<p>When I go through <a href="https://en.wikipedia.org/wiki/Electroencephalography" rel="nofollow noreferrer">Electroencephalography</a>,</p>
<pre><code>Band    Frequency (Hz)
Delta   &lt; 4
Theta   ≥ 4 and &lt; 8
Alpha   ≥ 8 and &lt; 14
Beta    ≥ 14 
</code></pre>
<p>How much are wave length of brain wave?</p>
<p>Thanks for  Bryan Krause's comment,&quot;Brain waves&quot; aren't EM waves,but mechanical wave has width as we known.</p>
<p>And it's obvious brain wave is some kinds of wave, with <a href="https://inbrain.tech/a-journey-into-the-nervous-system-brainwaves/1241/" rel="nofollow noreferrer">frequency and scale</a>.</p>
<blockquote>
<p>When someone is awake, with his eyes closed, the EEG is dominated by the <strong>α (alpha) band</strong>. This type of waves is characterized by a frequency of 8-13 Hz and a normal width &lt;50 microvolts (µV).</p>
<p>If the subject opens his eyes, α waves disappear and another wave type becomes evident: the <strong>β (beta) type</strong>. These brainwaves have a higher frequency (30-35 Hz) and a width of 25-30 µV.</p>
</blockquote>
<p>Then I still want to know <strong>Does brain wave has wave length?</strong>.</p>
<p><a href="https://i.sstatic.net/xKIAt.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/xKIAt.png" alt="representations of different brain wave bands" /></a></p>

CC BY-SA 4.0
2021-02-17T03:52:37.033Z
Does this answer your question? [Are brain waves electromagnetic waves?](https://psychology.stackexchange.com/questions/15222/are-brain-waves-electromagnetic-waves)
Bryan Krause
CC BY-SA 4.0
2021-02-17T03:55:13.197Z
"Brain waves" aren't EM waves, see attached duplicate. The frequencies are in Hz which is units of 1/s. So you could say the length (as in duration) of a 4 Hz brain wave is .25 seconds, but that's just another way of describing the frequency. There is no length in space like an EM wave.
Bryan Krause
CC BY-SA 4.0
2021-02-17T07:26:15.290Z
@BryanKrause,aren't EM waves.Can we say brain waves are waves with wave width?
kittygirl
CC BY-SA 4.0
2021-02-17T10:03:19.730Z
At this present moment your question is not clear to me. At the beginning of your question you listed the wavelength frequency ranges for each type of brain wave then you seem to be asking what the wavelengths are for the brain waves?
Chris Rogers
CC BY-SA 4.0
2021-02-17T13:09:53.030Z
@BryanKrause while I'm not a neuroscientist, my background is physics. In my understanding, in a purely physical point of view brain wave is EM wave. However, it seems to me that neuroscientists and physicists define EM wave differently. That lead to the confusion, because one can find one source says it's EM, then another source say it's not. I elaborate this in [this answer](https://psychology.stackexchange.com/a/23475/12937). Hope to have my understanding corrected.
Ooker
CC BY-SA 4.0
2021-02-17T13:16:59.980Z
@kittygirl did you mean "how long are brainwaves in one period?" In my understanding, we can apply the formula "length = velocity / frequency". In this case, the velocity is c, i.e. light velocity
Ooker
CC BY-SA 4.0
2021-02-17T13:46:28.307Z
@Ooker The thing people call brain waves is not an EM wave. It's a time-varying voltage. I recommend AliceD's answer on the linked post. That doesn't mean the brain isn't also producing EM, just that brain waves are not it.
Bryan Krause
CC BY-SA 4.0
2021-02-17T13:47:14.393Z
@kittygirl Width of what units? Time? Something else?
Bryan Krause
CC BY-SA 4.0
2021-02-17T20:49:13.043Z
@BryanKrause,width is something like 20m,400cm.
kittygirl
CC BY-SA 4.0
2021-02-17T21:01:01.403Z
@kittygirl There is no length (or width or anything else) in space, as I wrote in a comment above. The axes are voltage and time. The "waviness" at different frequency is because the signals in those plots are filtered to include only certain frequencies, so the "width" of a wave takes more or less time. Brain waves are not EM waves.
Bryan Krause
CC BY-SA 4.0
2021-02-20T03:56:16.030Z
All waves have wavelengths.  However, the unit of measure for wavelengths is not always in space (ie, it is not always in meters).  As you can see from the graphs included in the question itself, the length for brainwaves is in time (seconds), which you can calculate using s = 1/Hz, as @BryanKrause exampled above.  Other examples of waves with time-based wavelengths include heatwaves, ECG (heart beats), and economic cycles.  Closing this question as answered in comments.
Arnon Weinberg
CC BY-SA 4.0
2021-02-21T03:28:33.693Z
`When someone is awake, with his eyes closed, the EEG is dominated by the α (alpha) band. This type of waves is characterized by a frequency of 8-13 Hz and a normal width <50 microvolts (μV).`  https://inbrain.tech/a-journey-into-the-nervous-system-brainwaves/1241/
WhiteGirl
CC BY-SA 4.0
2021-02-21T20:32:06.080Z
@ close-voters - I find it a bit harsh to close this question. I was actually planning on answering it. Pointing out that wavelength doesn't apply is a valid answer to a valid question imho. Furthermore, the fact that the synchronous firing behavior is restricted to certain local areas of the brain may actually give an idea of the wavelength, although I'm uncertain if normal physiological waves actually progress unidirectionally through cortical areas like those so characteristic of epileptical activity - have to do research on that. I was too busy to jump in.
AliceD
CC BY-SA 4.0
2021-02-21T21:13:38.617Z
@AliceD I'd be really worried about answers that don't do enough to dispell this idea that brain waves are EM waves, including the sorts of answers on that linked question that argue that changing voltages must involve EM waves. Anyways, my vote to close was really only because I think this question has a dupe that already has some good (and bad) answers about what brain waves are.
Bryan Krause
CC BY-SA 4.0
2021-02-22T08:51:02.287Z
@ArnonWeinberg No wavelength is measured in relation to space are they? All wavelengths (radio waves, heat waves, sound waves... and brain waves) are in units of Hertz which is cycles per second. Brain waves are different as they are not constant, hence the **frequency ranges** mentioned in the question.
Chris Rogers
CC BY-SA 4.0
2021-02-22T18:41:46.397Z
@ChrisRogers From [Wikipedia](https://en.wikipedia.org/wiki/Wavelength): "wavelength is inversely proportional to frequency".  So WL = 1/f, or in units, m or s = 1/Hz.
Arnon Weinberg
CC BY-SA 4.0
2021-02-22T18:52:30.993Z
Ah yes @ArnonWeinberg. I got confused between wavelengths and frequency. Was a while since I studied it in school
Chris Rogers
<eeg><brain-waves>
Does brain wave has wave length?
kittygirl
# Does brain wave has wave length?

(Asked by: username_0 on 2021-02-17)

When I go through Electroencephalography,
Band    Frequency (Hz)
Delta   < 4
Theta   ≥ 4 and < 8
Alpha   ≥ 8 and < 14
Beta    ≥ 14 

How much are wave length of brain wave?
Thanks for  username_1's comment,"Brain waves" aren't EM waves,but mechanical wave has width as we known.
And it's obvious brain wave is some kinds of wave, with frequency and scale.

When someone is awake, with his eyes closed, the EEG is dominated by the α (alpha) band. This type of waves is characterized by a frequency of 8-13 Hz and a normal width <50 microvolts (µV).
If the subject opens his eyes, α waves disappear and another wave type becomes evident: the β (beta) type. These brainwaves have a higher frequency (30-35 Hz) and a width of 25-30 µV.

Then I still want to know Does brain wave has wave length?.

**Tags:** eeg, brain-waves

> **Comments:**
> **username_1**: Does this answer your question? [Are brain waves electromagnetic waves?](https://psychology.stackexchange.com/questions/15222/are-brain-waves-electromagnetic-waves)  
> **username_1**: "Brain waves" aren't EM waves, see attached duplicate. The frequencies are in Hz which is units of 1/s. So you could say the length (as in duration) of a 4 Hz brain wave is .25 seconds, but that's just another way of describing the frequency. There is no length in space like an EM wave.  
> **username_0**: @BryanKrause,aren't EM waves.Can we say brain waves are waves with wave width?  
> **username_2**: At this present moment your question is not clear to me. At the beginning of your question you listed the wavelength frequency ranges for each type of brain wave then you seem to be asking what the wavelengths are for the brain waves?  
> **username_3**: @BryanKrause while I'm not a neuroscientist, my background is physics. In my understanding, in a purely physical point of view brain wave is EM wave. However, it seems to me that neuroscientists and physicists define EM wave differently. That lead to the confusion, because one can find one source says it's EM, then another source say it's not. I elaborate this in [this answer](https://psychology.stackexchange.com/a/23475/12937). Hope to have my understanding corrected.  
> **username_3**: @username_0 did you mean "how long are brainwaves in one period?" In my understanding, we can apply the formula "length = velocity / frequency". In this case, the velocity is c, i.e. light velocity  
> **username_1**: @username_3 The thing people call brain waves is not an EM wave. It's a time-varying voltage. I recommend username_6's answer on the linked post. That doesn't mean the brain isn't also producing EM, just that brain waves are not it.  
> **username_1**: @username_0 Width of what units? Time? Something else?  
> **username_0**: @BryanKrause,width is something like 20m,400cm.  
> **username_1**: @username_0 There is no length (or width or anything else) in space, as I wrote in a comment above. The axes are voltage and time. The "waviness" at different frequency is because the signals in those plots are filtered to include only certain frequencies, so the "width" of a wave takes more or less time. Brain waves are not EM waves.  
> **username_4**: All waves have wavelengths.  However, the unit of measure for wavelengths is not always in space (ie, it is not always in meters).  As you can see from the graphs included in the question itself, the length for brainwaves is in time (seconds), which you can calculate using s = 1/Hz, as @BryanKrause exampled above.  Other examples of waves with time-based wavelengths include heatwaves, ECG (heart beats), and economic cycles.  Closing this question as answered in comments.  
> **username_5**: `When someone is awake, with his eyes closed, the EEG is dominated by the α (alpha) band. This type of waves is characterized by a frequency of 8-13 Hz and a normal width <50 microvolts (μV).`  https://inbrain.tech/a-journey-into-the-nervous-system-brainwaves/1241/  
> **username_6**: @ close-voters - I find it a bit harsh to close this question. I was actually planning on answering it. Pointing out that wavelength doesn't apply is a valid answer to a valid question imho. Furthermore, the fact that the synchronous firing behavior is restricted to certain local areas of the brain may actually give an idea of the wavelength, although I'm uncertain if normal physiological waves actually progress unidirectionally through cortical areas like those so characteristic of epileptical activity - have to do research on that. I was too busy to jump in.  
> **username_1**: @username_6 I'd be really worried about answers that don't do enough to dispell this idea that brain waves are EM waves, including the sorts of answers on that linked question that argue that changing voltages must involve EM waves. Anyways, my vote to close was really only because I think this question has a dupe that already has some good (and bad) answers about what brain waves are.  
> **username_2**: @ArnonWeinberg No wavelength is measured in relation to space are they? All wavelengths (radio waves, heat waves, sound waves... and brain waves) are in units of Hertz which is cycles per second. Brain waves are different as they are not constant, hence the **frequency ranges** mentioned in the question.  
> **username_4**: @ChrisRogers From [Wikipedia](https://en.wikipedia.org/wiki/Wavelength): "wavelength is inversely proportional to frequency".  So WL = 1/f, or in units, m or s = 1/Hz.  
> **username_2**: Ah yes @ArnonWeinberg. I got confused between wavelengths and frequency. Was a while since I studied it in school  

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## 0 answers

