The world is running out of water - can cloud-seeding save us?; Why some people get stuck in grief; Is our black hole actually a clump of dark matter?

Episode 346

The world is running out of water, with many countries suffering from significant water shortages. We’re now having to rely on groundwater that takes thousands of years to replenish – so what can we do? One group says, to save us from worldwide “water bankruptcy”, we need to artificially change the weather. Although “cloud-seeding” has been around for a long time, a new technique is getting big results in the US. But the idea is becoming increasingly controversial – with cloud-seeding held responsible for recent floods in Dubai and Texas. So will this help, or hurt?

Grief is a very normal experience for those who suffer a loss. But for 1 in 20 of us, this intense sadness doesn’t go away. “Prolonged grief disorder” was recognised as a distinct psychiatric condition in 2022 – but it was controversial, with some concerned we’re pathologising a normal human response. But new research suggests there really are unique things happening in the brains of those suffering from PGD. Could this help us find better ways to treat the condition?

Is the black hole in the centre of our universe actually a massive clump of dark matter? It seems ridiculous to ask, but the new theory is genuinely worth investigating. Researchers say Sagittarius A* is just the right size that it could defy everything we think we know about it. Could we have an answer to the puzzle of dark matter, right on our doorstep?

Hosted by Penny Sarchet and Timothy Revell, with guests Alec Luhn, Alexandra Thompson and Leah Crane.

To read more about these stories, visit https://www.newscientist.com/

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