> the team took a small sample from the cord’s loose end and used an instrument called a mass spectrometer to measure tiny variations in the hair’s isotopes of carbon, nitrogen, and sulfur. Those isotopes hold clues to a person’s diet, such as the amounts of maize and meat they ate in life. Maize, for example, is among the crops that rely on a form of photosynthesis known as C4 photosynthesis, which causes more of the isotope carbon-13 to build up in their tissues than in many other types of plants. Elevated levels of carbon-13 in a hair sample would most likely signal a maize-rich diet, Hyland says. Similarly, a meat-rich diet tends to raise the body’s levels of the isotope nitrogen-15.

It's so impressive that we can estimate someone's diet from a hair sample. I had no idea that this was possible.

▲ echelon 4 days ago | parent | next [-]

Spectroscopy is powerful.

There are various forms of spectroscopy that leverage different physical characteristics: vibration, absorbance, emission, charge, etc.

It's spectroscopy that allows us to read the molecular atmospheric composition of exoplanets and that has the greatest chance of yielding detection of alien biosignatures or technosignatures given our current scientific understanding and capability.

Spectroscopic techniques are vital for remote sensing, cancer detection, biochemistry, materials science, and more.

▲ dyauspitr 4 days ago | parent | prev | next [-]

You can tell if someone has smoked weed at any point in the past 3 months if your hair is long enough.

▲ dingnuts 4 days ago | parent [-]

that's why stoners are known for having buzz cuts

▲ AndrewOMartin 4 days ago | parent | next [-]

The stoners who have an interest in not being exposed as such.

▲ geoduck14 4 days ago | parent | prev [-]

Isn't this the reason why Britney Spears cut her hair a coupleb of decades back?

▲ n1b0m 4 days ago | parent [-]

No, she did it as an act of rebellion and to reclaim control amidst intense media scrutiny and a feeling of being constantly judged. She described it as a way to push back against the constant pressure and invasion of her privacy.

▲ aaron695 4 days ago | parent [-]

There is court testimony it was drug testing - https://www.reuters.com/article/business/britney-spears-hook...

Can you link your source?

I'd say it was part of some sort of manic/meltdown episode with multiple things going on with some logic. She was under a conservatorship for good reason, it's not some Deep State conspiracy.

I'd like to hear her explanation in her words.

[edit] - From her book

  I went into a hair salon, and I took the clippers, and I shaved off all my hair.

  Everyone thought it was hilarious. Look how crazy she is! Even my parents acted embarrassed by me. But nobody seemed to understand that I was simply out of my mind with grief. My children had been taken away from me.

  With my head shaved, everyone was scared of me, even my mom. No one would talk to me anymore because I was too ugly.

  My long hair was a big part of what people liked—I knew that. I knew a lot of guys thought long hair was hot.

  Shaving my head was a way of saying to the world: Fuck you. You want me to be pretty for you? Fuck you. You want me to be good for you? Fuck you. You want me to be your dream girl? Fuck you. I’d been the good girl for years. I’d smiled politely while TV show hosts leered at my breasts, while American parents said I was destroying their children by wearing a crop top, while executives patted my hand condescendingly and second-guessed my career choices even though I’d sold millions of records, while my family acted like I was evil. And I was tired of it.

  At the end of the day, I didn’t care. All I wanted to do was see my boys. It made me sick thinking about the hours, the days, the weeks I missed with them. My most special moments in life were taking naps with my children. That’s the closest I’ve ever felt to God—taking naps with my precious babies, smelling their hair, holding their tiny hands.

	▲	vintermann 3 days ago \| parent [-]
		> it's not some Deep State conspiracy I know very little about the drama around Britney Spears, but even I know that the question was if her conservator was abusing it, not "the deep state". It's a case of the breach of trust of one or a very few people, NOT a grand conspiracy requiring a supernatural level of coordination and control. It happens with alarming regularity that people abuse conservatorships. It's an inherently very abusable position. I hate it when people shout "conspiracy theory" over garden variety breach of trust/corruption. The latter actually exists, by using this accusation as a shield for it, you strengthen the actually unreasonable conspiracy theories. Now that doesn't mean Spears' conservatorship abused their position, they may or have not have, but it's not something that can be reject as a possibility.

▲ bbarnett 3 days ago | parent | prev [-]

I wonder, for when I look here:

https://en.wikipedia.org/wiki/Inca_agriculture

They not only used wood, but llama dung for fires. I wonder how much C4 ended up in the food via their dung, just from the smoke and air rising from the fire, as it would be rich in it.

Still a neat way to try to validate diet.

▲

IAmBroom 2 days ago | parent [-]

OK, first: food is rich in C4. Food is made from carbohydrates, which as the name suggests is made from Carbon, and the amount of C4 in the carbon is homogenous across compounds.

So the answer to your question is: insignificant amounts of smoke occur in fire-cooked foods, and the C4 composition wouldn't be affected anyway.

	▲	IAmBroom 2 days ago \| parent [-]
		I am incorrect: C4 is not homogenous, per the comment above yours, but really there just can't be that much smoke IN food ingested.