Why do we need to sleep?

Our memories are a big part of what makes us human. But why do some moments tend to stick in our brain for years, while others fade away? Neuroscientists Kausik Si and Elizabeth Kensinger explain the different types of memories and share tips for how we can remember better.

Humans spend one-third of their life sleeping, yet the purpose and function behind this regular state of unconsciousness remains a biological mystery. Sleep researcher Giorgio Gilestro is trying to understand some basic questions about it: like what sleep exactly is, and why it’s even necessary.

Human biology thankfully allows us to adapt to major changes in temperature, but only so quickly. Professor Cara Ocobock is working with reindeer herders in subarctic Finland to find out how the human body evolved to withstand the extreme cold over time. What can we learn from communities that have a long history of living and working in the frigid weather?

We’ve dug into a lot of fascinating topics this past year on Seeking a Scientist, but they’re all so complicated! That means there are a lot of lingering questions that we haven’t had a chance to tackle yet. As we close out 2024, we’re celebrating our favorite science stories of the year and answering the weirdest, wackiest, and most surprising science questions you all submitted — including space trash, immortal jellyfish, and why cats like to sit on puzzles.

Gravity dominates every moment of our experience here on Earth. We may take it for granted, but NASA astronaut Kate Rubins assuredly does not. She knows firsthand the fun and challenges of living in microgravity. During her time in space, Rubins conducted important experiments so that someday humans can handle even longer missions — like heading to Mars.

Stress is a part of every human’s life, but the way it feels and how we handle it varies based on the individual. That’s one of the reasons stress is such a challenging topic for scientists to study. Dr. Rajita Sinha of Yale’s Stress Center says new brain imaging technology is helping us better understand our stress biology, the lasting effects of chronic stress, and healthy ways of dealing with it.

A new “Jurassic Park” movie is coming out next year, the latest installment of the blockbuster series all about the dangerous hubris in trying to bring dinosaurs back from extinction. Paleogeneticist Beth Shapiro says the science may be flawed, but cloning extinct species is more realistic than you may think. In fact, that work is already underway — but with the slightly friendlier woolly mammoth.

To save Oklahoma from treacherous tornados, scientists in the 2024 blockbuster “Twisters” try to use a real-life technique called cloud seeding. But would this really work? Researchers have actually been using cloud seeding to modify the weather since the 1940s. For professor Katja Friedrich, it’s a promising way to address some of the issues caused by climate change.

Dogs don’t talk to us the way our human best friends do, but they are biologically prepared to communicate with us in a range of ways. What if we could understand our furry companions better? Dr. Emily Bray, a canine cognition specialist, says that dogs are better at understanding us than we are them, but there are ways we can bridge the gap.

Fireworks have been used to dazzle and entertain for centuries. These spectacles can seem out of this world, and they’re directly related to Kate the Chemist’s favorite subject: chemistry. Kate answers your questions about fireworks, including what causes their sound, colors and even smell.