Here's a quite good (but simplified) explanatory video:<p><a href="https://youtu.be/Ja4oMFOoK50" rel="nofollow">https://youtu.be/Ja4oMFOoK50</a><p>This one contains more real examples of them ballooning:<p><a href="https://youtu.be/VDL9VxLqdvw" rel="nofollow">https://youtu.be/VDL9VxLqdvw</a>
There is a beautifully illustrated arxiv paper Ballooning Spiders: The Case for Electrostatic Flight by Peter W. Gorham
at <a href="https://arxiv.org/abs/1309.4731" rel="nofollow">https://arxiv.org/abs/1309.4731</a>, which is a good read, if you want to get a bit more into the subject.
Original paper: <a href="https://www.sciencedirect.com/science/article/pii/S0960982218306936" rel="nofollow">https://www.sciencedirect.com/science/article/pii/S096098221...</a>
FWIW, I saw a small (~1cm length x >1mm wide) caterpillar doing this once in the woods. I thought it was dangling from a tree but then it just kept going.
More like a showerthought, but:<p>If arachnids are able to detect magnetic fields and react accordingly, are humans also able to do the same?<p>Anecdotally, I've always had people commenting on how their mood is down when it is storming outside, and that they feel a 'negative energy' that doesn't motivate them to do anything. So I wonder if there is a relation?
There's a video version of the University of Bristol research story too <a href="https://www.youtube.com/watch?v=GRrUxi6d7so" rel="nofollow">https://www.youtube.com/watch?v=GRrUxi6d7so</a>
>This idea—flight by electrostatic repulsion—was first proposed in the early 1800s, around the time of Darwin’s voyage. Peter Gorham, a physicist, resurrected the idea in 2013, and showed that it was mathematically plausible. And now, Morley and Robert have tested it with actual spiders.<p>>First, they showed that spiders can detect electric fields. They put the arachnids on vertical strips of cardboard in the center of a plastic box, and then generated electric fields between the floor and ceiling of similar strengths to what the spiders would experience outdoors. These fields ruffled tiny sensory hairs on the spiders’ feet, known as trichobothria. “It’s like when you rub a balloon and hold it up to your hairs,” Morley says.<p>>In response, the spiders performed a set of movements called tiptoeing—they stood on the ends of their legs and stuck their abdomens in the air. “That behavior is only ever seen before ballooning,” says Morley. Many of the spiders actually managed to take off, despite being in closed boxes with no airflow within them. And when Morley turned off the electric fields inside the boxes, the ballooning spiders dropped.<p>One amazing thing to me is how this is the sort of experiment that an educated layman could do in his garage without the need for millions of dollars in funding and a research institute. Quaint and inspiring to aspiring citizen scientists at the same time.