Easy Questions?

[Swatopluk]

The scale is only on the heating spiral (I wash out the thing before any new water is boiled).
From time to time I put acetic acid into it and let it boil. Afterwards the metal parts are perfectly clean.
So, the effect must be caused by the different surface structure and or heat conductivity of the heating spiral.
I simply do not know how how (although I could talk for awhile about the heat transition from surfaces to liquids and the temperature dependence because that is a standard exam question in technical chemistry).

[Scriblerus the Philosophe]

I remember playing with that stuff last year in my honors chem class. Fond memories of acetic acid.

So would the crud on the bottom of the pot affect the heat spiral? Even by a little bit?



New question!
Every time I want to go out for a photo walk, it rains. Every damn time. Why?

[Sibling Zono (anon1mat0)]

Murphy's laws are very clear about that.

[Sibling Chatty]

I say we find Murphy and take away his pen so he has to quit writing laws.

[Scriblerus the Philosophe]

I vote we punch him as well.


But! It did clear up today! As I walked out of the doctor's office this morning, the clouds broke and wonderful, soothing sunshine came out. It made me happy.

[Griffin NoName]

Ok this isn't exyactly science, but it is logic which is the next best thing.

There's a lift (elevator). It goes between floors G 1 2 3.

The doors of the lift on floors 1 and 2 have panels showing current floor number of the lift and an up arrow call button and a down arrow call button which can be pressed to call the lift.

Inside the lift is a disembodied voice continually and constantly proclaiming "lift going up" or "lift going down".

This voice can be heard at all times on any floor up to about 500 yards away. It is a very loud voice. Deaf people have an advantage.

All signs and buttons in and around this lift are also in braille.

On entering the lift, by observation and personal usage, everybody presses the button for the floor they want. The lift continues up or down, or changes direction accordingly. So does The Voice.

There is virtually no cross or bi-personal traffic. ie. normally only one person or (grouped) persons use the lift with a single destination. The lift travels fast with distance between floors being minimal. It then continues to go up and down by itself empty - usage is sporadic - with The Voice (female) talking to herself.

Is it necessary to have both an up and down arrow call button?

[Scriblerus the Philosophe]

Only if The Voice deems it necessary.

[Griffin NoName]

A valient try Scribbli which wins you a hug.

However, The Voice, I believe, has a different raison detre.

It's other functionality is a repetative repeating of the phrases "Doors Opening" and "Doors Closing".

It seems to possess an almost demonic irritating belief that it can fool excited and anticipatory people into rushing up the corridor thinking there's a chance of seeing Jim Morrison.

[Swatopluk]

With just 4 levels a simple call button should be enough. For a larger building, especially with more than 1 lift I'd prefer a system where the exact destination can be chosen outside the elevator, so the services can be coordinated strategically. While we are at it, a weight sensor would be useful, so a fully occupied cabin would not stop on a call, if another with less people in it is nearby.

[Aphos]

The lift continues up or down, or changes direction accordingly.

This means the elevator will go up or down, whichever you need, after it arrives.

There is virtually no cross or bi-personal traffic. ie. normally only one person or (grouped) persons use the lift with a single destination.

And this means that (almost never) will anyone else be using the elevator going in a different direction than you want.

Everything else described is superfluous.

All you need is a call button, not up and down buttons.

And the voice says, "Lift going down".

[Griffin NoName]

While we are at it, a weight sensor would be useful, so a fully occupied cabin would not stop on a call, if another with less people in it is nearby.

Yes, provided the cabins are side by side not one above another

[Swatopluk]

There are by now elevators with several independent cabins in the same shaft (only useful for very tall buildings).

[Swatopluk]

A typical ignorant question by a city-dweller (me): Do chicken lay eggs even in absence of roosters? Otherwise how does "battery laying" work?

[Sibling Zono (anon1mat0)]

AFAIK battery laying uses a special breed of hens that don't require a rooster.

Interestingly, my parents had a lady duck for a while and she layed eggs -not too frequently- without a male duck.

[Griffin NoName]

Human females lay eggs in the absence of the male. They are just not laid in places one can generally locate them as easily as hens eggs etc. (and they don't lend themselves to breakfast with soldiers..... ).