7 ms·

Start of Lightning Bolt Caught on Camera

224 points by lelf 11y ago

deleted 11y ago
[deleted]
timtadh 11y ago
Here is the Nature article that this video goes with. http://www.nature.com/articles/srep15180 http://www.nature.com/articles/srep15180 .
- dang 11y ago
  That's obviously more substantive, and HN prefers original sources, but unfortunately it doesn't include a link to the video, so I guess we'll leave the URL as is.
  - timtadh 11y ago
    It is unfortunately hidden at the bottom as .mov in the supplementary information section: http://www.nature.com/articles/srep15180#supplementary-information http://www.nature.com/articles/srep15180#supplementary-infor... .
nosnos 11y ago
Site down.
- rmcpherson 11y ago
  Direct link to the video: https://www.youtube.com/watch?v=4dwBS9nLPbE https://www.youtube.com/watch?v=4dwBS9nLPbE
  - nosnos 11y ago
    Thanks. Seems to be back now.
rmcpherson 11y ago
Great video, the nature article is much more informative than the one linked. From the nature article, it seems this was the first video of natural bidirectional lightning, not triggered by rockets or aircraft: "In contrast to studies of rocket-triggered lightning and lightning initiated by aircraft, which found delays of 3–6 ms between the onset of negative and positive leader branches, this natural event exhibited a delay of less than 90 μs (i.e. one video image)." This was a negative polarity lightning strike. the most common type. Less than 5% of lightning is positive polarity but they can carry ten times the charge and exceed a billion volts of potential. When you read about people surviving lightning strikes it's almost certainly a negative polarity strike. https://en.wikipedia.org/wiki/Lightning#Positive_and_negative_lightning https://en.wikipedia.org/wiki/Lightning#Positive_and_negativ...
- omribahumi 11y ago
  Are the positive ones the "bigger" ones? EDIT: From the linked Wikipedia entry: "Because of the much greater distance to ground, the positively charged region can develop considerably larger levels of charge and voltages than the negative charge regions in the lower part of the cloud."
  - TeMPOraL 11y ago
    I didn't know about positive/negative polarity types of discharges, thanks! Also, having Cloud to Butt extension installed made reading that Wikipedia quote quite interesting...
- ourmandave 11y ago
  ...carry ten times the charge and exceed a billion volts of potential. Great Scott!
webXL 11y ago
11k fps. Wow. I will never get tired of watching this stuff. That got me thinking, is there any theoretical limit to the number of frames that can be captured in one second?
- dalke 11y ago
  "Single-shot compressed ultrafast photography at one hundred billion frames per second" - http://www.cnet.com/news/worlds-fastest-2d-camera-can-capture-100-billion-frames-per-second/ http://www.cnet.com/news/worlds-fastest-2d-camera-can-captur...
- CapitalistCartr 11y ago
  Electricity travels at about one third the speed of light. That would make a hard limit. Both shutter and data transfer speed.
  - webXL 11y ago
    But that would just be for one recording device. If you could use multiple devices, perhaps with small POV differences that could be corrected, I would expect no limit in that "lossy" case.
    - TeMPOraL 11y ago
      Amount of total photons emitted or hitting the Planck limit, whichever comes first.
    - javajosh 11y ago
      But if you surrounded an event with a sphere of sensors, there is still an upper limit. The number of sensors is a function of sphere radius, and whether they are limited to the surface of the sphere (which is reasonable since tightly packed sensors will, in general, get in the way of other sensors). A sphere 1km across has a surface are of 4pi1km^2 which is roughly 10^7m^2. If you had 1cm^2 sensors then you get 10^4 sensors per m^2, which means you get 10^11 sensors total. At 11k fps (10^4) that's a total of 10^15 fps. Note that Planck time is 10^-44 so such an arrangement probably wouldn't help for detecting quantum gravity because you'd run out of matter in the universe before you could construct the sensors.
justifier 11y ago
lightning is enigmatic and the internet facing community surrounding its research seems divisive can anyone speak to the sort of research currently being done on the study of lightning and its initiation? are there efforts to recreate assumed initial conditions? thoughts on the source of the huge amounts of directed energy? does the strike harvest from the vast collection of charged particles within the cloud or is it created by electrostatic interaction of individual ions, similar to http://www.nature.com/nchem/journal/v7/n3/full/nchem.2161.html http://www.nature.com/nchem/journal/v7/n3/full/nchem.2161.ht...?
myth_buster 11y ago
I also like this 10,000 fps video [0] credited to Tim Samaras. [0] https://i.imgur.com/W1X1qFI.jpg https://i.imgur.com/W1X1qFI.jpg
- heinrich5991 11y ago
  I was wondering how you could talk about a video and then link to a single image (I think jpg doesn't support animation). But it turns out all of https://i.imgur.com/W1X1qFI.jpg https://i.imgur.com/W1X1qFI.jpg https://i.imgur.com/W1X1qFI.gif https://i.imgur.com/W1X1qFI.gif https://i.imgur.com/W1X1qFI.png https://i.imgur.com/W1X1qFI.png link to the same GIF. :)
  - raverbashing 11y ago
    Ah good thing, so imgur abstracts extensions apparently Better if you request with .gifv extension, then it's a much smaller (than a gif) html5 video)
    - jrowley 11y ago
      The only issue with gifv is that if you open one on iOS it will pause whatever music you're listening to at the time. Kind of a bummer and something that will hopefully eventually get fixed.
  - myth_buster 11y ago
    I think that makes sense as I believe in their system the identifier will be W1X1qFI which happens to be the url/filename and is auto-generated it ignores the extension instead of throwing a 404.
  - _puk 11y ago
    For a second there I though they'd done something really clever with progressive jpegs!
vegabook 11y ago
a) overloaded site b) very nice, but is this "Hacker" News? More like Discovery Channel. How is this interesting from a tech point of view? High FPS cameras. Got it. Got it long ago.
- wlievens 11y ago
  "High FPS Camera" is a lot more impressive than the latest twitter-controlled todo-list app or whatever.

224 points by lelf 11y ago

deleted 11y ago

[deleted]

Here is the Nature article that this video goes with. http://www.nature.com/articles/srep15180 http://www.nature.com/articles/srep15180 .

dang 11y ago
That's obviously more substantive, and HN prefers original sources, but unfortunately it doesn't include a link to the video, so I guess we'll leave the URL as is.
- timtadh 11y ago
  It is unfortunately hidden at the bottom as .mov in the supplementary information section: http://www.nature.com/articles/srep15180#supplementary-information http://www.nature.com/articles/srep15180#supplementary-infor... .

nosnos 11y ago

Site down.

rmcpherson 11y ago
Direct link to the video: https://www.youtube.com/watch?v=4dwBS9nLPbE https://www.youtube.com/watch?v=4dwBS9nLPbE
- nosnos 11y ago
  Thanks. Seems to be back now.

rmcpherson 11y ago

Great video, the nature article is much more informative than the one linked. From the nature article, it seems this was the first video of natural bidirectional lightning, not triggered by rockets or aircraft: "In contrast to studies of rocket-triggered lightning and lightning initiated by aircraft, which found delays of 3–6 ms between the onset of negative and positive leader branches, this natural event exhibited a delay of less than 90 μs (i.e. one video image)." This was a negative polarity lightning strike. the most common type. Less than 5% of lightning is positive polarity but they can carry ten times the charge and exceed a billion volts of potential. When you read about people surviving lightning strikes it's almost certainly a negative polarity strike. https://en.wikipedia.org/wiki/Lightning#Positive_and_negative_lightning https://en.wikipedia.org/wiki/Lightning#Positive_and_negativ...

omribahumi 11y ago
Are the positive ones the "bigger" ones? EDIT: From the linked Wikipedia entry: "Because of the much greater distance to ground, the positively charged region can develop considerably larger levels of charge and voltages than the negative charge regions in the lower part of the cloud."
- TeMPOraL 11y ago
  I didn't know about positive/negative polarity types of discharges, thanks! Also, having Cloud to Butt extension installed made reading that Wikipedia quote quite interesting...
ourmandave 11y ago
...carry ten times the charge and exceed a billion volts of potential. Great Scott!

webXL 11y ago

11k fps. Wow. I will never get tired of watching this stuff. That got me thinking, is there any theoretical limit to the number of frames that can be captured in one second?

dalke 11y ago
"Single-shot compressed ultrafast photography at one hundred billion frames per second" - http://www.cnet.com/news/worlds-fastest-2d-camera-can-capture-100-billion-frames-per-second/ http://www.cnet.com/news/worlds-fastest-2d-camera-can-captur...
CapitalistCartr 11y ago
Electricity travels at about one third the speed of light. That would make a hard limit. Both shutter and data transfer speed.
- webXL 11y ago
  But that would just be for one recording device. If you could use multiple devices, perhaps with small POV differences that could be corrected, I would expect no limit in that "lossy" case.
  - TeMPOraL 11y ago
    Amount of total photons emitted or hitting the Planck limit, whichever comes first.
  - javajosh 11y ago
    But if you surrounded an event with a sphere of sensors, there is still an upper limit. The number of sensors is a function of sphere radius, and whether they are limited to the surface of the sphere (which is reasonable since tightly packed sensors will, in general, get in the way of other sensors). A sphere 1km across has a surface are of 4pi1km^2 which is roughly 10^7m^2. If you had 1cm^2 sensors then you get 10^4 sensors per m^2, which means you get 10^11 sensors total. At 11k fps (10^4) that's a total of 10^15 fps. Note that Planck time is 10^-44 so such an arrangement probably wouldn't help for detecting quantum gravity because you'd run out of matter in the universe before you could construct the sensors.

justifier 11y ago

lightning is enigmatic and the internet facing community surrounding its research seems divisive can anyone speak to the sort of research currently being done on the study of lightning and its initiation? are there efforts to recreate assumed initial conditions? thoughts on the source of the huge amounts of directed energy? does the strike harvest from the vast collection of charged particles within the cloud or is it created by electrostatic interaction of individual ions, similar to http://www.nature.com/nchem/journal/v7/n3/full/nchem.2161.html http://www.nature.com/nchem/journal/v7/n3/full/nchem.2161.ht...?

myth_buster 11y ago

I also like this 10,000 fps video [0] credited to Tim Samaras. [0] https://i.imgur.com/W1X1qFI.jpg https://i.imgur.com/W1X1qFI.jpg

heinrich5991 11y ago
I was wondering how you could talk about a video and then link to a single image (I think jpg doesn't support animation). But it turns out all of https://i.imgur.com/W1X1qFI.jpg https://i.imgur.com/W1X1qFI.jpg https://i.imgur.com/W1X1qFI.gif https://i.imgur.com/W1X1qFI.gif https://i.imgur.com/W1X1qFI.png https://i.imgur.com/W1X1qFI.png link to the same GIF. :)
- raverbashing 11y ago
  Ah good thing, so imgur abstracts extensions apparently Better if you request with .gifv extension, then it's a much smaller (than a gif) html5 video)
  - jrowley 11y ago
    The only issue with gifv is that if you open one on iOS it will pause whatever music you're listening to at the time. Kind of a bummer and something that will hopefully eventually get fixed.
- myth_buster 11y ago
  I think that makes sense as I believe in their system the identifier will be W1X1qFI which happens to be the url/filename and is auto-generated it ignores the extension instead of throwing a 404.
- _puk 11y ago
  For a second there I though they'd done something really clever with progressive jpegs!

vegabook 11y ago

a) overloaded site b) very nice, but is this "Hacker" News? More like Discovery Channel. How is this interesting from a tech point of view? High FPS cameras. Got it. Got it long ago.

wlievens 11y ago
"High FPS Camera" is a lot more impressive than the latest twitter-controlled todo-list app or whatever.