# What’s the physics behind this lightning strike ? **URL:** \ **Category:** Factual Questions\ **Created:** [August 20, 2019, 10:41pm UTC](https://boards.straightdope.com/t/what-s-the-physics-behind-this-lightning-strike/838973 "2019-08-20T22:41:44Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![am77494](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@am77494](https://boards.straightdope.com/u/am77494)\ **Post date:** [August 20, 2019, 10:41pm UTC](https://boards.straightdope.com/t/what-s-the-physics-behind-this-lightning-strike/838973/1 "2019-08-20T22:41:44Z")
There are many videos of this lightning strike on the internet. You can find them here : [Romulus McNeill lightning - Google Search](https://www.google.com/search?client=safari&hl=en&biw=375&bih=549&tbm=vid&ei=C3ZcXcSFF9GWsAW9gLboDw&q=Romulus+McNeill+lightning&oq=Romulus+McNeill+lightning&gs_l=mobile-gws-serp.3..33i160k1.5546.9342.0.9717.12.11.0.1.1.0.309.1151.7j2j0j1.10.0....0...1c.1j2.64.mobile-gws-serp..1.11.1173.3..41j0i3k1j33i299k1.0.F8n4RZ_UTL4) It appears that a huge discharge rises from the ground to the man’s umbrella. Am I seeing this correctly ? What’s the physics behind this ? ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [August 20, 2019, 11:21pm UTC](https://boards.straightdope.com/t/what-s-the-physics-behind-this-lightning-strike/838973/2 "2019-08-20T23:21:09Z")
First, you can’t really tell anything about the strike from the video, because the strike moves much faster than the frame rate of the camera. It’s a very incomplete look at what really happened. I’ll link to an explanation of a lightning strike I made in a recent thread. So you are correct that the discharge you see rises from the ground, but it doesn’t terminate at the umbrella. > [@Lightning fell really close to me today - anybody else had lightning striking too close for comfort?](https://boards.straightdope.com/t/lightning-fell-really-close-to-me-today-anybody-else-had-lightning-striking-too-close-for-comfort/838606/9): > > Because it’s a fun fact, not because I’m trying to be pedantic: the lightning actually **rose** 10-15m away from you, not fell. A typical lightning strike is initiated by a flow of negative charge down from the cloud. As it approaches the ground (50-100 m), a positive streamer reaches up and meets the downward ladder, at which point a return stroke goes from ground to sky. This return stroke is what you see. This video uses ridiculously fast frame rates so you can actually see how a strike propagates. > [@Lightning fell really close to me today - anybody else had lightning striking too close for comfort?](https://boards.straightdope.com/t/lightning-fell-really-close-to-me-today-anybody-else-had-lightning-striking-too-close-for-comfort/838606/32): > > Check out the lightning strike when the [video starts playing](https://www.youtube.com/watch?v=qQKhIK4pvYo&feature=youtu.be&t=332). Pause the video and use the “,” and “.” keys to move backwards and forwards, frame by frame. With this strike, one can visibly see, in one frame, the return stroke starting from the ground. According to Wikipedia, “the rate at which the return stroke current travels has been found to be around 100,000 km/s.” ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 20, 2019, 11:24pm UTC](https://boards.straightdope.com/t/what-s-the-physics-behind-this-lightning-strike/838973/3 "2019-08-20T23:24:24Z")
There’s an extensive explanation of what happened in the first article on that page of results you linked to. What you see near the man is probably an upward leader (or streamer), one which did _not_ connect with the downward leader to form the main path of discharge - that happened nearby - otherwise he’d probably be dead. The second (small) picture in this article shows this happening over water: > **[A Lightning Bolt Hits Water, So Close You Can See Its Streamers](https://astroengine.com/2009/06/02/a-lightning-bolt-hits-water-so-close-you-can-see-its-streamers/)** > > It’s pictures like these that make me a) want to do more photography, b) feel more in awe of nature than I already am, and c) wonder how the photographer didn’t pack up his gear and run… > [@](#): > > In a typical cloud-to-ground lightning strike, as the leader approaches the ground, the large electric field at the leader tip induces these upward propagating streamers. The first one that connects to the downward propagating leader initiates the bright return stroke that we see with our eye. Another great picture of the phenomenon here: > ---
**Author:** ![Johanna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johanna/32/8318_2.png) [@Johanna](https://boards.straightdope.com/u/Johanna)\ **Post date:** [August 22, 2019, 3:58pm UTC](https://boards.straightdope.com/t/what-s-the-physics-behind-this-lightning-strike/838973/4 "2019-08-22T15:58:23Z")
I observed rising streamers in Rocky Mountain National Park in Colorado one summer. I climbed to the top of a col and looked down into a small bowl-shaped valley. A late afternoon storm gathered and I watched lightning flash _up_ just in front of me. It was rose-tinged purple at the bottom.