How fast can lightning change direction?

In summary, the article discusses how researchers have found that the cause of lighting is not what we thought it was. Instead, it is the result of runaway electrons that are created by high energy cosmic radiation. This information could help in the development of new technologies, such as better Tasers.
  • #1
DeeZee
18
0
Does lightning mainly just move in a straight line or can it change really quickly? Can it move around objects, like something that's not a good conductor, to get to something that is?
 
Science news on Phys.org
  • #2
OHh I also wonder why lightning doesn't propogate in a straight line ... but in a zigzag type of path. Is it because it chooses the path that is least resistive ?
 
  • #3
I'll take a whack at this question for you. The lightning choses the path of least resistance so it will zig zag around less conductive air to get to the ground easier. On the topic of changing direction: It obviously changes direction quickly but I only know that because I observe it. I have no information to back this up.
 
  • #4
So does anyone know for sure?
 
  • #5
Very complicated

Well, there's a couple of things going on. It is true that lightning travels along the path of least resistance. However, before there is the main stroke of a lightning bolt, there are hundreds of leader tracks- low current short arcs- that "feel out" the local ionization, looking for a path of low enough resistance to initiate an arc. Any contaminant in the air (water vapor, dust, pollutants) that happen to be in the way of the arc provide a lower resistance than air alone. Plus, as the arc progresses, the air gets super heated - creating an ionized path as it goes. This ionized path is subject to both the eddy currents in the air and the magnetic field of the earth. Plus, the arc itself has a strong magnetic field. Plasma in a magnetic field has very complicated motion, and chaotic paths are not entirely uncommon.

So to answer your question, I can't imagine that a lightning bolt would ever be straight, what with all the different things going on at once. :smile:
 
  • #6
DeeZee said:
So does anyone know for sure?

Keep in mind that a lightning is similar to an arcing or a discharge. The path that a lightning takes is very complicated due to a number of factors, such as density of the medium, polarizability, charge distribution, etc. Air in itself does not have a uniform density over a large distance (that's why we have winds). So this makes the path even more complicated.

Note that this isn't unique just for lightning. Arcing in a medium also does not follow a straight line path. In fact, it can be downright twisted since it depends on grain boundaries, defects, variation in density, etc. To illustrate this, I have a recent SEM image that I took of a ceramic of MgCaTi compound in which an electrical breakdown occurred right at the butted joint. You can see the tracks made by the arc and they look like "wormholes".

Zz.
 

Attachments

  • mct.jpg
    mct.jpg
    49.4 KB · Views: 649
  • #7
Thanks, ZapperZ. I don't get everything you said, though. :P
Are there any easy to understand examples of lightning changing direction quickly?
 
  • #9
According to an article in the latest issue of Scientific American, authored by Joseph Dwyer (researcher in Florida), the cause of lighting is much different than previously thought.

In brief: Dwyer found copious X-ray production that he states could only be generated by high-energy electrons he calls “runaway electrons”. The x-rays are not produced during the lighting flash, but during the “leader” period preceding the flash. The underlying cause of the energetic electrons is cosmic radiation that initiates a chain reaction of free electrons. The electrons must be accelerated by a 200,000 volt per meter field to reach energies sufficient to generate x-rays. Apparently accelerated electrons, not the presumed “electrons taking the path of least resistance”, create the leader. His sensors have detected x-ray production by the leader within a few meters of the ground.
 
  • #10
GENIERE said:
According to an article in the latest issue of Scientific American, authored by Joseph Dwyer (researcher in Florida), the cause of lighting is much different than previously thought.
A most interesting article; I was about to recommend it myself. That runaway electron effect seems as if it should have some practical uses if it can be harnessed. (Maybe a better Taser? :biggrin: )
Kidding about that, but some new stuff regarding high energy discharges could help with other areas of research perhaps, such as in plasmas or materials science.
 

Related to How fast can lightning change direction?

1. How fast can lightning change direction?

Lightning can change direction at speeds of up to 220,000 miles per hour, making it one of the fastest natural phenomena on Earth.

2. What factors influence the speed at which lightning changes direction?

The speed at which lightning changes direction depends on various factors such as wind speed, air temperature, and the electrical conductivity of the air.

3. Can lightning change direction multiple times during a single strike?

Yes, lightning can change direction multiple times during a single strike. This is known as "forked lightning" and is a common occurrence during thunderstorms.

4. Is it possible for lightning to completely reverse its direction?

In some cases, lightning can reverse its direction completely. This is known as "bolt from the blue" and is a rare phenomenon that occurs when the electrical charge from a thunderstorm travels horizontally through the upper atmosphere before striking the ground in a different location.

5. How does the speed of lightning compare to other natural phenomena?

The speed of lightning is incredibly fast and can be compared to other natural phenomena such as the speed of sound, which is 767 miles per hour, and the speed of light, which is 670,616,629 miles per hour.

Similar threads

Replies
2
Views
7K
Replies
8
Views
2K
Replies
17
Views
5K
Replies
44
Views
6K
  • Special and General Relativity
Replies
21
Views
686
Replies
2
Views
5K
  • Electromagnetism
Replies
10
Views
2K
Replies
3
Views
618
  • Computing and Technology
Replies
15
Views
2K
Back
Top