Q and A: Brains and knowledge

I received this question and I would like to answer it in two ways. First I will reason out an answer, then I will attempt to summarize my answer in a single paragraph based on the research and logic outlined.

Q: Would it be totally impossible to inject much knowledge into the brain using sound waves? Or maybe a laser to beam the information into a piece of machinery in the brain? 

A:The brain itself is not equipped to process sound waves, that is what our ears are for. Sound waves, as I'm sure you are aware, need something to move through just like waves in the ocean. Sound moves through air most commonly, but can also move through water, glass, wood, etc, but each material moves differently. A very dense material, like a metal door, will block out more sound that a less dense material like a wooden door. Air is the least dense state of matter on Earth which is one reason sound moves through it more efficiently than say water. Gas and liquid can both be described as fluid in motion, by this I just mean they move more easily than something solid.  This video has a good explanation for how sounds move through different materials. 

To get sound waves into the brain they would have pass through your skin, muscles, skull and the fluid around your brain. Whenever the waves pass through a different medium it would change the properties of the waves, as explained in the video above.

So even though we can encode waves with date by modifying the properties, the act of sending it through the head to the brain would contaminate the carefully modified data. If we found a way around this change to the sound wave, each attempt would have to be calculated at that point in time with specific measurements taken. Here's why: Everyone's head is going to vary. The thickness of the skin, the density of the muscle and skull, the consistency of the fluid around the brain and of the gray matter itself would all have to be taken into account. On top of that, we are alive so all of those variables are constantly changing for each person. Dehydration could change the density of the muscle or the fluid in the brain (This part is a little fuzzy for me, someone who knows more on the anatomy of the brain may be able to give a clearer picture), how much knowledge you have is going to change your brain, and even your mood could affect the brain's chemistry. What chemicals are present in your brain could change the movement of the wave.

As a clearer example, think of a clear, crisp autumn day, sound carries cleanly through the air. Now imagine a muggy day in the summer after an afternoon of rain, sounds don't carry as far. The air is now filled with water vapor (the humidity is higher) which will change how the sound waves carry through the air.

So my point is the “weather conditions” in your head would directly effect the injection of knowledge using sound waves. Which means while it might be possible, I doubt that it would be feasible. 

Now this is assuming that we can use these modified sound waves to stimulate the brain and some how get it to store or process information from these waves.  This is a huge assumption to even sugest that it could be possible.  But, I am no expert when it comes to the inter-workings of the brain, so with my limited knowledge I think the logical conclusion is it won't work.  

 

As far as using a laser to beam knowledge into the brain, there are several factors to consider.  One, let's assume we have the technology to interface the brain with a computer chip or mini motherboard.

 

Light is a continuous spectrum, from the Radio (low energy, wide waves of light) to gamma  (high energy, tiny waves of light) waves, as seen in the image below.  Lasers typically are created to emit light in the Ultra-Violet (UV) to the Infrared (IR) wavelengths.   This includes the visible spectrum.

 

Light Waves from High energy to Low energy

Let's start with the visible spectrum since that is what we are most familiar with.  Visible light is going to bounce off your skin.  It would not penetrate deep enough to reach machinery in your brain.

So, what about IR?  Well, we experience IR radiation (all light is radiation) in the form of heat.  So if you were to shine an IR laser at your head, you would warm up.  This could potentially interrupt your homeostasis (you're body's "happy" balance), so I'm not sure this would be wise either.

Two down, one to go.  UV?  Let me ask you this, what do we generally associate with UV light?  The sun/sun burns.  We know UV can damage your skin, even cause cancer.  I don't think shining a Laser emitting UV light would be very healthy.

Alright, well with those ruled out, what if we created a laser that emitted light in a different spectra? Let's go through them:

1. Microwaves? 
   1. Yum cooked brains?  Next Please!  Well, that's really only one wavelength in the Microwave spectrum.  So maybe, we will discuss this.
2.  Radio
   1.  Radio waves would probably be too large, they pass through us all the time and don't effect us, so this seems the most likely by far, but let's continue.
3. X-Rays
   1.  You really want to try to limit your exposure to X-Rays.  There is a reason X-Ray technicians don't stand there without protection if you are being X-Rayed so that won't work.
4. Gamma Rays 
   1. Long term exposure is also very bad for you.  Anything more energetic than Visible light, and you want to limit your exposure as much as possible.

So Radio would really be the safest option let's explore it to see if it would really work.  Radio waves include wavelengths starting at 0.1 meters and up.  There can be Radio Waves the width of a baseball or the width of the Earth.  This means the receiver would have to be that large.  That's why car antennas are long is so they can receive the right signals.  We get radio waves from Jupiter that need 20 foot long antennas.  This means that while it might be possible, your brain may have to be wired to be a receiver.  But wait, what was that I saw?

This is an interesting image of the spectrum. 

Pay special attention to the location of the Microwave Oven.

Notice where the Radio wave spectrum begins (about the size of a baseball) and where the source is under that (The microwave).  That's where the spectrum overlap a bit.  A microwave oven emits a wavelength of about 0.12 meters.  So there may be hazards at this area of the spectrum (Microwaves to small Radio waves) causing heating from the molecules in your brain, much the way a microwave uses water molecules to heat your food.  To learn more about how a microwave works to heat your food I suggest you watch this video (he gets into some more technical part of the microwave, but the section that discusses how the microwave uses water is very well done).  So that is my hesitation of using Microwaves.  Also, fun fact a Maser is a microwave producing laser!

 

I'm not seeing an easy way to work this, unless you had a fiber optic cable that connected the outside world to the machine in your brain, which has many problems associated with that. 

Here's the punch line:

Q: Would it be totally impossible to inject much knowledge into the brain using sound waves? Or maybe a laser to beam the information into a piece of machinery in the brain? 

A: While I hesitate to say "totally impossible" I'm not sure possible would be the right answer either.  The brain is a mysterious organ, having presented many challenges in science, so I do not want to say "impossible" but based on our current understand I would say no, it's not possible, not in the ways you have proposed. The second question proves to be more promising, but only if certain assumptions are made. Assuming we have a good way of hard-wiring the brain with machinery, then there may be a way to convey knowledge into the machine. This is a large assumption.