Astronomers know an object came from another star by measuring one number: its orbital eccentricity. Anything gravitationally bound to the Sun travels a closed path with an eccentricity below 1. An object arriving from interstellar space is moving too fast for the Sun’s gravity to ever capture it, so its path is hyperbolic and its
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One number settles it within days of discovery, and only three objects in history have ever cleared the threshold.
You inherit mitochondrial DNA only from your mother because the embryo actively destroys the father’s mitochondria after fertilization, rather than the sperm simply failing to deliver any in the first place. Sperm do carry mitochondria into the egg — they’re tagged for disposal and digested within days, leaving the mother’s set as the only one
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Sperm do deliver mitochondria into the egg. What happens next is targeted destruction, and the embryo appears to identify them by condition rather than origin.
Many scientific studies fail to replicate because the statistical threshold used to judge them — usually a p-value below 0.05 — was never designed to certify that a finding is true. It only measures how compatible the data are with a no-effect model. Combine that with journals preferring surprising positive results, and a steady supply
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Ninety-seven percent of the original studies were statistically significant. Thirty-six percent of the repeats were.
WORLD IN A DAY · MONDAY, SEPTEMBER 14, 2026 A war now in its seventh month claimed another ship in the Strait of Hormuz, world leaders wrapped a summit in New Delhi with dueling messages on artificial intelligence, and an outbreak with no approved vaccine became the deadliest in Congo’s history. BUSINESS Update: Container Ship
WORLD IN A DAY · SATURDAY, SEPTEMBER 5, 2026 U.S. hiring beat forecasts and a former British prime minister quit Parliament for good. But the sharper story this week is medicine catching up with its own ambitions, as a lung cancer pill and a single-injection autoimmune therapy both post real gains in patients, even while
WORLD IN A DAY · SATURDAY, SEPTEMBER 12, 2026 An AI chip startup’s valuation jumped fivefold in six months, on the same day regulators opened a probe into whether a rival’s biggest deal was built to dodge them. Elsewhere, three research teams found nature keeps more of its own history recoverable than expected, in a
WORLD IN A DAY · FRIDAY, SEPTEMBER 11, 2026 Twenty-five years after the September 11 attacks, a months-long war between the US and Iran is now the thing setting fuel prices worldwide, while researchers this week found answers by looking back four thousand years and out toward another star system. BUSINESS Brent Crude Tops $107
WORLD IN A DAY · FRIDAY, SEPTEMBER 4, 2026 Six stories worth five minutes: the UN votes to fix a map that has misrepresented Africa for five centuries, investigators trace the foreign networks arming both sides of Sudan’s war, and Andrew Tate faces new charges as one of several jurisdictions still trying to bring him
A genetic study of more than a million people linked over 1,000 variants to the Big Five traits — and showed how little any single one of them decides.
Your Genes Influence Your Personality—But They Do Not Write Your Destiny Read More »
A genetic study of more than a million people linked over 1,000 variants to the Big Five traits — and showed how little any single one of them decides.
WORLD IN A DAY · THURSDAY, SEPTEMBER 3, 2026 Six stories worth five minutes: Nvidia makes its biggest acquisition ever, a UN report concedes the world’s flagship climate target will likely be missed, and a Bronze Age Egyptian official’s tomb resurfaces after four thousand years underground. Technology Nvidia to Buy Hugging Face for $12.9 Billion