LISTSERV mailing list manager LISTSERV 16.5

Help for SCIENCE-FOR-THE-PEOPLE Archives


SCIENCE-FOR-THE-PEOPLE Archives

SCIENCE-FOR-THE-PEOPLE Archives


SCIENCE-FOR-THE-PEOPLE@LIST.UVM.EDU


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

SCIENCE-FOR-THE-PEOPLE Home

SCIENCE-FOR-THE-PEOPLE Home

SCIENCE-FOR-THE-PEOPLE  July 2007

SCIENCE-FOR-THE-PEOPLE July 2007

Subject:

Re: burning candle esperiment

From:

Eric Entemann <[log in to unmask]>

Reply-To:

Science for the People Discussion List <[log in to unmask]>

Date:

Sat, 21 Jul 2007 21:05:44 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (178 lines)

The "burning candle" experiment may have been largely replaced by the 
"rusting steel wool" experiment.  I would think the latter may actually be 
pretty good for demonstrating that air is roughly 20% oxygen.  But it takes 
several days, I believe.

Our testing of the "burning candle" experiment with teachers in Zanzibar 
some 15 yy ago generated a lot of good discussion about chemistry and 
physics and good thinking about experimental method and reproducibility and 
design.  I think a lot more learning happened than would have had we done 
the "rusting steel wool" experiment instead.

----Original Message Follows----
From: "Robert V. Lange" <[log in to unmask]>
Reply-To: Science for the People Discussion List              
<[log in to unmask]>
To: [log in to unmask]
Subject: burning candle esperiment
Date: Sat, 21 Jul 2007 17:39:42 -0400


Actually the burninig candle experiment is a great opportunity to introduce 
careful experimentation into the classroom.? Of course the usual 
interpretation is false.?? Eric Entemann and I and Mike Savage introduced 
this experiment in a workshop for teachers in Zanzibar.? Eric made a 
sparking device and was able to light the candle after the beaker was 
already firmly placed over the candle and in the water.? Of course, the 
candle went out long before the water level went up at all.? Obviously CO2 
takes up as much space as O2, and oxygen is simply replace by the gases 
given off in combustion.? And besides, there is still lots of oxygen in the 
beaker when the candle goes out anyway.? Combustion requires more than 
simply the presence of an O2 molecule or two.

The entire effect is due to the heating of the air around the candle before 
you put the beaker over it.? We and the teachers were able to get the water 
to rise up much further than one fifth by manipulating the air heating and 
the way we put the beaker on, and by having more than one candle, etc.

So rather than worry about expunging this falsely interpreted experiement, 
couldn't we consider it an opportunity to raise issues about interpretation, 
about having observation and interpretation being colored by apriori 
assumptions, and all that??? It should be kept as an example of false 
interpretation that is very educaitonal, maybe more educational then just 
the "right answer".

bob (lange)



-----Original Message-----
From: herb fox <[log in to unmask]>
To: [log in to unmask]
Sent: Sat, 21 Jul 2007 5:18 pm
Subject: Expunge the burning candle experiment from science TEXTBOOKS


Dear friends:
??? There is a cute "demonstration" that air is 20% O2 wherein a burning 
candle in an overturned glass on a saucer of water is extinguished by virtue 
of consuming 20% of the included volume of air.? Hopefully most of you know 
that the demonstration is a fraud.? In spite of the authenticity of the 
demonstration having been questioned since the mid 19th century, it still 
appears unquestioned in some elementary science, physical science and 1st 
year chemistry textbooks.
??? Sudipta Saraswati has written papers on various aspects of this myth 
from analytical and experimental demonstrations of its falsity to 
discussions of the persistence of science myths long after they are 
discredited.? At this point he is frustrated in his search for US textbooks 
that perpetuate the myth, primarily because of his limited access to the 
texts, not to mention the inappropriateness of writing publishers to 
identify texts from their catalog that are in error.
??? Dr Saraswati's email to me is attached.? I believe his work is important 
and would very much appreciate responses to his request.? Please respond to 
him directly at [log in to unmask]
thank you
herb fox





Attached Message




From:

Sudipta Saraswati <[log in to unmask]>



To:

herb fox <[log in to unmask]>



Cc:

Sudipta Saraswati <[log in to unmask]>



Subject:

Seeking your help in my search for the burning candle experiment in American 
school science TEXTBOOKS



Date:

Wed, 18 Jul 2007 22:43:34 -0400







Dear Herb,

As I explained to you during our meeting earlier, in spite of the best
of my efforts, I have not yet managed to get an access to
middle and high school physical science TEXTBOOKS in Boston to find out 
whether
the burning candle experiment (described below), which is being 
misinterpreted
in many countries including India and Britain, is featured in American 
school
science textbooks.

A typical description of the burning candle experiment is as follows:
Place a burning candle at the center of a shallow pool of water and then 
cover
it with an inverted beaker. Eventually, the candle goes out and the water 
level
rises to occupy approximately 20% of the beaker. It is claimed that this 
proves
that the proportion of oxygen by volume in the air is 20%.

It will be of great help for me if you could kindly request a few of your 
school
science teacher friends to browse through middle and high school textbooks 
of
physical sciences to look for whether the burning candle experiment is 
featured
in any of those as an experiment to measure the percentage of oxygen in the
air.

Looking forward to hearing from you.

Thank you.

Best regards,

Sudipta
-------













________________________________________________________________________
AOL now offers free email to everyone.  Find out more about what's free from 
AOL at AOL.com.

_________________________________________________________________
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003
December 2002
November 2002
October 2002
September 2002
August 2002
July 2002
June 2002
May 2002
April 2002
March 2002
February 2002
January 2002
December 2001
November 2001
October 2001
September 2001
August 2001
May 2001
March 2001
February 2001
January 2001
December 2000
November 2000
October 2000
September 2000
August 2000
July 2000
May 2000
April 2000
March 2000
February 2000
January 2000
December 1999
November 1999
October 1999
September 1999
August 1999
July 1999
June 1999
May 1999
April 1999
March 1999
February 1999
January 1999
December 1998
November 1998
September 1998
August 1998
July 1998
June 1998
May 1998

ATOM RSS1 RSS2



LIST.UVM.EDU

CataList Email List Search Powered by the LISTSERV Email List Manager