How is it possible to do round swings with a lightsaber?

Question

In Star Wars movies we often see poi-style lightsaber movements:

Poi performers (e.g. fire performers) use the weight of a prop to make it go round. To my understanding, to do this with a physical sword you need the center of mass (a.k.a. point of balance) to be out of the handle, which is typical for swords:

However, since lightsaber blade has near-zero mass, its POB must be inside of the handle. Moreover, the Wookieepedia article claims that the blade actually has a gyroscopic effect (which makes swinging almost impossible):

Due to the weightlessness of plasma and the strong gyroscopic effect generated by it, lightsabers required a great deal of strength and dexterity to wield, and it was extremely difficult—and dangerous—for the untrained to attempt using.

How the possibility of round movements with a lightsaber can be explained?

Update
I've checked several questions about lightsabers and the Force:

There were no answers, claiming that the Force changes lightsaber's physical properties somehow (i.e. adds weight to the blade). They say Force affects practitioner's body, mind (perception), all the surroundings, but the lightsaber remains the same.

The only exception could be channeling a lighting through the lightsaber blade, but I doubt that adds its weight somehow.

Update 2
In this video Lucas says that fight choreographic was inspired by kendo in the first three movies. Which is perfectly fine, since you actually can strike a weightless blade in kendo style. So the question is primarily about the later films (e.g. Count Dooku style).

Lightsaber blades are massless, but the conceit is that they still act as if they have pseudo-weight due to gyroscopic action. They're hard to move and once they start moving, they're hard to stop, hence why only trained force-users tend to use them. — Valorum, Jun 13 '16 at 13:13
@Valorum shouldn't gyroscopic effect actually prevent blade rotation, instead of helping it ? — enkryptor, Jun 13 '16 at 13:24
@enkryptor - I wouldn't think too hard about it. Just watch the acrobats having a laser-sword fight. — Valorum, Jun 13 '16 at 13:34
@enkryptor in regards to your update, the Force doesn't have to give weight to the blade for this to work. It just needs to affect the handle in a similar fashion to a blade with weight. We know the force can affect the handle from several instances in the movies (e.g. Luke in the ice cave) — David Starkey, Jun 13 '16 at 15:53
"weightlessness of plasma" What? Plasma has mass; it must therefore have weight. Maybe not much depending on the exact material, but it won't be truly weightless. I think you need to go back a few steps before trying to clarify any scientific questions. — jpmc26, Jun 13 '16 at 23:17
@jpmc26 I've never said plasma does not have mass. I said the blade has "near-zero mass" comparing with mass of the handle. — enkryptor, Jun 14 '16 at 07:23
@PieterB ask the wiki author, not me.. I'm a one who is arguing with the wiki, saying you actually can't use the blade with the properties described. — enkryptor, Jun 14 '16 at 08:11
My brother and I did this with pretty formidable sticks when we were kids. That's not an answer, since I don't know what the balance of a lightsaber is. — Mikey, Jun 14 '16 at 08:52
If the gyroscopic effect operates on a similar principle to a Segway, then it probably contains a ball gyroscope that anticipates the direction of the swing and optimizes the angular momentum of the motion. And now you have the image of Jedi riding Segways around the long halls of the temple. — Ber, Jun 15 '16 at 13:19
@Ber They're in the middle of a fight. It's been long discussed on this site and many others that out-of-universe this moment is for coolness factor to show off whirring lightsabers, and in-universe it's two highly skilled duelists who are intimately familiar with each others fighting style and tendencies and are trying to psych each other out/test each other, like two boxers circling each other trading feints and jabs to gauge distance, reaction time, tendencies, etc. — TylerH, Jun 15 '16 at 14:31
Heh, I know, it's just funny when you photograph a theatrical swordfight out of context; real swordfights are short and to the point. ;) Of course I guess there is some martial arts style where twirling your sword is not a theatrical style but a practical move to anticipate your opponent. — Ber, Jun 15 '16 at 15:11

score 65 · Accepted Answer · answered Jun 13 '16 at 15:39

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There's nothing impossible in those movements, the actors are performing them just fine.

You can replicate the effect by taking a long stick and doing the same movements until you get used to them, then chop the stick up so you've only got a piece the same length as a lightsaber handle. You'll find you can still twist it through the same permutations easily.

answered Jun 13 '16 at 15:39

Racheet

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Hmmm, sounds interesting. – Adamant Jun 13 '16 at 15:41
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Note that the actors were using non-weightless blades when filming those scenes--your second paragraph is better evidence. – Milo P Jun 13 '16 at 16:25
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I used a bottle of Coffee Mate. :) – Hack-R Jun 13 '16 at 22:43
Do it with your car keys. Easy peasy. – Lightness Races in Orbit Jun 13 '16 at 23:05
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A better example of prop would be a metallic/wooden handle and a polystyrene blade. – beppe9000 Jun 14 '16 at 00:15

score 31 · Answer 2 · edited Jun 14 '16 at 03:32

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As almost anything that has no explanation in SW universe... through the use of the Force.

Force users make incredible acrobatic feats, totally unable to achieve for a standard humanoid, they achieve this through Force use, manipulating the Force and improving their vaulting abilities with it.

The same can be applicable to blade-wielding. Maybe the physics of the blade makes it almost impossible to make certain movements without external help. When this happen, Force users can apply their abilities in the Force to alter the movement of the blade, exactly in the same way they do it when they make an acrobatic feat or when they throw the blade.

edited Jun 14 '16 at 03:32

Adamant

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answered Jun 13 '16 at 12:40

Bardo

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Updated the question. – enkryptor Jun 13 '16 at 12:54
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It's not just Force users who make incredible acrobatic feats, don't discount (obviously a Sith lord) Jar Jar doing a triple somersault 30 feet into the air from standing. God forbid he gets his hand on a more elegant weapon than his accent. – Chris Morris Jun 14 '16 at 14:22
That's not true. Far more in the SW universe can be explained by Hypermatter than the Force :D @ChrisMorris That's because Jar Jar was originally supposed to be a dark lord of the sith. – Shane Jun 14 '16 at 14:58

score 18 · Answer 3 · answered Jun 14 '16 at 01:00

To add a small amount more scientific explanation to the answers stating that this can be done easily (with a bottle of coffee mate no less!):

When poi performers use the weight of the sword to swing it they need to do this because the sword is heavy and therefore requires a large rotational moment to move it round, but once it's going it has a large mass moment of inertia, so it's own mass will keep it swinging.

A lightsaber handle (or a bottle of coffee mate!) is light, so the moment required to spin it in this manner can be easily provided with just a twist of the fingers. The lack of a weighted blade reduces the moment provided, but because the total mass is so much less there is a much smaller moment required - the two changes cancel out.

So in fact the very issue that inspired your question, the weightless blade, solves it!

score 9 · Answer 4 · answered Jun 13 '16 at 22:42

To your point, the blade presumably weighs basically nothing. So it's just the handle which, given how it's so easily handled by even children and Yoda, probably doesn't weigh much either.

As an experiment I just simulated a lightsaber handle with bottle of Coffee Mate. I had no problem swinging it around like "The Star Wars Kid" or the Jedi in your animated gif.

So, I think at least part of the answer is that it's simply easy to handle.

Also, they could've used the force (that's how it works right? OK perhaps not. Idk).

score 3 · Answer 5 · answered Jun 14 '16 at 17:58

while the lightsaber blade itself is weightless the hilt still holds weight to it which allows for a sense of weight and then if you factor in both the gyroscopic factor you could assume that by using that effect in tandem with the weight of the hilt that should be close enough to the over all weight to allow for a user to put the blade into that motion. another to consider is that once its moving all you need to do is keep the blade moving at all times to get to an eventual point where you have the equivalent velocity to use the technique similarly

How is it possible to do round swings with a lightsaber?

5 Answers5