# Light vs Thought **URL:** \ **Category:** Factual Questions\ **Created:** [June 28, 2000, 1:22am UTC](https://boards.straightdope.com/t/light-vs-thought/23815 "2000-06-28T01:22:23Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![John\_Kentzel-Griffin](https://avatars.discourse-cdn.com/v4/letter/j/ccd318/32.png) [@John\_Kentzel-Griffin](https://boards.straightdope.com/u/John_Kentzel-Griffin)\ **Post date:** [June 28, 2000, 9:04pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/21 "2000-06-28T21:04:41Z")
**Jeff\_42** said: > [@](#): > > From what I understand a human can perceive a ‘timeslice’ no smaller than 1/24th of a second (or thereabouts…I’d have to look it up). Whatever it is it is CONSIDERABLY slower than lightspeed. [another nitpick] The speed of light not measured in units of time, but distance per time. [/another nitpick] ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 29, 2000, 12:07am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/22 "2000-06-29T00:07:05Z")
> [@](#): > > [another nitpick] > The speed of light not measured in units of time, but distance per time. > [/another nitpick] You are, of course, correct. I was trying to imply a correlation between light speed and thought. Say an average brain is 6 inches across. A light beam in our head (if it were a vacuum like my head) could bounce back and forth not quite 2 billion times in one second. If we can perceive only 1/24th of one second as opposed to 1/2,000,000,000th of a second there must be some kind of delay happening up there. Whatever the reason we’re clearly not close to light speed on the thought side of things. _P.S. What? That wasn’t clear in my earlier post? Sheesh…gotta explain everything (that’s sarcasm for the humor inhibited)._ ---
**Author:** ![RM\_Mentock](https://avatars.discourse-cdn.com/v4/letter/r/e274bd/32.png) [@RM\_Mentock](https://boards.straightdope.com/u/RM_Mentock)\ **Post date:** [June 29, 2000, 8:18am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/23 "2000-06-29T08:18:49Z")
> [@](#): > > **jeff\_42 wrote:** > [nitpick back] > Then that’s the speed of light in silicon. \ > > If we all lived in silicon then we’d measure the speed of light at 100,000 m/s and that would be the top speed. I believe scientists have slowed light down considerably more than that…something like 50 mph. Doesn’t matter, the speed of light speed limit is still consistent. > [/nitpick back] That can’t be true. Isn’t the speed of electricity the average speed of electrons, which are not electromagnetic wavicles (light)? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 29, 2000, 11:47am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/24 "2000-06-29T11:47:37Z")
> [@](#): > > Isn’t the speed of electricity the average speed of electrons, which are not electromagnetic wavicles (light)? I thought electricity didn’t actually ‘move’ electrons. Electrons are excited as energy(?) propogates along a wire or through the atmosphere. Like shaking a string makes waves that look as if it is moving forward it is an energy wave moving forward…not the string. I thought this energy wave moves at the speed of light. ---
**Author:** ![gEEk](https://avatars.discourse-cdn.com/v4/letter/g/ed8c4c/32.png) [@gEEk](https://boards.straightdope.com/u/gEEk)\ **Post date:** [June 29, 2000, 2:42pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/25 "2000-06-29T14:42:50Z")
> [@](#): > > \*\* > > > [@](#): > > > > [nitpick] > > Not quite. For silicon the maximum velocity of electrons is 100,000 m/s which is 3000 times less than the speed of light. > > [/nitpick] > > [nitpick back] > Then that’s the speed of light in silicon. Speed of light in a vacuum is something on the order of 186,000 miles/sec. I’ll take your figure in silicon at face value. I assume the speed of light is also slower in our brains as most of us have maybe just a bit more than a vaccum between our ears (can’t wait for the ribbing on this one). > > If we all lived in silicon then we’d measure the speed of light at 100,000 m/s and that would be the top speed. I believe scientists have slowed light down considerably more than that…something like 50 mph. Doesn’t matter, the speed of light speed limit is still consistent. > [/nitpick back] > \*\* [rebuttal of rebuttal of nitpick] Nope. The speed of light in silicon can be calculated from it’s index of refraction. The index of refraction is defined as the ratio of the speed of light in a material to the speed of light in a vaccuum: R=c/v where R is the index of refraction, c is the speed of light in a vaccuum and v is the speed of light in the material. The index of refraction of silicon is 3.42. Rearranging the formula we have: v=c/R v=(3\*10^8 m/s)/3.42 v=9\*10^7 m/s This is a lot faster than the speed of electrons in silicon. [/rebuttal of rebuttal of nitpick] gEEk ---
**Author:** ![Drew\_Blade](https://avatars.discourse-cdn.com/v4/letter/d/958977/32.png) [@Drew\_Blade](https://boards.straightdope.com/u/Drew_Blade)\ **Post date:** [July 1, 2000, 3:16pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/26 "2000-07-01T15:16:56Z")
insider never returned to clarify the OP or to comment on the answers given (so I am probably off-base here), but I took him to be asking a different question–although the answer Chronos gave can as easily be applied to my interpretation. I thought insider was asking if the “speed of thought” would be faster than the speed of light IF thoughts could be transmitted ESP-style from one person to another. We can suppose that since thought-transmission does not currently exist, it does not necessarily follow current physical laws or limitations, but that is just a supposition. ---
**Author:** ![Saint\_Zero](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@Saint\_Zero](https://boards.straightdope.com/u/Saint_Zero)\ **Post date:** [July 1, 2000, 3:36pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/27 "2000-07-01T15:36:41Z")
Just as an aside, there are no electrical signals in the brain. Sorry. 😃 It’s an electrochemical reaction, which runs _lots_ slower than light. [http://neuroscience.about.com/science/neuroscience/library/weekly/aa060898.htm](http://neuroscience.about.com/science/neuroscience/library/weekly/aa060898.htm) Hope that comes out right… Anyway, the article mentions that it took about 1/2 second for an unfamiliar image, less time for something familiar. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 1, 2000, 4:16pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/28 "2000-07-01T16:16:26Z")
OK, there’s a few speeds of relevance here. In a typical circuit, metal or silicon, the electrons themselves travel at only a few centimeters a second, if that. The signal and energy, however, are transmitted by the electric field of the electrons, which travels much faster-- In fact, it travels at exactly the speed of light in that medium. The brain is rather more complicated than a man-made circuit, as Saint Zero points out. Within a given neuron, a signal is propagated by a wave of ionic transport. Again, the ions themselves move rather slowly, but the wave moves quickly, although not nearly the speed of light. When the signal reaches the end of the neuron, it’s actually transmitted across the synapse, or gap between neurons, by a chemical (called a neurotransmitter)which physically moves across the gap. Here, the speed of the information is the same as the speed of the matter which is actually moving, which is not very fast. When you consider the average speed of a signal which must traverse many neurons, it works out to about 300 miles per hour, much slower than light. This is the only meaningful answer to the OP in the context of what we now know about neurology and physics. If, on the other hand, the question was referring to some hypothetical telepathic abilities, then my earlier comments about information stand. If ESP can somehow transmit information at faster than the speed of light, then it can also transmit information backward in time, implying prescience. Admittedly, many folks who believe in the possibility of telepathy wouldn’t have a problem with this, but physicists would. The prevailing opinion among physicists (mostly, but not entirely, proven), is that any method which can accomplish this would require the use of exotic materials with a negative mass. Since no such material is known to exist, and certainly not in the human brain, it follows that telepathic abilities, should they exist, would also be restricted by the speed of light. ---
**Author:** ![TheThill](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheThill](https://boards.straightdope.com/u/TheThill)\ **Post date:** [July 3, 2000, 8:15am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/29 "2000-07-03T08:15:24Z")
Unless the concept of a “quantum leap” is taken into consideration pertaining to thought. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 3, 2000, 5:56pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/30 "2000-07-03T17:56:22Z")
Nope, quantum leaps don’t change any of this: Even though, in some sense, a leap may occur faster than light, it happens in such a way that any information transmitted is still limited to c. There were a few physicsts a little while back who claimed to be able to transmit information faster than that via quantum tunneling, but their experiment was extremely poorly designed, and isn’t really accepted as accurate. ---
**Author:** ![handy](https://avatars.discourse-cdn.com/v4/letter/h/b5a626/32.png) [@handy](https://boards.straightdope.com/u/handy)\ **Post date:** [July 3, 2000, 11:49pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/31 "2000-07-03T23:49:09Z")
Light is real. But to look upon the thought system is look upon nothing…an abstract concept at best. ---
**Author:** ![Wood\_Thrush](https://avatars.discourse-cdn.com/v4/letter/w/b38774/32.png) [@Wood\_Thrush](https://boards.straightdope.com/u/Wood_Thrush)\ **Post date:** [July 4, 2000, 1:01am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/32 "2000-07-04T01:01:33Z")
I assume **insider** meant a comparison of the speed of light to the speed of thought in the same way one would compare the speed of light to the speed of the calculations of a pocket calculator. I stand by what I said earlier, inasmuch as that was what **insider** meant: > [@](#): > > No. “Thought” is a series of complex electrochemical signals. These signals travel much slower than light. ---
**Author:** ![TheThill](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheThill](https://boards.straightdope.com/u/TheThill)\ **Post date:** [July 4, 2000, 10:56am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/33 "2000-07-04T10:56:12Z")
Even if one experiment has failed to channel information in this way, it still remains to be seen whether thought might behave in an other-dimensional manner. Sounds far fetched to many, perhaps, and would be a very complex matter, but might explain many an anomaly. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 4, 2000, 5:04pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/34 "2000-07-04T17:04:40Z")
As I said before, for thought (or any signal) to travel in an “extra-dimensional way”, as TheThrill puts it, would seem to require negative-mass matter. Last I checked, the lower limit on brain mass seems to be zero, so that would eliminate that possibility. I’m not basing this argument on that one experiment which failed, as TheThrill implies, but rather on the theoritical constraints imposed by relativity. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [July 5, 2000, 4:24am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/35 "2000-07-05T04:24:56Z")
> [@](#): > > \*Originally posted by Saint Zero \* > \*\*Just as an aside, there are no electrical signals in the brain. Sorry. 😃 It’s an electrochemical reaction, which runs _lots_ slower than light. > \*\* Assuming the aforesaid…what are researchers measuring when they are charting “brainwave” activity if not electrical activity/signals? Just curious. ---
**Author:** ![Wood\_Thrush](https://avatars.discourse-cdn.com/v4/letter/w/b38774/32.png) [@Wood\_Thrush](https://boards.straightdope.com/u/Wood_Thrush)\ **Post date:** [July 5, 2000, 6:12am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/36 "2000-07-05T06:12:44Z")
> [@](#): > > _Originally posted by astro_ > **what are researchers measuring when they are charting “brainwave” activity if not electrical activity/signals?** Actually, buddy, it’s _brain wave_. A brain wave is the rythmic fluctuation of potential in different regions of the brain. Electrochemistry, as is apparent from the word itself, has electricity involved and can thus create potential. Therefore, the existence of brain waves does not disprove the electrochemical nature of the brain, a fact strongly supported in the literature. The speed of any process as a whole is the same as the speed of the slowest point in that process. The slowest point in a nueral electrochemical process is the chemical movement. The chemical movement is slower than the speed of the electricity. And the speed of that electricity is slower than the speed of light in a vacuum. Therefore, thought is slower than light. ---
**Author:** ![Wood\_Thrush](https://avatars.discourse-cdn.com/v4/letter/w/b38774/32.png) [@Wood\_Thrush](https://boards.straightdope.com/u/Wood_Thrush)\ **Post date:** [July 5, 2000, 7:02am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/37 "2000-07-05T07:02:45Z")
[The Effects of Electrode Placement Upon EEG Biofeedback Training: The Monopolar-Bipolar Controversy](http://www.openfocus.com/journal.htm) by Lester G. Fehmi, Ph.D., and Adam Sundor, M.A. ---
**Author:** ![TheThill](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheThill](https://boards.straightdope.com/u/TheThill)\ **Post date:** [July 5, 2000, 8:37am UTC](https://boards.straightdope.com/t/light-vs-thought/23815/38 "2000-07-05T08:37:09Z")
> [@](#): > > \*Originally posted by Chronos \* > \*\*As I said before, for thought (or any signal) to travel in an “extra-dimensional way”, as TheThrill puts it, would seem to require negative-mass matter. Last I checked, the lower limit on brain mass seems to be zero, so that would eliminate that possibility. I’m not basing this argument on that one experiment which failed, as TheThrill implies, but rather on the theoritical constraints imposed by relativity. \*\* And of course, any other theory would supersede relativity, just as relativity superseded the tenets that came before it. Whether or not this is a good idea, or how soon this strain of thought may come to fruition is fodder for another discussion. Oh yes, btw, my user name has no r, but I guess I was asking for that when I chose it. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 5, 2000, 4:30pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/39 "2000-07-05T16:30:21Z")
Hmm… I’m not saying that nothing will ever supersede General Relativity (Special is another story), but the thing is, that when one scientific theory supersedes another, the two theories usually agree on most points. It’s rather probable that the next theory (Superstring theory? A modified version of Kaluza-Klein?) will also require negative mass for FTL information transfer, and in any event, that theory, whatever it is, is not yet fully developed, so we don’t know what it’ll say. In the meantime, the best we can do is go by the predictions of the theories we currently do have at our disposal. Sorry about the name, by the way… What exactly is a “thill”, anyway? ---
**Author:** ![TheThill](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheThill](https://boards.straightdope.com/u/TheThill)\ **Post date:** [July 5, 2000, 10:35pm UTC](https://boards.straightdope.com/t/light-vs-thought/23815/40 "2000-07-05T22:35:25Z")
Certainly I agree that there is no point in discussing theories yet developed. But with such a provocative OP, it seemed legitimate not to accept simple (or not-so-simple, actually) answers. > [@](#): > > \*\* > Sorry about the name, by the way… What exactly is a “thill”, anyway? \*\* It’s “either of the pair of shafts if a vehicle between which a draft animal is harnessed.” (Random House Webster’s College Dictionary). It may seem a bit odd as a user name, but it is in fact the English translation of my surname. [Previous page](https://boards.straightdope.com/t/light-vs-thought/23815.md?page=1) [Next page](https://boards.straightdope.com/t/light-vs-thought/23815.md?page=3)