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Physiology & Medicine / Re: What ideas are being implemented to curb the NHS winter crisis?

« on: Yesterday at 10:36:59 »

It's been done a thousand times before, and AFAIK even trialled in Scotland where health and social services are better integrated. IIRC my wife was a district nurse attached to an NHS GP surgery but closely integrated with the local SS team. Great idea, as long as HM Govt ring-fences local government budget provision for social services, and imposes reasonable service standards for home delivery. Said wife later became a hospital-based discharge coordinator: same problem - it all depends on social service funding.

Unfortunately successive governments have thought it preferable to give taxpayers' money to incompetent bankers and railway "consultants", ignoring Rule 1 for survival: don't feed the sharks!

The joy of being a virus is that you can mutate and evolve at random, so this week's vaccine is for last week's epidemic. Sensibly, viruses don't kill all of their hosts (having more intelligence than humans, who happily shoot buffalo and pigeons to extinction and turn prairies into dustbowls). The way to contain a viral epidemic is, surely, home nursing. Have I mentioned that before?   

One way to prevent long-distance transmission of airborne disease is to reintroduce smoking in public transport. Not sure what the figures are for trains and boats, but a non-smoking airliner only requires 3 air changes per hour, which saves a lot of fuel compared with 5 - 7 cph if smoking is permitted. AFAIK Air Malta was one of the last majors to permit smoking - worth checking their heath records!  Also bring back "slam door" trains with compartments (you can't infect more than 7 others on a given journey) and fresh air ventilation. Judging from current experience on Diamond Princess, and previous fun with norovirus on ships and Legionella in hospitals, recirculating air conditioning is not merely "green" but a neat way of rebalancing the ecology by reducing the human population.

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Technology / Re: Is there an alternative to the HS2 version of Stephenson's Rocket

« on: 18/02/2020 22:02:45 »

Yes, it happens a few times a year, particularly at high speeds,  but not specially with maglevs.  I think Steve's idea has much to commend it: why spend a ridiculous sum on a marginal improvement to a third-rate system when you can invest in a radical new technology that actually competes with air travel over land.

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Physiology & Medicine / Re: What ideas are being implemented to curb the NHS winter crisis?

« on: 18/02/2020 16:51:05 »

I'm pretty sure the NHS is working on it. Problem is that it is thwarted at every move by government incompetence, demographics, and customer expectations. Fiddling about with GP contracts and refusing to integrate health and social care (because acute health services can be privatised and run at a profit, but everything else is a guaranteed loss) has resulted in an almost complete absence of home care or GP appointments, so every sniffle and scratch goes straight to A&E "just in case". No integrated home care, and no funds for local authority social services, means you can't discharge anyone over 75 for fear of them either dying from untreated postoperative infection or turning up at A&E tomorrow and going through the mill again. Add a touch of bad weather, some crowded, overheated trains, and a seasonal obsession with alcohol, and a service that might just work on a sunny day, collapses. 

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Plant Sciences, Zoology & Evolution / Re: If we can’t replicate life in a lab, how could it happen randomly?

« on: 17/02/2020 16:58:32 »

Why did life only generate once?

[ What evidence do you have for this assertion? Life as we know it probably evolved on Mars, the conditions elsewhere in the solar system seem favourable, and there are at least 40 000 000 000 000 000 000 000  potentially observable solar systems that we haven't begun to explore. Beware of the Kruger-Dunning syndrome. 

We don't see new life crawling around the tidal pools.

Possibly the best place for it to evolve, but (a) there's lots of competition in a tide pool and (b) there's something like 8 000 miles of coastline to explore in the UK alone. The chances of anyone finding a new bug and proving that it had no organic ancestors are pretty small - we haven't catalogued all  the "known" species yet.

Why does life have only one manner of replication? Is DNA the only answer?

I think the answer lies in the question. If you define life as being the effect of replicating DNA, there cannot be another.

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Physiology & Medicine / Re: How should an unfit driver behave

« on: 13/02/2020 00:23:36 »

Call the police and ask them to come and arrest you.

Not the safest or most socially responsible option.

Assuming there is a hard shoulder, you will have your vehicle parked on it for at least 30 minutes, then two, with coppers walking about and blue lights flashing for another 30 minutes, all of which is an accident waiting to happen as other marginally less drunk drivers start rubbernecking (local copper informed me, after I had been rearended in a motorway queue "the biggest cause of accidents is other accidents"), then a convoy to the cop shop which will be some way off the motorway, then a near--sober police doctor and duty solicitor will be called from their beds.....all potential hazards when the sleep-deprived gentlemen drive to their offices the next morning. And meanwhile you have occupied the time of two traffic cops and the custody sergeant whilst others are creating real mayhem on the roads and in town. Then you throw up in the cell and soil Her Majesty's Blanket, and weeks later occupy a whole raft of Court officers and three magistrates who have better things to do and probably a solicitor who has trained and studied for five years so he can stand up and protest that a person he has never actually set eyes on is a model citizen who had One Moment of Misjudgement but threw himself on the mercy of the law which he respects, and a Crown Prosecutor who hasn't read the case notes will describe you as a habitual drunk and menace to society who should be incarcerated for gross stupidity....and everyone will be thinking "For gawdsake why didn't he just keep stumm and sleep it off in a field?"

If there isn't a hard shoulder, you and some innocent trucker will also tie up an ambulance crew, A&E staff, duty radiographer and anesthetist, and a couple of surgeons,  and enjoy the full panoply of intensive care and NHS catering, before the law takes its course. Unless you are hit by a bus, of course.

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New Theories / Re: How does a massive human body stand on feet weak toes ?

« on: 27/01/2020 09:16:40 »

It is biological that this phenomenon appears only to humans.

And several other bipedal species from Tyrannosaurus to chickens. And all quadruped mammals walk on fewer toes than bipeds.

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Physics, Astronomy & Cosmology / Re: Do the electrons that generate an electric current come from the wire's atoms?

« on: 23/01/2020 09:17:51 »

Bloch's magnon is a quasiparticle with no electric charge, so whatever happens to them, they won't constitute an electric current.

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New Theories / Re: Would Lenz's law refined apply to a gravitational field?

« on: 22/01/2020 19:09:29 »

No evidence AFAIK. Remember the "laws" of physics are descriptions, not prescriptions.

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Question of the Week / Re: QotW - 20.01.12 - Why doesn't a woman's body reject sperm as a foreign object?

« on: 16/01/2020 16:12:30 »

Most of it is indeed rejected most of the time.

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Physics, Astronomy & Cosmology / Re: Is it possible that human body has its own physical laws ?

« on: 14/01/2020 07:48:31 »

Our body with all its components exists, something exists must be made , why we can't build and explain how the body made? then we don't now the process of building it , and we don't know the laws behind that , right?

As with rockets and bridges, there's a huge gap between knowing (physics) and doing (engineering). In the case of living cells, the entire planet worked for about 1,000,000,000 years to produce the first one, entirely by accident, and didn't leave any notes as to how it was done. It will be a supreme (if pointless) triumph of human intellect and ingenuity to make another, and whoever does it will almost certainly be accused of "playing god" and crucified for it.   

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Physics, Astronomy & Cosmology / Re: How fast will a rocket cool down once outside the atmosphere?

« on: 06/01/2020 22:25:26 »

Huge difference between Concorde flying at 40 - 60,000 ft for several hours and generating aerodynamic lift (hence also drag) as it did so, and a rocket spending less than 4 minutes in the atmosphere with no aerodynamic lift component and hence minimal drag.

Thermal mass and diffusivity are crucial to determine surface temperature. You can regard the heat input to the rocket as being an adiabatic pulse lasting about 2 minutes as it accelerates from Mach 1 to Mach12, so the eventual surface temperature depends on the rate at which the sonic compression heating power is dissipated from the leading edges to the whole mass of the vehicle. The nose cone is in any case dumped in the cruise phase so as long as the surface doesn't melt and run over the separation joints, it doesn't really matter if it gets a bit hot. This is quite different from a low-level missile or supersonic aircraft, where the bits at the front are important throughout the mission!

I think the primary reason for "throttling back" is to maintain a reasonable g force. If you are burning at n tons/sec initially to get off the ground (g=1), the rocket weighs n tons less every second so g will increase if you hold a constant burn rate. 3 - 5 g is manageable but higher accelerations severely impair crew performance, hydraulic reliability and ultimately structural integrity of minimal structures like a LEM. The difference between early "slam-bang" manned rockets and Saturn was described by astronauts as "an old man's ride" - I gather the Soyuz is equally civilised.

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Plant Sciences, Zoology & Evolution / Re: What is life?

« on: 31/12/2019 10:38:39 »

Why life exists is essentially asking "what is the origin of life?". It has nothing to do with intention per se.

To answer the question "what is life?" it may be relevant to know/question how it came into existence / what could explain it (why it exists).

The answer to "why" is "because....." or "in order to...."

The answer to "what" is "that which...…"

The answer to "how" is "since A causes B...."

Colloquially, we sometimes use "why" to mean "how", but you have to be more pedantic in a science forum, lest the argument be hijacked by philosophy. 

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Chemistry / Re: Why does my black powder mixture not burn?

« on: 30/12/2019 10:10:52 »

Try weighing your components, 70/30 w/w. The density of charcoal is not reliable, so a mix by volume is unlikely to be optimum.

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Physics, Astronomy & Cosmology / Re: Can the whole universe be considered a quantum system?

« on: 29/12/2019 13:02:08 »

I think it all depends on what you mean by "the same". Suppose we polarise the unpaired spins of a sample in a homogeneous magnetic field. Then with respect to the field, they are all in the same state, but because they are in different positions in the sample, they are in individual states. If we reverse the field, the spins do not all flip at the same time but follow a relaxation curve.

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General Science / Re: Can I turn Pixie into a diamond?

« on: 17/12/2019 17:44:20 »

Definitely a good process. You can deposit the "diamond-like carbon" on all sorts of substrates. I had a brief flirtation with disposable DLC-edged scalpels and trochars for use in MRI and CAT scanners - much more use than a rock in someone's earlobe.

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General Science / Re: When do YOU die in a many worlds interpretation?

« on: 06/12/2019 23:14:43 »

You have a death sentence anyway. It's just that most people don't know when or how it will be enacted. There is no evidence of the existence of other you's - "many worlds" is just a mathematical tool for assessing probabilities.

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Physics, Astronomy & Cosmology / Re: What happens when both slits are observed by in the double slit experiment?

« on: 09/11/2019 07:37:47 »

QM theory says no amount of measuring of a system will allow you to predict it.

Be careful how you state this. The test of quantum mechanics is not merely that it explains obvious quantum phenomena like line spectra, but that it scales to classical mechanics for large assemblies. And it does.

The wave function of a billiard ball is negligible in comparison with its apparent diameter, so for all practical purposes (e.g. potting the black) it is adequately predictable. But its structure, mass and elasticity are all calculable from quantum mechanics.

Indeed the "measuring" test isn't fundamental to QM. The classical model of bouncing a photon off an electron sort of illustrates the problem of measurement influencing the measurand, but masks the inherent indeterminacy of Heisenberg's statement that Δp.Δx ≥ h.

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Physics, Astronomy & Cosmology / Re: What happens when both slits are observed by in the double slit experiment?

« on: 08/11/2019 19:10:08 »

When we fire bullets (particles) at a slit they will, as you said, go through one slit or the other and form the 2 slit shadow we expect.

No! There is a calculable probability that a bullet will, in effect,  "go through both slits". As Eddington said, "If a student of physics should fall through the floor and find himself in the room below, he would not be surprised but mildly elated at having observed an extremely rare phenomenon."

That's what I meant by quantum mechanics scaling up to continuum physics at a mesoscopic level. So far, it's only been demonstrated with large molecules like buckyballs, but the maths is sound.

You can work the model two ways: either map an enormous number of parallel universes onto one timeline to get "now", or wait a very long time in one universe for everything to happen. Problem is that once you get beyond 60 carbon atoms, the numbers become ridiculous.

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Physics, Astronomy & Cosmology / Re: What happens when both slits are observed by in the double slit experiment?

« on: 07/11/2019 13:25:35 »

You really need to abandon the particle/wave duality business to make progress in physics. Photons, atoms, indeed everything, behaves as it does because it is what it is, not what you choose to model it as.

Quantum mechanics gives us an excellent predictive model of the behaviour of very small things, but doesn't say what they "are". Continuum mechanics gives us an adequately predictive model of mesoscopic entities that allows us to build houses and fly to the planets. The important question to ask of quantum mechanics is "does it scale up to the observed behaviour of radio waves and billiard balls?", which it does. Likewise the test of relativity is "does it scale down to Newtonian mechanics if v<<c?", which it does.

The problem with poking a particulate photon through two slits is manifold.

1. Only half the energy can go through each slit, so the wavelength of the emerging "photons" will be twice as long - but it isn't!   

2. If we rotate the receiver, we will alter the time at which the two bits of photon reach it, so they can't interfere - but they do!

Equally, however, if we presume a wave passing through both slits, all the interference peaks will occur simultaneously, however weak the source (down to one photon at a time) - but they don't!

It gets even more exciting when we pass "solid" objects like electrons, atoms or buckyballs through a diffraction grating. There's no way they can disintegrate and recombine at the receptor (if we move the receptor further away, where does the recombination happen?  If we remove it altogether, have we created partial electrons wandering through space?) but they form the predicted pattern!

The answer: believe what you see, and choose the most appropriate model to predict what you might see next time, but don't be surprised if something else happens - it just means your model was incomplete.

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Cells, Microbes & Viruses / Re: Who is older?

« on: 25/10/2019 17:43:14 »

Legally, your birth date determines your age, because this is precisely known, and even determines the precedence of twins. Medically, your date of conception is what matters, at least for the first few weeks of life.