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Messages - Sprool

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26
The risk of contracting some type of cancer is about 30%, thats nearly one in three of us will contract cancer in some form at some stage. I would say its impossible to detect if someone has ever contracted cancer from mere background radiation, since other influences such as UV from sun will have had to be ruled out first, and very few people manage to avoid sunshine during their lives. I would assume that background radiation is negligible and insignificant in comparison.

27
I like Richard Dawkins views that all these creatures are just shells for the DNA that lives within them. It is the genes that continue to evolve and the best ones at surviving will be available to reproduce further generations. Ants and mosquitos are all highly successful packages for the genetic data within them, they each seek a different niche in the ecosystem. Their purpose is to survive.

28
Einstein's laws of relativity state that light moves at a set speed relative to the observer and independant of the speed of the object that emits it. Consider 2 spaceships both travelling at c/2 away from eachother. One shines a torch at the other from the rear window - would it be seen? Since the light from that torch moves at the speed of light as soon as the photon is emitted, even though the torch is moving away at c/2. The light, travelling at c will catch up with the other spaceship moving the opposite direction.

29
Geology, Palaeontology & Archaeology / Re: What rock?
« on: 15/03/2012 15:28:52 »
looks to me like a small disc of some type of copper alloy?

30
Chemistry / Re: Can we separate soap from oil?
« on: 15/03/2012 15:25:17 »
The oil and surfactant can be separated using conventional flocculants.
The soap is not magnetic - the soap contains tiny Iron particles that are attracted to a magnet. Those are two differnt things. This does not mean it will make a magnetic film.
Whether the small nano-clumps of iron within the surfactant can retain some magnetism on their own would need some further research.

31
any small traces of detergent in your mouth will be washed away when you eat and drink, they will get mashed to bits in the stomach full of hydrochloric acid and any surviving traces will be washed through your guts, eventually finding their way back into the drainage system via your toilet bowl. At least they may in some small way contribute to keeping the bowl clean

32
that would be one heck of a fairground ride.

33
Chemistry / Re: What makes ocean water salty?
« on: 12/03/2012 15:56:24 »
Salt in the ocean comes from the land. The elements that make up salts, such as chlorine and sodium, started out in rocks. Water and acids eroded the rocks, and rivers carried the elements into the sea. The oceans usually contain 35 parts of salts for every 1000 parts of sea water. This is lower in some places where there is a lot of fresh water coming into the ocean. It is higher where the Sun is very strong and evaporates more of the water. When all the water is gone, the salts are left behind as solid, white crystals.
THe water cycle takes evapotated water from the sea (leaving the salt behind) and depositing it as rain over the land masses, thus rainwater is not salty, so rivers are initially not salty but will continue to carry with them traces of salts from the land the flow over, back into the sea again.
 

34
two extrusion tubes, one inside the other, with suitable cross-section profile to make the desired design, both forcing different coloured dough out at same rate. Same as the excellent diagram above, but all in linear arrangement to maintain optimum pressure.

35
I think this is a really interesting question, and I am in agreement that religion as a social and anthropological function comes about to improve aspects of community within a tribe - to help set acceptable codes of conduct, to improve tribal bonding, give a cause and a morality to the group which all helps improve survival chance. This happened at the most fundamental level when humans were evolving into social group creatures, with sun worship, rituals giving thanks for food availability and the birth of new tribe members.
In this respect there is no superstition or spirituality but an evolvement of group conscience as an evolutionary step.

36
Chemistry / Re: What makes my books go \
« on: 12/03/2012 12:43:00 »
Surely it can't be rust? There needs to be iron and moisture and oxygen fro rust to form. As far as I know, Iron is not a normal ingredient in paper. Are there higher than normal traces of metals from use of recycled pulp stock?
Is it photo-oxidative effect the paper sizing, or discoloration due to growth of mould or similar?

37
I am surprised that an extra amount of yellowness is perceived as being healthy or more attractive. Yellow can be sallow skin or jaundice. Western caucasian culture perceives a healthy golden tan to be desirable, but thius is rooted in socio-economic reasons rather than dietary. On the opposite side of the argument, the Indian nation now spends millions of dollars a year on skin lightening cosmetics as a paler skin is perceived to be a sign of wealth and higher caste. This mimics the earlier historical times in Europe when pale skin meant good breeding and wealth - it was the poorer folk that had to work on the fland every day gaining a ruddy, tanned complexion.
Despite all this, the stronger flag for desirability is symmetrical features and a smooth, even, unblemished skin, the sign of healthy youth. This can over-ride the overall level of skin pigmentation as a signal.

38
Technology / Re: Particle beam technology could this work?
« on: 09/03/2012 16:32:28 »
... inhuman to use lasers as defense weaponry do to the radiation it gives off and the trail left behind, and if a person was struck by a laser it would seal the wound, and the person would die slowly of radiation poisoning ergo it must be hi intensity plasma.
Think you have been reading too many sci fi adventure comics. Where does radiation poisoning play a part with laser technology? If you cut someone's head off with a high power laser beam it is rather unlikely that all the blood vessels would be adequately sealed shut during the blow. My bet is that he doesn't die slowly of radiation poisoning, he dies pretty quickly of having his head severed from his torso.
What are you planning?

39
Chemistry / Re: How can I make a home gamma ray gun?
« on: 09/03/2012 14:49:24 »
Have you tried www.makeurowngammagunat home.org?
Theres a lot of useful starter info there for enthusiasts like yourself.

40
Physics, Astronomy & Cosmology / Re: Earth Gravity anomaly
« on: 08/03/2012 12:14:37 »
THere is also geological theory of salt domes - large chambers of less dense rock bouyant in the mantle causing uplift above them, that can explain some apparent disparities between mountain masses and local gravitational field. Sometimes the field is stronger than average, sometimes less, depending on the local geology.

41
Whilst circumventing the Plimsol line, Sir Francis Einstein discovered that water at 10C has a density of approx 999.7g/l, whilst on heating up to 99C, the density reduced to 958.4g/l. This makes good sense when you visualise all those extra energy water molecules dashing about everywhere bumping into stuff.
Thus that eveng he mused that hot bottles of fixed volume would have nearly 4% less mass liquid in it than a cold one even though he hadn't accounted for thermal expansion coefficient. From this was derived the invention of the potato which strangely has almost exactly the same density as his own head.
I rest my case.

42
That CAN'T be true ! / Re: Ancient Theory of the Universe.
« on: 07/03/2012 16:20:24 »
if it is an expanding baloon inside a bottle, what's outside that bottle? Is there anyone waiting to take the cap off and drink it?

43
Physics, Astronomy & Cosmology / Re: Earth Gravity anomaly
« on: 07/03/2012 12:24:28 »
All the gravitational anomolies I can see are adequately explained by the differnces in density of the underlying rocks, into the deeper mantle and in the crustal region. That is my 2c worth - hotspots exist in the crust due to the underlying geology and laying rise to plate tectonics. Together with this are the differnces in mass and density of the underlying rocks since the crust and mantle are not homogeneous.

44
Physics, Astronomy & Cosmology / Re: Earth Gravity anomaly
« on: 06/03/2012 12:50:09 »
Quote
When mountain is created using plate tectonic like Himalayas it would have higher density, but that density is also limited, but if mountain is created using volcanic action the density of that mountain is low, under sea mountain ranges near Philippines, Malaysia and Indonesia would have less density compared to a normal sedimentary rock from a normal earth region.
Let6s bring this back down to earth again before you start on dark matter. Are you saying that sedimentary rocks are denser than volcanic rocks? That simply is not true as a generalisation. If you are basing your whole anomaly argument on one fact that is not correct then you do not have a logical case.
Sedimentary rocks are mostly quartz and clays, their density is determioned more by their packing than by theuir chemical composition. In general expect 1.8 - 2.4g/cm3 for most sedimentary rocks.
Igneous and metamorphic rocks will normally have densities above 2.5 and be determined more by their chemical composition rather than their packing. Normally expect 2.5 - 2.8g/cm3 but igneous rocks high in iron, lead, etc (pyrite, galena minerals.....) densities will push up to 5 and above. While these can be found in sedimentary rocks, by their very nature many will have been weathered, oxidised and washed away, so again density is more about particle packing and sedimentary rocks are in general more porous = lower density.

Another point you make is about mountains being under water and gravity being measured at the surface. While the average depth of the oceans globally is about 4km, the radius of the earth is about 6300km, so thats only 0.063% of the earths radius. Not enough to be of much significance.

You should add a further option to your poll: Gravitational anomaly - there isn't one.

45
Physics, Astronomy & Cosmology / Re: Production of Light
« on: 28/02/2012 12:30:09 »
is that why pond water only ever comes halfway up a duck?

46
i think origami's post belongs in the Deja Vu thread?

47
calcite tends to be a lot more milky in appearance, quartz is normally more translucent. Calcite is much softer (Moh 3 compared to quartz 7)

48
Technology / Re: cold fusion
« on: 23/02/2012 12:13:08 »
what's the copper diode for?

49
General Science / Re: Are mist and steam the same thing?
« on: 22/02/2012 13:08:13 »
Not-so-simple explanation though technically correct, since most people will have come across 'steam' every day as hot gas + condensing water vapour = white cloud, whereas not very many people will ever have seen 'pure' steam without the accompanying droplets. (if its invisible, no-one can see it...)

50
In his marvellous book "The man who mistook his wife for a hat", Oliver Sachs hinted at a process which could explain deja vu, which consisted of a small delay in the brain processing memory and interpreting events, thus the eye could picture a scene and the brain register it in the memory banks, then a moment afterwards the interpretation of the scene could take place whereby the 'live' image was compared to the initial one already preserved in the short term memory only 1/10 of a second beforehand. The brain would thus see the live scene as the same as the memory and you would get a feeling you had 'been there before'.

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