An interesting demographics exercise is to add up the number of humans who've existed. This is different from how many people are in a population—which in late November 2022, is about 8 billion. But using data going back as far as possible, the number of people who've existed is reckoned at over 100 billion.

Host: Dr Karl Kruszelnicki

The number of humans ever born

From the ground breaking and life saving to the wacky and implausible, Dr Karl Kruszelnicki reveals some of the best moments in science.

Natural Sciences

Science & Medicine

Science

Dr Karl was first heard on the wireless in 1981 when he convinced Triple J that a talk about the space shuttle would be good listening because he had applied to be a NASA astronaut. The shuttle did (eventually) launch ... and along with it, the all-science-media career of one Dr Karl Kruszelnicki.

This is Dr Karl's last Great Moment in Science, as we know it—but don't worry, he'll still be around and firing on all cylinders—including on Triple J's Science with Dr Karl podcast.

Science with Dr Karl

The Greatest Moment in Science

We know that the drug called cannabis, or marijuana, increases the appetitecommonly called the 'Marijuana Munchies', and we are finally getting closer to knowing what makes it happen. Half-a-billion years ago a biological system evolved to make sure that hungry animals would eat.

Why the 'marijuana munchies' make you feel good

The ancient Romans thought that insects were attracted to bright light, and then there's the well-known phrase, "drawn like a moth to a flame", so it seems like people over many years have spotted insects coming into the lights, at night. But what's the real reason?

Host: Dr Karl Kruszelnicki

Insects fly to the light

Some sleepers who act out their dreams are later diagnosed with Parkinson's disease. As Dr Karl explains, it's one of a few slightly odd new diagnostic tools.

Dreaming a diagnosis with Dr Karl

The power of smell can't be understated — our noses don't just sniff out tasty treats, they can also alert us to danger. 

In this episode of Great Moments in Science, Dr Karl tells the story of a super-sniffer who might've unlocked a powerful diagnostic tool.

The number of humans ever born

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