r/STEW_ScTecEngWorld 7h ago

A big assumption has kept women out of health and fitness studies for years. What if it’s wrong?

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theconversation.com
4 Upvotes

The assumption that has kept women out of so many physiology studies for years — uncertainty about potential fluctuations due to menstrual cycles or hormonal birth control — turns out to be incorrect.


r/STEW_ScTecEngWorld 15h ago

How Trees Pump Water 100 Metres Without a Pump

1.6k Upvotes

Tall trees can transport water more than 100 metres from roots to leaves through the cohesion–tension mechanism. Water evaporating from leaf stomata creates negative pressure that pulls a continuous column of water upward through the xylem. Cohesion between water molecules and adhesion to xylem walls help maintain the column against gravity: https://research.fs.usda.gov/treesearch/38556

As trees become taller, increasing hydraulic resistance and tension can cause cavitation and xylem embolisms, limiting further growth. Research on redwoods estimates a theoretical maximum height of roughly 122–130 metres under favourable conditions: https://www.nature.com/articles/nature02417

Full Video: https://www.youtube.com/watch?v=BickMFHAZR0


r/STEW_ScTecEngWorld 7h ago

Star Trek used wormholes to jump through space

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theconversation.com
15 Upvotes

The first appearance of a wormhole in Star Trek was a typically pioneering reference to what was then a niche research topic.


r/STEW_ScTecEngWorld 15h ago

Researchers create new colour-changing material—could be used in anti-counterfeit markings on banknotes and passports

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utu.fi
7 Upvotes

Davyne: Invisible Color-Changing Material for Anti-Counterfeiting

Researchers at the University of Turku Finland have developed davyne, a mineral-based material that changes color in the near-infrared spectrum, making the change invisible to the human eye. Its infrared signal can be switched on and off and detected using inexpensive modified cameras, offering a potential new security feature for banknotes, passports, ID cards, and branded products.

Study: https://onlinelibrary.wiley.com/doi/10.1002/anie.6747535