sethoflagos

I have been pondering the idea of trying to create a hydrogen gas combustion engine for a while. Using electrolysis to split hydrogen and oxygen to use water to fuel the engine. However, I do not have the automotive back ground or lots of experience as I am still a undergraduate. Creating stacked water and purification, the pressure and seals needed to inject the gas into the engine as well as other process I have looked into but have no way to test. If anyone has any details to add so I can add to my notes or help test. It would be amazing. Thank you for reading

I don't think many reading this would be in a position to 'help test' anything here unless they happened to be working within an organisation developing this technology. And they're hardly likely to divulge their proprietary secrets to a stranger in an open forum are they?

Pressurised hydrogen is not a material you can safely handle in any garden shed development programme. As mentioned above, keeping it contained is particularly difficult and way beyond the capabilities of the inexperienced layman. If you really want to get into the field, probably the only practical way is to get a good mechanical engineering degree with a hefty loading of thermo and materials science, and apply to one of the automotive companies working in this area.

Having said that, there's no harm in a bit of theoretical research via google (much more effective than asking questions on an open internet forum). Start with https://en.wikipedia.org/wiki/Hydrogen_internal_combustion_engine_vehicle and follow the linked references where ever they lead.

Btw We generally don't produce hydrogen in bulk by electrolysis. Steam reforming of natural gas is far more cost effective. But you don't want to try that in a garden shed either.

Perhaps if we think backwards.

There are a few universal clocks.

The exact here and now will vary, but every observer in the universe will be able to pinpoint a moment when the average CMB temperature in their observable universe matched the triple point temperature of helium for example.

Going back in time there will be a series of similar thermodynamic milestones which one would presume ultimately to converge on a common state at a time of universal causal linkage when all clocks could be synchronised. Even if that synchronisation was at an asymptotic approach to zero.

Or maybe I'm just talking cojones. Wouldn't be the first time.

It's conceivable that astronomers all over at least the local area of our observable universe are watching the highly unstable star Eta Carinae and waiting for it to go bang. Which should give us all a really nice fireworks display. (I have a small hope but possibly in vain).

Not one of them, whatever their distance and relative speed to Eta Carinae or anything else; whether they're observing from an orbit within an event horizon; whether they have a long garishly coloured scarf and call themselves Doctor; even if they're boldly going where none have gone before; will see this event run backwards.

The Second Law will not be denied, and all observers shall see order beget chaos.

It all springs from there.

If the object is submerged in brine, you maybe shouldn't be expecting to see the typically scaly orange rust.

If it's sufficiently anaerobic, the Schikorr reaction may well be in play which may give a degree of passive protection via a magnetite surface layer. The 'thin black film' you mention is also suggestive of this.

Errors involving sound-alike word (homonym) substitution are more agreeable to me...

You're going to hate this. I'm sure you meant to type 'homophone' there/their/they're!

Just to show that your advice has yielded concrete results, here's one of the pretty pictures that comes out of it.

Which indicates that a simple approximate model deviates from the fully analytic solution (that's taken me maybe a month to derive) by about 1 degree of phase shift here and there. May as well not have bothered!

Thanks again anyway!

Seth

 

Why then would we expect something with no intelligence at all to assemble any live cell or entity?

Trillions of random experiments every second for a couple of hundred million years?

Seems as good a way as any for turning the staggeringly improbable into practically a foregone conclusion.

We see the evidence of this process all around us, And no evidence whatsoever for anything else.

That seems to be what most authors suggest, I just can't quite see it.

 

Take a farm for example. Leptospira can live in mud or water for weeks,....

Is this typically true for the UK?

Examples of European outbreaks quoted by Wasiński B, Dutkiewicz J (2013). "Leptospirosis—current risk factors connected with human activity and the environment".Ann Agric Environ Med. 20) seem to correlate with periods of continuous high temperature (>18 C) coupled with high rainfall. This is situation normal for the tropics but not for the UK, If a cool night is enough to kill off any bacterium not kept warm by a mammalian body, then standing water is not going to remain infective for very long.

.............. if I ever have a hellish or distressing near death experience someday..........

........you will feel absolutely elated to have survived it.

Or totally unmoved because you're a bit of a psychopath. Or a bit guilty because you made it and others didn't.

You won't know until you've been there.

One thing is for sure. Tormenting yourself with the thought of the possibility is (I was about to say 'really stupid') irrational. It will happen one day, but maybe only once, and you may not be aware of it. If you are, the pain will probably be fleeting, followed by everlasting peace. Why spoil the precious time we all have between now and then worrying about an eventual certainty. Immortality probably gets a bit boring after a while anyway.

In Special Relativity

Relativistic Doppler Effect has formula

 

[math]f=f_0(1+v)\gamma[/math]

 

[math]\gamma=\frac{1}{\sqrt{1-v^2}}[/math]

 

Which is also equal to

[math]f=f_0\sqrt{\frac{1+v}{1-v}}[/math]

 

with v normalized to 0...1 (divided by c).

 

With v near 1.0 (or near c, without normalization), gamma is so high that regular photons at visible spectrum (average 2.32 eV green photon), could be blueshifted to more than 1.022 MeV (0.4-0.5 million times than green photon)

 

In such situation there is starting pair production, of matter and antimatter,

and positrons are starting annihilating with body of spacecraft, damaging it and destroying.

So Warp Factor 8 is a bit of a no go? Unless we travel into the void, which seems a bit pointless.

Your subconscious knows your deepest anxieties and will happily play them out for you under some (fortunately for me, fairly rare) circumstances.

I've had a couple of serious scares in real life, but the adrenaline surge seems to focus you on how best to react (guess this probably varies by individual). Also I tend to get this strange curiosity for 'Ooh, I wonder what happens next'.

But dreams can take all that precious control away from you (trying to run through a lake of bitumen springs to mind). Now it gets really scary!

This one has perplexed me for some time.

Scenario:

Travelling close to light speed towards say the Andromeda galaxy.

If we were to look directly towards our destination, would we be totally frazzled by intensely blue-shifted radiation? (Assuming we didn't have a really good pair of Ray-Bans)

 

I don't see from where this "ever increasing "apparent" vector in the Westward direction" could come from.

 

If you are speaking about the atmosphere drag, a very simple vectorial computing gives us (in 2 dimensions)

angle (with the southward direction) = inv tangent (1670/1000) = 59°

speed = SQRT(1000² + 1670²) = 1886 km/h which would make the plane crash.

 

Whatever it is, the atmosphere drag is not a solution, because if the plane flies straight ahead to the equator, the atmosphere displacement would mean a lateral wind which very fastly would make it to crash.

You are not being specific about what you mean by 'south'

There are essentially two extremes to choose from:

1) Earth based, following a line of longitude.

2) Astronomically based eg following the stars as waypoints.

Either way you will experience significant lateral forces (in the real world at least).

In the earth based case, it is the coriolis 'force' (or rather 'effect') which manifests itself as an apparent acceleration westward as you move further away from the axis of rotation - hence the need for left rudder as mentioned by John Cuthber.

In the astronomically based southern heading you will encounter an ever increasing sidewind tending to drive you eastwards from the air which is broadly coupled to the earth's rotation. You would need serious supersonic capability to beat that one.

Doesn't lightning cause water to dissociate into hydrogen and oxygen not by so much by electrolysis but by thermolysis?

As I understand it, above 2000 C water starts splitting and by 3000 C over half of it is dissociated at equilibrium. So the 25,000+C core plasma temperature generated in the return stroke should easily be enough if only for a split second before it cools and the plasma recombines.

 

That's what for are computers.. To compute

 

If some application has not sufficient built-in features (or they're too slow), you can always make your own application (with little GUI or command-line).

You will spend time writing program, and get result quickly,

instead of spending time calculating everything on paper.

 

From time to time, it's good to make some computing manually, though.

I'm quite familiar with solving systems such as the one I'm working on now, by numerical methods on computer (since the late '70s). That's bread and butter for some of the work I've done in the past, and indeed it is how I would normally have approached the system I'm currently working on. Pretty standard for hyperbolic PDEs. Clients pay for results in a cost-effective time-frame, not the beauty of the mathematics.

But to have fully analytic solutions readily available to really quite complex systems is pretty mindblowing!

I found this paper quite fascinating.

http://www.nature.com/articles/srep00263

Could competition for very rare and limited sources of biologically available molybdenum have put a serious restriction on multiple contenders for the first life, as this paper seems to infer?

Isn't this is another flavour of the "irreducible complexity" argument?

Probably. The intention being to ensnare you in the logical paradox of stating that (for instance) human blood circulated in the veins of a non-human ancestor. And by recursive reasoning, that your non-human ancestor was therefore in fact human. And the house of cards comes tumbling down.

It's a sad fact that for certain sections of society, there is little point in responding to such questions with logic and reason. Because your adversary (and it is an adversarial exchange) will not respect those rules.

What is being exploited here, as mentioned by Phi for All, is the inherent logical weakness of the taxonomic system in handling a continuum of variation.

If the question must be answered, maybe one strategy would be to reply that they were all simultaneously jury-rigged from the corresponding parts of the final missing link. It's a naughty argument. But it sidesteps the paradox, and they deserve no better.

It really depends on what you want to remember.

If you want to improve your memory of names and faces, you practise strategies for learning how to associate names and faces - there are books on this sort of thing.

If you want to learn how to commit long poems to memory, you start by memorising short poems, repeating them daily until they stick. Then gradually work up to longer poems.

There are three golden rules to this sort of activity.

1) Don't waste time practising something that is of no direct use to you. Practise only what you want to be able to do.

2) Practising stuff you can do perfectly and practising stuff that is way in advance of your abilities are both a waste of time.

3) You have not completed mastery of a particular level until you can execute it perfectly.

I suspect that practising remembering playing cards will only help you learn how to remember playing cards. If that's what you want to do, then joining a bridge club or a poker school may be more fun. I can remember card for card some bridge hands I played 30-odd years ago. Ask me my own telephone number and I've to look it up.

Actually I only brought up the Bantu expansion to elaborate on your haplogroup thesis. Specifically to elaborate that haplogroup L3e carriers are not necessarily as fair skinned (and also because we have a bit of an idea about their expansion). In contrast, the evidence suggest that populations that have stayed or originated recently near central Africa do have darker skin, which coincides with the UV/folate hypothesis. I.e. so far even in the confines of this thread we have evidence that pointing to darker skin color.

Under these assumptions the hue of the skin will be primarily driven between the needs of folate conservation and vitamin D3 synthesis. Considering the latter not to be limiting (and we find also evidence for this in lit) being darker would be a selective advantage (which follows the argument of Joplin's research).

Isn't there some new thinking about the significance of pigmentation to dermal D3 synthesis?

It's a moot point for us since childhood rickets remains fairly common in Nigeria and the Federal Government would very much like to eradicate it - the means and will are there.

But the old assumption that it was due to low intake of dairy products seems to be questioned by work such as Signorello LB, Williams SM, Zheng W, Smith JR, Long J, Cai Q, Hargreaves MK, Hollis BW, Blot WJ (2010). "Blood vitamin D levels in relation to genetic estimation of African ancestry".Cancer Epidemiology, Biomarkers & Prevention.

........However, if we really want to use current populations as a kind of proxy how skin color may have appeared as a function of UV radiation, I refer you to Jablonski and Chaplin (2000, J human evolution) where they have gathered UV data and compared it with skin reflectance (as a measure of skin color) and clearly found darker complexions in higher radiation areas. Of course, the values won't fit perfectly as access to folates, clothing etc. will have modulated the selective pressures somewhat from what they used to be. But looking specifically at near-equator populations I think it is safe to say that our ancestors will have been rather on the darker rather than the lighter side.

This is all very good informative stuff CharonY.

Going back to the OP, what struck me was an apparent underlying assumption that (and I paraphrase quite wildly here) 'If you come from the Albertine Rift your skin colour will be precisely RAL 8028 Terra Brown.'

Now I know no one used those precise words, and yet there seems to be a great deal of resistance to any suggestion from me that there may well have been significant variance in the skin tone of our ancestors. Whether as much back then as there is in tropical Africa today, is neither here nor there.as far as I'm concerned. But any suggestion that there was zero or even insignificant variance smacks of a less than scientific agenda.

As for the Bantu tribal group, yes I know a little, having been married to one for nearly 15 years. But then the Bantu expansion was a mere 3,000 years ago, coinciding with their discovery of iron smelting. Before that, their range was quite restricted. So extrapolating a stereotypically modern Bantu physiognomy back 200,000 years to being characteristic of all of humanity at that time seems a little far-fetched doesn't it?

I know these visual arts people have to pick something to go on, but surely we realise that the artistic license here may well exceed the scientific justification.

Or does it?

I was talking about spectroscopy- not evolution.

The fact is that black + white skins lose heat by radiation at pretty much the same rate because, in the far IR where people radiate, water is black,

So, why the stuff about my lack of understanding- when you were the one who missed the point?

The point wasn't missed, it was ignored as (IMHO) non sequitur.

Maybe a more constructive way of blowing my hypothesis out of the water would have been to refer me to something like 'Spectral Emissivity of Skin and Pericardium' (Steketee). From which I learn that the emissivities of pale and dark human skin in the mid-IR are not only equal, they are both phenomenally high. Much higher than water, higher even than black rubber and charcoal.

Now that is food for thought!

For those interested in the depths of depravity from whence this abomination originates

https://twitter.com/realityrandd

http://www.realityrandd.com/

How about the example given for haplogroups L3, E, B from the National Geographic site on the human genome project.

An Algerian subject which one would expect to be subject to very high incident levels of UVB.

Regardless, it is almost certain that our ancestors were very dark-skinned.

I was fine with you up to this final point. But if moderate 'darkness' yielded sufficient advantage to balance African level UVB flux over the somewhat lower fluxes of elsewhere, then where is the driver for 'very dark'?

'Very dark' is at least in modern times a minority characteristic in Africa both locally and as a whole.

The fact that the male generative organ is particularly well designed for the removal of previously deposited fluids from the vicinity of the female generative organ is a pretty good guide to the comings and goings of our ancestors.

Conspicuously different to the chimp strategy and seems weighted towards gaining maximum reproductive advantage from an infrequent opportunity. Make of that what you will.

Mind you, the shenanigans that went on half a million years ago are not necessarily a good guide to current practice.