Ground Latitude & Space latitude

Hi Sparkstation,

Very Good explaination, conclusion from a point in ground to 90 deg 200meters high the lat/long is same.

Cheers!!

Kalai Selvan..

<....very long buildings with tall columns....The building must be designed with earth curvature in mind, or the columns will be splayed outwards at the tops, if perpendicularity is measured with a "plumb-bob", and on a larger and larger basis, the further apart the two columns actually are placed....>

According to legend, the Severn Road Bridge's two main piers are about 50mm further away from each other at the top than they are at the bottom. http://en.wikipedia.org/wiki/Severn_Bridge

The ladder example is all well and good, just don't forget to pay the ladder-tax.

That was pretty IT related answer, not something related to my post. anyway thanks

That was a good tip..

thanks

To answer your question specifically, and without getting into deep math...

Picture yourself trying to cut good old earth into two equal hemispheres at the equator. But before doing this you first increase the earth's radius by a certain "Δ". Now start cutting the earth at the new higher and longer equator... After cutting through the "Δ" you will start cutting through the original equator.... Gotcha?

Wangito

Good!!!

Cheeers!!!

I'm finding the explanations more confusing than the reality. If latitude and longitude are based on the angles between lines and planes going through the centre of the sphere, why do we need to take the ground or the shape of the spheroid into account when determining our latitude? Are people merely trying to warn that local or gravitational 'vertical' does not generally go through the centre of the Earth, particularly if you include the effect of centripetal acceleration in your definition of vertical?
If so, it seems a strange way of saying that "you need to take into account your height and the local gravitational direction when determining the coordinates of the ground beneath you".

Hello Guest,

We don't need to <"take the ground or the shape of the spheroid into account when determining our latitude...">

The latitude/longitude remains the same.

In my earlier post, I mentioned the "long building problem", and how earth's curvature needs to be taken into account.

I'm talking there about a building a mile in length or more.

In a building, the columns should be vertical, otherwise there is a tendency for them to fall over, once the centre of gravity is outside the base. Unless there is extra support given, the object, (column in this case), must fall.

In a tall narrow column, if there is even a small "inclination" or "leaning" away from the vertical, the column will fall, unless supported.

You can note this effect easily: try and stand a pencil on the pointed end, and you find it is not easy for the pencil to remain standing (If you ever get it to actually stand on the point, without extra support).

But if you have a level flat surface, such as a strong non-shaking table, you may be able to get the pencil to stand for a while upon the end which was sawn flat by the pencil maker.

Remember when an object "falls" that it does not "fall" all the way to the ground.

The Law of Gravitation shows that the Earth also moves towards the apple, as the apple moves ("falls") from the tree towards the ground.

In fact the gravitational field of the apple extends to the far edges of the created Universe, (Every object attracts every other object), but gets weaker with distance, so is not normally taken into the calculations, as the apple has small mass, compared with planets, stars, galaxies and such.

Because the movement of each is "Inversely proportional to the mass of the objects", also distance between the objects, we can say, and see, that the "falling" Earth moves very little, and the "falling" apple most of the distance.

So, the columns in the large building are made vertical, so they are stronger that way, less tendency to fall.

You do not need mathematics to understand this, because it may be reasoned out, as Isaac Newton suddenly understood years ago.

Please realise I am not sneering at mathematics, because the basics are easily understood, mathematics make for the actual calculated effects, so we can learn in numerical terms, and apply learning from the bridge erection job, to help us design the next major construction job.

Engineering does certainly require mathematics, but you do not need mathematics to understand basic principles.

EXAMPLE:

If you get a round orange, and stick some toothpicks at right angles to the orange surface into it, you will see the effect of distance around a spherical curve, along the surface of the orange, upon columns, as the toothpicks diverge (become further apart at the outside (prickly) ends).

We do not otherwise have to take the ground shape, or know the oblate spheroid shape of the Earth, because they have nothing to do with the angle of latitude or longitude.

As mentioned before, very tall towers, such as used on suspension bridges, and the towers are far apart, need to be vertical, and as the toothpick/orange example shows, the tops of the columns are further apart than the bases, if a line is run through the column centres vertically.

But, the tower columns bases and tops have exactly the same latitude and longitude.

Refer to those toothpicks and orange, and you should clearly see this.

Trust that clarifies it for you.

Advise here if you're still wondering about it.

Kind Regards....

OK. I got my Fuji, and I'm moving all of us to Andromeda!

It's supposed to be a much nicer galaxy. Affordable rent and plenty of job opportunities as tentacle cleaners.

Ooh my ?.

My ? is taking a huge cross sections, its very simple ?. A person standing in point "A"

Moves up from the same spot straight 90deg 20 feet, the lat/long will remain the same,only the altitude differs. Eg. 0,0 is my original position, my new spot will be 0,0,20 feet msl. Does someone have to say anything..this is the answer that i learnt after referring many articles. and i was only expecting answer of this sort from the list.

Whereas its very complex explanation and words of war are taking place.

Thanks anyway.

i have a satisfactory answer now..

Cheers!!!

Up?? Neither vertically under gravity, nor perpendicular to the surface, but along a radius through the exact centre of the spinning Earth. For ultimate accuracy, you need to decide which time-frame you are working in - as you will be moving at a different speed from the surface.

A major aspect of bridge building is keeping the thing supported as it's built. Until the 2 sides meet in the middle it doesn't have full strength. Towers on a suspension bridge don't have to be vertical, so long as you can actually erect them and direct thrust throught the angle of incline.

Good anchorage helps !

Hello Kris

Nice photos, thanks.

<"Good anchorage helps !">

That is useful for the nautical trade, too.

Kind Regards....

Without posting the calculations (posting equations to CR4 is a bloody nightmare) the sort of splaying you would get in the columns of a skyscraper that has a base 100 m by 100 m and height of 450 m is about 684 μm

That is a bit over half a millimeter and even the best skyscraper construction techniques wouldn't come anywhere near being that accurate.

However, if you stand at the base of the outer columns on most if not all skyscrapers you will see a far more pronounced tapering of the columns. As you go from floor to floor in a building the amount of material above you decreases and therefore the weight any columns need to support decreases. As a result engineers reduce the cross sectional area of the columns as you get higher up the building. This form of tapering is far in excess of the half millimeter splaying that the curvature of the Earth would produce.

While in theory it would be possible to measure the splaying due to the curvature of the Earth in practice it would inconsequential and completely overwhelmed by the reduced cross sectional area and bowing of the structure due to wind and temperature differentials.

By the way, as far as I know there are no buildings in existence that are even close to 1,608 m (5,280 feet or 1 mile) high as measured from the ground to their top even when you count the spires or lightning conductors on the top.