questions
Type a question the way you would type it into Google. Find the answer, the study, the video. Every question on this page links to a dedicated answer page with the citation in plain view. The library grows weekly. If a question you have is missing, drop it in the comments under any kuz video. Most-asked questions move to the front of the production queue.
Filters land with the JS upgrade. Top six shown below. Order reflects search demand.
Question
No. A 2018 Northeastern University audit of 17,000 Android apps found zero cases of microphone audio sent to advertisers. Ads feel uncanny because of location sharing, browser fingerprinting, and cross-store purchase matching.
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Walking through a doorway measurably erases short-term memory. Gabriel Radvansky and colleagues at Notre Dame proved it in 2011 across three experiments. Your brain treats each room as a separate event.
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No. You use 100 percent of your brain, just not all at once. A 2004 Scientific American review by Barry Beyerstein called the claim dead wrong. fMRI scans show every region active across normal tasks.
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Each year is a smaller fraction of your life. At age five, one year is 20 percent of your memory. At age fifty, one year is 2 percent. Paul Janet published the proportional theory in 1877. Novelty extends subjective time.
Question
No. Eagleman 2007 dropped 20 people 31 metres at a Dallas free-fall ride. Each wore a wrist chronometer flashing digits faster than normal vision. Same accuracy in free-fall as on the ground. Time stayed put. Memory got denser.
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When you speak, sound reaches your inner ear two ways. Through the air, the way a microphone picks it up, and through your skull bones vibrating directly into the cochlea. Bone conduction adds bass that air does not. A recording captures only air conduction, which is why it sounds thinner than the voice in your head.
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The reaction is called frisson. In 2011, Valorie Salimpoor at McGill ran PET scans during peak musical chills and found dopamine release in the nucleus accumbens, the same reward circuit that fires for food and sex. Roughly half of humans get frisson. The trait correlates with Openness on the Big Five personality scale.
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Almost none of it. Visible light spans roughly 380 to 700 nanometres, a thin band of the electromagnetic spectrum that runs from radio waves to gamma rays. By wavelength, human vision captures a vanishingly small fraction of what is physically there. Most of reality is permanently invisible to your eyes.
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Yes. The gut and brain trade signals constantly along the vagus nerve and through chemicals produced by gut microbes, including a large share of the body’s serotonin. Your microbiome can measurably influence mood, stress and cravings, which is why scientists call the gut a second brain.
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The past. Light and sound take time to travel, and your brain needs roughly a tenth of a second to turn them into perception. Everything you experience is a slightly delayed reconstruction of a moment that has already gone. You never perceive the true present.
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Inner speech recruits the same brain machinery as talking out loud, including Broca’s area, minus the final command to move your mouth. It is your own brain narrating to itself. A minority of people report no inner voice at all and think without one.
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Even sitting still you spin with the Earth at about 1,600 km/h at the equator, orbit the sun at roughly 107,000 km/h, and ride the galaxy through the universe at over 2 million km/h. You feel none of it because steady motion produces no force you can sense.
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Constantly. Skin renews in weeks, most blood cells over months, and the skeleton remodels across roughly a decade. The widely cited figure that about 98% of your atoms turn over each year traces to mid-century radioisotope studies. You persist as a pattern, not a fixed set of matter.
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Not exactly. Retrieving a memory briefly makes it editable, and your brain re-saves an updated version, a process called reconsolidation. The memories you revisit most are reconstructed most often, and high confidence is no guarantee of accuracy.
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During REM sleep, the hippocampus is partially deactivated and the brain actively suppresses memory consolidation. A 2019 Science paper identified the MCH neurons responsible.
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Anne Cleary at Colorado State proposed the leading explanation: a current scene shares structural features with a previously encountered scene, the familiarity signal fires, but the source memory does not retrieve.
