The problem with health advice is the space is completely polluted with all kinds of grifters relating personal anecdotes as fact, hucksters hawking pills and gym-bunnies yelling about stuff that only affects people like them.  It's all a bit of a mess and there is a lot of mis-information out there.

Some notes ...

* You need extra protein if you're trying to build muscle following exercise
 -- This is true, but you don't need anywhere near what they will tell you and protein bars/shakes/yoghurts/whey powder are likely unnecessary!  In order to maintain muscle mass, nutritionists recommend 0.8g of protein for every kg of weight - so if you weigh 75kg then you should be consuming 60g of protein a day.  In order to make gains you want a tiny bit more than this but not a lot.  Hitting that much protein a day turns out to be pretty easy - there is plenty of protein in grains (such as wheat) and the like, and loads in meat cheese and nuts, and the added protein bars / yoghurts are unnecessary.  *Maybe* if you're vegan you might struggle, but if that's the case, eat more beans of various types.

* X diet is a miracle and you will lead to significant weight-loss
 -- All diets that aim to lose weight are proxies for calorie counting.  I don't care what it is, whether it's slimming world or weight watchers or slim-fast or keto or caveman or whatever the latest fad is right now.  There's no easy way, it is going to take willpower and you will feel hungry occasionally (at least without pharmaceutical help).  That said, I think it is useful to switch diets around as it means that you pay attention to what you eat (and therefore hopefully eat both better and less!).  It's a massive pain in the arse, but I would strongly recommend that you do a full calorie-counting diet for a while (2-4 weeks, example https://docs.google.com/spreadsheets/d/1KSpSIzbg1Zb231qd1DawTsEIcJ98UyeBJCnyU142kJ0/edit?usp=sharing ) so that you inform yourself better on what is good and what isn't (please make sure you have adequate protein intake too and note the exercise calories as negatives!).  The broad recommendation to maintain weight is 2000 kcal for women and 2500 kcal for men - so aim for less than this but bear in mind you'll have to figure out what works for you personally.

* You should eat 5 fruit and veg a day
 -- Fruit and Veg are both great in terms of micronutrients, fibre and also help fill you up (100g of apples is less calories than 100g of beef).  So fruit and veg are *great* but the 5 a day thing is very much governments trying to encourage people to eat more rather than any scientific basis - in other countries it's 3 a day and others 7 - it's much more "what can we get away with recommending" rather than any particular scientific basis.  That said, given that one of the things you're trying to do here is to adequately provide yourself with micronutrients, then as wide a variety as possible is better.  So if you eat your 5 a day but it's always the same fruit and veg every day, then this is not as good as say, eating 3 a day but different ones every day so 21 different fruit and veg a week.

* "Breakfast is the most important meal of the day"
 -- Cereal companies came up with this.  It's largely horse-shit.  Breakfast cereals are not great nutritionally - you know why they all have added vitamins and iron?  Because they were found to be so nutritionally deficient as to not be worth consuming - so they now advertise that they are fortified with vitamins and iron - but that's mainly because they started from such a low bar in the first place!  If you want breakfast and want to be healthy, go for something with high fibre (Bran Flakes, Muesli) rather than very sugary (crunchy nut cornflakes, sugar puffs)

* Nuts are good for you
 -- I mean, it depends on what you're going for, but generally no.  They are high in protein, but they are also extremely high in saturated fat.  Macadamia nuts are basically lumps of saturated fat for example.  Delicious but not healthy!  Some nuts are better than others - e.g. almonds and hazelnuts look decent, and pecans and macadamia look particularly bad!  Read the labels!

* Fat is bad for you
 -- Fat is extremely calorific but as part of a calorie controlled diet, it's perfectly ok to have some and fat is where the flavour is.  Generally, unsaturated fat like olive oil and sunflower oil is fine, saturated fat like butter and most nut oils isn't great as it will raise your cholestorol, and trans fats found in deep-fried food is really bad for you (even worse on the bad cholestorol and linked to various cancers).

* You should walk 10000 steps a day
 -- Whilst almost all exercise is good, the 10000 steps is completely unscientific and arbitrary - along the lines of "what can we get away with recommending" rather than having a scientific basis.  Exercise is very good for you not just physically but mentally too.  So definitely do some.  And do something that you enjoy or can tolerate because then you'll keep it up.  But walking 20000 steps isn't twice as good as 10000.  Variety here is key - so if you do a bit of swimming, or yoga, or weightlifting, or callisthenics or football rather than focusing on a single thing, this is going to be much better for you than just doing more walking.  I think there's something to be said for doing exercise in a non-controlled environment too - so running outside is better for you than on a treadmill because outside you'll be subtly training other muscles because of uneven terrain, obstacles and the like (downside: higher injury likelyhood)

* X is the best form of exercise
 -- There is no one good form of exercise.  Swimming is non-load bearing which means it's very difficult to injure yourself, but is very upper-body focused.  Running is extremely intense but it's awfully easy to injure yourself and does little for the upper body.  Yoga is great for the joints but doesn't get the heart rate up enough.  (I think rowing might be close to the ideal personally but it's awful hard).  It's best to do a variety of different exercise.

* A glass of wine is good for your health
 -- Absolute garbage.  Shouldn't stop you though, just because it's bad for you physically, it can be great mentally!

* Exercise will make you lose weight
 -- Without careful dieting, exercise can often make you gain weight, as muscle is denser than bone.  You should *absolutely* be doing exercise when trying to lose weight but your primary goal wth exercise should be to feel good/maintain muscle rather than lose weight.  You kind of need to do exercise whilst trying to lose weight because otherwise you will just lose muscle and bone rather than fat, which is absolutely not what you want.  See the calorie controlled diet thing above - make sure you are getting enough protein and are doing a reasonable amount of exercise (including some resistance training) - that should mean you lose *fat* not muscle/bone.   Having said all that, it is deeply depressing how few calories exercise actually uses -- want to make up for an extra bag of crisps that you ate?  Yeah, that'll be 20 minutes running, half an hour of swimming, or an hour's walk.  So you should absolutely exercise when losing weight to try to maintain muscle and bone BUT don't rely on it to actually help you lose weight much - what you eat is generally more important (unless you're like a polar explorer or something).

* You should take supplement X
 -- Probably not.  If it's recommended by your doctor then definitely, otherwise probably not.  Largely down to de-regulation in the US, the supplements industry is a seething mass of scammers, mis-information and poorly regulated products.  It's better in the EU (where you likely can't sell much apart from vitamin supplements anyway).  Maybe if you're Irish take some Vitamin D due to the lack of sunshine, or in India an iodine supplement, but if you have a reasonable diet then supplements should be unnecessary.  If your diet is particularly low in fruit and veg, maybe a vitamin supplement can help.

* Should I pay attention to dieticians or nutritionists?
 -- nutritionists.  You need precisely zero qualifications to call yourself a dietician, so ignoring any and all dietician advice is probably safest.  nutritionists are typically doctors with a speciality, or related to sports where it is very important to know your stuff rather than a shady quack whose job it is to hawk you pills.  So listen to a nutritionist's advice, not dieticians.

* Should I worry about ultra-processed foods ?
 -- Probably yes.  The EU has far better regulation of the additives that can be put in food than the US, so in the EU most food additives are broadly safe - the same cannot be said for the US which is much more lightly regulated.  Some examples of ultra-processed foods:  Most shop-bought bread, ready-meals, yoghurt, ice-cream, cured meats, some cheeses.  That said, the majority of ultra-processed food is FINE.  Don't listen to the idiots who think sultanas are ultra-processed (they're grapes treated with grape acid.  Big deal).  We all have busy lives so a bit of ultra-processed I think is ok, just don't try to completely live off a diet of chicken nuggets, white bread and ice-cream and you'll be ok.

 A complaint about Tescos

Here in Ireland we effectively have just a handful of supermarkets to choose from -- Tescos, Dunnes, SuperValu, Lidl, Aldi and maybe a couple of other over-size corner shops like Centra and Spar.  Tescos have gone absolutely all-in with their clubcard over the last few years, but the price with a clubcard is the normal equivalent price in other supermarkets - and if you don't have a clubcard it will be much more expensive.  For all other supermarket cards, you effectively have to just download the app and start using it.  With Tescos, you need to provide a whole bunch of personalised information for them to be able to track you and sell your data to other people as well (I assume linked either via phone number or email).  I also have other gripes with Tescos, namely

• Their weighing scales at the automated checkouts are so strict they seem badly misconfigured.  On several occasions I have placed a single can of diet coke on there only it to tell me it's the wrong weight.
• The local Tescos in town is downstairs, out of range of mobile phone networks, and as such, you can't use the clubcard app.   The nearest Tescos near my house closes 8pm most evenings and doesn't really have much that my local SuperValu doesn't have.  And the SuperValu is nearer and similarly priced.  Also, why is the clubcard scan buried like 4 levels deep in the app - the design is awful.  Compared to the very simple SuperValu €5 off €35 which seems great for a loyalty card.
• The meal deal is fine if you're looking for calories.  If you're on a diet, the meal deal is not great, and you can get better food elsewhere for less than the meal deal. 
• Tescos has very little unique stuff that's worth a special visit and generally the quality is higher in either Dunnes or SuperValu, and either similar price (with clubcard) or more expensive in Tescos.  For me, the only things that I go into Tescos for are:  Tinned new potatoes (they only seem to have these in stock roughly 20% of the time anyway), Toffee cheddar (only available christmas time and wasn't available at all last year), Flat gammon steaks (which I have like once a year).  Puff pastry (for some reason my local SuperValu never seems to have any)

 The thing is, if Tescos is not your nearest supermarket and you don't currently have a clubcard for whatever reason, I can't see why people would start using Tescos instead.  Without a clubcard, everything is outrageously priced, like M&S prices for slightly better than Lidl quality.  So why sign up in the first place - just go to a different supermarket.

 

 

 

 

 The Rest is History Drinking Game

  

Dominic mentions Wolverhampton

Tom mentions cricket

Dominic says "Blimey"!

Tom says "sacral"

Dominic says "poor form" or "disappointing behaviour" 

Tom describes someone as a "lad" (a massive lad, etc.)

 

 

 The Simplest Diet

 Assign a value of -1, 0 or 1 to every meal.  Add these up for the day.  Add one for alcohol in the evening and one for a snack in the evening.  Subtract one for significant exercise.  Aim to get zero every day.

 

On Intelligent Life

There's constant search for extra-terrestrial intelligence but could intelligent life have developed on earth in the past?

First let's define intelligent life - dolphins are intelligent, as are ravens, as are octopuses, as are wolves.  There are two things that make homo sapiens seemingly unique amongst intelligent species of today - tool usage and communication.  Whilst other species have tool-using abilities (ravens, octopuses, the great apes) and rich communication (dolphins and other cetaceans), no other current species combines these two characteristics, and it's allowed humans to dominate the planet.  It's unlikely that these two characteristics haven't occurred together in the same species at some point in the earth's evolutionary past.

So, could the kind of intelligence that we're looking for in the SETI programme have existed in the past history of earth?

We need to look at the artifacts left by our civilisation - if humans disappeared tomorrow, what artifacts of our culture would remain for future species to discover?   The world without us covers this in significant depth.  The plastics we've created should remain as a thin but detectable layer of strata though it's probable that a microbe will evolve to eat most of the synthetic polymers we produce.  The other significant relic of human civilisation is that from the nuclear industry - nothing in nature concentrates isotopes the way we do and these will leave a significant signature that should be relatively easy to detect - indeed the discovery of the natural nuclear reactor at Oklo was initially thought perhaps to be the product of an ancient culture.  The satellites placed in high earth orbit will probably be there until the sun expands to a red giant, but are extremely hard to detect.

Our culture also produces objects of high durability yet are likely difficult to detect over geologic time - glass and ceramics will eventually be ground to a powder or eroded; stainless steel cutlery and bronze sculpture lasts an incredible amount of time yet will eventually become an unusual deposit in rock strata; Gigantic engineering achievements such as the Suez canal or the Hoover dam would silt up and be gone within a few hundred years.

It's interesting that if we were looking for a civilisation equal to our own in the distant geologic past, we would not be looking for evidence of cities (eroded to unrecognisability in a few millennia), agriculture (reclaimed by native species within decades) or even the spike in atmospheric carbon dioxide (could be due to extremely large volcanic eruptions instead).   Instead, we'd be looking for buried bronze sculpture, rubbish dumps, and radioactive waste.

On balance, it's unlikely that a society as advanced as our own has existed on earth before - though the discovery of inhuman bronzes, or unpleasant waters would certainly change that.

Dark matter and an electron-poor universe

This started out as a fantastic idea but quickly I realised that it just didn't stack up!  But as a physics idiot, I'll try to demonstrate here how to first set up and then destroy your own theories instead of going down the pathological science route!

Hypothesis

The universe as a whole contains far more nuclei than there are electrons.

What it explains

Dark matter - without electrons the only interactions between nuclei is via the repulsive electromagnetic field between the postitively charged nuclei and should they be travelling fast enough, the strong force.  The lack of electrons means no spectral absorption lines, no bonding means little to no clumping together of matter, and nuclei are massive enough to avoid being "hot" dark matter like neutrinos.

A bit more detail/Research needed

When Big Bang recombination occurred, the universe went from opaque - where a free electron would capture any passing photon - to transparent - where the universe had cooled enough to bind electrons to nuclei.  If there were a large excess of electrons in comparison to the number of nuclei the universe would not become transparent (it would be "foggy" whereas we see the opposite).  If the number of nuclei was the same as, or was in excess of the number of electrons around then we get transparency.  Existing theory suggests that the universe is electrically neutral [need cites] - i.e. the number of nuclei matches the number of required electrons.  [need to check if there's evidence]

The problems

Why does the local area have an excess of electrons?  (possible answer: It's related to the fact that the local area is a supernova remnant).  (Maths/reading required).

Ramifications

Early stars composed of primordial BBN materials will be electron deficient.  Whilst this doesn't affect fusion, it will affect electron degeneracy pressure at the core of stars - thus no helium flashes/carbon detonation due to the lack of free electrons.

Testable Predictions

In areas where BBN primordial abundances are observed, the amount of lithium and beryllium should be lower than the theory predicts.  This isn't because less lithium is actually produced by BBN, it's because one of lithium's electrons sits in the second shell requiring a lower temperature for the electron to bind, making it more likely that H or He would capture that electron beforehand leaving a bare lithium atom that doesn't show it's absorption lines in the CMB.

I don't think we can test the overall positive electrical charge of a galaxy (this theory suggests that anything with a lot of electron-less nuclei around then there would be a large net-positive charge) - there's not enough for it to interact with?

Decay Channels

I started looking in detail at lots of decay channels - but it's actually very simple when you consider conservation of charge.  Essentially, every proton converted to a neutron (e.g. in diproton He2 decay to deuterium H2 but other decay channels as well) would emit a positron to conserve charge - this positron would then annhilate with an electron producing gamma ray energies.  Very generally, for every neutron you get around here (i.e. earth) then a positron was created in the process that then annhilated with an electron.

Follow Up (Hypothesis goes bang)

Somebody has actually come up with exactly the same theory too but I can't see them addressing the "why is it not like that round here" problem.


This paper points to the universe being electrically neutral during BBN, and in addition to this, we would see different results in the very early universe regarding expansion - it'd be influenced more by electromagnetism rather than gravity.  We'd also probably see large scale electromagnetic effects from such a postively charged proton cloud that would wash-out any gravitational effects - and these would probably be observable.

And finally, the most important question "why is it not like that round here" has been utterly trounced - in large supernovae that would produce the elements that we see on earth, we would actually expect vast numbers of electrons to be destroyed in the process - one electron destroyed for every neutron created.  Instead, we have an excess of electrons around here.  This does lead to a further question - given that large stars and particularly type II supernovae will destroy a vast number of electrons by annhilating them with positrons - and we live in an area where a type II supernova occurred (because we have lots of elements > He around here!) - why do we still have charge balance?

SSL is broken

There's a magic padlock icon that appears in your browser indicating that you're secure - and that nobody in the middle can read the traffic - and it's probably broken.

Certificate Authorities

The problem is not that the encryption scheme is broken - the public/private keys structure is fine and has been demonstrated to be secure, it's that there are way too many certificate authorities and a single mistake or deliberate outside party interference (for example, from governments) can allow a man in the middle to decrypt all traffic, read what's being sent to and fro.

There's a lot of certificate authorities - most are telecoms companies or related to a national government in some way, and all of these can issue certificates for any website.  In addition, it's possible for a certificate authority to issue a wildcard intermediate certificate to an organisation that does exactly the same.

The way an SSL certificate is validated is that when your browser contacts a secure site, the site returns their certificate and a chain up to a valid root certificate.  As soon as the browser finds a root certificate that it already knows about then it assumes it's all fine and the connection is secure.
The problem is that if one of these certificates is compromised, or abused in some way by the company owning it, a man in the middle can read all of the traffic in between.  This is not a hypothetical situation - it's happened already - with Turktrust, with Nokia, and with DigiNotar.  What's worrying is there are lots of certificate authorities and it only takes one of them to be incompetent to render traffic insecure.
 
There's also other instances of https traffic being decrypted with varying levels of validity - company firewalls occasionally do it by using their own CA authority (which requires modification of each client computer), and anti-virus software with parental controls can also do this.  Needless to say I believe these should simply not be allowed.  By installing parental controls (on some anti-virus systems) you are effectively giving permission to your anti-virus company to view your bank details, and I don't think most people would be happy with that.

Just as concerning are government security agencies.  Whilst the examples above are the result of incompetence, security agencies could go to the certificate authorities directly and request a wildcard certificate - which would probably be granted.  But this means that the security agency could happily decrypt all traffic and nobody would be able to detect that they are doing so.

When a root CA is found to be compromised in some way, revoking it is a deeply painful process that can take months whilst each browsers list of root certificates is replaced. Even worse are embedded systems which may never have their CA list refreshed.

Whilst most companies applications won't change, I would recommend that all banking and financial transaction apps use some man-in-the-middle prevention - namely, EKE encryption to detect that this is taking place and prevent data being transferred.  Whilst some banks do this already, Natwest does not and it really should!

Quantum Computing

A little further ahead, we have quantum computing, especially with the new we-think-it's-quantum-but-we're-not-really-sure D-wave systems.  Using Shor's algorithm and a sufficiently powerful quantum computer, all root certificates could be compromised (again, probably by national security agencies) and again, it would be extremely difficult to detect that a man in the middle attack was being perpetrated.  There's something the certificate authorities could do now to combat this, and that's use an algorithm that can't be solved using Shor's algorithm - i.e. not prime number factorization or the discrete logarithm problem - there's other ways but these don't seem to have any take up right now by certificate authorities.