Tag Archives: physics

Tweaking Newton’s Law of Universal Gravitation

I answered a question on Quora about the consequences of Newton’s law of Universal Gravitation being in inverse law and not an inverse square law for 60 seconds. The outcome is not so good, what with all matter acting as a black hole and all.

https://www.quora.com/What-would-happen-if-the-law-of-gravity-becomes-1-r-instead-of-1-r%C2%B2-for-60-seconds/answer/Colin-Turner-6

Aikido in Dead Straight Lines

There’s been an elephant in the room on my blog for quite a while now, and it has prevented me completing a number of articles that I have had in draft for some time.

A bit over a year ago, my friend and mentor, Alan Ruddock died. I’ve been trying to articulate what that meant for me, and what I thought about Alan, but I have repeatedly failed. This doesn’t fully resolve that issue, but at least I can put down some thoughts about Alan here now, or at least about Aikido

Disclaimer: this post probably badly needs some photos, and I’ll try to retro-fit that at some point.

I was kindly asked to present an hour at this year’s Galway Aikido Summer School, where Alan Ruddock and Henry Kono traditionally taught together for many years. This year Henry continued with his excellent classes in the morning and other instructors that knew Alan took an hour each in the afternoon. I confess I was a bit daunted by some of the others teaching in these slots, particularly the inestimable Lorcan Gogan of PSAC, with whom I shared a session. When I said to him I would have to follow that, he simply replied “Hey, I had to follow Henry!”. A fair point. But I did find myself more reticent than usual in my teaching style.

I chose to try and present some thoughts that have arisen from Alan talking about his “dead straight line”. That is that Aikido is often thought of as being circular in nature but Alan was keen to stress it was not at its heart.

In Aikido, we often see uke (the attacker) whirled around nage (the defender) in circles. There are beautiful diagrams about this, and allusion to circles everywhere. Our own club is called the Belfast Aikido Circle. So it’s impossible to deny circles don’t appear. Indeed, there are semi-physical, semi-mystical links to squares and triangles too.

But what Alan meant, in my opinion, (all disclaimers apply) is that you always behaved as if you were operating in a dead straight line.

Aristotle believed that objects, in a perfect (celestial) environment travel in perfect circles, but many centuries later, Newton thought otherwise.

A body will continue in its state of rest, or uniform motion in a straight line, unless acted upon by a resultant force.

is better known as Newton’s First Law of Motion. In Aikido terms its consequences are simple, if an attacker comes along a straight line, and is subsequently diverted off that straight line, Force, and Energy has been added by someone. Not in some kind of mystical sense of the use of these words you might see in other places, but in their elementary definitions in Physics. So the Force has been added, the big question then is by whom, followed up by why, and an analysis of the consequences.

Let’s look at the question of “whom” first. In a previous article, I wrote at some length about the spectator problem in Aikido. Sitting at the side lines you can never know for sure just who is doing what to whom. You can see the nage’s hands rise, move or turn, but you cannot know, from outside, whether this is nage initiating these things, or a reaction to uke’s movements and attack.

In fact, we can take it a step further than this and say that at best only the two involved can fully know, since it is entirely possible that neither of them will fully know either. In other words, the problem of “whom” is a really knotty one; it’s altogether possible that no-one knows.

In theory, at the beginning of a “technique” the nage first moves to a position of safety from the immediate attack and then “blends” with the attack. Even this is an over simplification since nage can be more proactive, but let’s set that side for a moment. This moment of initial blending is pivotal. Alan used to tell a story about O-Sensei coming to watch a class of aikido at the Hombu dojo, and after watching, smiling, for some time, he announced “you are all doing a wonderful job, after having your heads cut off.” The analysis of this could be that, especially when facing an armed attack, even if the blend if a bit out, there may be more than a bit of you missing by the time you start your technique.

Aiki means the harmony of ki, or energy, so your blend is the moment where you, and your attacked end in a position of aiki, where both your energies are pointed in the same direction. If the uke’s energy was directed at you in a dead straight line, as it often is, then in theory, you should both be pointing in the same dead straight line.

But this is often not the case. You can immediately see deviation from the straight line. Why is this? From Newton, the answer is obvious, one or both person(s) have put extra force into the situation.

This may have been uke, who immediately realising things are not going as planned, starts to react and often turns towards nage to strike them; this being the case nage has to move off the original straight line too to provide space for uke, and to keep the aiki principle, continuing to move with the uke. If that’s all it is then this is fine. The force and energy being contributed by nage are minimal, it is necessary and sufficient.

But all too often, the honest truth is that as nage, we anticipate the move from uke, or worse don’t even think about it, and just start whirling them around us. It may not be immediately clear why this is a Bad Thing. There are two reasons; one is that the aiki principle has been immediately broken, you are no longer in harmony with the attacker but attempting to direct them. The second is why the aiki principle itself matters; when you inject force and energy into the situation a skilled opponent can make use of it. In fact that’s practically the central principle of aikido. Probably 90% of the time, particularly in training, your opponent may not even notice, so we all get away with it, and we probably never learn.

So here are some thoughts on training to enforce honesty on this.

Try and do some techniques along a straight line on the mats. You’ll need your uke to be initially very well behaved. Don’t even think of it as an attack, imagine that you meet a friend at the gates of a park. You see them as they approach and you walk backwards, then sideways, then alongside them as you extend your hand to shake hands with them. They key here is not to make it a conflict. This is astoundingly easy to do when you aren’t worrying about having your head punched; just practice the naturalness of this first.

Then, as you walk along your straight line, just allow your hand to rise across the line, the analogy I used as if you are pointing at a squirrel in a tree. It’s a simple, gentle irimi-nage that requires a compliant sensible uke who just has to keep walking straight, even into the “throw”.

It’s a silly exercise, and you can play with greatly shortening it, but the big deal is, practising doing the throw along a straight line.

The next phase is to allow your uke to, once every so often (and without prior warning), lifting their free hand and turning to – well – lovingly caress your face shall we say? This changes the dynamic, the uke wants to move off the straight line, and so you have to as well. But the key of this exercise is:

  1. do you actually pull them off the line on occasions where they do not turn;
  2. can you really convince yourself you don’t move off the line with a little extra force?

It may be a useful exercise.

Another example worthy of note is Shomen Uchi, Ikkyo (tenkan). Or that when your opponent tries to strike your forehead, you turn, contact their arm and bring it, and the uke to the ground.

Traditionally this is often done by grabbing the arm as it descends and whirling your uke around you. There can be real consequences to this because their other fist is being whirled around you too. There are other problems too: you can have a tendency to pull the arm so closely into your space that uke can merely step behind you and topple you over their leg. It isn’t a nice fall. It also provides, ironically, a slow descent of uke into the ground, since you provide them with a lot of implicit support.

So try, from the moment of Shomen Uchi contact where your hands meet, to step to the side, and without gripping contact the arm with both hands (the other hand at the elbow). Let your uke continue on their straight line straight forward and downwards. Potentially this is a hard fall, you are providing no force or breaking but just allowing them to sail majestically (potentially teeth first) into the mat. Some care needs be taken with this initially! It is most important that you do not push them down, just act as a ratchet so as they descend they cannot rise.

Again, in real life uke will often start heading towards you early on, trying to recover their balance, and also because in aikido, the tendency for uke and nage to start running around in circles is ever present, and once again, that’s fine, the issue is not to interfere with this, but also not to seek to amplify it by hauling them around.

At an early stage you may find it useful not to grab their wrist; this can, in any case, cause all sorts of postural problems, and once you grab something the urge to pull it in is not far behind.

A suitable training for this can be found at your local Supermarket. Find yourself an empty trolley, and as you move it around, you will probably grip it with both hands and pull in one while you push out the other. If you are really mindful to your body you may notice muscles in your abdomen and spine taking the strain. But then fill the trolley to the brim, you will rapidly discover that this trick is not so easy. It’s also not so wise, your muscles will shriek in protest at you, and if you do this kind of thing with a large opponent you will likely both be unable to move them, and injure yourself trying.

These are some simple thoughts on the Dead Straight Line that Alan used to talk about. There should always be a delicate positive pressure in that straight line in front of you, so that as things move and the gap appears there you will be immediately slot yourself into it. It is the spike in O-sensei’s “Ki” calligraphy; it is the imaginary sword held in front of you that tells you always where you want to go.

Your curved movements are still a succession of Dead Straight Lines.

There is a nice, and relatively elementary parallel from Einstein‘s General Theory of Relativity. The curved paths that objects like planets make, as commented on by Aristotle appear circular and curved, but actually they are Dead Straight Lines (geodesics) through curved space-time. When the Moon travels around the Earth, it does so in a series of Dead Straight Lines so that it keeps missing the Earth and it perpetually falls towards it. If you do decide to have uke orbit around you, then this is the same principle you need to prevent them spiralling into you, complete with their body weaponry.

But anyway, try playing with Dead Straight Line. I hope you will find it rewarding.