I'd never seen this before

On 1 Jan, 17:19, Mxsmanic wrote:
Kyle Boatright writes:
Anyway, it probably took me 20 minutes to reach the tower and by the time I
reached it, it was well below my altitude, (which hadn't changed). * After a
little thought, I realized that the curvature of the earth had resulted in
an illusion that the tower was extremely tall when viewed from a distance,
but was only 1000' AGl (or 1800' MSL) in reality.

The curvature of the planet won't do this; it makes things seem lower, not
higher, just as a tower behind a hill might not appear as tall as it does once
you reach the crest of the hill.

However, some atmospheric effects can make things seem larger or taller than
they are from a distance.

At an altitude of 3000 feet AGL over smooth terrain, you'll be able to see the
top of a 1000' tower (but not the whole thing) from up to 92 nm away.


Sez the gy who has never flown


Ever

Fjukkwit


Bertie

You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.




On Jan 1, 4:52*pm, Bertie the Bunyip
wrote:
On 1 Jan, 17:19, Mxsmanic wrote:





Kyle Boatright writes:
Anyway, it probably took me 20 minutes to reach the tower and by the time I
reached it, it was well below my altitude, (which hadn't changed). * After a
little thought, I realized that the curvature of the earth had resulted in
an illusion that the tower was extremely tall when viewed from a distance,
but was only 1000' AGl (or 1800' MSL) in reality.

The curvature of the planet won't do this; it makes things seem lower, not
higher, just as a tower behind a hill might not appear as tall as it does once
you reach the crest of the hill.

However, some atmospheric effects can make things seem larger or taller than
they are from a distance.

At an altitude of 3000 feet AGL over smooth terrain, you'll be able to see the
top of a 1000' tower (but not the whole thing) from up to 92 nm away.

Sez the gy who has never flown

Ever

Fjukkwit

Bertie- Hide quoted text -

- Show quoted text -

On 1 Jan, 22:07, Tina wrote:
You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.


Him and counting using popsicle sticks wouldn't get along!

Bertie

Tina wrote:
You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

True and the equations are easy to find on the internet, but they are
all rough approximations.

There is the geometric horizon which assumes the Earth is a perfectly
round billiard ball and the optical horizon which attempts to account
for the fact that the atmosphere bends light and increases the
distance around 10% depending on state of the atmosphere between the
two points.

Given all the ambiguities in the problem, numbers like 92 instead of
"approximatly 90" just show someone can punch numbers into a calculator
without any understanding of the true nature of the problem.

What a surprise.

--
Jim Pennino

Remove .spam.sux to reply.

MX's calculations remember something that was said in an undergraduate
physics course I took: "Assume a spherical cow. . . "

On Jan 1, 6:05*pm, wrote:
Tina wrote:
You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

True and the equations are easy to find on the internet, but they are
all rough approximations.

There is the geometric horizon which assumes the Earth is a perfectly
round billiard ball and the optical horizon which attempts to account
for the fact that the atmosphere bends light and increases the
distance around 10% depending on state of the atmosphere between the
two points.

Given all the ambiguities in the problem, numbers like 92 instead of
"approximatly 90" just show someone can punch numbers into a calculator
without any understanding of the true nature of the problem.

What a surprise.

--
Jim Pennino

Remove .spam.sux to reply.

Tina writes:

You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

It's just simple trig. In fact, it's just solving for different sides of a
right triangle, as should be obvious from the description I gave.

prove it.
show your work

On Jan 1, 8:53 pm, Mxsmanic wrote:
Tina writes:
You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

It's just simple trig. In fact, it's just solving for different sides of a
right triangle, as should be obvious from the description I gave.

Mxsmanic wrote:
Tina writes:

You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

It's just simple trig. In fact, it's just solving for different sides of a
right triangle, as should be obvious from the description I gave.

Wrong; the optical line of sight is different than the geometric line of
sight because the atmosphere bends light.


--
Jim Pennino

Remove .spam.sux to reply.

Mxsmanic wrote in
:

Tina writes:

You can be fairly sure he used someone else's equations for line of
sight. I'd bet a significant sum he could not derive them himself. He
and Euclid would not have gotten along.

It's just simple trig. In fact, it's just solving for different sides
of a right triangle, as should be obvious from the description I gave.


Nope


Bertie