Re: Questions (Space)

On Thu, 13 Sep 2007 22:26:00 GMT+1, Tina Hall wrote:

Ric Locke <warlocke@xxxxxxxxxxxx> wrote:
Tina Hall wrote:
Ric Locke <warlocke@xxxxxxxxxxxx> wrote:
Tina Hall wrote:

[...]
"Weight" is a vector; it's always down, toward the center
of the planet, and it's different according to which planet.

Leave out the 'vector', and that makes sense. Not that I know why
(how gravity does its thing).

Since I obviously don't have a single picture to give you, I'm giving
several different examples of "vector" in the hope that you can
eventually build one for yourself.

So far I don't even have one. The word itself interferes, because it
doesn't tell me anything.

[...]
As an analogy: you and I probably agree pretty well on what "blue"
means, so if I mention "The Blue Window" we can talk about TV
programs in the DDR instead of going off about light and
wavelengths.

Huh? What Blue Window? The only DDR TV program I watched was the
Sandmann. :)

Blue, for me, is a colour.

Me, too.

"The Blue Window" was a DDR television program that showcased the
kind of things a lot of Americans find silly about Socialist-oriented
stuff. The children of Public School No. 19 doing an interpretive
dance based on the life of Mao Tse-Tung, for instance.

Don't know how that's connected (the socialist oriented with the dance
you give as example). But that's digressing.

[...]
If we relay that to you, and it doesn't get through, it's
frustrating on both sides --and most people just turn away after
that, especially when you start accusing us of frustrating you on
purpose.

I haven't done that lately, have I?

No, you haven't, and we appreciate it. Thank you.

I'm grateful for the explanations and info that got through so far.

At least in the way I use the word, "merge" is the wrong concept.
Speed and direction don't combine into a single thing and lose
their original identity.

Ok. Didn't know what other word to use. Perhaps because I don't
understand it ('combine' would be another alternative, which you say
here isn't it).

Not so fast. "Merge" (at least to me) means the original bits
disappear, like dissolving sugar or milk in coffee.

I think there are two options; dough (like your coffee with milk and
sugar), and the way molecules do it. In the latter case the atoms are
still what they are. Or something. (I just made the example up because
it seems to apply.)

Maybe "combine" is just right:

Let's stick to that, then.

But I would also say that distance and time taken combine to speed.
And there we already have a problem that I don't have a picture for
it. (The time slips out.) I can use it (the word speed) with some
meaning, but thinking about it it gets unravelled into different,
not linked, pictures. (The hour on my mental 24 hour clock image,
for example, and the distance as a piece of landscape.) There's
deliberate thought involved, unlike things that spring up an image
on its own (like apple, or liter).

Yes, distance and time (two things) combine to make speed. Distance
and time and direction (three things) combine to make velocity,

I think that's two too many things for me.

Why are we talking about this again? Where's the use for the mass and
energy thing?

which is one example of a vector.

There's that word again. And I don't know what it refers to. That it's
three things? One particular part of them?

To work with it I treat it as numbers (similar to calculating 30% of
1500 euro), with a check afterwards whether the relation of one to
the other makes some sense.

That's a good way to do it.

Yes, but there's no image, either. It's just technical, numbers.

The vector "velocity" specifies both speed and direction at the
same time.

My mind switches off at the 'vector "velocity"'. It just vaguely
sounds like an attribute.

Actually, "vaguely sounds like an attribute" is a good start.

Ok. Like in 'green plant', green is an attribute of plant.

Yet it seems to be treated as a noun. The green (I don't mean grass, but
just the colour) is something else than a plant being green. Or high, or
leafy, where height and 'leafage' are the nouns.

(If you see differences in my examples, please out the one which would
apply more, is closer to what kind of attribute you mean. Perhaps I
could see something in that.)

Other way 'round, actually. "Vector" is the name of a class of things,
like "plant". One of the attributes every vector has is a direction,
like the plant has a color, except that the existence of the "direction"
attribute is what makes it a vector instead of something else. The other
attributes of the vector describe what kind of vector it is.

For visualizing, I use a line with an arrowhead. The arrowhead tells
what direction, and the length of the line tells the size of the other
attributes.

Sometimes, from my side, it looks as if you're being stubborn --

I'm not.

Yes, I know that now. It took a while to figure it out, though.

[...]

Blank means there is nothing. No information, no image. Not even a
label, it's just an empty drawer.

Hmm, that is hard. Can you do it the other way if you try? Can you label
the empty box, then search for things to fill it up with?

The thing with the photon was easier, where even with not getting the
start the rest built up a fine picture.

Matrix: [Explanation goes here]. If a scrap should show up you have a
place to put it, and from time to time you can take the scraps out and
see if they fit together yet.

Vector is the problem. ('Scalar' is improving, see other posters
offering their explanations, if you like.) If a matrix is a grid, I
don't object. (3D would be ok, too.)

This is English we're using :-) "Matrix" can mean several different
things, but in the sense we're talking about here, yes, it's a grid with
numbers in the individual squares.

[...]

I'd rather return to the mass and energy that got lost in all this. What
I wondered concerning 'imagined' mass didn't get a comment (even just
'no') yet.

Mass is so simple [that is, it doesn't have many parts; simple is not
necessarily "easy"](1) that it's impossible to tell the difference
between "imaginary" mass and the real thing. Even if there is some
difference it doesn't matter. If it causes gravity it's "mass"
regardless of where it came from.

That's the really interesting thing. I don't know what this about
direction in combination with speed has to do with it, and even less why
you keep mentioning that 'vector' thing.

Let's see how this goes. I will get back to it, I promise.

Regards,
Ric
(1)Actually, the German fits perfectly here. "Einfach", literally "one
face" or "one attribute" = "simple". Mass has only one thing, mass.

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