Archive for the ‘Amazing Facts’ Category

More Data

Wednesday, November 12th, 2014

 test both (click to enlarge)

A follow up on my last post.  More data just in from the bleeding-edge trenches of audio engineering! These from my fellow researcher G.M. showing the cumulative spectral decay (waterfall) plots of normal and hypercube-enclosed drivers.

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sealed waterfallHere is the sealed box waterfall. Click to enlarge

You can see that in a sealed box there is a lot of ringing across the lower part of the spectrum muddying the sound and coloring the notes.
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sealed waterfallAnd here is the Hypercube waterfall. Click to enlarge
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As you can see, the box ringing is almost all gone.
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Much purer sound.
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sealed waterfall

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And here is the Sealed Box vs Hypercube distortion.

As you can see, the hypercube (green line) is always less than the ordinary sealed box (purple line) — usually by 3 to 6 dB.

— MRK

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Independent Validation

Saturday, November 8th, 2014

enclosures.jpg (click to enlarge)

My new fellow researcher G.M. has recently been courageous enough to test for himself my claim that the Rhombic Docecahedron (parallel projected hypercube) is far superior as a speaker box than the standard designs. He is building his own set for listening tests as well as objective comparison measurements.

He built his first hypercube out of clear polycarbonate so that witnesses could see there was no acoustic padding inside it. For simplicity’s sake he energized it with a fullrange driver to avoid the complications of crossover effects on the sound.

Today I received his first impressions. G.M. writes:

“OH MY GOD THESE THINGS ARE INCREDIBLE. I have just one hypercube speaker completed so far. It’s SO much cleaner sounding than the sealed box…It’s not even close. The sealed boxes have twice the panel thickness and a fair amount of foam stuffing, yet resonate like crazy, muddying the sound to the extent that it’s instantly noticeable with bass and drums. To the contrary, it’s almost unbelievable how tight and dry sounding the hypercube speaker is. I feel very little vibration from the panels. Voices seem much less colored as well and I did notice a bit less directionality to the sound. It’s just as you said. I’m floored…..”

I envy him. It’s not every day you get to enlarge your own world-view. You never forget the first time you hear a speaker in a hypercube compared to the same speaker in an ordinary padded box.

Bravo, G.M.! I hope that when you have completed your testing you will permit me to use your real name for all the doubters who will think I made you up. I am certain you will find that objective measurements back up what your ears have already told you. Although any audiophile will drone that audio is a very subjective industry, once you have numbers and graphs you can challenge skeptics to perform the same experiment for themselves. Microphones and printers and FFT analyzers etc do not have subjective opinions.

— MRK

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The State of Reality

Saturday, May 25th, 2013

meOnce in a while somebody should hold a State of the Reality address.

As far as I know, there are at least two new problems for modern physics now:

1. If the structure of spacetime is not as foamy as thought, as indicated by the two-photon observation, what is responsible for quantum jittering?

2. If neutrinos can actually travel faster than light as some experiments suggest, does this mean a total revision of General Relativity — or an exception for special-interest particles?

If we combine these, however: that space isn’t a bumpy ride even at trans-galactic distances and that some particles can go faster than light, then FTL drive or radio doesn’t look so far away.

—MRK

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Quantum Dots

Friday, April 12th, 2013

me in RiftOMG I didn’t even post in March!  If anyone is still reading, I’m sorry.

I’d like to think that completing the second novel in my Gamers and Gods trilogy is a good excuse — but it isn’t, because there’s no way for you to read it yet.  Oh well.

Word must have gotten out that I am an encyclopedia of useless facts;  some of you even ask me about them.  Quantum Dots have been in the news, in stories ranging from their potential to improve solar cells to their application to quantum computers.  So what, exactly, you may ask is this thing called a “quantum dot?”

I’ve decided to try to answer this question without resorting to the equations, eigenfunctions, and quantum wells that most physicists like me resort to.  (Maybe it’s vanity, but I like to set myself impossible tasks to keep my aging brain active. )  I’m afraid I will have to mention atoms, the tiniest bits of identifiable matter and electrons, those invisible pieces of electricity.  So here goes.

Many of you might still, in spite of the Great Recession, be holding onto the American dream of the two car garage, or at least have two cars in the driveway, because it’s pretty hard to raise a family on one paycheck these days.  Think of your house as an atom — one that can hold onto only two electrons (the cars).

Long before I studied physics and had a career in Web development, my parents, for a time, lived in (I swear!) a place called Webwood Court.  A branch off a main road, it ended in a big disk of asphalt with driveways radiating off  it like the spokes of a wagon wheel.  (A brother of mine lives on one of these places today, although the street that ends in it is called a lane instead of a court.)

My point is this:  although the driveways radiating from a “court” may only hold two cars each,  you can park cars in the central area, instead of in the driveways. That can be rude, if you block the driveways.  But what I’m saying is, if houses were atoms, and driveways the “orbitals” that hold two electrons, this central unclaimed area is like a Quantum Dot:  it can hold more than two car/electrons that are not actually attached to any of the surrounding atom/houses.  A quantum dot is like a parking lot for electrons.  You can push electrons into it, and they will tend to stay there.

If you don’t already know, these quantum dots have some peculiar (and useful) properties.  For example, you may know that different chemicals are usually different colors.  But did you know that when you make quantum dots, you can make them all out of the same chemical –and get different colors?  It’s true.  It turns out that the size of the dot, rather than its ingredients, controls the color.  I won’t waste your time with math.  The relationship is simple.  Big dots are red (lower energy), tiny ones are purple (higher energy), and you can get all the colors of the rainbow from sizes between big and small — and all without having to use a lot of different ingredients.  Basically, this is because red light waves are longer — they need more room.  Purple light waves are shorter — they can fit into smaller regions.

That wasn’t so painful, was it?  Isn’t Nature amazing?  Yes, I said Nature.  You don’t need a lab.  Quantum dots are so easy to make, Nature was doing it a long time before we found out about them.

— MRK

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Building Rhombic Dodecahedra Resonators

Friday, March 2nd, 2012

hypercubeBuilding this shape can be challenging if you do not know the right geometry.

In conventional language, the shape is a truncated rhombic dodecahedron. It is made of 8 rhombuses (rhombi), 4 triangles, and 1 square.

The basic rhombus can be made from joining four triangles together. Each triangle has sides proportional to one, the square root of two, and the square root of three. Put simply, the small angles of the rhombus are both approximately 70.5 degrees and the large angles are both about 109.5 degrees.

rhombusIf you want more accuracy, the angles are 70.5287 degrees and 109.4712 degrees. This is generally accurate enough for most CAD/CAM systems.

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trianglesThe triangles (whose bases meet the square where you cut a whole for the woofer) are actually half-rhombi — that is, they come from slicing the rhombus down the middle of the two big angles, making two triangles whose angles are 70.5287 degrees and 54.73565 degrees and 54.73565 degrees.
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trianglesThe easiest way to proceed is to take three rhombi, lay them outer-face-up and tape them together like so.

Repeat this process to get two groups of 3 panels taped together (tripanels). Now apply a strip of tape to close up each tripanel and flip them over so you are looking at the insides or concave view.

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Putting a rubber glove on your hand, get some glue on the end of your gloved index finger and trace down the Y of the three internal seams so that they are glued. Do the same for the other tripanel, and then set them to dry for an hour.
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rhombus
Now take these two tripanels and tape them together to make a pyramidal point corner like this. Glue the seams on the inside as before. Looking at this “hexpanel” assembly, you will see two spaces for rhombi. Tape and glue rhombi into these spaces and you will see where to add the four triangles and the square.

—MRK

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Painting a Pentahedroid

Wednesday, August 31st, 2011

Painting a pentahedroid with pencils and ping-pong balls.

The simplest regular 3D solid is the tetrahedron.

Have you ever seen a  bubble with sharp edges? Let’s make one.


I couldn’t sleep tonight, so I took apart an old tootsie roll I found lurking in a drawer and stripped the cotton off 6 swabs and stuck them into the pieces of the tootsie roll to make a tetrahedron. You don’t have to make a perfect tetrahedron for this to work.

Now find a container deep enough to dunk the tetrahedron like a donut. Put water in it and add some soap. Dunk the tetrahedron. If you do it right, you will be surprised to see the 3-space projection of a 4-D hyper-tetrahedron (a pentahedroid) appear as the soap film, moving through time, balances forces and achieves stability, anchored to the tetrahedron as a base.

(Can you guess what happens next if you touch the bottom of the swab tetrahedron to the surface of the soapy water one more time, and then lift it? No?  Why don’t you try it out? Hint: I don’t mean the bubble will pop.)

If you click the picture above to enlarge it, you can clearly see the edges of the soap film, straight and sharp, connecting the four corners of the swab tetrahedron to a point at the center of the artifact. The tetrahedral symmetry of the soapfilm recalls to mind the bonding symmetry of the Carbon atom. Cute, ain’t it?

It also happens to be part of why diamond is so strong. What we call diamond is just an allotrope of carbon, a giant polycarbonate molecule with each carbon atom, ideally, bonded to 4 other carbon atoms.

We used to think the only way you could make diamond was to either (a) be Superman’s best friend, so he could crush a chunk of coal into one for you, or (b) look for places where carbonaceous material got squeezed really hard, and probably at high temperature too.

Now, there are lots of ways to make diamond. It’s been done with high pressure (had to build a machine for that; superman was out of town that year), explosions, ultrasonic cavatation, and chemical vapor deposition. We can even “dope” diamond with impurities and make diamond transistors which can operate at higher temperatures. Fact is, synthetic diamond is used to make heat sinks to conduct heat away from high power transistors and semiconductor lasers; diamond makes an excellent material for this because it is a superb conductor of heat but does not conduct electricity in a pure undoped state.

Truly we live in an age of marvels. When I took my electronics classes as an undergraduate heat sinks were made of aluminum. Now we can afford to make them from diamond. All of diamond’s unique properties stem from that tetrahedral bond structure.

There is another important thing to remember about carbon. It is the element all life on earth is built around. Those bonding angles make possible a dazzling multiplicity of molecular configurations, which includes, among them, DNA.  Everything is connected. You can look at a pile of sticks and a bit of soap and uncover the basic symmetries of the molecules of life. We are surrounded by wonders. –MRK

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