Google Chrome” is now more famous as a Web browser, and there is Chrome OS, too. I also sometimes use the browser.

One day I had a question. Why the logo of Google Chrome show four colors – red, yellow and green blades surrounding a blue circle, instead of shiny metallic silver?

Then I remembered a chemistry class in my schooldays. we made an experiment with some chrome compounds. They were no more metal, but soluble powders(fine crystals). One chrome compound showed bright red color, and other bright yellow.

Yes, an element chrome reacts with oxygen and turn into colorful compounds. We know well, that hard silver iron often turn into dark red flakes, it is because the element iron reacts with oxygen helped by water when aged. That dark read color is called “stain”, but oxidized chrome seem far more colorful.

But, while iron stains don’t have so much danger in chemically sense, those red and yellow chrome compound are quite hazardous. You can’t touch it with bare skin, much less take into the body. Indeed a beautiful appearance doesn’t always mean tenderness in nature…

And what about green and blue? I made a search and found, there is other chrome compounds which show blue-green color! A kind of pigment, so called as viridian, exemplifies that. It would look either green or more blue, under different effects of light.

Aha, Google knows chemistry!

And there was one more thing I have learned. Those green compounds of chrome are so stable and do less harm. Moreover, a trace of this type of chrome compounds are necessary to human body! Chrome element which are naturally contained in foods (some meat, fish, mushrooms etc.) are thus even recommended to take.

Oh, you element chrome, you have so colorful feature both in appearance and in nature. If all of your features were given by a woman, she might dominate all of the world.


Upside Down

The reason of my confusion on trial to explain inverter in the late post is partially caused by the fact “Current runs to the reverse direction against electron flow,” – or “Electron flows to the reverse direction against the current”???

This confusion is caused that the idea of current had been built before electrons were discovered. Long ago someone assumed that some invisible flow runs from a charged material to the ground. Even now it is quite easy to imagine that some shocking flow arose from an old washing machine and it went through my body to the ground!

But the shock given to a later scientist, who discovered that something bright flew from the end point of lower potential to the other of higher potential through the thinned air enclosed in the tube, might have been grater than that.

From that time on, those who think about electricity have been forced always think double ideas at the same time: if the current flows right to left through the wire, it means that electrons runs left to right through it. The ground is indeed not the absorbent of the current, but the source of electrons.

But human being has created such a civilization full of electricity, embracing this confusion. Isn’t it great?

Taking about confusions in the idea of electricity, I am always confused in using the name of electrodes ( two tips of a wire connected to both ends of a battery cell).
Cathode is…oh I did it again…negative electrode and Anode it positive. “Cathode” sounds to me like “Cat!…hode”, lively and positively, while “Anode” sounds like “annnn…no.”, negatively. Thus drawing the first picture I had to correct the description many times.

A new Pavement

I had walked along this road so frequently and seen men at work to newly pave it.
But they had made a miracle improvement for a couple of these days. When I came here yesterday, a large part of it were just covered by new asphalt and bright white paint.

(It’s indeed asphalt black)

(A white line. I didn’t stain it with my dusty shoes so I stepped aside.)

(An abundant paint looked like a sugar decoration on the cake.)

(The tip of a new arrow is as sharpened as a new pencil)

(From the skywalk above, captured this early morning, with less traffic)

I found there an interesting thing. a core sample, which must have been drilled out from somewhere on the new pavement.

(Left on the side of the road)

(I couldn’t find a clear border between the pavement and the earth below. Is the pavement so thick as to give a whole core?)

I suppose it is not for any tests, but just for embedding something, e.g. a signal light, in the drilled hole. Anyway we can closely look how the pavement is made of.

(Aggregated gravels, concreted by asphalt)

(A section area of the core. The fine stripes must have been made being scratched by the drill.)

I like a newly paved road very well. Each time I see a fresh black asphalt, I can’t help taking a picture of it, for it would be soon worn out and covered by dust under the traffic.

Brave Heart

This afternoon I was on my way back home from the bank. There was a little space in front of the station, where pigeons are picking food, bathing the sun, making tricks on each other, as is often the scene in anywhere the world.

Then there came a sparrow from somewhere.

Soon he came near the pigeons.

What a surprise, he came straightforward to where I stood.

“Hey, whaddaya want!?”

Then he gradually went back, still staring at me.

I started to leave then. After a few steps I looked back, then found that brave sparrow was standing solitarily against a group of pigeons.

…although it seems pigeons are scarcely aware of that tiny species.

Anyway, I like such a bird with proud and bravery in his heart.


You know what, it’s one of my dream to write the easiest book for computers, which everyone can read in a teatime or in bed before sleep, with as few technical terms as possible. It might not be somewhat inaccurate, but might encourage the reader to seek for an accurate answer by himself.

So is this today’s story. It will be easy to imagine a circuit, in which the current will flow when you turn on the switch and it will stop when you turn off the switch.
But how about one which behave reversely – on turning on the switch the current will top and turning off the switch will let it flow?
This kind of circuit, called inverter, is much important to build a processor.

How can you make such a circuit?

Before the age of semiconductors, engineers had much difficulty to build up ones.
Now various semiconductors can be chemically created. It is classified roughly into two types.

One is to let current flow when there is an input. There is no current, when there is no input. Quite natural.

The other is to store the charge when the current flow into it, which hinders the current to flow.
If the switch is turned of, this “stone” release the charge, which make the current flow from it.

The latter type is the basic concept of an inverter. But the problem is, when the “stone” let all its stored charge out, the circuit will stop again, despite that the switch is still off.

Hence, two more device is added to the circuit.
One is a constant power source to keep putting the charge into the “stones.”
The other is an everlasting “drain” of the input current. It’s the ground.
If the conductive material is bounded to ground, all input current escape to the ground and there is no output to any other direction.

So let’s think about a circuit like below. a conductive material and capacious material are bound with the wire, from which the output is taken.
Input is set into the conductive one, which is on the other hand bound to the ground. And the constant power source gives charge to the capacious one.

As illustrated above, when there is a current input, it escapes to the ground, while the current from the source is intercepted by the capacious stone.

If the input stops, the is a discharge from the capacious stone. Won’t the current escape to the ground through the conductive stone? Oh, I’m sorry, I couldn’t yet fully and simply explain about it. I’m not yet a good author in this field. Please take is for granted now that “there is a certain technique to prevent it.” The precise schematic illustration is shown in a couple of my other posts, Simple explanation of nMOS and CMOS and Inverter. I will try to give a better explanation again some day.

Anyway now we have such device to give an inverted output from its input.


There would be no electronics without semiconductors. Semiconductors are materials which carry very small electric current. But no matter how many kinds of Semiconductors may be found in how much amount, they would be of no use without methods to pick up such small current.

Below is there a typical method of such elaborate detection, that I have tried to express as simple as possible.

These two bars, which look much as in the same length, have indeed have a length ratio of 10.01(left) and 10.02(right).

When we cut 10.00 in ratio of each bar, their ratio comes to be 0.01 and 0.02, which shows a clear difference.

There is another method of pick up small difference. These two boxes look to stand just side by side.

When we set the background to a deeper color, we could find a slight interval between them.

There is no straightforward method to pick up such small difference. Many scientists and engineers make many trials and errors to bring a miracle idea for that. Thus we have today’s computers thanks for semiconductors and methods to evaluate them, and people who have discovered both the materials and the methods.

Dam You!

I wondered how to say in English a big water reserver constructed between the mountains, in order to stock drink water, at the same time preventing flood.

In Japan we call it “Da-mu.”

Since it is written in Katakana, to express words originated abroad, I guessed it derived from English or German.

It is my way to learn English, not to use Japanese-English dictionary, but to start within my English vocabulary. If I cannot find a similar word, I simply guess some keywords.

I input a in the google search box d, a, and m. Despite that the input assistant had offered me many phrases for a curse, I could confirm the word “dam” indeed to express that structure.

I thought of those people who works for such beneficial structure, possibly being aurally misunderstood when they talk about their occupation.

By the way, where did this word come from?
I made a quick research and knew it might have been from old Dutch.

I don’t know Dutch, but I can imagine that well, because Netherlands might have various way of construction to prevent flood, due to their Geography.
Indeed there is a German word “damm” which seems to mean an artificial way along the bank.

There are still many words, which we are accustomed to use, not knowing exactly how it has come.