Posts by Mike Hewson

11) Message boards : Cafe Einstein : LPTP #8... moving ahead, but slowing down (Message 133551)
Posted 8 days ago by Profile Mike Hewson
I found this neat George Westinghouse bio, and one which demonstrates a type of airbrake system. I kinda luv these old style tutes. While I think my Trainz does a good job of simulating all that, you get to do the real thing Phil ! :-)

David, that is a great fact sheet! Our clever Prof Bob's at the state health department could readily do worse ( our local boffins are really good at planning their own superannuation and I often learn more from the Mayo clinic website ). It points out a little emphasised feature - many enteric ( gut ) viruses and the respiratory ones are really cousins. They share modes of transmission particularly. In the old days there was the 'gastric flu'. Prior to say WWII children would often go to school with a handkerchief pinned onto their upper chest garment. Such simple measures have been forgotten, alas modern medicine has made us lazy with personal hygiene. Personally I use a hand rinse product between every consult ( even those without direct contact ) and generally don't offer a handshake. It can be hard to find a handwash that won't give you a skin issue with constant use ( FWIW I use J&J's Angel Blue Microshield ). Air travel gives me the willies with bugs, at 35K feet you can't open a window to get non-recirculated air, there's 500+ people onboard and they can't all be well !

Cheers, Mike.
12) Message boards : Cafe Einstein : LPTP #8... moving ahead, but slowing down (Message 133536)
Posted 9 days ago by Profile Mike Hewson
This has an interesting, and possibly counter-intuitive, implication here : all else being equal, a given steam engine will be more efficient in cooler circumstances ( eg. winter, night-time ) than hotter scenarios ( eg. summer, day time) ! :-)

Another interesting fact. Steam engines produce more tractive effort the faster they run, as opposed to todays diesel-electric, which produces more tractive effort at low speed.

It can be quite frustrating for a modern train crew. As you slow down while climbing a grade your wheels will lose traction from too much power and start to slip, further reducing your speed. Sometimes we get more traction at a LOWER throttle setting which can reduce slippage.

Absolutely. Traction is where the action is ! This is a fascinating and typically non-linear area of study - the friction of railways. You need some friction to produce a traction force parallel to the tracks and thus move around and about. No point otherwise. You don't want too little as even if you do get going you want to stop at some place and time of choosing. Furthermore you don't want too much as that saps the useful energy available. That leaves rather a bit of a goldilocks and three bears scenario.

If you will permit a digression ( and I hope I'm not telling you how to suck eggs as it were ). It turns out to be extra-ordinarily difficult to rigorously derive from deeper principles ( eg. quantum mechanics ) why it is even approximately true that the frictional force along the rail is linear proportional to the ( reaction ) force normal to the rail.

Certainly if one assumes that as true, then that easily explains why slipping is easier on slopes as some of the vehicle's weight is not acting in the normal direction, pushing harder on the track. Thus when going up a steeper grade the normal lowers, the friction lowers and thus your traction may be lost. That cuts both ways ie. running downhill it will be harder to pull up as friction is needed there too.

Now the Swiss got into those ratchet arrangements on steep climbs, a third/middle rail that meshed tooth & cog with a driving component on the car. It turns out that, up to a point, 'ordinary' friction might be seen as similiar. Both the wheel rim and rail upper surface are in close detail like rugged mountain ranges, so one could model as 'cog to cog' coupling mesh-like and giving purchase. But as we are not talking of a ( nano- ) engineering match of specifications here, then inevitably some 'lifting' or displacement in the normal direction has to happen. Roughly speaking a higher force compressing the two surfaces together will negate that up and down travel, the 'cog teeth' remained engaged, and there ( somewhere ) lies the origin of the normal force influencing the friction parallel to the interface. Evidently the detail is horrendous here for any seriously realistic model. But this also sort of explains why heat typically lowers friction, as the rumbling of the micro landscape on either side ( due to randomly directed oscillations of the material's lattice ) will tend to add to those normal displacements that encourage slippage between the surface profiles. Hence hot brakes can be very less effective, we pay much attention to cooling them by various means, though friction adds to the heat content of the components to boot.

Over longer timescales the peaks and valleys of these profiles tend to wear to flat ( as heat increases especially ) and entire slabs of this micro landscape are tossed away. Abrasion and destruction of the pieces. Things become smooth, the 'cogs' are stripped of their teeth, and parallel grip reduces. Oddly enough rusting of steel may assist to maintain friction here, as while a rail becomes shiny smooth with wear, ongoing rust will pit and roughen the surfaces without any special attention. The jagged profiles regenerate in the oxidising atmosphere that Earth has. Eventually entropy wins ..... :-) :-)

Cheers, Mike.

( edit ) Now there's an idea! The UN's WHO has asked ~ 200 researchers ( well outside of the UN's normally close & cuddly circle of 'accredited experts' ) about what to do with Ebola. Gee, who would have thunk it possible? No doubt they wanted to not appear to be incompetent ( as an overlay upon their standard state of actually being incompetent ). Fortunately ideas abound, but for US researchers one key obstacle remains : will the FDA not prosecute them for fast-tracking vaccine release by avoiding the normal time-consuming ethical analysis pathways typical of that category of products ? Stay tuned folks ...... and let's see if the WHO can get up to speed with that old logic that relates smoke to fires.
13) Message boards : Cafe Einstein : LPTP #8... moving ahead, but slowing down (Message 133534)
Posted 9 days ago by Profile Mike Hewson
[quote]Mike, I think you have that right. A much more modern arrangement in current Russian service is the CM-2 type, which attacks the snow at the front, and moves it to the back of the lead machine by a sort of conveyor mechanism. This dumps the snow to the first of series of gondola cars, each of which has a bottom conveyor mechanism to move the snow on to the next.

This page has lots more pictures and detail. The one that surprised me is that the last gondola can dump snow track side. So maybe the concept is that the gondolas are just temporary storage to get past confined areas where trackside disposal is not suitable.

That makes sense. On a mountainside you just toss it off as you can and probably it doesn't matter much where it lands, but on flat plains there may be an amenity problem with stuff adjacent to the track. Hence storing and sorting as it were. They also scrub and clean around the tracks to ground/sleeper level to be sure. I note the Ukraine has substantial rail and rail-side infrastructure around it's grain production.

Our local valley effort is here. While the line had gone out of regular use some 30 years ago, the fires of 2009 destroyed much of the bridging - that being of wooden construction. The ultimate aim is to rehabilitate around 10 miles of track across gentle undulations at the valley floor. There is one tunnel about 150 yards long.

I'm in my first year of volunteering and am ready to qualify as an operator on Chicago Surface Lines 3142, a 1923 Brill streetcar.

Go for it! :-)

An auger fed coal fire is a beastie, eh? It's amazing that Nick Carnot worked out a few major law of physics ( conservation of energy, entropy trends ) simply by thinking about steam engines. He wrote that in his own terms of course, but he was exactly right. The key expression is for maximum efficiency of a heat engine :

1 - T_c/T_h

T_c is the absolute temperature of the 'cold spot' ( the environment generally for steam trains ) and T_h is the temperature of the 'hot spot' ( eg. the firebox ). You never get 100% ie. you always lose some available energy as heat ( so that's the entropy statement ) and the very best efficiency for any hot/cold spot differential is for fully reversible devices ( a theoretical abstraction only approached in the limit of real devices ). As one can't do much about T_c then a really well fed firebox will burn quite hot, not only outputting more power in toto but a greater fraction converting to motive power when all the sums are done.

This has an interesting, and possibly counter-intuitive, implication here : all else being equal, a given steam engine will be more efficient in cooler circumstances ( eg. winter, night-time ) than hotter scenarios ( eg. summer, day time) ! :-)

Cheers, Mike.
14) Message boards : Cafe Einstein : LPTP #8... moving ahead, but slowing down (Message 133523)
Posted 10 days ago by Profile Mike Hewson
I also note that 'trainspotting' has been re-labelled as 'railfanning' which makes me far more comfortable about my mild to moderate obsession with trains. :-)

I remember the first steam train I saw, about age 10 ( which I think is the ideal age to induct children to rail fandom ), being rotated on a turntable, shunting and the like. It was big and black, choofed alot and had that funny combo smell of burnt coal and steam. I would place a copper coin on the track in advance of the train and inspect the results later. For me this was high experimental science, or alternatively I was easily amused ! :-)

I quite avidly inspected the train's underbits, and of course the key question was reciprocating to rotary motion. The thermodynamics came later. One late afternoon - when the show was over, so to speak - I just looked at it for about an hour before wandering home. I later had dreams about it, I was that sort of kid.

Now I clearly remember seeing that very same train - I am quite certain of the 'K 183' designation - some twenty years later. I believe it is a sister train to the one first listed on this page here. Let's hope it is still doing something other than sitting in some local park rusting.

In Novosibirsk I think the snow goes where the lady on the right is pointing : into it's belly. I think it just eats snow. :-)

Actually there's some hatches on the lower lateral face of the chomper, I could conceive of the snow shooting to the side from there if they were opened.

Cheers, Mike.

( edit ) Bless whom-so-ever wrote this Wikipaedia page :

Until 2002, K 183 was also operated by Steamrail Victoria. On 13 October 2002 this locomotive was involved in a serious level crossing accident with a B-double semi-trailer near Benalla, Victoria, derailing after impact. Tragically, three people on the footplate died in the collision. The locomotive was extensively damaged and is currently stored out of service. As of 2013, the locomotive is still receiving insurance money from the accident in which will go towards the future restoration of the steam train to its former glory.

( edit ) I've discovered a new remedy for a sore throat. Normally I advise good old honey and lemon drinks. Quite nice. My novel treatment, if that fails, is topical alcohol. :-)

( edit ) If I've understood my research correctly the Newport Workshop designed, built, maintained and finally retired the K-class. One thing I see with railways - which is very marked I think - is how their history parallels that of the communities it serves. Obviously you might say. But thesedays, what with being all global, connected, electronic and the like, that style of perspective is lost. It's not the only industry that has that strong character eg. Bethlehem Steel or copper mining in Montana, and I think I miss the sort of cohesion in society that I felt when younger ie. local industry-centric communities. Naturally that's the sort of whimsical codswallop emitted by older codgers like myself, but I still think that accounts for serious levels of nostalgia with trains. :-)

( edit ) You're quite right David, having less intelligent ( or less privileged ) parents will enhance the survival of the offspring. The clever ones may yet be educated by the death of their children, as to date no immunisation-contrary argument has explained the death of children by the illness ( because immunisation-contrarians never discuss death ). No doubt the paediatric medicos are killing the children in hospital as part of a conspiracy against the parents, with the microbiology being the cover story. One suspects more than a tad of marijuana in the relevant burbs here, THC is an outstanding cognitive fragmenter, virtually any proposition seems great after two decent sucks on the bong, and the paranoia comes for free.
15) Message boards : Cafe Einstein : LPTP #8... moving ahead, but slowing down (Message 133507)
Posted 11 days ago by Profile Mike Hewson
@archae86 : Joe Salk ( one of the polio vaccine pioneers in the 1940's + 50's ) actually expressed the concern that if the vaccines were to be as successful as hoped - and they have been - there would come a generation when the prevalence of the given illness would be so low that people would not really know what was being protected against. This prophecy has come true in as little as three generations.

For instance the triple antigen ( diptheria, whooping cough and tetanus ) immunisation rate in kids ( from the demographics of tertiary educated parents I might add ) has plummeted. So our regional children's hospital has opened a dedicated ward for infants with whooping cough, with several dozen new cases per week and some tragedies. This has deeply disappointed the paediatric care community. The cause is simple : presently, young highly educated people will not take instruction under any circumstances. Alas this hasn't reached wider acknowledgement due to news outlets being shy of telling their subscribers that they might be idiots ie. truth aside, you don't sell copy by criticizing motherhood and apple pie ( especially to articulate people with plenty of disposable cash ). When polled upon the topic their heads are revealed to be full of all manner of trendy egocentric social commentaries, faux* science and almost no true biological information resides. Contrast this with our many immigrants who come from a range of shocking contemporary circumstances elsewhere : they cannot believe that people who live in what is effectively Nirvana can be so utterly stupid. I have lost more than a few clients as a result of me suggesting that ( to obtain irrefutable proof ) they visit the local cemetery to read the little gravestones ( the cause of death is nearly always chiseled in ) in the older section. The comeback on this is a drive to (re-)immunise the grandparents of newborns who may not have ever been immunised ( or the decades have diminished the primary course ). That generation often has living memory of what we speak of and is commonly capable of taking advice. This may form another, admittedly de-referenced layer of shielding for the neonates, and just might flip the young parents in their views. Believe me, the conversations I've had can be quite surreal. If I were to suggest that a newborn child ought be cast upon freeway tarmac then the parents would be horrified. They don't appreciate that non-immunisation is in reality an equivalent risk.

In any case David is right, let's lighten up ! Mea culpa ..... :-)

I found this great piece on youtube describing the clearing of a rail line in the Sierra Nevada during the early 1950's after a prolonged blizzard season. What I really liked was the steam train with this big fan gizmo on the front which clears the big snow drifts. It also reminded me of a cooling fan with shroud for a graphics card ! :-)

Cheers, Mike.

* The issue here is not lack of studies by Professor Bob & co, but lack of studies done by Prof Bob & co that include meaningful metrics that refer to processes occurring in this universe. Chatterboxing by referral to specious 'authority' has replaced traditional effective scientific inquiry ie. displaced or arm's length psychosis.
16) Message boards : Science : Quantum, Light and Stuff (Message 133491)
Posted 11 days ago by Profile Mike Hewson
I haven't forgotten this, it's just that I'm having an issue or seventeen with my web hosting provider for illustrations etc.

Cheers, Mike.
17) Message boards : Science : "Save Lick Observatory" campaign (Message 133489)
Posted 12 days ago by Profile Mike Hewson
I always have that trouble ie. just which universe am I in ? I perpetually think that I am in the wrong one, but i don't know it's number. :-)

The trouble with Everett's ( no collapse ) interpretation of QM is that while he never originally mentioned other universes explicitly, his perfect deductive sequence from the mathematics certainly implied same. That hurled the cat amongst the pigeons and remains one of the QM conundrums that is still politely ignored today.

As for Lick : anytime someone wants to make me a billionaire I would be more than happy to fund them !

Cheers, Mike.
18) Message boards : Cafe Einstein : LPTP #8... moving ahead, but slowing down (Message 133486)
Posted 12 days ago by Profile Mike Hewson
For many years, I refused to get a flu shot because one year I got it and promptly got full-blown flu. I finally let my doctor talk me into it again a few years ago and I've been okay.

Ah. Alot of the trouble with the flu vaccines have been the sales pitches. That is, some perspective is needed. Some moderating observations if I may :

- remember that the manufacturer wants units shifted, so each year is always going to be expected to be the worst ever! That has been stated for each of the 29 years I've been practising. Now every week I may expect to win the Lotto, and so that hopeful optimism is always true, but the actual win is not.

- hence overseas there have always been so-and-so many people slain by the flu. This comment prior to winter primes the fears - it's coming, are you prepared? Which is only partly correct. Even though some have suffered from influenza in their last hours, if a causative factor in their decline it is nearly always in the presence of very substantial co-morbidities eg. advanced age ( 90+ ), illnesses that sap immune system vigour eg. diabetes, and chronic respiratory complaints to name but a few. Influenza is rarely the sole cause, so that otherwise young and fit people have almost nothing to fear ( c/w much larger daily risks of existence ).

- it's the ( secondary ) bacterial pneumonia as the follow on after the weakening of the respiratory linings that harkens the grim reaper from yonder.

- if you are in a caring role for those at risk then yes you should consider the 'herd effect' of you not being a vector. Hence I have it yearly and really it is not for my own sake, even though I may incidentally benefit.

- the vaccine is a 'false attack' and thus trains the immune system to recognise a particular variety and store that experience away for later ( what is formed is a monoclonal line of cells 'tuned' for that agent ). Thus if/when you meet the actual virus your immune response will be immediate, and not some ~ three days later in the de-novo/unimmunised instance. As with all infections it is a race b/w the germs establishment and progression within you vs your immune response to kick it's butt.

- typically full protection takes a number of weeks to establish after a given vaccination. Thus if you get a flu shot at the height of the season you may get the flu first before effective vaccine response. One may be led to blame the shot ie. post hoc ergo propter hoc.

- the younger you are the better your immune system is, thus your immune system stimulation from the vaccine may approach that expected from the illness itself. While the symptoms may compare the vaccine effects do not carry the morbidity of the viral infection itself.

- vaccine production almost always involves ( chicken ) eggs somewhere, so any trace protein from those may be present in a tiny amount in the product. If you have an egg allergy problem then consider this.

- it's the outer viral coat that the immune system responds to. Fortunately the flu has a limited number of permutations available. Admittedly that's several hundred permutations of sub-unit combinations, but still fewer than a Rubik's cube. It is possible with prolonged/recurrent yearly immunisation to get partial immunity for combinations not yet encountered.

- year to year there is typically a 'drift' in the latest and greatest viral coats ie. this year's is approximated by last year's. About once or twice per decade there is a 'jump' ie. no resemblance to last year's.

- the vaccine is trivalent ie. targeting the three most prevalent varieties. Vaccine production does take at least four months after specification and so there may be movement in the wild viral characteristics during that phase. So this April's flu-shot is based on last November's information.

Cheers, Mike.
19) Message boards : Science : "Save Lick Observatory" campaign (Message 133468)
Posted 12 days ago by Profile Mike Hewson

It seems to a typical stoush b/w those that do versus those that count beans.

Them there is fightin' words.

It always shocks me to learn that those that "do" feel that those that "don't" owe them whatever beans they care to consume.

We know what the outcome is when too many beans are consumed.

Touche! We are assuming alot here ie. what 'seems' and there in lies the rub with such matters when information is highly de-referenced. As you say budget nitty gritty transparency would address many concerns. I agree in that if you want to raise a general subscription/shareholding then such diligence queries are fair game. ;-)

@MAGIC : a clear case of quantum entanglement! Were we subject to correlated cosmic ray annihilation photons way back whenever ? :-)

Cheers, Mike.
20) Message boards : Science : "Save Lick Observatory" campaign (Message 133463)
Posted 13 days ago by Profile Mike Hewson
(and Mike and I appear here at the exact same time )

LOL, in all my time here that has never happened before. Yep, great minds think alike ... and fools never differ! :-)

{ ... but seeing that Unix/Linux is granular to milliseconds, I wanna see the server log. :-) }

Cheers, Mike.

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This material is based upon work supported by the National Science Foundation (NSF) under Grants PHY-1104902, PHY-1104617 and PHY-1105572 and by the Max Planck Gesellschaft (MPG). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the investigators and do not necessarily reflect the views of the NSF or the MPG.

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