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As fascinated as I was with how fast light moved, I was even more interested in the speed that sound moved, because that was something that I could perceive under certain circumstances. I was astounded to learn that the speed of sound actually changed because of atmospheric conditions and elevation. It is not a constant like the speed of light. If you are trying to break the sound barrier in a plane or a car, the speed you break the sound barrier will be slightly different depending on the atmosphere, the temperature, and the weather. 

You may have noticed during a thunderstorm that sometimes there is time between a lightning flash and the sound of thunder. This is because light travels much faster than sound.  In fact, if you see lightning and start timing until the thunder, you can estimate the distance the lightning is from you, and whether it is getting closer or moving away.  If it is getting closer, the light and sound will be closer together.  If it is getting farther away the light and the sound will be spread farther apart in time. 

It takes about 5 seconds for sound to travel one mile. Light travels a mile in about 5 microseconds.  Microseconds are a millionth of a second which means light travels about a million times faster than sound. If the time between lightning and thunder is  around one second, then the lightning is about a fifth of a mile away (352 yards or 3.5 football fields), or less than a quarter of a mile away.  If the light and sound are less than a second apart, the lightning is very close.  A few times I have been in really bad thunderstorms, and when I realized the light and sound was getting longer and longer apart, I was relieved, because I knew the storm was travelling away from me.

Sonar

When we yell across a  canyon, and we hear our echo, the delay between when we yell and our echo returns is the time it takes for our voice to carry to the rock wall on the other side of the canyon and bounce off and travel back.  Similarly, in a large empty room we will hear echoes of various delays depending on how big the room is. 

Sometimes the echo is less noticeable depending on how reflective the surfaces are and how much the sound bounces around.  In fact, in a small bathroom with tile walks you will notice a lot of echo, because the sound is bouncing around multiple times off the walls. 

This is also how bats use sonar to navigate through dark caves.  They squeak and their voice bounces off the cave wall and they can tell how close they are to the walls by the sound or the delay in the return of the echo.  No, bats are not supercomputers or digital tape measurers.  They are just tuned into the differences in sound just like you can tell the difference of the sound of a coin dropping on a hard floor a few feet from you, and one that is dropped on the same floor on the other side of the room. Bats just have more sensitive hearing and their brains are more aware of subtle differences in the sound. 

Sonar used in submarines, and in underwater research to map the floor of the ocean use the same principle, and radar and ground-penetrating radar uses a similar process except it uses radio waves instead sound to bounce off objects to either detect or map things that we cannot easily see like the bottom of the ocean or if there is something buried or a cave underground.

Sound and Temperature

If you go to weather.gov , there is a calculator that will give you the speed of sound based on temperature. Temperature is  the primary factor that affects the speed of sound in the Earth’s atmosphere.

Concerts and the Speed of Sound

In a large auditorium, the distance from the stage to a seat in the very farthest point in the building is probably less than a quarter mile. This means the time it takes for sound to travel from one end to another is going to be less than a second.  There will be a fraction of a fraction of a second delay for the sound to travel from one end of the auditorium to the other. 

 In a very large auditorium or stadium, however, there can be problems. If you have all the speakers up on the stage, the sound would have to be so loud to reach people in the back that it would be too loud for the people close to the stage.  This is because sound falls off the farther distance it has to travel.

In order to compensate, musicians put additional speakers in a large auditorium or stadium at various intervals along the sides.  This can cause a problem, too, if the venue is large enough, because the signal going through the speaker wire is going at the speed of light. The speakers in the back will sound at the same time the ones at the front, but the sound coming from the front of the house will follow to the back at the speed of sound. It will be fraction of a second later, causing a noticeable delay or echo.

To compensate for this, larger auditoriums and stadiums will put a delay on the speakers that are farther back in the house, so that they are in synch with the sound coming from the speakers on the stage and closer to the front of the house.

Echo Chambers in Music Recording

Musicians, rock groups, and singers often use what are called modulation effects such as reverb, echo, and delay to create depth or texture to a song, but these effects were originally created to emulate the sound of an echo in a large room or auditorium. In fact, in Abbey Road Studios where the Beatles, the Foo Fighters, Miley Cyrus, Queen, the Red Hot Chili Peppers, Kanye West, and many others have recorded music, they have special rooms, called echo chambers, that they sometimes use to create various echo effects using the actual accoustic properties of the room instead of an electronic filter or effect. 

If that does not blow your mind, there are manufacturers of electronic and computer generated effects that have gone to a great deal of trouble and effort to emulate the sound of the echo chambers at Abbey Road Studios. I guess art and science really do mimic each other.

Amp Technology: How Sometimes the New Stuff Struggles To Be As Good As the Old Stuff 

It’s always a Catch-22 situation. They hate you if you’re the same, and they hate you if you’re different.

 

— Eddie Van Halen

Great Balls of Fire

In the 1950s, when the electric guitar and rock and roll were first taking off, Jerry Lee Lewis was told he should give up the piano and play guitar.  The guitar was latest thing, guitar players move around more, and the guitar was more exciting. 

Jerry Lee Lewis showed them the piano could be exciting. When he played Great Balls of Fire on the piano, he would stand up and kick the piano bench away and start dancing and rocking as he played keyboard.

It is still hard to beat Chuck Berry’s duck walk, Jimi Hendrix setting his guitar on fire, Pete Townsend smashing his guitar on stage, or T-bone Walker playing his guitar behind his head, but Jerry Lee Lewis managed to shake things up at the time.

Eruption

By the late 1970s things had changed. Keyboards and synthesizer technology seemed to mimic any instrument, as well as produce new and different and modern sounds. The same type of people who told Jerry Lee Lewis the piano was dead now said the electric guitar was dead.

In 1978, Van Halen released an album with the short instrumental track called Eruption.

In that track, Eddie Van Halen, played the guitar and made it sound like no one else had ever played it. He tapped the strings with his fingers in parts instead of just picking, he used the whammy bar to dive bomb notes, and he used amp distortion in a way that made the notes sing and do impossible things.  Eddie Halen has said many times that he considers himself a tone chaser.  In fact, the story behind music technology is often a back and forth between the technology chasing the tone and the tone chasing the technology.

Fender & Guitar Amp Technology

In 1938 Leo Fender opened a radio repair shop. Leo Fender would go on develop a number of inventions and designs related to amplifiers and electric guitars. Two of the three most common electric guitar body designs today are based on designs by Fender.

At that time, vacuum tubes were the cutting edge of electronic technology.  Fender designed a guitar amp using vacuum tubes. It was a challenge because tube amps, particularly earlier tube amps, use a technology where hum and distortion can be a problem. The guitar pickups added noise, feedback. and hum. Fender designed an amp that worked to prevent this, creating amps that put out some of the best clean, undistorted tones on a guitar.

Now, when you want to design an amplifier, the two things you want to do is remove hum and distortion, particularly if you are using the amplifier to play back sound recordings. In general, a musician does not want the amplifier changing or distorting the sound of the recording.

Guitarists are not radio repair techs or sound engineers. Most of them just twist the dials on an amp until it sounds good, particularly back in the day.  If they were sound engineers, they would explain that a guitar amp is actually two amps: a preamp that boosts the signal of the guitar input from the pickup to an ideal level for the second amp, the power amp, to amplify the signal for the speaker of the amp. 

If the input level is too low, the power amp needs to be turned up louder to get the same level of amplification. The louder the input level the less hard the power amplifier has to work.  The reason it is so important for an amplifier not to have to work so hard is that the amplifier not only amplifies the sound, it amplifies the noise and hum of an input as well.  Also, the louder the amplifier, the more distorted it tends to get, particularly with tube amps.

Different guitar pickups have different signal levels. By adjusting the preamp you can adjust the input level to the optimal level.  Both guitar pickups and microphones use preamps to adjust their input level or their level of sensitivity.  There is a knob on a guitar amp called “gain” which controls the preamp volume and then a knob marked “volume” that controls the power amp level. Gain is equivalent to the recording level on a sound recorder.

You might think that that was a lot of explanation when you could just turn the knobs around on an amp until it sounded ok.  This is what most guitar players of the 1950s did. Crank up the gain on an amp too high, you get distortion. The power amp amplifies that distortion so as you turn up the power amp more, it amplifies the distortion more and adds it own distortion to the distortion. This means by fiddling with the two knobs you can go from a very clean signal to a very distorted signal.  

Transistors & Solid-state Electronics

While all this was going on, the transistor was invented at Bell Labs in 1947.  The transistor was invented as a replacement for the vacuum tube, and is considered to the beginning of solid-state electronics. When we use the terms semiconductor or chip, we are talking about solid-state electronics. Because almost all electronics are solid-state now, we do not use the term as much.  We might refer to something as having tubes in it now, but back when vacuum tubes where the main technology, people referred to electronics without tubes as solid-state, because that was the new and unusual thing.

Solid-state guitar amps are great at creating clean, undistorted tones. The problem is that the “disadvantages” of the vacuum tubes produce the great distorted tones that cannot be fully reproduced with solid-state or digital technology. The distortion on tube amps is quirky and responds to how a guitarist plays the guitar in ways that are hard to or impossible to entirely reproduce in a solid-state amp.

Leo Fender and others spent the first part of amplifier history chasing the perfect clean tone for an amplifier with technology that wanted to distort the sound. Meanwhile, guitar players started experimenting with distorted sound from the amplifiers, because they liked what they heard. They realized that some of the best tones on an electric guitar are distorted to some degree even if it is just slightly. 

Eddie Van Halen

During the 1960s and 1970s, vacuum tube technology was being replaced by solid-state technology. While Eddie Van Halen is often credited with saving the electric guitar in rock music, no one seems to mention that he also may have had a part in saving tube technology from the junk heap as well.  You see, the main place where vacuum tubes are still used today is in guitar amps.

Fast forward back to 1978 and Eddie Van Halen was using a whammy bar of a design created by Leo Fender along with the distortion from a tube amp and finger tapping that was being used by Emmett Chapman, inventor of the Chapman Stick, in the late 1960s.  Eddie Van Halen’s big moment when he saved the electric guitar was forty years in the making and partially based on what was once considered a weakness in the technology.

What is the Difference?

To get an idea of the difference between tube and solid-state guitar amps, you can go to a flooring store and look at the different types of wood and artificial wood flooring. At one end you have real wood flooring — solid wood that has all the benefits and drawbacks of real wood. Next you have various engineered wood flooring which might be real wood on the top, but underneath is made of composite material or a cheaper type of wood, etc.  Finally, you have laminate flooring made of manufactured materials. 

The best laminate flooring is often hard to tell from real wood, so many people would not notice the difference at first. However, if you stand and look at a laminate floor for a while, you will start to notice that some planks have the exact same wood grain. This is because manufacturers make only a half dozen plank variations. 

In a real wood floor, each plank is unique. The same is true of tube amps and solid-state amps and digital modelling amps. Digital modelling amps may use computer technology to try to reproduce tube distortion, but you tend to end up with the tonal equivalent of a laminate wood floor.

The digital world is clean and precise, but it is also pixelated and predictable.  The analog world is warm, fuzzy, less predictable and has smooth slopes instead of stair stepped ones and zeros.  This is one reason that you might hear of some electronic device that uses an analog solid-state circuit instead of a purely digital one.

Sometimes we discover an old technology is better for a particular application and other times we get ideas from old technologies on how to implement new technologies.

Korg, the synthesizer company, developed an electronic component they call a NuTube.  A NuTube is basically a solid-state tube, a semiconductor that is designed to behave like a vacuum tube.

The jury is still out on whether a NuTube is as good as a vacuum tube for a guitar amp, but the results the NuTube have gotten so far look promising and seems to be one of the better attempts at a way to emulate a vacuum tube amp with solid-state technology.

–Dean McIntyre, May 28, 2020

If I ever go looking for my heart’s desire again, I won’t look any further than my own backyard. Because if it isn’t there….then I never really lost it to begin with.
–Dorothy Gale, The Wizard of Oz

It turns out that a technology that was originally used to help search for intelligent life on other planets, has developed into a technology that allows people to share their PC’s idle time to help research treatments for  COVID-19.

The Search for Extraterrestrial Life  

The SETI Project (Search for Extraterrestrial Intelligence) was founded in 1984 with the goal of detecting intelligent life outside earth. It had its roots in the beginning of radio technology.

Although most people would  say that is would be great to know if there was intelligent life on other planets (and most people have probably wondered about it at one point or another) it is the type of thing that tends to lose funding during budget cuts. 

When SETI started to lose funding, scientists looked for ways to continue their research. They could not cut the cost of renting radio telescopes time or funding arrays of radio telescopes — this is how they collected their data. However, they could think of  different ways to  listen to and analyze the data. 

You have to listen to a lot of signals over time to find one you can prove is being generated by intelligent life. The easiest way to do that is to have computers look at the signals and tag the ones for researchers to look at. 

Scientists could purchase a supercomputer to do this, or they could use a group of smaller computers to do this using parallel computing. Both solutions are expensive.  Not only do you have to cover the cost of the equipment,  SETI would have to house the computers, cool them, and supply power to the CPUs and the massive cooling system to  cool off the heat generated by that many computers.

About SETI

The roots of SETI began with radio technology. In 1899 Nikola Tesla heard what he believed to be radio signals from either space, Venus, or Mars. 

The signals were probably just naturally occurring radio signals or interference.  We might scoff at Tesla and others for thinking they might be able to receive radio signals from Mars or even communicate with Martians via a two-way radio.

In fairness, at the end of the 19th century, humans had not been in space. It is only in the later part of the 20th century that we have been able to go beyond the telescope and explore space with manned and unmanned missions. 

World Community Grid, which supports cutting-edge research into important global humanitarian causes, is looking for volunteers to donate spare computing power to help find treatments for the COVID-19.
Learn More:

• Worldcommunitygrid.org  
• Open Pandemics – COVID-19
• About World Community Grid

Distributed Computing

In 1999, the SETI project based at U.C. Berkeley created a volunteer distributed computing project, known as grid computing, called SETI@home. Volunteers loaded a program on their home computers to process radio signals when they were not using their computers.

The idea was that most of the time PCs are idle. Even when they are being used, the central processing unit (CPU) is  being utilized at a fraction of its capacity.

SETI@home sent files to volunteers’ computers to be processed on a user’s machine during the idle time.  Because the program was written to use idle time and not to interfere with what the user was doing, it could be run in the background without users even noticing it was running, adjusted to only run when the user was not using the machine,  turned off entirely by the user.

The current program (client) allows volunteers to  specify times of day when to run, the maximum percentage of CPU time it can use at once, the maximum about of disk space it will use, and when it will do file transfers.

Beyond E.T.’s:
BOINC

SETI@home was so successful that the University of California, Berkeley created BIONC (Berkeley Open Infrastructure for Network Computing.) This expanded the client to include other science projects.

BOINC  is open source which allowed others to adopt the technology. In 2004, World Community Grid,  IBM’s philanthropic initiative, developed grid computing software to power scientific research on health, poverty and sustainability. 

Currently one of the projects at the World Community Grid uses computer time to help find treatments for the COVID-19.

It is hard to find a radio signal in space that you can prove is being generated by intelligent life. It takes time, and people are impatient. Why do it? This article explains reasons why research projects may sound silly, but are actually very valuable.

Shrimp on treadmills? Some science only sounds silly

Experiments that may seem odd almost always have a valuable purpose
Science & Society article from ScienceNewsforStudents 

Did you know that electronic music started in 1928, with the invention of the Theremin?

You might think that electronic music started sometime in the 1980s or 1990s with digital synthesizers and the beginnings of the personal computer.

Or you might imagine it started at the beginning of this century with the development of looping and sampling software on the PC and music production apps on the iPad. 

Or, if you are into the current modular analog synthesizer scene (or if you are a hipster into LPs, film cameras, retro analog technology, and nitro cold brew coffee) you are probably certain it started in 1964 with the invention of the first commercial analog synthesizer, the Moog synthesizer. 

What’s a Theremin?

A theremin is one of the first electronic instruments, predating the first commercially available electric guitar by a few years. It is hard to date it exactly. We can date it by patents, when it was commercially available, or when hobbyists, inventors and scientists began experimenting with it.  With electronic music technology, someone has to invent it and produce the technology before musicians and composers could to produce live and recorded music.

A theremin has two antennas that control tone and volume based on how close the musician’s hands are to each antenna. The musician never actually touches he instrument. The instrument can slide between notes and create vibrato effects similar to a stringed instrument or the trombone.

The theremin is probably most famous for producing the eerie music you hear in old classic 1950s Sci Fi movies like Forbidden Planet and The Day the Earth Stood Still, but it also has been used in recordings and performances by popular groups such as The Rolling Stones, Phish, Tesla, and Led Zepplin.

Leon Theremin

In 1928, the Russian inventor Leon Theremin invented the theremin. He was involved in the music scene in New York City until 1938, when he was kidnapped by Soviet agents and returned to the Soviet Union.

The Soviet Union had other plans for him and he ended up inventing various devices for spies to eavesdrop, including a device that could record conversations by using an infrared beam to detect the sound vibrations in the glass of windows. There are more modern versions of this device that use lasers and are still in use today.

Good Vibrations

In 1966, the Beach Boys recorded a song called Good Vibrations, which is considered one of the most important recordings in rock music, because of the way it used multi-tracking techniques and placed the emphasis on studio production to create the music. It was not a merely a recording of a live performance. 

The recording techniques used in Good Vibrations and in songs by The Beatles in the mid-1960s were really when techniques like digital sampling, looping and layering used in music production today were first developed. Today computers and technology make using these techniques much easier.

The Beach Boys also used an electro-theremin in the song Good Vibrations. An electro-theremin is a bit different than a theremin, but it produces a similar sound, and was inspired by the Theremin.

Electro-Theremin

When Tanner could not perform live with them, the Beach Boys went to Bob Moog. Moog designed a ribbon controller for a keyboard, a strip above the keyboard that the musician could run a finger along to change the pitch of the note. It produces a similar sound to an electro-theremin or a theremin.

In the late 1950s, trombonist Paul Tanner and inventor Bob Whitsell invented the electro-theremin, which used a knob and a mechanical slider to produce a sound that mimicked the Theremin. In 1966, The Beach Boys hired Paul Tanner to play the electro-theremin on the recording of Good Vibrations.