Theory #1

[Robittybob1]

Physics isn't a strong point of mine, Rob, so if anyone can explain how the door could have slammed shut behind Madeleine I'm happy to accept a scientific explanation. (Cue Alice.......)

It might be a different story in the daytime if there was a sea breeze.

[misty]

It might be a different story in the daytime if there was a sea breeze.

I agree with that but know from experience what strange things happen to internal doors when an external door is opened. I'm just not sure how it  would work with those 2 doors in in 5A & a wind force acting against the front door closing.

[Alice Purjorick]

Physics isn't a strong point of mine, Rob, so if anyone can explain how the door could have slammed shut behind Madeleine I'm happy to accept a scientific explanation. (Cue Alice.......)

Don't encourage me!.
The door slammed shut because a force was applied to it sufficient to overcome friction and generate sufficient momentum to operate the latch.
Cutting to the chase the mechanics is easy enough, the difficult bit is determining all the true variable conditions that obtained at the precise time and location which produced that force.
If we could determine those we would not be sitting here discussing it at some nebulous level as with that skill,by now, we would all have predicted winning lottery numbers and be loafing on our very own island paradises.

[misty]

Don't encourage me!.
The door slammed shut because a force was applied to it sufficient to overcome friction and generate sufficient momentum to operate the latch.
Cutting to the chase the mechanics is easy enough, the difficult bit is determining all the true variable conditions that obtained at the precise time and location which produced that force.
If we could determine those we would not be sitting here discussing it at some nebulous level as with that skill,by now, we would all have predicted winning lottery numbers and be loafing on our very own island paradises.

LOL - we can keep dreaming. It didn't do Sonia's buddy much good, though.


If the bedroom window was open & the patio door ajar, would that make an open front door more or less likely to slam shut when the patio door was opened wider to allow access, using the known wind-speed & direction?

[sadie]

Don't encourage me!.
The door slammed shut because a force was applied to it sufficient to overcome friction and generate sufficient momentum to operate the latch.

-snip-

Dont encourage me either !

I studied Mechanics and fluid flow (Gases included) too, although only principles remembered now, 60 years on.    However, everyone can see, that the roughly north direction gusting that caused the curtains to blow in, would also cause the Front door to blow in (open) and NOT closed.

Misty and i came to the same conclusion at about the same time.   Seems that you, Alice missed this?

A northerly wind, experienced by Kate when the curtains fluttered, would also have been playing on the front door and would have likely have made it too difficult for Madeleine to have pulled the door closed.

Soz, Rob, but this small detail seems to have been overlooked by us all.  I really am VERY doubtful that Madeleine could have shut that door with the height mechanical disadvantage and the large knob for her little fingers .... and the wind against her.   And the prevailing wind conditions would have acted against the front door banging to.  IMO

Anyway, as if a 3-4 year old would bother to close the doot, if frightened and in a rush!

Madeleine did not go out of that front door with almost certainty


AIMHO

[sadie]

LOL - we can keep dreaming. It didn't do Sonia's buddy much good, though.


If the bedroom window was open & the patio door ajar, would that make an open front door more or less likely to slam shut when the patio door was opened wider to allow access, using the known wind-speed & direction?

Less likely misty.  The door would have been MORE DIFFICULT to close and Madeleine did not have a lot of weight to produce the necessary forces to close the door.  IMO

Let us not forget that both the sitting room and the parents bedroom would have heated up noticeably during the day.  I wonder were the sitting room windows left ajar a little to cool the place down?

And did The parents, perchance, leave their patio windows a little open to cool the place down?

No Air Con.  Very difficult to sleep in a hot bedroom ?

[Innominate]

Don't encourage me!.
The door slammed shut because a force was applied to it sufficient to overcome friction and generate sufficient momentum to operate the latch.
Cutting to the chase the mechanics is easy enough, the difficult bit is determining all the true variable conditions that obtained at the precise time and location which produced that force.
If we could determine those we would not be sitting here discussing it at some nebulous level as with that skill,by now, we would all have predicted winning lottery numbers and be loafing on our very own island paradises.

Agree.

Momentum vs resistance of the latch.

[Innominate]

LOL - we can keep dreaming. It didn't do Sonia's buddy much good, though.


If the bedroom window was open & the patio door ajar, would that make an open front door more or less likely to slam shut when the patio door was opened wider to allow access, using the known wind-speed & direction?

Is the wind direction known with absolute certainty, from local weather stations? Do you have the data? I not sure how easy it would be to be certain of how the various wind conditions near the coast would interact.

[Robittybob1]

Is the wind direction known with absolute certainty, from local weather stations? Do you have the data? I not sure how easy it would be to be certain of how the various wind conditions near the coast would interact.

So true.

[Alice Purjorick]

Is the wind direction known with absolute certainty, from local weather stations? Do you have the data? I not sure how easy it would be to be certain of how the various wind conditions near the coast would interact.

Indeed!
During the summer the prevailing wind is from the north when a wind blows. [prevailing wind = a wind from the direction that is predominant or most usual at a particular place or season;note it is not blowing all the time or at a constant velocity]. In the evening there will be an onshore breeze i.e the sea breeze and the prevailing wind if any would be in opposition; what we don't know is the velocity of either at the time and place in question. At this point without definitive data anyone's guess is as good another wrt to what happens.

[Angelo222]

Less likely misty.  The door would have been MORE DIFFICULT to close and Madeleine did not have a lot of weight to produce the necessary forces to close the door.  IMO

Let us not forget that both the sitting room and the parents bedroom would have heated up noticeably during the day.  I wonder were the sitting room windows left ajar a little to cool the place down?

And did The parents, perchance, leave their patio windows a little open to cool the place down?

No Air Con.  Very difficult to sleep in a hot bedroom ?

There wouldn't have been much heat around on a cold windy night.  I thought you dealt in reality Sadie and not myths?

[Alice Purjorick]

LOL - we can keep dreaming. It didn't do Sonia's buddy much good, though.


If the bedroom window was open & the patio door ajar, would that make an open front door more or less likely to slam shut when the patio door was opened wider to allow access, using the known wind-speed & direction?

What were they then?.

I am sure Sadie will be only too happy to plot it all out for you.

[slartibartfast]

What were they then?.

I am sure Sadie will be only too happy to plot it all out for you.

Thought we were going to get into unladen swallows....

[misty]

What were they then?.

I am sure Sadie will be only too happy to plot it all out for you.

Prevailing wind May in Luz NNW 337°
https://www.windfinder.com/windstatistics/praia_da_luz

Screenshot of weather conditions recorded from nearest weather station below.

Taking into consideration
 a) the front door is on the easterly end of the north-facing side of the block & set in a recess at the end of a potential wind tunnel
b) the patio door is on the south-facing side, protected in a recess on the patio by an adjacent wall & a balcony overhead
c) the bedroom window beside the front door was open (for the purpose of this theory)

are any of my learned friends/adversaries able to state the probability of the front door slamming shut behind Madeleine?

[Innominate]

Prevailing wind May in Luz NNW 337°
https://www.windfinder.com/windstatistics/praia_da_luz

Screenshot of weather conditions recorded from nearest weather station below.

Taking into consideration
 a) the front door is on the easterly of the north-facing side of the block & set in a recess at the end of a potential wind tunnel
b) the patio door is on the south-facing side, protected in a recess on the patio by an adjacent wall & a balcony overhead
c) the bedroom window beside the front door was open (for the purpose of this theory)

are any of my learned friends/adversaries able to state the probability of the front door slamming shut behind Madeleine?
b) the patio door is on the south

The website itself states:

"Statistics based on observations taken between 06/2013 - 02/2017 daily from 7am to 7pm local time."

and

"Dominant wind direction"

and

"The wind statistics are based on real observations from the weather station at Praia da Luz."

===

Is the screenshot the raw data? It does not look like raw data - I would like see the actual raw observation data that was used to generate the statistics, before drawing any firm conclusions.

If the raw data shows that there are sufficient observations to be reasonably accurate, and the weather station is reliable (a lot of these statistics appear to come from amateur locations) then that would be a question mark over whether the door slammed.

It does not take much of a breeze to slam a door. Once the door starts accelerating under the application of a force it is building up speed, which increases momentum.