Schneier on Security

Clive Robinson • July 8, 2017 1:38 PM

@ Tatütata,

Insert here old joke about ANSI vs BSI cup of tea

Are you refering to the old NAFI joke about NATO wanting to standardize every thing that resulted in the expression of “Standard NATO” for “Strong, milky and two sugars”?

Or perhaps, the fact, of ISO standard 3103: ‘Method for preparation of a liquor of tea for use in sensory tests.’[1], derived from the 1980 British Standard BS6008.

Being “British” however means we take things tea related more seriously hence, there are also British Standards Institute specifications for black tea (BS 3720), and for green tea (BS 11287). And (BS 7390) for “instant tea”. And the now obsolete BS 6048 “specification for black tea”.

However there is not a BSI standard for the rather delicate “white tea”, which I’m fond of.

Of course there is not just the milk-v-lemon debate (lemon seen by some as a European perversion). But also the debate of when to add milk.

For those confused about when to add milk the rule is “first brew the tea”. Thus if you are a tea bag in a mug type, add freshly drawn just off of the boil water, stir the bag in the water untill the desired strength then remove the bag and add cold fresh milk (no “plastic cow” or abomination such as “non dairy creamer”[2] or for that matter real cream, it tasts uck).

If however you brew in a pot as I do you can add the milk to the cup befor or after the tea, however there is a small taste difference. Originally the milk was added first to help avoid damaging fine almost paper thin china tea cups with thermal expansion shock. The reason for the taste difference is the extent of caramelization of components of the milk, thus only matters if the tea is very hot. If you want to realy taste the difference, try using the steamer on an espresso machine and compare the flavour when at room temprature with that of unsteamed but similarly diluted milk.

[1] https://www.iso.org/standard/8250.html

[2] Non dairy creamer is an abomination thought up by the same certifiable loonies that came up with “corn syrup” which is noe killing people by the million in the US alone. The best use I’ve seen for non dairy creamer is as a SFX FAE “Dry Powder Expanding Dust Cloud Explosion” (DPEDCE) which is similar to a “Boiling Liquid Expanding Vapor Explosion” (BLEVE). You use two charges, the first blows the creamer that is the Fuel into an expanding cloud that mixes it with the Air making the Explosive FAE mix that the second charge sets off. Mythbusters did one once, however their mix was not optimal, however still impresive.

Clive Robinson • July 12, 2017 2:48 AM

@ TS2,

The tea pot is a subtle method, most likely you want to use something that doesn’t act quickly, so it kills a few hours later, after the guest has left your house.

The problem is that untill relatively recently most poisons were of the “organic” form obtained from plants and occasionaly animals.

Plants have a complex life cycle and the poison in quite a few cases is seasonal or in some parts but not all. The point is in most cases those poisons are generally not designed to kill the animal, but deter them, thus the poisons are identifiable by tast as extreamly bitter.

Genuine “Tea” actually contains contains some poisons which could make you feel quite ill if you ate the raw leaves fresh. However drying / fermenting breaks a lot of them down. The reason for this is the plant only wants to kill some creatures that predate it with no benifit but not allanimals. Thus the plant does not want fallen leaves to kill soil based animals etc, that it has a symbiotic relationship with.

But some poisons from plants effect different creature different ways thus we have the likes of chocolate which kills dogs with very little injestion whilst the leathal does for man is so large even a choco-holic is unlikely to feel any effect.

Likewise animal derived poisons such as venoms are not designed to kill by anything other than by injection via fangs etc, and serve two purposes to debilitate the prey quickly and in some cases start the digestive process. Some are not true poisons but just temporarily inhibit certain biological process and then break down quickly (these often have medical uses in the likes of surgery).

Many other animal poisons are we now know are actually not made by the animal but bacteria that colonize it, but these are realy quite rare (see tiger fish venom).

The point being that all but a very tiny number of poisons work by “tasteless injestion” and they are comparitively rare. Thus the assassin does not have much choice on the strength or time delay.

Modern poisons made by man however are different, look up dioxin and diethyil mercury to see some real nasties, oh and perhaps one that will open your eyes wide. It has the lowest LD50 of any natural poison, it is also the most valuable substance by weight in the world, and mad as it may sound like arsenic long before it, it’s used as a “beauty product” and people have parties to use it and is most commonly called “botox”…

Clive Robinson • July 12, 2017 4:01 AM

@ Tatütata, Rachel,

Yes prophylactics have an interesting history in the hands of the military, including propergander.

I linked to an article in my earlier post above about “the mercury treatment” which gives a good run down of why various governments issued prophylactics to their soldiers in large numbers, and made it a chargable offence not to carry them at all times. However most soldiers have found other uses for them, including keeping dusy, dirt and water out of the business end of their personal weapons to prevent misfires or worse[1].

They also in the military “tough as old boots” form make rather usefull water carriers. The reason for this is they also “don’t slosh” much infantry and similar training / action is in attacking by stealth in the dark, where the rattle of a water bottle can be a “dead” give away to those you are trying to creep up on.

Oh and they have another use as “piss pots” by special forces… As the rye saying goes “When a man has to poo what a man has to poo” for special forces it means “carrying your own 541t” literally. To minimise scent/visual tracking they collect all their waste in bags and put it in their kit and carry it with them. Suffice it to say that the “physical security” of thr liquid carrying properties of an extra strong condom are much appreciated.

Thus the need for extra large, extra strong prophylactics is real, but that did not stop various propergander people realising that going overboard on the idea could have a demoralizing effect on the enemy… So military grade prophylactics are quite large, and this as per usual squadie humour and practical sillyness gets involved. This includes putting them on your head not just as a hat but also so your nose is inside and by controled breathing from the mouth inflate them till they get extraordinarily large…

A use I and a couple of friends put them to back whilst the cold war was still on, was to fill them with helium and use them like weather balloons to hang small VHF and UHF transmitters off. We had one go from NE London all the way across the North Sea and it would have if it or the batteries not failed (not sure which) made it’s way on the track it was on close to Russia as it was heard in Sweden… It’s one reason I smile and get slightly mist eyed when I hear a German Punk Rock group have their record played on the air[2]. Our prophylactic balloons may not have been as many as 99 nor where they red just pinkish in some cases, but they could have baited the bear.

[1] Many rifles have what are called “flash arresters” at the end of the barrel. These slots are easy to get gravel trapped in. Thus the next time the rifle is fired the rifle gets damaged as do people around it. As a lot of military engagements are at night without light the chances of getting foreign objects in a weapon go up considerably. Thus a prophylactic over the barrel held on by a little black insulating tape is a known squadie trick.

[2] https://en.m.wikipedia.org/wiki/99_Luftballons

Clive Robinson • July 12, 2017 7:46 AM

@ Wael,

How ’bout polonium? A lethal dosage can be measured in fractions of micrograms, and its effect is not immediate!

I did differentiate on time with

The problem is that untill relatively recently most poisons were of the “organic” form obtained from plants and occasionaly animals.

and

“Modern poisons made by man however are different, look up dioxin and diethyil mercury to see some real nasties”

and polonium definitely falls into both exceptions 😉

Oh Polonium is also the name of an international coach company working out of Poland, and according to some politico types in the UK causing more problems than a couple of Russian hit men protected by Putin’s legislation.

Clive Robinson • July 14, 2017 2:52 PM

@ EvilKiru, Wael,

I just figured that if it was poisoned, re-cooking it would hardly remove the poison,

I guess you don’t do much “whole food cooking”. You could start by looking up “red kidneybeans” and “Casava”. Both can kill you if you eat them raw, however cook them at around boiling point for around ten minutes will break down the poison.

Likewise certain bacteria will poison you quite effectively. In most but not all cases the bacteria will be killed at tempratures bellow the boiling point of water. However there is one that can be found in cooked rice, because it will survive 100C and the breaking down of the rice due to cooking will kick start it to reproduce rapidly (it’s why the recommend you don’t keep cooked rice for very long).

Any way as Douglas Adams observed through his charecter Ford Prefect “The secret to survival whilst hitchhiking is eat fast food”.

Clive Robinson • July 17, 2017 11:48 AM

@ Cutangle,

I order for the tea to escape the spout with its air hole covered – thus creating vacuum in the pot…

It’s a bit more complex than that as a simple experiment shows. Find a flexible plastic bottle that will not melt or deform when a hot liquid is poured in. Then gently squease the bottle to remove some of the air then screw the top on tightly. If you then shake the bottle it will expand out due to the energy from the hot liquid transfering into the remaining air causing it’s effective preasure to rise[1].

How much energy gets transferred into the air in the top of the poison chamber and how much it consequently expands due to the agitation involved with pouring I don’t know (due to insufficient details). But it is reasonable to assume that some of the poison tea may well get into the cup that is not intended to be poisoned…

[1] If you can not find a bottle that is sufficiently heat proof, you can do the experiment in reverse, by pouring in very cold liquid screwing the top on shaking the bottle and watching atmospheric preasure crush the bottle as the energy in the air inside is taken up by the cold liquid.

Clive Robinson • July 17, 2017 5:25 PM

@ SparkyGSX,

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Not sure of the physics myself, but the story appears to have some basis in fact,

http://www.dailymail.co.uk/sciencetech/article-3635710/How-cool-apartment-free-Electricity-free-DIY-aircon-uses-old-plastic-bottles-used-used-25-000-Indian-homes.html

My guessing is that it involves both the chimney and ventury effect. When Spain had the Olympics some years ago they used similar shaped objects but big enough to get 50-100 people underneath. With the nozzle end upper most they sprayed a fine mist of water into the neck just below the nozzle.

So yes there is the potential that the idea might work, but I must admit it’s quite a few years since I did calculations on the Bernoulli effect and continuity equation needed to work it out. But I do know there are others who have used them to design passively cooled housing.

With regards,

Let’s look at it another way: if thermal energy is being remove from the air, where exactly is it going?

Where does it go in a heat engine like a tornado?… It produces movment of the air…

Clive Robinson • July 19, 2017 3:26 AM

@ EvilKiru,

Which just goes to show I’m not half as clever as I think I am. ^(=.=)^

Oh I don’t know that’s a fairly good emoji of Neko the cat as a ninja assassin 😉

More seriously, it’s a demonstration of why science has both experimental and theoretical paths.

If you have kids who have got to the exam stage in school physics you get to see some realy fun questions. One in the physics revision notes was about a person leaping out an aircraft and their rate of acceleration after a minute…

Now most people will get it wrong, and even those who get it right will usually do so for the wrong reason (including the exam answer in the back of the book).

The reason is, whilst they might consider drag, they often forget change in air density, and almost never include buoyancy. That is terminal velocity goes down as you descend because air density increases thus the buoyancy changes as well… Especially when the density of the ground is reached, and acceleration is close enough to zero for the body to be considered “at rest” in more ways than one 😉

As was pointed out to me by a fairly good teacher of physics many many years ago “Physics is taught as one lie after another, each a little closer to the truth”.

Clive Robinson • July 19, 2017 6:40 AM

@ Dirk Praet,

“One lie after another, each a little further from the truth”.

That almost exactly sums up what I tell my son 😉

I give him helpful hints such as,

The best place to be when there is trouble, is somewhere else.

Then I teach him bit by bit situational awareness so he can spot trouble brewing up long before it boils over.

But I’ve told him as I have people here,

Truth is a mater of perspective, thus there is one more truth than there are observers

Which leads into a conversation about the three main types of lies,

1, Lies of ommission.
2, White lies.
3, Lies of perspective.
4, Outright lies.

And how to spot 1&4 and why 2&3 exist and how they can glue society together. I’ve also told him about “perspective shifting” and how to spot people who are doing it themselves and those who are trying to do it to you. I’ve also mentioned when a “Bold lie” works and why and what it’s limits are and why they sometimes have to be used (ie when you are in effect in charge of a group or need to take charge of a group that need to stick/work together for their own well being).

But the important lesson I mention to him often is to evaluate what you know against what you are being told. If something you are being told disagrees with what you know then there is something wrong with either what you are being told or what you know. The hard part is getting him to understand what constitutes proof and what does not. It’s caused a degree of friction due to a course they “have to take” that is so obviously biased it’s unbelievable… Worse it’s effective lies have secondary effects. They get given questions about morals where the script is religious people are moral and religious people are truthfull. Thus trying to brain wash children into a false belief that religion is about truth and morals and thus the secondary conclusion that those who do not believe in an all seeing deity are not truthfull or moral. Iv’e pointed out that there are religions that do not have gods but still teach about truth and morals, and I’ve also pointed out there are groups of people who require neither a God or orchastrated belief system to be honest and moral. I’ve also had no trouble what so ever finding examples of those who claim to have both an orhcistrated religion and God that are clearly nrither moral or truthfull.

It led to a long conversation as to why he would have to lie to pass the examination. Which in turn led to a conversation about the politicians with apparently strong religion but why (in the UK) they were considerably more dishonest than the average citizen (the simple fact being that politicians are four times more likely to go to jail in the UK than the average person who has no criminal conviction).

Thus he is growing up in a way I suspect many politicians don’t want him to do, and already spot’s many of their lies straight off…