelerate climate change, researchers said yesterday. The gas is bubbling up from the East Siberian Arctic Shelf because warming ocean water is thawing permafrost, allowing methane trapped underneath to escape. The amount of methane emitted by that one patch of seabed roughly equals the amount scientists believed was released by all of the world’s oceans....

Infectious disease watchers are again wondering what is going on in Saudi Arabia. Since the beginning of February the Saudis have reported 52 cases of Middle East respiratory syndrome—better known as MERS; 40 have come to light in the past week or so alone. Since the disease first hit the world’s radar in September 2012 only two months have racked up more cases than this one has. They were April and May 2014, when Saudi Arabia had rampant MERS outbreaks in several hospitals....

LIGHT AND THE BIG BANG In “A Beacon from the Big Bang,” Lawrence M. Krauss suggests that, if verified, possible observation of gravitational waves from the early universe could provide evidence for a theory in which the universe underwent a period of explosive expansion, or inflation, shortly after the big bang. Because so much of the described event occurs within an infinitesimal fraction of a second, would not the early universe’s components have to have been moving at many multiples of the speed of light?...

A secret population of polar bears in Greenland has been discovered in a seemingly impossible habitat — one that, for most of the year, lacks the floating platforms of sea ice the beasts use to hunt. The unusual group, which scientists previously thought was part of another nearby population, has been hiding in plain sight for hundreds of years. The bears live on the steep slopes around fjords — long and narrow coastal inlets, where glaciers meet the ocean — and hunt on a patchwork of glacial ice that breaks up in these inlets....

Key concepts The five senses Neuroscience Sound waves Audition Introduction In the popular pool game “Marco Polo,” one sightless swimmer calls out “Marco” and seeks out other swimmers when they respond “Polo.” If you’ve tried it, you’ll know it’s not an easy game. Every splash, whisper or giggle is a clue, but these hints can be surprisingly misleading. In this activity you’ll learn a little bit more about your sense of hearing and how it works....

President Trump on Thursday said his administration would declare the opioid crisis a national emergency, just two days after his top health official said, after meeting with the president, that such a step was not necessary. Trump’s remarks came after his commission on combatting drug abuse issued an “urgent” recommendation last week that he issue an emergency declaration. It’s still unclear what the emergency declaration will look like. The laws that govern such declarations stipulate that the president himself spell out what resources will become available and what new authorities the administration will take on....

In 2020 experts at the U.S. Biomedical Advanced Research and Development Authority (BARDA) and other public health agencies watched a presentation that many thought was impractical at the time. Several companies proposed to regularly sample wastewater from sewers and treatment plants and run tests to detect SARS-CoV-2—the virus that causes COVID-19. People excrete the virus in their waste, and the companies suggested that tracking levels of its genetic material, or RNA, in sewage over time would provide a quick glimpse into whether the virus was rising in an area days or even weeks before a surge in patients with COVID....