Tag Archives: energy

More uncertainty about matter and energy


When I wrote about wave-particle duality and an electron possessing the characteristics of both matter and energy [see my post entitled ‘Electron uncertainty’ on July 27th, 2016], I dodged the issue of what are matter and energy.  As an engineer, I think of matter as being the solids, liquids and gases that are both manufactured and occur in nature.  We should probably add plasmas to this list, as they are created in an increasing number of engineering processes, including power generation using nuclear fission.  But maybe plasmas should be classified as energy, since they are clouds of unbounded charged particles, often electrons.   Matter is constructed from atoms and atoms from sub-atomic particles, such as electrons that can behave as particles or waves of energy.  So clearly, the boundary between matter and energy is blurred or fuzzy.  And, Einstein’s famous equation describes how energy and matter can be equated, i.e. energy is equal to mass times the speed of light squared.

Engineers tend to define energy as the capacity to do work, which is fine for manufactured or generated energy, but is inadequate when thinking about the energy of sub-atomic particles, which probably is why Feynman said we don’t really know what energy is.  Most of us think about energy as the stuff that comes down an electricity cable or that we get from eating a banana.  However, Evelyn Pielou points out in her book, The Nature of Energy, that energy in nature surrounds us all of the time, not just in the atmosphere or water flowing in rivers and oceans but locked into the structure of plants and rocks.

Matter and energy are human constructs and nature does not do rigid classifications, so perhaps we should think about a plant as a highly-organised localised zone of high density energy [see my post entitled ‘Fields of flowers‘ on July 8th, 2015].  We will always be uncertain about some things and as our ability to probe the world around us improves we will find that we are no longer certain about things we thought we understood.  For instance, research has shown that Bucky balls, which are spherical fullerene molecules containing sixty carbon atoms with a mass of 720 atomic mass units, and so seem to be quite substantial bits of matter, exhibit wave-particle duality in certain conditions.

We need to learn to accept uncertainty and appreciate the opportunities it presents to us rather than seek unattainable certainty.

Note: an atomic mass unit is also known as a Dalton and is equivalent to 1.66×10-27kg


Pielou EC, The Energy of Nature, Chicago: The University of Chicago Press, 2001.

Arndt M, Nairz O, Vos-Andreae J, Keller C, van der Zouw G & Zeilinger A, Wave-particle duality of C60 molecules, Nature 401, 680-682 (14 October 1999).


Electron uncertainty

daisyMost of us are uncomfortable with uncertainty.  Michael Faraday’s ability to ‘accept the given – certainties and uncertainties’ [see my post entitled ‘Steadiness and placidity’ on July 18th, 2016] was exceptional and perhaps is one reason he was able to make such outstanding contributions to science and engineering.  It has been said that his ‘Expts. on the production of Electricity from Magnetism, etc. etc.’ [Note 148 from Faraday’s notebooks] on August 29th 1831  began the age of electricity.  Electricity is associated with the flow of electric charge, which is often equated with the flow of electrons and electrons are subatomic particles with a negative elementary charge and a mass that is approximately 1/1836 atomic mass units.  A moving electron, and it is difficult to find a stationary one, has wave-particle duality – that is, it simultaneously has the characteristics of a particle and a wave.  So, there is uncertainty about the nature of an electron and most of us find this concept difficult to handle.

An electron is both matter and energy.  It is a particle in its materialisation as matter but a wave in its incarnation as energy.  However, this is probably too much of a reductionist description of a systemic phenomenon.  Nevertheless let’s stay with it for a moment, because it might help elucidate why the method of measurement employed in experiments with electrons influences whether our measurements reflect the behaviour of a particle or a wave.  Perhaps when we design our experiments from an energy perspective then electrons oblige by behaving as waves of energy and when we design from a matter perspective then electrons materialise as particles.

All of this leads to a pair of questions about what is matter and what is energy?  But, these are enormous questions, and even the Nobel Laureate Richard Feynman said ‘in physics today, we have no knowledge of what energy is’, so I’m going to leave them unanswered.  I’ve probably already riled enough physicists with my simplistic discussion.

Note: an atomic mass unit is also known as a Dalton and is equivalent to 1.66×10-27kg


Hamilton, J., A life of discovery: Michael Faraday, giant of the scientific revolution. New York: Random House, 2002.

Pielou EC, The Energy of Nature [the epilogue], Chicago: The University of Chicago Press, 2001.

Engaging learners on-line

Filming at Quarry Bank Mill

Filming at Quarry Bank Mill

The Everyday Engineering Examples page of this blog continue to be very popular.  More than 70 engineering schools in the USA have signed up to use this approach to teaching engineering science as part of the ENGAGE project.  The lesson plans on that page assist instructors to deliver traditional lectures that are engaging and effective.  Now, we have transferred the approach to online delivery in a MOOC that was designed to support undergraduate learning as well as to increase public engagement and understanding of engineering science.

The MOOC entitled ‘Energy: Thermodynamics in Everyday Life‘ was completed by more than 960 learners from about 35 countries who ranged in age from 13 to 78 years old with a correspondingly wide range of qualifications in terms of both subject and level.  I believe that this is the first MOOC to use Everyday Engineering Examples within a framework of the 5E lesson plans and it seems to have been effective because the completion rate was 50% higher than the average for FutureLearn MOOCs.

We also included some experiments for MOOC learners to do at home in their kitchen.  Disappointingly only a quarter of learners performed the experiments but surprisingly almost half of all learners(46%) reported that the experiments contributed to their understanding of the topics.  This might be because results and photos from the experiments were posted on a media wall by learners.  There was also a vibrant discussion throughout the five-week course with a comment posted every 8 minutes (or more than 6,500 comments in total).

More than half the undergraduates (53%) who followed the MOOC did not continue to attend the traditional lectures and roughly the same percentage agreed or agreed strongly that the MOOC could replace the traditional lecture course with only 11% disagreeing.  So maybe the answer to my question about death knell for lectures [see my post ‘Death Knell for the lecture?‘ on October 7th, 2015] is that I can hear the bell tolling.

I gave a Pecha Kucha 20×20 on these developments at an International Symposium on Inclusive Engineering Education in London last month, which is available as a short video.