Motion is Relative (and so is Self)

This started as a foot note to a previous post but decided to give it its own post. It concerns the simple physical journey we might make to a grave stone (but obviously there is the metaphorical journey of life which is also very similar).

If we try to think about how far a grave stone moves in a year we get an interesting result.

We drive the same route as we did last year and so we think it has not moved. Perhaps a little bit of subsidence due to the soil settling.

And it is the same time of day and year which means the Earth is in the same place around the Sun. So it has not moved locally and it has not moved in the solar system.

But then we find that the solar system itself rotates around the galaxy. Relative to galactic centre the grave stone has actually moved almost a billion kilometres in a year. This is utterly bonkers and we kind of ignore it. But it is true.

But it gets even more crazy because the while Milky-Way galaxy is itself moving relative to the galactic cluster centre.

This is all completely bewildering. But there is just one thing to grasp here:

Motion is relative. Which means there is no, and can never be, just one answer.

That is to say that we can only know our state of motion by measuring it against something else and depending upon what we chose we get a different answer.

From this we can say we have no definitive state of motion. So we cannot actually answer the question of how far the grave stone has moved in a year in an absolute way. It can only be answered relative to something else.

Sitting there reading this how fast are you moving? There is no one answer. Relative to the the seat then no motion, but relative to the Earth 1000 miles per hour due to rotation, and then also 30km/s due to the orbit of the Sun. But which does it feel like? Well both are true. This is why you cannot sense state of motion because how then could you have different answers. (Technically it is acceleration which is absolute and that you can sense and measure absolutely.)

This seems really odd. We have always (probably) assumed that movement and "going places" was something that was definable and under our control. But actually there is no absolute state of rest or motion. It actually makes no sense to say--in an absolute way--what out position or state of motion is.

Now this is a window into a completely fundamental truth that in fact everything is like this and has no absolute foundation. It is all relative to something else. Homework is figuring out how we can make what seems to be an absolute statement like that which says that all things are relative and stand in relation to something else.

This was written in the context of sacred landscapes. The reason why we feel some solidity to our location and motion is because we implicitly (even today in the post Star Trek generation) assume things relative to the land, or more generally the surface of the Earth. Land, all these 100s of 1000s of years after the start of humanity, is still fundamental to our whole concept of place and motion.

Calling up Google Maps and getting directions we will be told it will take so long to cover some distance. But how far will we have moved? Google Maps is just showing us the distance and movement relative to the start point on the land, but the land itself is moving. Actually we can never know how much we move, because such a value does not even exist. Belief in absolute "motion" is exactly like belief in fixed "self" they are always only relative, there is no absolute thing there. And yet we are here even with no fixed position or speed!

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Rehash that in another way:

Someone once said to me ages ago if we could understand motion we would understand everything. Perhaps he was right.

So we have a state of motion right? What is it?

Perhaps seated it is zero relative to the floor. But relative to the Sun it is 100,000km/h with orbital speed on top of that. Relative to the Galactic Centre it is more like 828,000 km/h. So while we sit here our "state of motion" has many values and a different value depending on how we look at it. But it has no definitive fixed value.

What we are more aware of it acceleration. Sitting at rest relative to the ground we have only the acceleration of gravity and so know that our state of motion is not changing. When we accelerate we know exactly how much our state of motion changes, even while we do not know what it is absolutely.

All this is because: State of motion is relative.

Now in fact all "things" are relative especially the self.

By analogy then self is the same as our state of motion. As we sit here our self depends on how or who measures or looks at it, it has no definitive fixed state.