Into Unscientific

Chapter 304 Undecided (7.4K)

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inside the laboratory.

Looking at Babbage and Ada who looked excited, Xu Yun shook his head helplessly.

With a deep sigh in his heart, he led the two of them towards the table:

"Please come with me."

As a result, as soon as he approached the edge of the table, Babbage's eyes were attracted by the vacuum tube on the table.

More than half an hour ago.

Babbage was doing research with Ada in the attic when Ada's husband, Earl Lovelace, appeared outside the door with Kirchhoff.

Then Kirchhoff, as the spokesperson of the sponsor's father, gave Babbage and Ada a master's task:

Elbow, follow me to school!

However, due to time constraints.

Kirchhoff simply mentioned Wheat's idea, roughly that there is such a special vacuum tube that may replace gears and so on.

After speaking, he rushed to the laboratory with Babbage and Ada.

Therefore, Babbage only roughly knew that there was such a test tube in the laboratory that might help him, but he didn't know much about the specific appearance and principle.

But on the other hand.

As a parts specialist who has been in contact with electronic components day and night for nearly thirty years, Babbage is very sensitive to various components.

So at the moment of seeing the electron tube.

An inexplicable premonition emerged in Babbage's heart:

This thing must be of great use to me!

Xu Yun at the side cast a look at Mai Mai, the meaning is obvious:

Explain what you did yourself.

Mai Jiansuo nodded, came to Babbage's side, and said:

"Mr. Babbage, I heard that the Analytical Engine you designed uses gears to store data?"

Babbage looked up at Mai Mai. Although he and Mai had never met before, he understood a reason:

It is absolutely extraordinary to be able to conduct experiments with the three of Faraday Gauss Weber.

Either a close blood descendant, or a future star with unlimited potential.

Therefore, he was not angry at Maimai's abrupt question, but smiled politely, and answered patiently:

"That's right, Ada and I designed a kind of close-tooth gear. Oh yes, I'm taking it with me now."

As he spoke, Babbage untied a backpack from behind and rummaged through it.

over the past few years.

In order to be able to find interested investors, Babbage is basically like the small vendors selling CDs and sunglasses in the 1990s, carrying some parts samples anytime and anywhere, the purpose is to explain his invention in more detail.

After about ten seconds.

Babbage took out a gear from it, handed it to Wheat, and said:

"This classmate, this is it, it's a bit heavy, you hold it steady."

Taking advantage of the opportunity, Maimai took over the gear and looked at it seriously.

This is a standard cast iron gear, about the size of a palm, with densely packed tiny tooth holes on it.

While Wheat was observing the gears, Babbage also volunteered to explain:

"A gear has 118 teeth, which can store ten 50-digit numbers. After every seven gears form a number axis, calculations within ten digits can be performed."

Xu Yun glanced at him lightly, but did not expose his lie.

The so-called "calculation within ten digits" in Babbage's mouth actually refers to addition and subtraction, and can only contain up to three decimal places.

If we discuss multiplication, division or even square root, the five-digit number is almost at the top.

Of course.

This refers to the equipment that has been completed so far, not the expectation—after all, there is no upper limit for painting cakes. If you really want to brag, you can say fifty figures.

Kirchhoff on the side was aroused by these words, this is also a circuit enthusiast:

"Mr. Babbage, from the perspective of workmanship, the cost of a gear should not be low?"

Babbage took back the gear from Wheat's hand, turned it up and down, and sighed:

"Yes, the number of teeth of 118 cannot be divisible by 360 degrees, so the precision requirements are extremely high, and it can even be said that there is no real technical upper limit."

"At present, on average, the cost of a gear needs to be about 0.2 pounds."

Kirchhoff opened his mouth, smacked his tongue and said:

"It's so expensive"

mentioned earlier.

These days, the purchasing power of a British pound is roughly equivalent to 900 yuan in later generations, and 0.2 pounds is almost one hundred and eight small two hundred.

In later generations, a 160-tooth gear with an outer diameter of 162mm was priced at about 30 yuan, and the cost was even lower.

The reason for this huge expenditure is mainly related to the current forging process. A considerable part of the so-called average manufacturing cost is the expenditure of modules.

Not to mention the complicated craftsmanship required by the original module, even if you forge a suitable module, it will not take long if you lack large-scale pressure equipment.

So repeatedly, the expenses will naturally be large.

It’s no wonder that Babbage failed to start a business. Clement’s rebound is certainly the main reason, but the expenditure on these equipment is also a big pit that cannot be ignored.

For example, Babbage's Difference Engine No. 2, which was not completed until his death, required more than 4,300 gears.

Even if there is no work loss in the whole process, the investment of light gear is close to 900 pounds.

Afterwards, Wheat asked Babbage some other questions, and with a general idea in mind, he said to Babbage:

"So Mr. Babbage, in your design, data storage, or handover, is actually the most costly link?"

Babbage nodded, looked at Ada beside him again, and sighed:

"That's right, compared to Ada's algorithm writing, data storage is undoubtedly much simpler-it only needs to have enough gears."

"But on the other hand, it's the most invested project, and if it goes wrong, it can be lost."

After listening to Babbage's words quietly, Mai Mai snapped her fingers briskly, and said to Babbage:

"So that's it, I understand!"

"Mr. Babbage, I can now be sure that Xiao Yanguan will definitely help you!"

finished.

He led Babbage to the table and picked up a vacuum tube from it.

Precisely.

It is a vacuum tube filled with mercury.

Then Wheat pinched the end of the nozzle, put it in front of his eyes, and said to Babbage:

"Mr. Babbage, you should know that sound waves travel slower in mercury than electrical signals travel in wire?"

Babbage nodded.

Compared with the speed of light calculated by Xu Yun before, the level of science and technology in 1850 has already thoroughly studied sound waves—even in the original history.

At this time, the scientific community not only knew that the propagation speed of sound waves in different media was different, but also mastered their specific values.

For example, the speed in the air is relatively slow, about 340 meters per second.

Faster in solids and liquids.

For example, the propagation speed in a copper rod is 3750 meters per second, and that of mercury is about 1450 meters per second.

But no matter how fast the sound wave is, it is still 108,000 times slower than the propagation speed of the electrical signal.

Seeing that Babbage was able to communicate without hindrance, Wheat continued to explain:

"In that case, here's an idea"

"Can we connect a closed wire to the outside of this Xiaoyan tube filled with mercury, and then connect multiple Xiaoyan tubes in series to form a closed loop."

"Then use the time difference between internal and external information transmission as the principle, and add some other small means to replace gears to achieve the effect of information storage?"

Babbage's eyes widened as he listened, while Xu Yun's expression on the side was

.

Poor.jpg.

how to say

After wheat said those words before.

Xu Yun was almost mentally prepared for the current situation.

After all, the idea of ​​wheat is obviously going to the mercury delay line memory.

That's right.

Mercury delay line memory.

As mentioned above.

If the history of computers is regarded as a protagonist in a novel, then the history of memory development is undoubtedly a standard heroine—the kind that appeared in the second chapter.

Except for the "adder" invented by the Gaul Pascal at the beginning, which did not require storage (because it is enough to write down the answer directly), the development of all other computers is inseparable from the memory.

The earliest data storage medium in history is called punched card, also known as punched card.

It is a piece of cardboard that can store data, and records numbers, letters, special symbols and other characters by punching holes in predetermined positions.

The punch hole first appeared in 1725 and was invented by the Gaul Boucheau.

At first it was used to store information for the control of the working process of the textile machine, and then it went wrong:

This thing was once used as a storage device for counting the number of slaves, and it will not return to the right track until around 1900. It is not recommended to laugh at it here, because the statistics include Chinese laborers in addition to black slaves.

In 1928, IBM introduced a punch card hole with a size of 190x84mm, which used rectangular holes to increase storage density.

This card hole can store 80 columns x 12 rows of data, equivalent to 120 bytes.

After the card punch hole is the instruction tape, which is somewhat similar to the tick timer in the high school laboratory, which is a symbol of the era of mechanized storage technology.

After punching the card hole, it entered the real storage development stage of modern computers.

The storage device that first appeared has a nice name called a magnetic drum.

The earliest magnetic drums looked similar to massage sticks. When they were in operation, they buzzed and sometimes sprayed water—it rotated very fast and often needed to add water for water cooling.

And after the drum.

The debut is the mercury delay line memory.

The principle of the mercury delay line memory is similar to what Mai said, and the core is one:

The difference in travel time between sound waves and electrical signals.

Of course.

We are talking about electrical signals here, not electrons.

The movement speed of electrons in metal wires is very, very slow, and in some cases, it may even only move a few centimeters in a second.

The speed of the electrical signal is actually the speed of the field, depending on the dielectric constant of the material

Generally speaking, the electrical signal of a copper wire is about 230,000 kilometers per second.

The transmission time difference between sound waves and electrical signals is huge, which provides a theoretical basis for the emergence of mercury delayed storage technology:

One end of it is an electroacoustic conversion device, which converts electrical signals into sound waves and propagates in mercury.

Due to the relatively slow propagation speed, it takes almost one to several seconds for the sound wave signal to propagate to the other end.

The other end is an acoustic-electric conversion device, which converts the received acoustic signal into an electrical signal, and then re-inputs the processed signal to the electrical-acoustic conversion end.

In this way, a closed loop is formed, and the signal can be stored in the mercury tube.

in the original history.

The first universal automatic computer UNIVAC-1 used this technology, and the time difference is about 960ms.

This idea is undoubtedly far ahead of this era, but it is better than Xu Yun's extreme situation - after all, wheat is just a wall, and has not yet obtained the GM's version development rights.

As for the mercury delayed storage technology in the future?

That's William tubes, magnetic cores, and now disks.

As for the future trend, it is the DNA storage technology that Xu Yun has obtained before.

The line of sight returns to reality.

Wheat's idea quickly attracted everyone's attention, including Ada and Riemann, and many elders gathered at the table again.

Babbage is the person with the strongest manual ability on site, so while excited, he also quickly thought of the practical problems:

"Student Maxwell, although your idea is very good, how can we ensure that the time difference is as long as possible?"

"If it's just a test tube of a few centimeters or ten centimeters, then there is almost no time difference between the sound wave and the electrical signal—at least there is no time difference enough to store data."

Ada also nodded.

For a test tube of more than ten centimeters, the sound wave will basically arrive in seconds with a single swish. Although there is still a time difference between the sound wave and the electrical signal, it is obviously unable to be used.

However, Wheat obviously had a plan for this, and he smiled confidently at Babbage:

"Mr. Babbage, I have actually thought about this question before."

"First of all, we can expand the length of the Xiaoyan tube. Its material is only transparent glass. In the case of mass production, the cost difference between ten centimeters and one meter is actually not that big."

"In addition, we can add some other small equipment, such as"

"Mr. Luo Feng invented the detector when he was testing electromagnetic waves."

Babbage blinked, and asked inexplicably:

"Geophone?"

Mai Mai nodded, and took out a small object about ten centimeters from the drawer-this object was the iron filing detector invented by Xu Yun before.

Smart students should all remember it.

When verifying the photoelectric effect, Xu Yun used two key detection methods:

He first used the standing wave method to form a standing wave in the house, then checked the peaks and valleys of the wave with the fabricated iron chip detector, and finally calculated the wavelength of the electromagnetic wave.

The principle of the detector is simple:

When the photoelectric effect does not occur, iron filings are loosely distributed.

The entire detector is equivalent to an open circuit, and the ammeter will not display the current.

And once the electromagnetic wave is detected.

The iron filings will come to life, gather into a ball, act as a conductor, and activate the voltmeter.

The closer to the peak or trough, the more iron filings will condense, and the greater the value on the meter will be.

The less the iron filings in other positions are condensed, the lower the electric value will be or even be 0.

After introducing the principle of the geophone designed by Xu Yun to Babbage, Wheat said:

"Mr. Babbage, I think this way. We can add one or several small components based on the principle of detectors at the entrance of the signal."

"Then control the strength of the signal, and periodically restrict the transmission of electrical signals in the external wires, somewhat similar to waves."

"In this way, it should be possible to extend the time difference to a certain extent, and even help subsequent calculations."

Hearing this, Babbage fell into deep thought.

The principle mentioned by wheat is somewhat similar to the pulse current of later generations, but the concept of pulse will not officially appear until 1936-just like William Whewell proposed the title of scientist, many modern words or words that seem to be sparse and ordinary, In fact, it does not exist innately.

Therefore, today's wheat cannot directly explain to Babbage with the concept of pulse, and successfully assisted a certain writer to write a few words.

"Wave?"

Babbage thought about it for a while, stroked his chin and said:

"It is indeed feasible. In that case, Maxwell, can we try it now?"

Mai Mai looked up at Faraday, and Faraday nodded sharply:

"It's in the equipment lab, of course."

mentioned earlier.

The vacuum tube designed by Faraday in Cambridge can be split and connected, in order to increase the observation effect.

If necessary, even unlimited human centipedes.

So the ultra-long test tube that wheat said, just need to spend some time splicing.

As for detectors?

When Xu Yun measured the standing waves, he basically had one person in charge, so the number was naturally not too small.

After more than ten minutes.

A simple vacuum tube with a length of nearly two meters, filled with mercury inside, and metal shavings and wires on the outside is assembled.

Wheat then added a set of polarizers to it, and a powered chronograph was attached to the end of the vacuum tube.

That's right.

Chronograph.

well known.

Space and time make up our world.

Since the birth of human beings, human exploration of space and time has never stopped.

Even elementary school students in future generations will know it.

Human beings in 1850 had completed their voyage around the earth and discovered all known land, at most, some small islands had not yet been included in the territory.

But when it comes to the accuracy of time, many people may have a vague concept:

There are definitely seconds, but how accurate are they?

Or 1/2 second?

1/5 second?

Or 1/10th of a second?

Unfortunately, the above is too conservative.

The concept of "timekeeping" actually achieved a development that surprised many people in later generations in the early 19th century.

The first chronograph in history appeared in 1815, and its inventor was Louis Moinet—yes, the founder of the later Louis Moinet.

The chronograph he invented can vibrate 216,000 times per hour, with an accuracy of 1/60 second.

The original history is still like this, let alone 1850 when the timeline changed.

Today's timers can be accurate to 1/140th of a second, which is the centisecond level, but there is still a lot of gaps in milliseconds.

Wheat has added a balance spring on the basis of this accuracy, which can ensure that the timer trips and cuts off the power as soon as it receives an electrical signal.

After everything is ready.

Mai Mai came to the table and pressed the power switch.

With the press of the switch.

An electromotive force is quickly generated inside the Rumkov coil.

The invisible electrical signal instantly crosses to the other end of the coil along with the electric field, and then enters the inside of the vacuum tube.

clatter--

In less than a blink of an eye.

The circuit connected to the balance spring tripped, and a number was clearly displayed on the timer:

0.09 seconds.

This number represents the time it takes for the electrical signal to travel through the interior of mercury, and whether it can transmit information is another matter.

And according to the vision of wheat and Babbage.

This time difference is at least the least, and it must be more than 0.5 seconds.

That is to say

Relying on a pulse voltage alone cannot achieve the desired effect at all.

"Failed"

Think here.

Mai Mai couldn't help scratching her hair, and then

Looking at Xu Yun:

"Student Luo Feng."

Undecided when things happen, classmate Luo Feng.