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Author Topic: HOw often are experimental conclusions flawed because of wrong cause/effect?  (Read 7013 times)

Offline annie123

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The kitchen science expt. with the candle /water in a jar  was explained by talking about CO2, heated gases etc etc..The water rose about a fifth into the jar and this was explained when I first saw this expt. in school years ago as showing that air contained 1/5 oxygen which was used up by the candle flame burning. Apparently this is not why the water rose that much yet it looked convincing and fitted the existing facts about air/oxygen content.SO, how often could it happen that a result fits a known fact but isn't actually what is happening?


 

Offline damocles

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I think it is the sort of thing that can, and does, happen quite frequently. But it is usually a matter of an explanation or an interpretation or a "theory" fitting a result or fact rather than the observation fitting "existing facts".

Example 1: Air pressure: Sir Isaac Newton thought about air pressure, and thought that its elastic behaviour must be due to forces of repulsion between particles of air. We now know that there are no such repulsive forces, and that the air pressure is due to fast moving gas particles colliding with the surfaces where the pressure is detected.

Example 2: Antarctic "ozone hole": many scientists initially believed that the low levels of ozone in the Antarctic springtime were due to an upwelling of low-ozone surface air in polar regions caused by the sunrise. This was thought to push aside the air in the ozone-rich stratosphere to lower latitudes. An increase in ozone at sub-Antarctic latitudes was indeed observed at that time (But it had also been observed every springtime since before the ozone hole appeared).

They thought this a much better explanation than "novel and exotic chemistry" in the stratosphere. But a programme of direct observation in the Antarctic stratosphere firmly established that the "hole" was indeed largely due to unusual and unexpected chemical reactions in the Antarctic stratosphere.

Example 3: My own post-doctoral experience: "Isotope effects" provide a very good tool for exploring the rates of chemical reactions. Substances with heavier isotopes, most notably deuterium replacing hydrogen-1, have the same reactions, but tend to react more sluggishly. Comparing rates of particular reactions for hydrogen-1 or hydrogen-2 compounds provides a lot of information about reaction mechanism.

In the late 1960s and early 1970s the mass spectrometer was applied to these problems. For the first time, relative rates of reaction could be compared to better than parts per thousand. Usually rates of reaction are only measured accurate to about 2-5%. As well as hydrogen/deuterium, this also opened up the field to comparison of isotopes of carbon, oxygen, and chlorine. Chlorine has two naturally abundant isotopes -- three quarters is chlorine-35 and one quarter is chlorine-37. When ethyl chloride is heated up (mass 64 and 66 for the material containing Cl-35 and Cl-37 respectively), it reacts to lose hydrogen chloride. But when the experiment was done, the mass 66 to mass 64 peak ratio in the mass spectrum actually decreased, indicating that the heavier Cl-37 material was reacting faster. I was a theoretician, and my project was to find a reason why the heavier isotope was reacting faster in this case, when it "should  have" been reacting slower! I worked for many months on that problem, and every approach I tried indicated that this particular reaction should have been absolutely typical -- i.e. heavier isotope reacts slower.

After just over a year I had a "eureka moment". A tiny amount of a side reaction leading to loss of H2 would lead to a 64 peak in a product that was really vinyl chloride-37 rather than unreacted ethyl chloride-35. About 0.5% of this side reaction, in conjunction with a normal isotope effect, was all that was needed to produce the illusion of a sluggish reaction by ethyl chloride-35, a highly atypical isotope effect. Further investigation proved that this was indeed what was happening.

Other (chemical) examples: It is worth checking out the stories of "coronium", "polywater", and "cold fusion". The last of these is still not totally resolved, except that it is quite clear that no nuclear fusion is involved.
« Last Edit: 12/03/2012 03:46:42 by damocles »
 

Offline cheryl j

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Well they often say in science that correlation dues not prove causation.
 

Offline CliffordK

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I haven't tried the candle in the bottle experiment.  It is interesting to think about though.

Simplifying things a bit, if one had:

CnH2n + 1.5nO2 --> nCO2 +  nH2O

So, after everything cools down, one ends up with about 2/3 as much CO2 as the quantity of O2 that one began with.

So, if one began with 20% oxygen, one would expect the water to raise by 7%. 

I presume a chunk of the difference (if any) would be due to the much higher solubility of CO2 in water than O2.  Can CO2 escape from the enclosure through the water?

I would be curious if you would see a difference in the level of the water if you ran the experiment in an acidic water bath vs a basic water bath.  You could use Sodium Bicarbonate, for one sample, but I'd choose a different base.

http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html


(oops, had the formula off, corrected it to reflect 2/3 ratio CO2 to O2).
« Last Edit: 23/03/2012 00:25:19 by CliffordK »
 

Offline William McCormick

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I think it is the sort of thing that can, and does, happen quite frequently. But it is usually a matter of an explanation or an interpretation or a "theory" fitting a result or fact rather than the observation fitting "existing facts".

Example 1: Air pressure: Sir Isaac Newton thought about air pressure, and thought that its elastic behaviour must be due to forces of repulsion between particles of air. We now know that there are no such repulsive forces, and that the air pressure is due to fast moving gas particles colliding with the surfaces where the pressure is detected.


More then you might know.

Repulsion forces are the only forces in this universe. Despite what is popular or current belief. In fact this is not a new subject, or a friendly subject. Most of the problems of science stem from just such a debate. A debate between Universal Scientists and "modern scientists".

The "modern scientists" left, and condemned Universal Science. Universal Science had built just about everything we have today. The first transistor was built by our beloved Benjamin Franklin, He was a Universal Scientist, and built the first known transistor, in his basement. Using lightning as the power source, he turned lightning on and off using electricity. Universal Science is off the leash. But you have to be a responsible person.

The "modern scientists" condemned universal science, by claiming that forces of attraction existed. And that ambient radiation creating universal pressure did not exist. The German ether is similar to the Universal Science, ambient radiation, or cosmic radiation, if you must.

When the "modern scientists" were called on their attraction theory, by Universal Scientists, it ended with two "modern scientists" making hugging gestures around each other. Not known to the "modern scientists" or the government education board, they were trying to convince. They actually proved that even they the "modern scientists" believed a pushing force was necessary to push the two "modern scientists" together. To create the illusion of attraction.

Today most new students believe that theories represent science, that is not true. Anything you cannot demonstrate, is not science. 

There is no attraction force in this universe. If you want to move something you have to push it. That is why no one has ever created a perfect vacuum and no one ever will. You cannot get the last particles of air in a chamber to push themselves, or will themselves, out of the chamber into the pump.

The refrigerator magnet is not sucked, pulled or attracted to the refrigerator. The area between the two objects is made less repulsive by a flow of particles setup by the magnet, between the two objects.

If anyone has ever worked with high pressure air or water, you may have noticed that as you move an unblocked hose closer to an outlet of pressure, at some point the hose actually starts to get pushed towards the high pressure outlet. There are many variables involved but it is a demonstration, that confirms the possibility, and demonstrates the phenomena does exist.

You will find no Scientist that demonstrates attraction forces. Just offering you an old tried and true understanding of the Universe.

                      Sincerely,

                            William McCormick

 

Offline JP

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moderator note

William, as this forum is meant to be a discussion of what you term "modern science," please refrain from pushing "universal science" (what we call non-mainstream) outside of the New Theories forum. 

Thanks!
 

Offline William McCormick

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Does modern science allow you to call something science if you cannot demonstrate it?

If they do they are not following the scientific method, as it was created.

I was just highlighting how the experiment of modern science, got messed up pretty much forever, until they right a few basic flaws and variables they overlooked in their experiment. What I stated can easily be demonstrated and duplicated.


                      Sincerely,

                            William McCormick
 

Offline damocles

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I haven't tried the candle in the bottle experiment.  It is interesting to think about though.

Simplifying things a bit, if one had:

CnH2n + 1.5nO2 --> nCO2 +  nH2O

So, after everything cools down, one ends up with about 2/3 as much CO2 as the quantity of O2 that one began with.

So, if one began with 20% oxygen, one would expect the water to raise by 7%. 

I presume a chunk of the difference (if any) would be due to the much higher solubility of CO2 in water than O2.  Can CO2 escape from the enclosure through the water?

I would be curious if you would see a difference in the level of the water if you ran the experiment in an acidic water bath vs a basic water bath.  You could use Sodium Bicarbonate, for one sample, but I'd choose a different base.

http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html


(oops, had the formula off, corrected it to reflect 2/3 ratio CO2 to O2).

If you consider the volume rather than the mass of carbon dioxide, you will find that a sample of this gas at 18C has a mass of 1.8 g/L, and if you look at your engineering graphs you will find that at 18C is the temperature where the solubility of carbon dioxide is 1.8 g/L, and you will also find that tap water comes at about 18C. So carbon dioxide will dissolve in the water from your candle in jar experiment to near completion provided that the volume of available water is at least as big as the original volume of air in the jar.

But the solution process is very slow; you would have to leave the jar for a day or so before the volume reduction would get to be around 20%. Provided you wait for as long as this, a 20% reduction will be observed. Use of an alkali -- would have to be carbonate, hydroxide, or silicate; bicarbonate can not take up more carbon dioxide -- would speed up the process.
 

Offline cheryl j

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One story I read involved the unfortunate theory in the early 1900s that crib death was caused by an enlarged thymus gland in infants, because that is what they found when they autopsied them. And they actually irradiated the glands of some infants in order to try to prevent it. Amazingly, scientists at the time did not realize that the thymus gland in all infants is much larger than adults. It had been misrepresented in medical textbooks for years.
 

Offline CliffordK

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Interesting about the thymus.

I suppose this issue is about correlation vs causation.

Another thing that has been in the news a lot is paleoclimatology. 
Some people will point that past warmer periods had higher atmospheric CO2 levels, and thus attribute the warmer interglacial periods to the higher atmospheric CO2

However, looking for the source of CO2, one quickly learns that the warmer oceans drive the CO2 out, so it is in fact warmer weather that causes the higher CO2 levels. 

Of course, that doesn't mean that there isn't a complex feedback mechanism in which a little warming from solar output variation or Milankovitch cycles causes an increase in atmospheric CO2 levels, which in turn causes the temperatures to rise further.  However, it involves a complex feedback mechanism that is ignored by some people.
 

Offline JP

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Mod note:
William, this is the second time we've had to lock a thread because you have gone well off topic with your opinions rather than sticking to science.  Please review the acceptable usage policy: in particular keep it science, and keep it a discussion

AUP: http://www.thenakedscientists.com/forum/index.php?topic=8535.0

The proper forum for discussing non-mainstream science is in the New Theories forum.  Future off-topic discussion of new theories or conspiracy theories will be moderated or moved to that forum.

Thanks,
JP moderator
 

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