BadScience

yes, but its a 30 second exposure with a 28mm lens? I would expect much longer trails than here. Anything above 5 seconds is normally a bit dodgy. Looks like two exposures to me: especially...

hmmm.

30 seconds, blurred coulds but no star trails?

"Ugandan engineer does not rely on the skin color but the fact that Romania is part of Europe when Uganda is not..."

yes, and one is essentially a proxy for the other. The native white population...

Ken, I've worked in Uganda - and I am white - so can confirm what you claim is bullsht.

The EU has it enshrined in the constitution that foreigners from one EU country working in another EU...

dick in the UK

At the moment the EU legally profiles - essentially - by race. The vast majority of Europeans are white. People from EU countries are allowed to move and work freely in any other EU...

"many"
"plenty"

these words are essentially meaningless; do you care to put numbers?.

Hence, in your own words
"slide film *WAS* the standard for publications"

What fraction of published...

danart - the pertinent word of your first sentence is "was".

"the force is pushing period"

What is generating this force? Where is the energy coming from?

You seem to be stuck in this hole that pushing is "correct" and pulling is "incorrect"; its wooly...

I am quite happy to take this offline, rather than de-rail this thread further.
I can direct you towards my research group, and the work we do, some of which is directly related to bulk flow of...

no it is not ok.

I will define the word precsely for you
suction
The bulk movement of a fluid flowing down a pressure gradient.

There is a statistical bulk movement from regions of high...

cosina -"without atmospheric pressure what you call suction could not occur"

That is absolutely incorrect.

You need two pressures pa; pb

where pa>pb

that's it.

The bigger the value of dp/ds...

Roland, that's just how humans percieve temperature
https://en.wikipedia.org/wiki/Thermoreceptor
(btw temperature and heat are not the same thing. An object has a temperature, heat is the flow of...

Tommi K1
"Heat doesn't radiate."

jesus wept, ...
The DEFINTION of heat is the radiation of (non-work) energy.

I have no idea what that second paragraph of yours means. It is...

* meant gradient in the pressure

an example in art it the Last Supper which was painted at the end of a corridor.

Viewed close up, or reproduced in a book or on a screen, you lose the sense of perspective.

he asked how many feet in a gallon,

of which there is no answer, certainly not the anwer you gave.

length and volume are not the same thing.

suction IS a change gradient.

These words mean exactly the same thing.

If you have a pressure gradient, air will move.

It wil move from high pressure to low pressure.

It is how our weather...

it is NOT an incorrect belief.

It is a sound beief because it is based on a physical fact.

it depends upon the angular displacement.

For a given displacement (hand movement):

on a wide angle...