"Heavy metals" is more of a colloquial term than a scientific one. There are lots of very heavy metals that aren’t dangerous at all. We wear gold and silver and platinum in our jewelry. Bismuth is all up in your PeptoBismol and most of the lanthanides and actinides are safe. Also, lots of the lighter metals (particularly sodium and lithium) while being great in certain chemical forms, in their pure forms will kill you extremely quickly (and violently.)
What it comes down to is simply whether the metal interferes with the normal functioning of your body. And we’ve got complicated bodily chemistries so it turns out that there are around a dozen metals that you don’t want to get in your body. At the same time, some of them, like zinc, are helpful it certain chemical configurations. A great example of how it’s not about the metal so much as the chemistry of the body…copper is safe for humans, but is extremely toxic to fish.
SciShow Space shares the latest developments from around the universe, including news about the first material ever collected from outside the solar system, and a backyard astronomers’ guide to two upcoming planetary conjunctions.
Danny Weinkauf has, for like 15 years, been the bassist for They Might Be Giants. He wrote their song “I’m a Paleontologist" which you may have heard…he’s also won two grammies and written and produced music for dozens of TV shows. So when he was like "Hey, I’m doing a children’s album, do you want to write a song with me?" I was like "GHGHHFHFHHDHWWW!"
So, together we wrote “The Kidney That Lived in Four People" which is the (semi) true story of a Kidney that existed inside of four different bodies (so far). The names have been changed, everything else is true.
A couple weeks ago, we decided it would be cool to hold a little contest.
So, for all filmmakers, animators, artists, and etc…if you’d like to create a music video for the song, the winner (as selected by us) and three runners up will win this very nice Kidney model signed by me and Danny. The top submission will have their video posted on Hankschannel and Danny’s YouTube channel.
You can get Danny’s full album “No School Today” on Amazon and iTunes and most other places where music comes from.
So, the way we experience…pretty much everything is via proteins and ion channels. Very basically…there are proteins that are designed to sense certain things….the presence of sugar, whether they’ve been struck by light, the concentration of CO2 in the blood. When they sense those things, they open an ion channel changing the electrical charge of the cell, which then get transferred through the nervous system to the brain where that area of the brain is like “Cool…we’ve got sugar…or light…or too much CO2 in the blood.”
Well, sometimes these proteins can be fooled. A chemical will, just by chance (or by natural selection) be able to bind with that protein and cause that whole cascade to occur without the real stimulus. This is what happens with menthol in mint and capsaicin in peppers. Those chemicals bind to the cold / hot receptors respectively, fooling your body into thinking that something cold / hot is happening in your mouth. Pretty cool.
What wiped out the dinosaurs? Most of us were taught it was a killer asteroid — which is true. But it turns out there was more than one disaster movie playing at the cineplex that was Earth 66 million years ago.