Coolstuff Newsletters

Playing in Galileo's Lab (part 1)

Posted on October 2, 2012 by Buzz Putnam There have been 12 comment(s)

As I was watching a kayak quietly slip under the Ponte Vecchio in the morning light, I was thinking what it must have been like for Galileo Galilei while living and teaching in Florence, Italy, looking down every day at the beautiful Arno River. In Galileo’s time, the Ponte Vecchio bridge, the ONLY bridge in Florence to survive the bombings of WWII, was populated by butcher shops with meat cutters throwing the leftovers into the Arno River.

Vecchio Bridge Ponte Vecchio bridge over the Arno River

Galileo Sculpture Sculpture of Galileo

While the other members of my family shopped on the famous Ponte Vecchio bridge, now replaced with gold and diamond jewelry shops, I was first in line to see the gold standard in science museums, Museo Galileo or the Galileo Museum.

It was 8:45 AM in Florence, and I was waiting for one of the highlights of my 2012 Italian family vacation, which was the chance to see the resting place of original creations from one of the greatest minds of the 16th century.  Like a little kid waiting in line for the newest roller coaster at Disney World, I stood by the door with eager anticipation, excited to finally see in person what I had only seen in college textbooks or on YouTube. As the door opened at 9:30 AM, I paid my 9 Euros and raced up the stairs with great anticipation.

When entering the Galilean room, you are met by three glass-enclosed bell jars that house probably the oddest, yet eeriest of all the displays of the museum, Galileo himself!  Because of Galileo’s status as a revered scientist and statesman, grave robbers and souvenir seekers wanted remembrances of the famous scientist and raided his remains.  Preserved under glass, in what could only resemble a saint’s reliquary, are Galileo’s vertebrae, molar, thumb, and middle finger. An ironic gesture to the world that he was right all along about the motion of the Earth and its place in the solar system. This item exemplifies the celebration of Galileo as a hero and martyr of science.

Displayed on the first wall was one of the most famous of all of Galileo’s experiments, the Inclined Plane. This apparatus used five small bells, along with a pendulum to provide an experimental demonstration of the Galilean law of falling bodies. The Law was demonstrated with the pendulum connected to the inclined plane, acting as a “timepiece”. The experiment consisted of releasing a ball from the top of the plane at the same time as the pendulum was swung. For each complete period of the pendulum, the ball would strike one of the small bells placed along the inclined plane at increasing distances, specifically arranged in the order of odd number distances. The experiment made it possible to measure the increase in the distances traveled by the ball as it rolled through equal time intervals starting from the rest position. The ringing bells would also provide an additional auditory observation of the ball's constant acceleration during its fall.

Inclined Plane Galileo’s Inclined Plane

In the background of the Inclined Plane was the Brachistochronous, an apparatus demonstrating the observable effects of a physical principle discovered by Galileo on November 29, 1602. Using geometrical methods, Galileo proved that a body takes less time to fall along the arc of a circumference than along the corresponding chord, even though the latter is a shorter path. The device consisted of a wooden frame with a cycloidal channel and a straight channel which was adjustable by means of pegs fixed in holes with brass rings under the cycloid.  By dropping two balls simultaneously down the two channels, he was able to observe that the ball falling down the circular channel reaches the bottom well before the ball traveling down the inclined plane.

Inclined Plane Alternate View Close-up view of Galileo’s Inclined Plane Bells

On the far wall was the original telescope made by Galileo consisting of a main tube with separate housings at either end for the objective and the eyepiece. The tube was formed by strips of wood joined together and covered with red leather and gold trim. The plano-convex objective, with the convex side facing outward, had a diameter of 37 mm with a focal length of 0.980 meters and magnification of 21X. However, the original eyepiece was lost. In 1611, Prince Federico Cesi, founder of the Accademia dei Lincei, suggested calling this instrument telescopio [from the Greek tēle ("far") and scopeo ("I see")].  Galileo designed ingenious accessories for the telescope's various applications. Among those were the micrometer, an indispensable device for measuring distances between Jupiter and its moons, and the helioscope, which made it possible to observe sunspots through the telescope without risking eye damage.

Galileo’s Original Telescope Galileo’s Original Telescope

Galileo's Motion Diagram Galileo’s Original Projectile Motion Diagrams

On the far wall of the Galilean chamber was a gorgeous wooden instrument used for studying Horizontal Projectile Motion.  A ball would be rolled from the top of the cycloidal ramp, exit the ramp and pass through a series of metal rings placed in a parabolic pattern, all driven by inertia and gravity.  It is well-known that Galileo studied projectile motion and its effect on the motion of an object on Earth. His writings are well known and illustrate his fascination with the motion of falling bodies.

Projectile Motion Demonstration Galileo’s Projectile Motion Demonstration

What is amazing is that students STILL study projectile motion in the same way as Galileo did some 400 years ago.  Although not as artistically designed as Galileo’s version, the modern-day aluminum Horizontal Projectile Ramp still demonstrates the laws that govern horizontal projectile motion.

Museo Galileo showcased Galileo’s accomplishments throughout his life; his writings, his works, original devices and famous experiments, which allowed many scientists to build their theories upon.

The museum’s remaining rooms exhibited numerous other scientists' work and laboratory equipment.  What I found absolutely fascinating was that the demonstrations used in today’s classrooms bear a strikingly similar appearance to what our predecessors used in their labs.  The more equipment I saw, the more I said to myself “Wait, I use that in my classroom!” or “That looks just like the lab I did with my students last year!”.  I realized that I was REALLY playing in Galileo’s Lab!  Given the equipment in the museum and the writings of the various scientists, I could have brought my class to Florence and had no problem teaching Physics in the SAME way I always had.  One device after another would demonstrate a Physics concept in the same manner that I might have done it.  Then I knew why, the very devices we “modern-day” Physics teachers are showing to our students, actually thinking that these are unique demonstrations that few have seen before, except in a catalog, are really 400 years old!  The following are many of the devices that I saw that day at the museum and after taking pictures of them, I tried to think of a cool way to prove my earlier point:  that our modern day Physics demos and device are frighteningly similar to their 400 year-old counterparts. Here are a few I encountered...

A Chemistry Lab Bench.I really would rather do my experiments at the 400 year old bench... Wouldn’t you?

Chemistry Laboratory Experiment Bench Chemistry Laboratory Experimental Bench (circa 1600’s)

Set of armed lodestones used by Galileo for his studies on magnets (1600-1609).  These DEFINITELY look “armed”!

Galileo’s Armed Lodestones Galileo’s Armed Lodestones

 

Newton’s Cradle Newton’s Cradle (1600’s)

Force vector table hasn't changed much in 250 years!

Force Vector Table Force Vector Table

That concludes part 1 of Playing in Galileo's Lab. More to come including Galileo's Inertial Mass Balance with Chair and Air pressure Demonstration with a balloon.

author

About the Author

Buzz Putnam, Physics Teacher, Whitesboro, New York
Buzz is a 25 year veteran Physics and Nanotechnology teacher who has served as Whitesboro High School's Science Department Chair since 1997. Buzz also conducts Teaching Methods classes for science teachers at Utica College of Syracuse University. In addition, he is part of the Cornell University Laboratory Development Team and a member of the Cornell NanoScale Institute for Physics Teachers. He is also a frequent presenter at NY, NJ, Texas and National Science Teachers Association Conferences and has won numerous teaching awards throughout his career.

Modern Day Devices

Horizontal Projectile Ramp with Ball

Horizontal Projectile Ramp with Ball

Product # P2-8490

$14.00

Horizontal Projectile Lab

Horizontal Projectile Lab

Product # P4-1406

$39.00

Galileoscope Kit

Galileoscope Kit

Product # 11-0020

$49.95

Car and Ramp Lab

Car and Ramp Lab

Product # P4-1405

$179.00

Newtonian Demonstrator - Newton's Cradle

Newtonian Demonstrator - Newton's Cradle

Product # P1-6001

$28.00

Force Table

Force Table

Product # P3-3537

$185.00

This post was posted in CoolStuff Newsletters, Force & Motion, Electrostatics, Energy, Magnetism, Measurement and was tagged with Galileo, Italy, Florence, Galileo Galilee, Museo Galileo

12 Responses to Playing in Galileo's Lab (part 1)

  • Beautiful photographs of some very beautiful instruments! Thanks for sharing.

    Posted on October 2, 2012 at 3:54 pm

  • Great idea, photographs, and story. Gave me inspiration to plan a trip to Europe...

    Posted on October 3, 2012 at 2:25 pm

  • Thank you for this - I was just explaining galileo to my class and plan on showing your photo essay tomorrow!

    Posted on October 3, 2012 at 2:32 pm

  • Hi Buzz,
    You really did find the Cool Stuff. I had no idea that those things had survived all these years. I hope I get to go on an Italian vacation someday so I can go see them. Fill us in on any other science destinations in Italy. Thanks.

    Posted on October 3, 2012 at 2:39 pm

  • Hi, Buzz!

    What a trip! I have seen the same museum and I was just as amazed as you. When I was there, we could not take private pictures of the exhibits. We even found Galileo's finger on display.

    I do remember one of the physics professors in our group tried to get the docent to alter the position of the bells on the ramp. As the bells were evenly spaced by distance, he tried to explain that hte bells had to be placed by even "sounds".....his English was not a match for her Italian. Needless to say, he did not win.

    I think of that trip often and I can't wait to return. And I will next summer if all goes well.

    Posted on October 3, 2012 at 3:47 pm

  • Buzz Putnam, that sounds like the Museum visit made the whole trip. I envy you!

    Question, did you see anything about a water clock that was used for the inclined plane measurements as discussed by Galileo? Here's a link that talked more about them from Rice University:

    http://galileo.rice.edu/lib/student_work/experiment95/inclined_plane.html

    Posted on October 12, 2012 at 6:56 pm

  • Eric;
    The model of the inclined plane that they had in Florence used a pendulum for timing but all I have read was that Galileo used a water clock, as you have eluded to. I wish I could be more precise with my answer but the time I spent in the museum was so filled with sights that I didn't get that detail. Now that you point it out, there may have been a model of a water clock but I didn't get a picture of it. As far as I know, you ARE correct with your assessment as to how he handled the timing issues in his day. In fact, I developed such a lab in conjunction with the Cornell Institute for Physics teachers (CIPT) using similar equipment that Galileo had used in his own lab... a modern water clock for timing. The lab can be found and downloaded at...

    http://www.arborsci.com/cool/acceleration-galileos-inclined-plane

    Hope this answers your question. You do need to visit Florence sometime... Forget the "David" statue or shopping, hit up the Galileo Museum!
    Buzz Putnam

    Posted on October 15, 2012 at 11:06 am

  • How I envy you! Thanks for the great pictures- I was trying to explain to my class how Galileo used a very long inclined plane for his experiments, since we use the water clock with a 1 meter long ramp. Results in that short of an acceleration time tend to be inaccurate! looking forward to Part 2.

    Posted on October 17, 2012 at 1:52 pm

  • I have been teaching physics for 37 years, and have been telling my students about Galileo's inclines all those years. Like you, I had the chance to visit Florence this past summer, and also like you, the Galileo Museum was the highlight of the trip for me. Not only Galileo's beautifully made equipment, but the collection of other astronomical instruments and static electric machines from the later years was awesome! I agree with the poster above, skip the shopping, skip the crowds and see the Galileo Museum! But, do see Michelangelo's David - not just for the tremendous sculpture, but they have an optical stress system monitoring the cracks it it that is cool too!

    Posted on October 17, 2012 at 5:18 pm

  • Fascinating piece. I learned more about Galileo's daily life on your page than I have at one sitting before. I can feel your enthusiasm, and, for a brief moment, the agony of flu relented. Thanks. May you continue to teach and inspire, and may your students appreciate what they have.

    Posted on January 16, 2013 at 6:38 pm

  • To whom it may concern, I would like to know how to make a 'Galileo's Cradle'.
    Thanking You, Lester.

    Posted on July 25, 2013 at 5:28 am

  • Hi Lester, We sell a kit to make your own Galileo's Cradle, called the Pendulum Wave http://www.arborsci.com/pendulum-wave

    Posted on August 26, 2013 at 11:09 am

Comments