How can you easily draw dotted chalk lines on a blackboard?

On Monday I discussed the hour-long video celebrating Professor Walter Lewin’s book For the Love of Physics. During the question and answer period (at 52:30), one of his former students comments:

“So, I sat in on your lectures here, I think about twenty years ago, and I’d forgotten one thing that I learned from you was how to draw dotted lines on chalkboards - which I actually used myself when I was a professor (at Northwestern) for some number of years , so very useful skill.”

Then he asks how did your lectures evolve over time? Professor Lewin replies:

“I think I was always eccentric. It’s true, and so from day one my lectures were always different from the mean. But, of course, they evolved in a way that grew substantially, and that is not because of the dotting of the line - because I could already do that in high school.

....But, it is amazing that many physics professors want to know how I make those dotted lines. There is a two-minute videotape which someone made. Someone looked at all the dotted lines I ever drew in 8.01, and put that in one videotape. It’s a riot!”

Here is that video:



Can you see how he makes those dotted lines? I had to look carefully before I saw what he does differently. When you pull the chalk along behind your hand. you get a normal solid line. Look carefully at 0:50 on that video, as shown in the following still photo:

When you instead push the chalk ahead of your hand you can get a dotted line. In a comment on another video by Walter Lewin someone said:

“I know chalk boards are hard to find nowadays. but it's easy to do: hold the chalk loosely in your hand and hold it at an angle so that it's ahead of your hand. Push it in the direction of your line and it skips making a dotted line. Too easy.”

Is it easy to explain in detail though? No! Look at this University of Bristol web page. (Benjamin Hall did both a web site and report about it). There also is a 28-page paper (Hall's Ref. [10]) on Periodic Motion and Bifurcations Induced by the Painlevé Paradox about all the math involved in this and similar situations.

Added January 4, 2012

Another place this trick would be useful is in laying out chalk art.

Does your use of jargon need tweaking?

One common definition for the word tweak is to make small changes in order to improve something. Back in 2008 Peggy Jordan blogged about Why Clarity Counts and mentioned an unfortunate specialized use of an acronym. An expert on short term disability insurance got into the bad habit of using the acronym STD - which most people would interpret as instead referring to a sexually transmitted disease. Another example of confusing jargon is death and dismemberment insurance, which really covers either situation rather than requiring both (like in the movie Fargo).

Tweaking has another meaning in the drug subculture:

“Methamphetamine use that goes on for day after day is called tweaking, and you really get into a very strange state. You might just sit there quietly and with all kinds of crazy ideas going through your brain. Nobody knows what’s going on. You have to deal with someone like that very carefully. They can go through repetitive activities. One of the favorite ones for people is to take things apart  - take the TV apart - take the cell phone apart - but not in any way be able to put it back together.” 

On December 15th I heard an early-morning radio interview of Erik Makrush, an education policy analyst (polite euphemism for lobbyist) at the Idaho Freedom Foundation. While discussing reform in the state he commented that:

“There’s going to be some tweaking by the legislature.”

I doubt Erik was thinking about that other meaning for tweaking, but I had a good laugh imagining those legislators. His word choice probably was influenced by one or two article headlines from the preceding day.

The image of a recording control board being tweaked came from Wikimedia Commons.

Finding and communicating wonder in physics

Back in junior year of high school my first physics teacher, Mr. Rankin, proclaimed that:

“Physics is fun, ‘cause you get to play.”

On the new books shelf in the Boise public library I just found Professor Walter Lewin’s recent book, For the Love of Physics. As the promo video shows, he communicated his sense of wonder to university students at MIT. A hundred of his lectures have been posted on YouTube, written about in the New York Times, and currently are being viewed by about 6000 people per day from around the world. There is a marvelous one-hour video showing him discussing several topics.

One is the above equation describing the period of a pendulum. Professor Lewin shows his audience a long pendulum, like a cannon ball suspended from the ceiling of the lecture hall. First he demonstrates that the period doesn’t change when you swing the pendulum five or ten degrees from vertical. Then he shows that it also doesn’t depend on the mass of the pendulum - becoming part of the experiment by riding that cannon ball. He also uses that pendulum to discuss the conservation of energy, and the topic of demolishing buildings with wrecking balls.

In my senior year of high school, I recall checking that same equation by hanging a fifty-foot pendulum in a four-story tall stairwell. Back in our Advanced Placement physics classroom, we also proclaimed that physics works.

During the answers to questions at the 57-minute mark in the longer video, Professor Lewin reveals that it took him forty to sixty hours to prepare for each lecture. He did three full-length rehearsals (or dry runs) - one two weeks before, one a week before, and one at 5:30 AM the morning before doing those 10 AM and 11 AM lectures. However, for the book signing lecture he did six full rehearsals!

Would you rather be heard, or be able to read your notes?

That’s not a pleasant choice! Please check out the whole room setup before you speak - including both sound and lights.

If the light on that lectern needs to be on for your speech, then check to see it doesn’t generate a buzz that interferes with the microphone. Things might have been fine until when the incandescent lamp burned out, and it got replaced by a compact fluorescent bulb, as was discussed by a 2007 article in EDN magazine.

Images from the History of Medicine showed Margo Heygood speaking at the 1976 NIH Conference on DNA. 

Three recent proposals for improving presentations at conferences

Communications of the ACM (Association for Computing Machinery) is one of the most venerable computer science magazines. In the September 2011 issue their editor-in-chief, Moshe Y. Vardi, proposed three ways to improve presentations:

“Conferences should, in my opinion, take active measures to improve presentation quality. A radical proposal would be to require authors to submit not only papers but also video recordings of their talks. The quality of those presentations would be considered in making program decisions. 

Less radical a move is to require authors to send draft presentations before the conference, and receive feedback from their session chairs. 

It should also be relatively easy to augment conference-management systems with feedback pages where conference participants can give speakers anonymous feedback on their presentations. (That would give attendees something constructive to do during poor presentations!)”

You can download the full text of his article, "Are you talking to me?" here (click on PDF).

I like his radical proposal of requiring a video recording. But, when Togrstent Grust approved of that he got comments with the expected objection that this would make it significantly more time consuming to submit a paper. Well, of course. Improved quality isn’t free. Back in March 2010 I blogged about how the quality of presentations at the annual conference of the American Society of Colon and Rectal Surgeons had improved. A possible explanation was requiring submission of a written manuscript. I suspect also requiring a video would have a similar effect.

The image of a conference audience is from Wikimedia Commons.

Twenty useful blogs on presentations

In a December 13th post on his All About Presentations blog Vivek Singh asked for a short list (10 to 15) of useful blogs about presentation.  I easily thought of ten just from the United States. However, I read many more and thought it would be more useful to include another ten from the rest of the world. My list of twenty follows.

UNITED STATES
Nancy Duarte: Duarte blog

James Feudo: Overnight Sensation

Ellen Finkelstein: PowerPoint Tips Blog

Tom Fishburne: (Marketoonist)

Denise Graveline: The Eloquent Woman

Rich Hopkins: Speak and Deliver

Nick Morgan: Public Words

Scott Schwertly: Ethos3

Jon Thomas: Presentation Advisors

Jerry Weissman: Power Presentations

CANADA
Andrew Dlugan: Six Minutes

Dave Paradi: Dave Paradi’s PowerPoint Blog

INDIA
Vivek Singh: All About Presentations

ISRAEL
Jan Schultink: Idea Transplant

JAPAN
R. L. Howser: Presentation Dynamics

Garr Reynolds: Presentation Zen

NEW ZEALAND
Olivia Mitchell: Speaking About Presenting

SPAIN
Conor Neill: The Rhetorical Journey

SWITZERLAND
John Zimmer: Manner of Speaking

UNITED KINGDOM
Max Atkinson: Max Atkinson’s Blog

Lessons on humor from the December issues of the Canadian Medical Association Journal

This morning National Public Radio had a three-minute Weekend Edition segment about how the December issues of that normally serious magazine poke fun at medicine.

In 2006 they explained how we are able to overeat at holiday dinners: Room for dessert: an expanded anatomy of the stomach.

Some articles parody dense jargon, like the 2010 one on: The anemic maternal proxy and the seven resident stakeholders (Snow White and the Seven Dwarfs), and a 2001 Case report: microcardia secondary to chronic adrenocortical insufficiency (Dr. Seuss’s Grinch).

Other stories for children were scrutinized generally in 2003: Head injuries in nursery rhymes: evidence of a dangerous subtext in children’s literature. Winnie the Pooh was analyzed both a decade ago: Pathology in the Hundred Acre Wood: a neurodevelopmental perspective on A. A. Milne, and more concisely last year: Pooh has an addiction issue.

Last year I blogged about their 2005 article analyzing: Incidence of and risk factors for nodding off at scientific sessions. In 2005 they also described using a Super Soaker to dislodge ear wax: A novel method for the removal of ear cerumen. (Don’t try this at home - a direct hit will puncture the eardrum).

Finally, back in 2004 they considered many occupational hazards that Santa encounters during his annual circumnavigation: Referral request for S. Claus.

Can homeopathic gelsemium reduce anxiety about public speaking?

Gelsemium sempervirens (yellow jessamine or jasmine) is a homeopathic remedy recommended for fear of public speaking, and many other ailments (like flu). Very small amounts of the root are used to prepare remedies, because the plant contains three toxic strychnine-related alkaloids: gelsemine, gelseminine, and sempervirine. (Just because something is completely natural doesn’t mean that it is either harmless or safe).   

In The Complete Homeopathy Handbook by Miranda Castro (St. Martin’s Press, New York, 1990) on page 91 she says that:

“Gelsemium is also one of the favorite remedies for people who become paralysed with fear prior to giving a talk or before an exam. This is not the active fear of Argentum Nitricum or Lycopodium; it is an acute anxiety which causes a person to seize up both mentally and physically.”

Similarly, in Easy Homeopathy: the 7 essential remedies you need for common illnesses and first aid by Edward Shalts (McGraw-Hill, New York, 2005) on page 139 he says that:

“Gelsemium is an excellent remedy for stage fright and test anxiety. People who need this remedy to perform better under various circumstances literally feel paralyzed, weak and dizzy. Their limbs become heavy. This is not a good bouquet of symptoms to have during performances or exams.”
For test anxiety he recommends taking three pellets of Gelsemium 30 C on the morning of the exam. He also suggests using what he calls the plussing method; dissolving three pellets of 30C in a small bottle of spring water and then sipping from it as needed. 

On Amazon.com you can find tubes of pellets from Boiron with potencies of 6C, 12C, 30C, or even 200C.

Is Gelsemium effective for relieving anticipatory anxiety? Apparently not. This year A. Paris et al. published the results of a detailed clinical study in a magazine called Fundamental and Clinical Pharmacology. You can read the abstract here. They compared the effects of Gelsemium at potencies of 5CH and 15CH with a placebo. The study began with 180 people split evenly among those three groups, but a few dropped out. Most of the co-authors are in Grenoble, France but two are with the Boiron laboratories in St Foy-le`s-Lyon (who also provided the remedies).    

What does the potency ‘5CH’ mean? (It’s the same as 10X). The material has been diluted by a factor of 1:100 five times, so the final concentration is 1 part in 10,000,000,000. Similarly, ‘15CH’ means diluted by a factor of 1:100 fifteen times, so the final concentration is 1 part in 1,000,000,000,000,000,000,000,000,000,000.

There also are some very preliminary (and curious) results from Verona, Italy with positive results for gelsemium on anxiety-related responses in mice. You can read the full texts on PubMed Central here and here. I’m not sure what to make of these, but did note that the reported response did not increase consistently with potency as was long ago hypothesized to occur for homeopathy. 

The plant image is from Wikimedia.

Avoid impending doom when opening your speech

On December 8th Doug Savage posted the fifth of his hilarious and thoughtful Savage Chickens cartoons about public speaking.

What should you do when opening your speech? Be prepared so you don't chicken out. If you’re nervous, then write out the first few sentences on a note card, so you don’t go blank.

What should you avoid when opening your speech? Don’t drink alcohol beforehand. Don’t imagine the audience naked. Don’t grip the lectern like you are driving a bus, or bang your fists on it (like Dwight did in The Office).

Will homeopathic lycopodium reduce your anxiety about public speaking?

Lycopodium clavatum (commonly known as club moss and pronounced like-o-podium) is a homeopathic remedy recommended for fear of public speaking (and many other ailments). In summer, spikes from the plant are collected and the very small spores are shaken out to produce a yellow powder (pollen dust) as shown above.

For example, in The Complete Guide to Homeopathy by Dr. Andrew Lockie and Dr. Nicola Geddes (Dorling Kindersley, London, 1995), under Emotional Problems in the tables on pages 190 and 191 they describe:

AILMENT:
Anxiety with a loss of confidence

SYMPTOMS:
Apprehension about performing in public
Inability to sleep at night with continual reviewing of what happened during the day
Appetite is disturbed
A craving for sweet foods may accompany insomnia

CAUSE & ONSET:
A forthcoming event or performance
Most likely to occur in the very ambitious who have high standards

YOU FEEL BETTER:
In cool surroundings
From hot food and drinks
After midnight
With movement

YOU FEEL WORSE:
In stuffy rooms
After overeating
Between 4 PM and 8 PM

REMEDY & DOSAGE:
Lycopodium - take 6C every 2 hours for up to 10 doses

You can find pellets of 6C lycopodium clavatum online. For example, Amazon shows Boiron has packages with tubes containing 80 pellets for less than $8.

What does the potency or dilution ‘6C’ mean? (It’s the same as 12X). The material has been diluted by a factor of 1:100 six times, so the final concentration is 1 part in 1,000,000,000,000. 

Is lycopodium effective? In 2006 Karen Pilkington and her colleagues published a long article in Homeopathy magazine titled Homeopathy for Anxiety and Anxiety Disorders: A Systematic Review of the Research. You can read the abstract and conclusion here at PubMed. They found no clear and compelling evidence that homeopathy was effective for treating anxiety. Lycopodium only was mentioned near the beginning of the article, where they referred to it being mentioned by Dr. Lockie  in another more recent book, the Encyclopedia of Homeopathy (2001).

Does lycopodium have undesirable side effects? A web article by Susan Kaye noted that:

“The book Synoptic Materia Medica I points out that Lycopodium may cause lack of self-confidence, feelings of inferiority and insecurity, and the possibility of a person developing bullying behavior which acts like a cover-up for these feelings of being ‘lesser-than.’ A person may be bossy, dominating and downright nasty to those who know him best, like family, yet act meek and fearful in public. The remedy may cause a fear of public speaking and even the inability to stand up for oneself in a conflict.”

I have not read that rather obscure book, so I’m not sure if this is a problem only with this remedy, or an example of a general problem with homeopathic remedies noted on the Dr. Lockie web site:

“The homeopathic equivalent of an overdose is when a remedy is ‘proved’ or begins to cause the symptoms that it is intended to cure. This can happen when a remedy is taken for very prolonged periods, so don’t continue with a remedy once it has worked in order to prevent a relapse, it’s quite unnecessary and actually counter-productive.”

Images of the plant and powder are both from Wikimedia.

‘Tis the season for Christmas Camouflage in graphics

For most people the festive Christmas color combination of red and green shown above has excellent contrast. Unfortunately, for a mostly male minority (up to ~10%) with red-green color blindness, it has almost no contrast. In a February 2009 blog post I called that Christmas Camouflage. An online tool called Vischeck lets us see a simulation of how someone with red-green blindness (a deuteranope) would see it. Now both Santa and his elves look like they’ve joined the army and have been issued identical olive drab uniforms.

Unless you ask them, you won’t know if someone is color blind. People with that problem usually adapt by having others help them color coordinate their clothes. In a cafeteria line they will be careful to ask for the soup by name, because otherwise they might get served split pea soup (green) instead of cream of tomato (orange).

The Santa Claus icon (recolored to make the elves) came from Mizunoryu on Wikimedia Commons.

Bridging the Uncanny Valley

On November 19th R. L. Howser blogged about how painful it was to watch a speaker use carefully prepared gestures that failed to connect with the audience. He titled it The Uncanny Valley, which is a term from robotics.

When we watch a robot behave, initially the more human-like it looks the more familiar it seems. But, at some point (when it looks like a human but still acts like a robot) our reaction reverses to it seeming unfamiliar and downright creepy. 

C.S. Lewis had Mr. Beaver say something similar in The Lion, The Witch and The Wardrobe (my italics):

“But in general, take my advice,
when you meet anything that’s going to be human and isn’t yet, or used to be human once and isn’t now,
or ought to be human and isn’t,
you keep your eyes on it and feel for your hatchet.”

The following YouTube Video with James May’s reaction to a Gemenoid robot illustrates the problem.





What makes a human speaker seem inhuman? How can we bridge over the Uncanny Valley? In a November 2008 article in the Harvard Business Review on How to Become an Authentic Speaker, Nick Morgan revealed that trying to make our gestures conscious gets the timing wrong. The solution is to practice making them unconscious. That idea is described in detail in his 2009 book: Trust Me four steps to authenticity and charisma. Nick did a series of podcasts about the book, which I blogged about in August.

Human reactions to robots (and robot reactions to humans) are a running gag in the alternative universe envisioned by J. Jacques in his online comic strip Questionable Content (QC). He refers to them as AnthroPCs or AIs. A recent series, #1994 to #2010, chronicled Momo-tan going to the local Idoru dealer at a mall to get a new chassis. Two very curious signs on their wall read:

AJos 4.0.
The all-new artificial intelligence paradigm.
Guaranteed not to go insane
and kill your loved ones.

and

Make Your Robot Happy.
That isn’t a euphemism.

A more recent comic claimed that humans sometimes acted creepier than robots.

Should you put haikus in your handouts?

On Saturday morning I heard a story on National Public Radio about a dozen new traffic warning signs in New York City that were written as haiku poems. That’s an interesting approach to a typically dull subject. My versions for two of them are shown above.

Haiku might be used as headlines or titles for graphic slides. Better still, they could be used in handouts. I Googled the combination of public speaking and haiku, and found the following excellent one in an August 2009 blog post by Angela DeFinis.

What’s the story on valerian and anxiety?

On November 28th Joe and Teresa Graedon’s People’s Pharmacy had a brief article titled Public Speaking Phobia Dissolves with Herbs. Someone wrote them about how taking a valerian capsule had reduced her anxiety, which let her speak at her retirement party. If it worked for her, will it work for you?

People’s Pharmacy articles also appears as newspaper features. Sometimes the articles get different titles. The Durham, North Carolina Herald-Sun and the Athens (Ohio) Banner-Herald both used the same title. The Houston Chronicle said that Valerian takes the edge off public speaking, while the Jackson, Mississippi Clarion-Ledger just said Capsule may relieve anxiety. Which title is closest to the truth?

When we look up valerian at the National Center for Complementary and Alternative Medicine, we find their summary web page says that:

“* Research suggests that valerian may be helpful for insomnia, but there is not enough evidence from well-designed studies to confirm this.


*  There is not enough scientific evidence to determine whether valerian works for other conditions, such as anxiety or depression.”

In September 2009 I blogged about herbal remedies for anxiety, and mentioned two review articles about valerian - one by Ernst and a Cochrane review. Both concluded there was no clear evidence for it reducing anxiety.

Ten years earlier Carolyn Mar and Stephen Bent published An evidence based review of the 10 most commonly used herbs. They also said the evidence for valerian being effective then was inconclusive. (See the summary table in the full .pdf file version. It was printed too light to show in a scan for the single page.) In 2008 Stephen Bent took a look at the current top ten herbs in Herbal Medicine in the United States: Review of Efficacy, Safety, and Regulation, but valerian wasn’t on that list.

What can we learn from this? Just because something is popular doesn’t mean that it is effective (or completely safe). Do your own homework. Don’t uncritically believe someone else’s story, even if it got whispered right in your ear.

The image came from here at the Library of Congress.

Detailed advice on how to overcome the fear of public speaking

 If you are among the 1 in 5 of us with a fear of public speaking, then you should read an excellent book by a clinical psychologist, Peter Desberg, PhD. Speaking Scared Sounding Good: Public Speaking for the Private Person was published in 2007. You can look inside it at Amazon.com. This book contains lots of exercises, stories, and even jokes. Each of the 14 chapters begins with a brief paragraph describing the big idea. They are:

PART ONE: Understanding Your Fear of Public Speaking

1. WHAT REALLY CAUSES STAGE FRIGHT?: Your emotions are a direct result of what’s on your mind. If you think you will give a bad speech, you will be afraid to give that speech. Just thinking about it negatively weeks before the scheduled date can make you tremble. This is because your negative thoughts cause your fear. 

2. IDENTIFYING YOUR FEAR-PROVOKING THOUGHTS: The thoughts that lead to your feelings are not always easy to identify. But once you are able to identify them, they will become the foundation of your plan to control your fear.

3. EVALUATING YOUR FEAR-PROVOKING THOUGHTS: Your fear-provoking thoughts might be based on real-life experiences and may actually be reasonable. On the other hand, they might be the result of exaggeration and/or shaky logic. Identify the thinking process that fuels your fear-provoking thoughts.

4. CONTROLLING YOUR FEAR-PROVOKING THOUGHTS: Reality-testing strategies and positive self-statements can give you a firm handle on your fear-provoking thoughts and can help you get them under control.

PART TWO: Tools for Reducing Your Fear-Provoking Thoughts

5. SETTING GOALS: Set goals that are completely under your control and identify ways to measure how effectively you have met them.

6. LEARNING TO RELAX: Relaxation exercises can help you combat anxiety - your internal response to danger - by lowering it to more manageable levels while making you more alert.

7. DEALING WITH AVOIDANCE AND PROCRASTINATION: Avoidance can lead to missed opportunities in your career and personal life, and procrastination reduces your chances of adequately preparing for a presentation or speech.

8. IMPROVING YOUR MEMORY: Organized information is much easier to remember, especially when the information is personally meaningful to you - and your audience.

9. PRACTICING FOR OPTIMAL PERFORMANCE: After you have thoroughly learned your material, practice under performance conditions. Try to simulate every detail - the minor ones as well as the main ones.

PART THREE: Broadening Your Presentation Skills

10. USING THE PUBLIC SPEAKER’S TOOLBOX: Organize your presentation for maximum effectiveness. State a clear intention for your talk, establish your credentials, and make use of your presentation skills.

11. CREATING THE RIGHT IMPRESSION: Certain strategies can help you be more effective with your audience. Analyzing your audience provides a great deal of information that can improve their impression of you and your presentation.

12. USING HUMOR IN PUBLIC SPEAKING: When used correctly, humor can help you gain the audience’s acceptance and increase the likelihood you’ll be remembered in a good light. Used poorly, it can wreck your presentation. And when used inappropriately, it can even threaten your standing or your job.

13. INTERVIEWING SUCCESSFULLY: The keys to interviewing successfully for a new position are research, preparation, and practice. Take all three very seriously.

14. OVERCOMING SHYNESS: By practicing basic social skills and preparing for social interactions, you can manage the effects of shyness and learn to “sound good” in social situations.

Dr. Desberg is an emeritus professor at California Sate University in Dominguez Hills. Speaking Scared Sounding Good is his third book about stage fright. The other two were Controlling Stagefright : Presenting Yourself to Audiences from One to One Thousand (1988) and No More Butterflies : Overcoming Stagefright, Shyness, Interview Anxiety, & Fear of Public Speaking (1996). His latest funny book is Show Me the Funny.