Clive Robinson • May 30, 2020 3:05 AM

@ SpaceLifeForm,

It’s reasonable to propose that SARS-CoV-2 did not originate in the wet market.

Also it’s reasonable to say we may never know where it started.

What it is also reasonable to say is that the wet market is a point that many of those who were originaly recognised as having a new disease had contact with.

The more we learn about this disease the more dificult it becomes to actually trace it back.

That is of those early patients that apparently had no contact with the wet market, they may have had contact with a “silent spreader” who did. Or conversly those who apparently had a commonality of the wet market may not have caught it there, they may have had contact with a “silent spreader” else where.

I suspect the actual infection started well away from the wet market in some rural location where humans come into contact with wild creatures. Some hunter possibly quite young caught the disease and was not visably effected nor were most around them. The few who were got noticed got diagnosed with some other disease or death. And as it was a rural area the number of deaths would have been low and like as not the Drs just put it down to random events. Like other diseases it then traveled up the supply chain mainly going unnoticed for the same reasons. It was only on reaching a highly populated place that the number of odd illnesses and deaths got sufficient to cause a Dr to realise it was something new… By which time, as we now know from Italy and Spain, it was probably into “community spread”.

Clive Robinson • May 31, 2020 12:16 AM

@ vas pup,

Could you please advice how to attach voltmeter to cable box so I could actually monitor electricity consumption

.

You want a “power meter” rather than a “voltmeter”.

Electronics engineers go quite a long way out of their way to try and ensure that the voltage on power supplies remains constant to very small fractions of a volt irrespective of the power being consumed.

You can buy “digital power meters” relatively cheaply from a large number of places. Some are to be connected between the AC wall socket and the device mains lead, others are designed to be connected between a DC Power source such as a battery and the load device. These DC power meters often have an “input voltage range” specified so you need to check that before aquiring one.

Some are realy fancy and have Bluetooth interfaces to speak to power monitoring apps on your phone.

Beyond what I’ve said above it’s difficult to say anything else without going into actual indepth details of the devices and power supplies.

Clive Robinson • May 31, 2020 7:23 AM

@ SpaceLifeForm,

I should open up a antibody test lab.

The scam you describe is one that the UK government appear to keep finding with both their PPE (from Turkey) and anti-body tests (from China).

However you and one or two others may remember the discussion over a side effect of “Vampire antiaging” transfusion. The “good stuff” as it were is actually in the serum, where all the antibodies for disease are found.

Well there are a number of places near Silicon Valley which do these transfusions for certain well paid or well invested persons who want to be “forever young”…

Thus it’s only a tiny step from “high tech vampire anti-aging” to giving people short term immunity, or… Enable them to falsely pass an antibody test to get a “passport to work”, thus actually significantly endangering others.

There could be a lot of money in such “pass the anti-body” transfusions…

Clive Robinson • June 1, 2020 10:59 AM

@ myliit, MarkH

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blockquote>Reference please.

I read it to mean that @MarkH had not seen evidence that bats were a SARS-CoV-2 reservoir species (which I’ve not seen either). Unlike evidence that domestic cats and some rodents appear to be capable of being not just infected but with minimal symptoms as well.

For instance we have eradicated ebola several times from the human population, but it comes back because one or more wild species act as disease reservoirs and occasionaly zoonotic transfer occures, thus ebola in an original or varient strain comes back into humans every few years. But ebola is unlikely to become endemic because it is just way to lethal and without modern transportation/communications would kill faster than it could spread so would in earlier times have been self limiting.

If you have a reservoir species in which a virus mutates and you get zoonotic transfer, then to eradicate the virus you have not only to deprive it of human hosts you have to deprive it of the reservoir species hosts as well.

One of the ways a pathogen becomes endemic is through reservoir spiecies where it can mutate without killing that host spiecies. Thus opportunisticaly get to another spiecies by zoonotic transfer chain prior to humans.

It’s believed but not proved that SARS-CoV-2 originated as a different corona virus in bats that have a much much faster immune system than many creatures. Then into a mammal and then on to humans. Originaly it was hypothesized that this intermediate host was the heavily traded and increasingly endangered spieces the pangolin. This has apparently been now depreciated in the thinking and others are looking at felines or rodents or both.

The problem as I indicated is that both felines and rodents are “domestic pets” and felines frequently come into contact with wild rodents such as rats and mice that invade domestic dwellings, especially where they cohabit with other livestock such as porcines and fowl that account for about one third of the worlds protien foods for humans.

Such environments are almost as optimum for interspecies viral transfer[1]. Which is why a lot of flu or cold virus mutations are from avian or porcine roots.

Oddly if you step back a couple of steps SARS-Cov-2 with it’s very high rate of asymptomatic infection in humans would tend to make us a reservoir spiecies…

That is without modern medicine those above child bearing age and nolonger capable of hunting/farming such as men in their late fourties would get eradicated. The fact that women are less than half as likely to succumb as men also reinforces the point, in that older women in hunter-gatherer and rural farming communities are needed to look after children whilst the younger women carry out gathering and food preperation as well as harvesting.

In such societies women are considerably more valuable than men in terms of survival of the spiecies. The fact that women are capable of producing a child every 18-36months from early teens onwards for a quater of a century or so, means that a sufficient supply of new hosts would be born every year to ensure that SARS-CoV-2 remained endemic as a background almost invisable infection.

Whilst we do not yet know I suspect that human immunity to SARS-Cov-2 is going to be measured in a handfull of years not decades. As we already know SARS-CoV-2 is a mutation from an earlier virus it is probable that it will mutate again, it only being a question of when not if.

All of which makes us a quite respectable reservoir spiecies…

[1] What we do know is that corona viruses that are very common in wild animals where they infect the GI tract not the respiritory tract rarely infect humans. SARS-CoV-2 however uses the ACE2 receptors found in the respirotory tract in some creatures as it’s entry point into cells. Interestingly the number of ACE2 receptors people have is related to PM2.5 or smaller particles strongly associated with both smoking and polution. That is the less PM2.5 or smaller particles that you have got in your lungs the less inflamation related ACE2 receptors you have and the lower your chance of infection by SARS-CoV-2.

Clive Robinson • June 1, 2020 1:40 PM

@ vas pup,

@JonKnowsNothing and @Clive:
Thank you very much for your input.

I can not say for Jon, but from my point of view, a lack of information leads to speculation which can be not just be bad but potentially dangerous to others…

In science speculation tends to be good because generaly it is treated as a hypothesis, thus bounded by what is known and established, then tested etc untill sufficient evidence verifies or rejects the hypothesis. Thus science moves forward a step.

However in other areas of life speculation often is unbounded, lacks evidence and even contradicts the laws of nature. Thus is not good at all, and people have been burned at stakes etc for such speculation.

As just one recent example “COVID-19 blaimed on 5G”, where radio masts and even power pylons have been burned and engineers threatened with similar… Could fairly be described as a modern day witch hunt.

Such unreasoned behaviour rarely gets going on it’s own, it requires “organisation” and “funding” even in this Internet age. One thing that is becoming more noticable is that people with both money and political agendas tend not to find it too difficult to find what might charitably be called “cranks” and give them a platform and prestige.

When you follow the money back as the UK police did with Cambridge Analytica, suddenly those with political agendas and money get nervous and investigations mysteriously get called off, and other politicians raise questions about it…

So hopefully by supplying information that reduces speculation, you effectively spike the guns not only of the cranks but those who chose to use them as at the very least “usefull idiots” for a political agenda. One or two who have been seen poping up on this site with their “faux news facts”.

Clive Robinson • June 2, 2020 10:52 AM

@ MarkH, ALL,

But now I’m hearing from people who are getting ready to fly.

On the radio news in the UK this morning courtesy of Murdoch’s Sky, a UK Minister was quoted as saying that those flying into the UK would be subject to a fourteen day voluntary quarantine at a known location. But he went on to state that this was a temporary measure untill “air bridges” had been established…

This idea of “air bridges” is another bumb ass political idea dreamed up to make vested interests happy at the expense of every one elses health and life and economic well being of the country.

The idea is passengers traveling from certain “desegnated countries” would not be subject to 14day quarantine… Whilst passengers traveling from other countries would be.

As with all such ideas it places trust in the hands of people who by definition should not be trusted (other countries over which you have no hold over).

Put simply there is no way to make sure that passengers from a desegnated country have actually been their safely for more than 14 days. Thus there is no control or prevention a host nation has at the end of an “air bridge”.

People will “cheat the system” because it is in their interest to do so. Even if individuals do not have the information required to “cheat the system” effectively, there will be more than enough “People Traffickers” who do, who will slip people past for a few thousand US dollars etc.

Thus the “air bridge” idea is just another bit of politically inspired nonsense, that will lead to increased infection rate spreding and a very high likely hood of starting a second pandemic wave arising and all the subsequent missery and grief.

Clive Robinson • June 3, 2020 3:47 AM

@ Rachel, MarkH,

I thought you didn’t believe in conspiracy theories 😉

On the less leg pulling side “formal salutations” even in very recent times, historically have an awkward side, including getting murdered for supposadly “Offending God” if you did not give them correctly…

It might be why the Irish comedian Dave Allan who was popular during “The Troubles” used to say at the end of his shows,

May your God go with you.

Thus it matters not what I believe, when passing on a blessing[1][2], it’s what the person receiving my blessing thinks or believes they have an entitlement to.

From my point of view if people wish to believe in “deities”, “Mythical Stories” or even “low flying meatballs”, etc, that is their choice not mine thus their responsability to carry. And like having “an embarrassing boil on the bum” is something I might feel sorry for them if I knew of their predicament, but realy wish they would keep it to themselves, and most definately not put on public display 😉

That said I’ve often wished that people would spend a little more time believing in what mankind can do to benift not just man but the fragile environment we currently have no choice but to live in, so our childrens children etc have a better existance than we do.

[1] In times past “blessings” were a form of “formal etiquette” much as we still use “Dear Sir,” and “Yours faithfully” at the begining and end of letters to a “post holder” such as “To the company secretary”. Thus not giving them was a breach in an established social contract, that these days we’ve watered down to just “being polite”…

[2] Due to a technicality I’m entitled to hand out more “theological blessings”. Not that I would, I got a DD via one of those postal colleges that used to be common in the US, but have since been cracked down upon for good reason. I won’t go into why I got the DD but needless to say it was not for belief or theological reasons, rather more to make a point (yes my hooves are bigger than that of a donkey, and I can stick them in even harder 😉

Clive Robinson • June 6, 2020 2:39 AM

@ Chris,

So.. modern encryptions needs randomness
and modern machines lacks entrop that creates randomess… that smells like a rat.

One of the original and perhaps most famous comments on this[1] aspect was made by John von Neumann in the early 1950’s,

“Any one who considers arithmetical methods of producing random digits is, of course, in a state of sin. For, as has been pointed out several times, there is no such thing as a random number – there are only methods to produce random numbers, and a strict arithmetic procedure of course is not such a method.”

These days we refer not to “arithmetic methods” but “Determanistic Methods” when talking of generating entropy which for cryptography of the highest levels of security should be “Truly Random” that is “Have no determanism”, because “Determinism of any form eventually reveals it’s self”.

I’ve made comment on this blog several times about the problems of generating random numbers on “network devices” and the more general class of “embedded systems” that all Internet of Things (IoT) devices fall in. And importantly practical ways to solve them.

Likewise I’ve mentioned the “perversion” of “magic pixie dust thinking”[2] and the likes of Intel CPU’s and it applies especially to the way they generate random numbers. The up shot of which is put simply “As you can not test the source directly it should never be used” because you as an observer can not tell if the available RNG output is from a true random source, or a counter encrypted with a whitened version of the CPU serial number because you will not live long enough to test it and with the general quality issues of Intel CPU’s used in NAS boxes and the like the chip will malfunction or die long before you will…

Which is one of the reasons on reading the TechRepublic article from the link you provide alarm bells started ringing when I saw,

“The haveged service seeds a system’s random source by executing a loop repeatedly and using the differences in the processor’s time stamp counter–this gains entropy without having to use a mouse or a keyboard.”

All CPU’s are by definition “fully determanistic” otherwise we would not use them after all if you use do “2*2” you want to get “4” all the time every time. As part of this CPU’s use a central clock source for all the processing logic and various techniques[3] to keep all the internal states to the correct values.

As I indicated long ago this central clock is derived from a quartz crystal that is usually AT-Cut which defines it’s characteristics in terms of frequency stability with respect to temprature, in “Parts Per Million” (ppm) over an operating temprature range. The cut also effects the “aging time” that is quartz crystals frequencies change over time the longer they are used.

But these changes effect all the processing logic as they are synchronised to it. Whilst there are tricks you can pull with “time delay elements” to pull out the “Delta F” or very short term frequency change, these are generally very unwise to do. Because the central limit theorm acts against you (the time delay acts as a low pass filter, the output of which “follows” the input).

People often confuse the use of a delay line with the “Waggon Wheel effect” where in movies the coach waggon wheels appear to turn slowly or even backwards due to the “Strobascopic effect” of the way the individual still frames are “gated” (sampled). A varient is known as the “roulette wheel effect”. The difference between the delay line and the sampling methods is that there is only one frequency source in the delay line and very importantly “two independent” frequency sources in the sampling method.

Thus without a lot of further information I would advise treating the “haveged service” method with deep suspicion.

But even if it is producing “True Randomness” it is going to be in very very small amounts over significant periods of time. That is I would not expect to get a true random bit in anything less than 5-10 seconds due to thermal latency of the quartz crystal and it’s housing. You will however get a lot of faux entropy[4] that is then biased.

[1] From “Various techniques used in connection with random digits” by John von Neumann in “Monte Carlo Method” edited by A.S. Householder, G.E. Forsythe and H.H. Germond, 1951.

[2] Magic Pixie Dust thinking is a form of delusion. The idea is that by taking a signal with little or no entropy in it, puting it through an encryption function some how “magicaly” gives it entropy is not understanding what the difference is between entropy and a mathmatical method that is fully determanistic but gives the illusion of randomness. To see this think of encrypting a text message made of ten thousand characters, if the characters are all “A” then most would agree the text has little or no entropy if the message is a book then most would agree there is some entropy, however with a good encryption algorithm and mode as an observer of the output of the process you would not be able to tell the difference between the two messages unless you knew what algorithms were used the keys and any Initialisation Vectors (IVs)

[3] It would take to long to go into but all sequential logic especially certain logic circuits such as flip flops and latches have “metastability” issues that can cause indeterminacy at the output or “soft latch ups” thus various techniques are used to reduce this issue to near zero occurrence in human time scales. See these lecture slides for more info,

https://web.stanford.edu/class/ee183/ee121_win2002_handouts/lectB.pdf

[4] All physical entropy sources have a lot of issues when it comes to true entropy. Primarilly they have a significant “signal to noise” issue in both the time and frequency domains. What you want is the “true entropy” signal that is in a great deal of noise. The noise can be considered to be that which is easily predictable and that which is not as easily predictable. The latter is “faux entropy”. There is a fairly easy demonstration of this with “sampling” a clock signal with another clock signal of different frequency using a D-Type latch. If you look at the Q output of the latch with an oscilloscope close in the changes look atleast chaotic if not random. However as you adjust the oscilloscope such that the time base is about the same as two cycles of the difference frequency between the two clocks at the latch inputs you can see the output is quite determanistic because what you have is a sampled sinwave of the difference frequency. The only potential entropy is in the “jitter” on the zero crossing points of the difference frequency. That jitter consists of the true entropy you are looking for and mainly determanistic “system noise” that modulated the clock signals either in the oscilator, amplifier, sampling process, or following logic. To see how dificult it is to see the true entropy you are looking for use just one oscillator and divide it down using two frequency dividers (counter followed by a divide two latch) where the counts are mainly prime. The signal looks almost the same as that of the signal using two independent oscillators of approximately the same frequency. That very slight difference which you probably can not see without careful filtering is your “true entropy signal” hidden in that “faux entropy noise”.