How Big is the Universe?

 By Hans Jørgen Jensen



Do we know? Can we know? Will we know?

I remember asking my father this question when I was just a ten-year-old boy. I went further to raise a similar question: “What is the smallest thing we know?” At the time I did not have any knowledge about molecules and atoms, but somehow intuitively I drew a connection between the infinitely small and the infinitely large. I remember sitting outside in the garden, observing a few insects crawling on our plants, and in a sudden flash of inspiration I felt that everything was connected from the smallest end of the spectrum to the largest. Little did I know that in 2022, over 60 years later, scientists would still be searching for the “theory of everything” (TOE), the model that would unify the four natural phenomena of gravity, electromagnetism, and the weak and strong nuclear forces. [1] The TOE was the riddle that Einstein spent the last 30 years of his life trying to solve but never did. At present, the “superstring theory,” which conceptualizes ten dimensions or more, is the best attempt we have of explaining this riddle.


The size of our visible Universe (yellow), along with the amount we could reach (magenta) if we left, today, on a journey at the speed of light. The limit of the visible Universe is 46.1 billion light-years, as that is the limit of how far away an object that emitted light that would just be reaching us today would be after expanding away from us for 13.8 billion years. There are an estimated 2 trillion galaxies contained within the yellow sphere drawn here, but that estimate is likely low, perhaps by as much as a factor of 3-to-10.

(Credit: Andrew Z. Colvin and Frederic Michel, Wikimedia Commons; Annotations: E. Siegel)


My father’s response to the question I had posed was more philosophical than scientific, but he made it clear to me that scientists around the world were constantly making new discoveries and that, in the same way, it was important that I never stop asking questions about any topic that I did not understand. Since that day I have been fascinated with the search for answers to difficult and complicated questions. It is also not a coincidence that a deep curiosity about the latest discoveries in astronomy and quantum physics has stayed with me to this day. It goes without saying then, that as a teacher of the cello I have always possessed an incredible thirst for trying to understand how and why certain things “work” on the cello and why certain things do not. The pursuit of these answers has been and will continue to be a never-ending journey.

As a cello teacher, I spend a great deal of time and effort encouraging my students to understand and find the perfect balance between the following three aspects of instrumental playing and music making:

  1. The intelligent and creative musical mind.
  2. Kinesiology, the science of physiology and biomechanics.
  3. The physics of the cello.

Although over-analyzing what we do can get in the way when performing, it is important for a musician to get to the core of things and understand how they work. We are all different, however, and so what we each need to know and do to solve our own problems and issues depends upon our unique and individual characteristics.

One of my biggest fascinations is the relationship between physics and string music. Here are some examples where scientific discoveries are helpful and informative for musicians:

The science involved in the vibration of the bowed string is the only well-understood example of vibration excited by friction. [1] However, a number of important and fascinating discoveries by scientists in string acoustics have not been fully integrated into the general understanding and vocabulary of string teaching.

In sports training centers all over the world a lot of time and money is invested into research about sports science. The study of sports science incorporates areas of physiology, psychology, motor control, and biomechanics, all of which are important to musicians. The physical aspect of playing an instrument has a tremendous amount of similarity to a great number of sports disciplines. There is so much that musicians can learn from the latest research in sports science.

Motor learning can be defined as the process of improving the motor skills—the smoothness and efficiency of movements—in order to master a particular task. As an area of research, it has held a very important position in both physical education and psychology for more than 100 years. Many scientific experiments have taken place over the years, controlled by leading scientists in motor learning. To take a case in point, blocked practice has often been compared to random practice in scientific studies. Blocked practice involves giving total focus to one aspect of technique, practicing the same thing over and over until it is correct. Random practice on the other hand is where a number of skills are practiced in random order, with the goal of avoiding or minimizing repetition of any single task. While it is encouraged for musicians to use both methods, random practice has been proven by numerous experiments to be much more effective for long term retention. The idea of repeating a skill over and over is often a waste of time and has been proven to be less efficient in terms of practice technique. This point can be summed up in the words of the late Russian physiologist N.I. Bernstein:

The process of practice towards the achievement of new motor habits essentially consists in the gradual success of a search for optimal motor solutions to the appropriate problems. Because of this, practice, when properly undertaken, does not consist in repeating the means of solution of a motor problem time after time, but in the process of solving this problem again and again. [2]

Kinesiology, derived from the Greek words kinesis (movement) and kinein (to move), also known as human kinetics, is the science of human movement. Over the years I have read as many books about string teaching as possible. One of the books that had the most profound influence on me as a young teacher was The Teaching of Action in String Playing by Paul Rolland. In that book there are numerous examples of specific practice and performing techniques where string players can learn a tremendous amount from knowledge gained from kinesiology. Here is one example: The speed at which a skill is first practiced should be approximately that of the speed at which it is to be used later. [3] 

That quote is one of the most important aspects of instrumental practice. If the end goal is not clear in the mind of the performer, then practicing is a waste of time. In order to master a fast passage, one has to practice it fast in order to find the most efficient movement pattern. In addition, the muscles involved with executing a fast movement are completely different than the muscles involved in executing a slow movement.

Science and violin Playing

Kinesiologists work in the fields of sciences that relate to human movement, as well as in fitness and sport, occupational therapy, and the movie animation industry. This discipline incorporates special equipment to measure human movement, including optical cameras or electromagnetic sensors in 3-dimensional space or in the 2-dimensional plane to measure telemetry. There are a great number of scientific discoveries that we can incorporate into our instrumental teaching and understanding from research in kinesiology.

Look at the video below to see how motion capture systems can be used to visualize bowing gestures in violin playing. The circular bowing gestures and the figure 8 bowings are very easy to observe. This experiment was supervised by Erwin Schoonderwaldt, a brilliant scientist from Sweden.



The Constrained Action Hypothesis refers to knowledge gained from measuring EMG (Electromyography) activity in performers’ muscles. [4] EMG clearly shows in numerous experiments that when performers utilize an internal focus of attention, they constrain and interfere with automatic control processes that would normally regulate the movement, whereas an external focus of attention (focus on the movement effect) allows the motor system to more naturally self-organize. [5] Although many musicians intuitively understand this process, recognizing the scientific fact makes it much more powerful.




[1] Woodhouse, Jim and PM Galluzzo. “The Bowed String As We Know It Today.” Acta Acustica United with Acustica 90 (2004): 579-589.

[2] Bernstein, Nikolai A. The co-ordination and regulation of movements. Oxford: Pergamon Press, 1967.

[3] Rolland, Paul. “The teaching of action in string playing: Developmental and remedial techniques for violin and viola.” 2nd ed. Illinois String Research Associates, 2000. Pg. 205. Also see the film series based off of the same material at

[4] McNevin, Nancy H., Charles H. Shea, and Gabriele Wulf. “Increasing the distance of an external focus of attention enhances learning.” Psychological Research 67 (2003): 22-29. Link.

[5] Wulf, Gabriele, Barbara Lauterbach, and Tonya Toole. “The learning advantages of an external focus of attention in golf.” Research Quarterly for Exercise and Sport 70 (1999): 120-126.,%20L%20and%20T.pdf