Will Holtz:

Carrying current down makes a magnetic field, but it’s not structurally significant. The electrodynamics of the whole circuit are complex, with return current flowing through the air, a la lightning–which is just sporatic sparking to readjust the charge imbalances. We live between the plates of a spherical capacitor–ground &…[Read more]

Vandanta:
“One thing that concerns me about geoengineering is that its large scale makes it difficult to see how you’d stop or reverse it if things go wrong.”
Start with spraying at high troposphere levels, so they rain out within days. Then move to strato, with weeks or months residence time. Experiment! Summer Arctic season is 4 months so a…[Read more]

I did a study for DARPA on suppressing Arctic warming in summer–where the major threat of methane exhales lies. Dispersing SO2 droplets (or H2SO4 in presence of H2O in the air, ie clouds) which reflect sunlight can cool the Arctic, stopping retreat of sea ice. The K-10 Extenders we have now can do this at cost ~$200 million/summer, with SO2…[Read more]

I thought about using the tower to tap the potential drop from Earth’s surface to an altitude. The drop is 120 Volts/m at the equator, rising to 155 V/m at 60 degrees latitude. Take it to be 140 V/m at 30 degrees. the potential drop from Earth’s surface to an altitude. The drop is 120 Volts/m at the equator, rising to 155 V/m at 60 degrees lat…[Read more]

Here’s a note I sent Neal last year:

A magnetic acceleration evacuated tube can be wrapped around the Tower to launch to orbit. Approximating the Tower as a helix with a mean radius R, the tube length S will be […]