Fungus Fire Spores With 180,000 G Acceleration 69
Hugh Pickens writes "Although a variety of spore discharge processes have evolved among the fungi, those with the longest ranges are powered by hydrostatic pressure and include 'squirt guns' that are most common in the Ascomycota and Zygomycota. In these fungi, fluid-filled stalks that support single spores or spore-filled sporangia, or cells called asci that contain multiple spores, are pressurized by osmosis. Because spores are discharged at such high speeds, most of the information on launch processes from previous studies has been inferred from mathematical models and is subject to a number of errors, but now Nicholas Money, an expert on fungi at Miami University, has recorded the discharges with high-speed cameras at 250,000 frames-a-second and discovered that fungi fire their spores with accelerations up to 180,000 g, calling it 'the fastest flight in nature.' Money and his students, in a justified fit of ecstasy, have created a video of the first fungus opera."
acceleration !=fast (Score:3, Interesting)
Loosely related acceleration question (Score:1, Interesting)
Shouldn't Stopping be impossible?
I'll explain. Assuming you've a steady linear deceleration and it takes you 10 seconds to come to a stop. The closer you get to 10 seconds, the closer you are to zero velocity. However at some point, you have to reach 0m/s. The problem is, going from any value even something amazingly small like 1 x 10^-99999m/s to 0m/s instantly would be infinate G's. It could only be possible if you continued accelerating by an infintessimal amount past 0 or never actually stopped.
Is coming to a complete stop (or a constant, fixed velocity) actually impossible, is there some effect at low velocities I was never taught or is this a case of a fired arrow never hitting a turtle?
Re:Loosely related acceleration question (Score:4, Interesting)
That's another variation on the concept of Xeno's Paradox, really (wiki it). In both cases, in order for this to be an actual paradox, time would have to be infinitely smooth, as in not have a minimum possible unit - you can keep on having shorter and shorter amounts of time.
From what I understand, because time and distance seem to be granular (with the minimum units being Planck distance and Planck seconds or something like that), the whole problem gets avoided since EVERYTHING is granular and the deceleration from one moment to the next (even before a full stop) would go in a kind of quantum way - either you're at a speed of 1000 planck distances per planck second, or you're at 999 planck distances per planck second, not 999.99 p/p etc.
It made sense at the time I heard it, but you know, that was undergrad and I was probably really high.
Another fun animal (Score:3, Interesting)
Bombardier beetle [google.com].