Learn about how you can slash your exercise time with high-intensity interval training (HIIT) — and the science that backs it up; how “collective narcissism” can make groups toxic; and how dolphins make friends strategically.

Learn about why it’s harder to clean grease off of plastic than glass; how zoos use their own version of dating apps for breeding programs; and why science says you don’t have to be married to be happy.

Learn about why people prefer round numbers over precise ones, thanks to a principle behavioral economists call attribute framing; and whether there really are wasps inside figs.

Learn what environmental cardiology has taught us about how we should live, with help from Dr. Aruni Bhatnagar. Then, you’ll learn about the world’s first 3D-printed nuclear reactor core; and why spaghetti always breaks in three.

Environmental cardiology researcher Dr. Aruni Bhatnagar explains why experts are looking at our environment to improve our health. Then, learn how Polynesians and Native Americans connected across more than 2,000 miles of ocean — all the way back in the 1

Learn about why you have false memories of doing daily tasks; how we know that dogs might be able to sense Earth’s magnetic field via magnetoreception; and the science behind why there’s no up or down in space.

To wrap up our Shark Week coverage, learn about why the US military tried to develop shark repellent during World War II. Then, learn about the leading theories explaining why moths are drawn to lights; and the difference between mummies and fossils.

Forrest Galante, host of “Extinct or Alive” on Animal Planet, explains how we search for — and find! — lost species in the open ocean. Then, you’ll learn about the two types of nostalgia and how they can influence your well-being.

Forrest Galante, host of “Extinct or Alive” on Animal Planet, explains why sharks are so important to their ecosystems. You’ll also learn about giant prehistoric sea scorpions who used to rule the sea and how cats affect online dating.

Learn about whether sharks can really smell a drop of blood from a mile away; how some sharks give birth from two uteruses (and why that’s not even the weirdest part); and the complicated way interstellar travel can mess with language.