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[ta0]

I was made aware of this video by Dale:



Unfortunately, I don't think this could really work. He should still have 40 pounds of weight on his hand.

[Dick Stohr]

In the classic bicycle wheel demo we have kids tip the spinning wheel from vertical to horizontal the wheel reacts to move horizontal (90 deg to the force applied).  In this case he is moving the bar horizontal and the reactive force is 90 deg, up.  Therefore the weight is very much reduced.  If he moved the bar in the other horizontal direction the force would be additive down and much heavier.   I think it works just as he says.  Anyone else?

[the Earl of Whirl]

I need one of those for my top spinning exercise room!

[ta0]

In this case he is moving the bar horizontal and the reactive force is 90 deg, up.

The apparent torque is at 90 degrees to the one applied, true.  But the force of gravity still needs to be canceled by a vertical force applied to the gyroscope.  The difference is that instead of going through the center of mass, it is at the supported end.

[Dick Stohr]

OK, throw a trapeze, when the tip is pointing to the right, turn your body to the left.  The top should fall off of the string.  When the tip is pointing right turn your body to the right, the top tries to stands up.  Now extend the tip some distance from the top and do it again, same results?  I am not a scholar about this but my logic says this is why it works.  Someone more learned want to chime in?

[ta0]

Yes, your are right, if you speed up the (stable) precession rate it will stand up, while if you slow it down it will sink. But the weight on your hand will remain almost the same (except for the vertical acceleration imparted: it will weigh a little less when it drops and a little more when it rises).

I am not saying that the gyroscopic effect is not what lets him hold just the end of the bar; in fact that is the case and if it was not spinning he would never be able to do that.  What's more, he is correct when he says he is "steering it along the path the gyro has already decided it wants to go" (i.e., he follows the precession).

The problem is that he quite explicitly says that the weight decreases because it is spinning: "as light as a feather"
Maybe he is using "politician-like" miscues to imply something while he is not actually saying it.   But he ends with: "a fact of a spinning wheel who everyone so far has missed".  That is baloney!

[Kirk]

The problem is that he quite explicitly says that the weight decreases because it is spinning: "as light as a feather"
Maybe he is using "politician-like" miscues to imply something while he is not actually saying it.   

OK with all the talk and theory I thought I would try it.  I got my $2.90 ebay gyroscope (that sings happy birthday) and a small aluminum rod from my hobby junk box. A bit of masking tape and I had a miniature duplicate of the video.  Then I added an elastic band and a hanging type postal scale.

The mass is 48 grams (about 1 5/8 oz.)  While it is hard to read the scale well as everything is moving about, I was able to consistently read 15 grams (about a 1/2 oz.) on the scale when spinning the rig as on the video.

Other observations:

• The length of the rod was critical to "success". Rather than cut the rod, I moved the pivot point. I swung the rig in my fingers and I found a good place to attach the elastic band.  Too long a rod and the precession was not enough to lift the gyro.  Too short a rod and the weight reduction effect was not noticeable.
• The effect seems to be dependent on the rotation speed of the rig about the (vertical) axis of the elastic band. As the rotation about the vertical axis slowed the weight reduction effect went away. 
• If I did not raise my hand as the professor did the gyro turned nearly vertical.
• Opposite rotation produced a greater weight.

Conclusion:
In a 10 minute experiment, with on hand materials and no attempt to optimize the effect, I observed a weight reduction of more than a factor of 3.

Other Notes:
Try it, you'll like it!

[Kirk]

I tried to post a photo.  I got this message.
"Your attachment has failed security checks and cannot be uploaded. Please consult the forum administrator."
The photo is 33.7k in size.

[ta0]

The mass is 48 grams (about 1 5/8 oz.)  While it is hard to read the scale well as everything is moving about, I was able to consistently read 15 grams (about a 1/2 oz.) on the scale when spinning the rig as on the video.

Experiments run supreme against theory so it is great that you tried it.  But I am convinced there must be a problem with the experiment.
The only thing it occurs to me is that the gyroscope is applying a sideways force on your balance that makes the measurement invalid.  I am trying to rig a similar experiment myself.

The attachment message you get seems to tell me that the file does not have one of the accepted extensions for images: gif, jpg, png.

Update: with a gyro spinning on one end I don't see any change in weight, except sometimes for oscillations around the static value probably due to up and down movement of the gyro (nutation). I still need to find a good way of attaching a longer rod.

[Kirk]

file name is gyro1.jpg

[Kirk]

Experiments run supreme against theory .......

I am puzzled about what theory(s) are violated. 
Conservation of energy? Not so. Tops trade kinetic energy of rotation to rise to sleep.
This "top" simply has a longer lever.
I wish I has a video camera

[ta0]

Experiments run supreme against theory .......

I am puzzled about what theory(s) are violated. 
Conservation of energy? Not so. Tops trade kinetic energy of rotation to rise to sleep.
This "top" simply has a longer lever.
I wish I has a video camera

As I understand the video, he is claiming that it weighs less than the initial 40 lb when it is spinning. But there has to be an external force that cancels the pull of gravity (Newton's attraction law) or the whole thing would accelerate downwards (Newton second law of motion). That external force can only come through the hand, and there will be a reaction force (Newton third law) on the hand equal to the weight of the gyro.
Now, when the gyro is dipping or rising it can be accelerating down or up, so the force on the hand could vary some.  But it will be heavier, not lighter, while it is rising.

[ta0]

There is a long entry in Wikipedia about Professor Eric Laithwaite.  He was a professor of electrical engineering at Imperial College in London and after retiring visiting Professor at Sussex University.  He was involved among other things in the development of the linear motor such as used in the Maglev, and had several other patents.  He also made frequent appearances on TV.

Two times he was invited to give the famous Royal Institution Christmas Lectures.  For the second one he chose gyroscopes but it seems that lecture remains the only one ever that the Royal Institution never published. Strangely, he believed that Newtonian physics was wrong and that reactionless propulsion could be obtained with gyroscopes 

An unusual fellow, I would say.  He was also a serious amateur entomologist what may explain something (entomologists are said to be strange people).

[johnm]

Two times he was invited to give the famous Royal Institution Christmas Lectures.  For the second one he chose gyroscopes but it seems that lecture remains the only one ever that the Royal Institution never published.

His one hour Christmas lecture on gyroscopes can be found in 19 parts at this site link = gyroscope lecture
It is a lot of show with no explanation
or on Youtube in seven parts from this playlist link =

The first segment is this

[ta0]

Thanks for the link, John, the presentation was very, very, interesting 

I am completely stupefied about him.    It would seem impossible, with all the gyros he has and simple experiments he can do (not counting basic physical principles that he surely knows) that he would deceive himself in such a way.   But, if he didn't, why would he try to deceive others in such a public way when all scientists and engineers are going to call him out?  Did he sell stock in a gyroscope propulsion company? Did he want to start a sect?  Was it an experiment in collective hypnosis?  A joke?

On part 6/7 (12/19) he shows a large gyroscope on a stand that has a spring.  "I can make it rise, and as I do so that spring says it weighs less . . ."  But looking at the closeup of the spring on the video, it is not at all clear to me that it rises.  Is he just seeing what he wants to see?

The experiment at the end of part 4/7 (8/19), "possibly the most remarkable experiment I have ever done", I find interesting and I need to think about it.  I am not sure if it works like that or if he is faking it.  But after that he says: "let those who say that I cannot make a body appear lighter than it is put holes on that one."  The operating word there may be "appear".