Once the gas helium is cooled below 2.2 Kelvin or minus 271 degrees Celsius, it becomes a superfluid: incredibly, it can flow without resistance, defy gravity by climbing up walls, slide through tiny pores that other liquids cannot penetrate and even produce a fountain that never stops flowing. Video footage of superfluid helium is quite rare and, as a student, the best I ever saw were some small black and white photographs in a textbook, something that hardly conveys the bizarre and fascinating behaviour of this liquid. Today, however, any physics students can see what few of their physics lecturers have ever seen, thanks to the wonders of YouTube.
Indeed, anyone can see it because YouTube is a public-access online video-sharing site. There, users can post short video clips (up to 10 minutes in length) that everyone can watch. It is one of a family of web sites including the social networking sites MySpace and Facebook, image servers (such as Photobucket and Flickr), journal sites (such as Blogspot) and online encyclopaedias (such as Wikipedia) that have evolved to cater to the public's desire to share information and express themselves via the internet.
In its original incarnation, YouTube mostly contained short video snippets that users filmed with digital video cameras and posted on the site for friends to see. However, it has grown to be so much more as businesses, community groups and political organisations have realised its potential for advertising products, presenting policies and so on to the public.
Most recently, the higher education sector has even taken notice, with universities beginning to open their own YouTube channels to publicise research, present teaching resources in a more accessible way and attract new students. But YouTube's potential as a digital video library for teaching purposes has not been realised, as that liquid helium example aptly demonstrates.
The quantity, quality and diversity of video postings on YouTube and similar sites have increased rapidly. YouTube alone currently hosts more than 83 million videos and receives more than 50,000 new contributions per day. Interesting news clips, interviews with public figures, footage of physical phenomena, tutorials on how to do various things, computer-generated simulations, time-lapse videos - you name it, you'll probably find it there.
In a sense, YouTube has now evolved from an amateur film-sharing site into an enormous, online film archive with easy access from your computer, 24 hours a day, seven days a week. Other online video web sites have now emerged, such as GoogleVideo, DailyMotion, Brightcove and iFilm as well, rapidly increasing the quantity of video content available.
Nothing like this has ever existed before and, as a lecturer seeking short snippets of video footage to present in class, these online video archive web sites are a dream come true. My own subject, physics, is a challenging one that combines experimental observations and mathematical descriptions, and it calls on physical intuition to provide scientifically tested explanations for the various physical phenomena.
The first two are comparatively easy to teach and relatively well catered for by traditional laboratory classes, lectures and tutorials. The intuitive aspect of physics, however, is more nebulous and difficult to convey, and usually comes to a student indirectly via accumulated experience, for example, by noting that common skills and techniques can be applied to often quite different physical systems.
One way to facilitate the development of physical intuition and accelerate the process of gaining 'experience' is to provide a strong background context for the technical aspects of the course, either by performing live demonstrations or by presenting relevant examples and anecdotes in the lectures.
Youtube: My crushed can demo
Although the efficacy of live demonstrations is established, they tend to become less viable in higher year courses because more sophisticated, expensive and cumbersome equipment is required as the physics becomes more complex. Demonstrations of basic physics can be done easily using simple apparatus such as masses, springs, batteries, beakers of water, etc.
But the same is not true for quantum physics, where the effects can often only be observed at the atomic scale. As well, the set of useful demonstrations is often smaller in higher year courses because the students have often already seen many of the most common and best ones in their first year courses. Hence, the onus tends to fall back on examples and anecdotes or worked problems in higher year courses.
In my experience as a student and as a lecturer, examples and anecdotes are often not as effective because they lack the visual dimension and dynamic of live demonstrations. One way to enhance the value of examples and anecdotes is to use video footage. Video has some key advantages: it allows students to see demonstrations of physics that could never otherwise be done in a lecture theatre, such as detonating a nuclear weapon or freezing a lake.
Providing a visual dimension to many of the examples and anecdotes given in the lecture enhances their effectiveness and memorability. What's more, it makes the course more interesting, engaging and more relevant to students' everyday experiences.
In the past, the use of video in lectures was rather difficult unless you were in the fortunate position of having access to a very large film archive or were willing to invest the considerable time and effort involved in producing your own video clips. But the advent of YouTube, digital video processing software and digital presentation technologies in lecture theatres has the potential to change all this: in future, a lecturer may have online access to thousands of hours of video footage that is more easily searched, prepared and presented than ever before.
This doesn't just apply to physics: in fact, I find it hard to think of a subject that could not benefit from this approach because the possibilities are almost endless. There are limitations though: copyright and legal aspects of using online video can be quite confining in terms of the potential for online video in lectures and using the web interface in the lecture environment can also be problematic.
Australian copyright law allows the use of various copyrighted materials for educational purposes under licence, without the need to obtain direct permission from the copyright owner. But most web-based media, that is, webcasts, do not fall under the legal definition of broadcasting; hence there are limits about what can be done with this material.
It must be restricted to only staff and students of the educational institution; no more than 10% of a work can be used or made available online at any one time; and an 'electronic use notice' indicating that the material has been copied under licence must be placed so that the material cannot be reached without the notice being viewed.
If someone has made an illegal copy of an original work, however, using that copy is a copyright infringement. This is an important issue when it comes to online video, which can be broadly classified into three groups.
Original creations posted by the legal copyright holder such as home videos are quite amenable to use providing the owner gives permission. Video web sites generally facilitate direct contact with users who post video content, so obtaining permission is often reasonably straightforward.
But considerable care needs to be taken with the other two kinds of online video: 'transformative derivatives' (some mix or remix of original content altered to such an extent that it is something new and creative), and copied material posted to the web site by someone other than its creator (who may or may not have the permission of the legal copyright holder).
A large proportion of these latter videos infringe copyright, ranging from blatant infringement through to material that on the surface appears quite benign in terms of 'fair use' but which could be competently argued in court as copyright infringing content.
With some small changes to YouTube we could better facilitate the use of online video for teaching. Those changes are basically a) some sort of archiving, such as an educational library, to allow people to find useful educational material easily, and b) people making it clear whether they are willing for their videos to be used by the public and under what terms. Do they demand full copyright rights or are they willing to use a creative commons licence, for example?
As it stands, YouTube doesn't encourage this but a few checkboxes during the submission process would save much time and resolve uncertainties. More widespread use of creative commons licensing for YouTube submissions would also help significantly, in effect allowing YouTube contributors to 'donate' their videos for non-profit uses such as education automatically.
It also demands that videos be viewed only through the website itself, on the YouTube embeddable player. So how might we deal with these limitations in practice? By far the easiest option would be to simply provide a url so students could watch the desired video in their own time after the class. Unfortunately, this option is also the least effective: most students won't bother and you can't be there with them to emphasise important parts and avoid misinterpretations.
The video could also be played during the lecture using the web-based video player embedded in the site. This would be relatively straightforward to implement: most lecture theatres now have internet connections to the computers that control the display projector, and it is very easy to put an internet hyperlink into a PowerPoint presentation.
Technical issues arise, however: web connections may fail or be slow; the video player may be small and not clearly visible in the lecture theatre; and the video stream must be taken as it comes, making it difficult or time-consuming to isolate one relevant section.
If all this sounds like a deal of trouble it's worth remembering that YouTube is not just about video footage. It contains many simulations and visualisations contributed to the public domain by scientists and research groups. Examples range from how black holes act as gravitational lenses to the molecular machinery that replicates DNA.
YouTube: The singing lake.
Another potential use for YouTube videos is to set a question that introduces a new concept needing to be taught. There is one fantastic home video (one of many on this phenomenon) that works very well in demonstrating a phenomenon known as 'singing' in frozen lakes (see links).
This video works well because the person who filmed it put the camera down on the ice where the microphone picks up the strange pinging and beeping noises coming from the ice quite well. Where do these noises come from? The answer is that water expands when it freezes, unlike most other substances, which contract. The noises are stress building up and releasing as various frozen sections push against one another. This is related to the Clausius-Clapeyron equation, which describes phase transitions such as that from water to ice.
Beyond motivating a more technical discussion, this video can help to make the concept more memorable, demonstrate that even quite technical equations such as the Clausius-Clapeyron equation can be used to explain everyday phenomena in nature, and it stops a lecture from becoming just an hour of mathematics and technical talk.
It's also worth noting that live demonstrations in lectures don't always succeed, meaning that video is a reliable fallback - especially when demonstrations have a higher than usual probability of failing. These include failing to get an airtight seal during a demonstration of pressure, or electrostatics demonstrations on a humid summer afternoon when Murphy's law gets you.
Finally, YouTube videos can add some spice to your lectures and remind students that learning can be fun. Teaching about engines in thermodynamics, for example, can be livened up by showing the extraordinary singing Formula One race car. Or, in discussing probability and quantum information theory, you could show the Ricoh 'Intelligent models' commercial (the contents of which were allegedly plagiarised from the lectures of an MIT physics professor).
I hope you'll find, as I have, that with more than 59 million videos on YouTube alone, there are some that might be of use for your course.
Links to examples given in the article and other useful links:
The Singing Lake
My Crushed Can Demo
Singing Formula 1 Car
Ricoh Intelligent Models
UNSW's YouTube Channel
Information on Creative Commons
*Dr Micolich is a senior lecturer in the school of physics at the University of New South Wales in Sydney on whose site this article first appeared. Additional research, comments and editing of this article were proviied by Rosanne Quinnell, Michelle Kofod, Richard Newbury, Theodore Martin, Merlinde Kay, Debbie Gibson and Bob Beale.
View Dr Micolich's YouTube Channel: www.youtube.com
His blog can bee seen at www.blogspot.com
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