Does the Earth's rotation affect flight time?

Flying from Auckland to Santiago takes about eleven hours. Coming home takes closer to thirteen. The explanation everyone reaches for is that the Earth spins eastward, so on the way east the destination comes to meet you, and on the way back you have to chase it. This is wrong, and it is wrong in a way I find genuinely satisfying, because the thing people are blaming turns out to be responsible after all. Just not for the reason they think. ...

July 10, 2026 · 10 min · Nathan Broadbent

No, bacteria do not outnumber your cells ten to one

I asked a question I had heard the answer to a hundred times: is it true that half the cells in my body are foreign bacteria? The answer turns out to be yes, roughly. Which is strange, because the version everyone repeats is that bacteria outnumber your own cells ten to one, and that version is wrong. The numbers In 2016, Ron Sender, Shai Fuchs and Ron Milo went and did the arithmetic properly. For a reference adult male of 70 kg: ...

July 10, 2026 · 4 min · Nathan Broadbent

Is the Caspian Sea salty? Yes, but only a third as salty as the ocean

The question I typed was “is the caspian sea salty?”, which I assumed had a one word answer. It has a one sentence answer. The Caspian Sea has a salinity of about 1.2%, or 12 grams per litre, which is roughly a third of the salinity of average seawater. So yes, it is salty. It is brackish rather than briny. You would not want to drink it, and you would not mistake it for the Pacific either. ...

July 10, 2026 · 4 min · Nathan Broadbent

Are Bats Good at Echolocation, or Do They Just Heal Fast?

My wife told me an amazing fact she had picked up from a Russian account on TikTok. For years, the story goes, scientists believed bats were extremely good at echolocation. That was how they flew around dark caves without constantly hitting the walls. Then one scientist X-rayed a batch of bats and found that many of them carried multiple healed fractures. Bats were not brilliant navigators after all. They were terrible at echolocation, crashing into things and breaking bones the whole time. They were just extraordinarily good at healing. ...

July 10, 2026 · 8 min · Nathan Broadbent