Science

Dans la science / In science

In French

1) Navette spatiale (Fevrier 2000)

2) T-shirt anti-portables (Aout 2000)

3) Médicament belge (Mars2001)

4) Régime séminal (Mars 2002)

5) Canettes (Juin 2002)

6) Métro Parisien (Septembre 2003)

7) Baleines (Octobre 2003)

8) Rapidité intellectuelle (Octobre 2003)

9) Nuages (Novembre 2003)

1) Navette spatiale (Fevrier 2000)

PARIS, 22 fév (AFP) - Des positions amoureuses, sélectionnées après simulation sur ordinateur, auraient été testées en 1996 à bord d'une navette spatiale américaine, d'après un document cité par Pierre Kohler dans un chapitre de son livre consacré à la "Dernière mission" de la station russe "Mir", qui vient de paraître.

Astronome de formation devenu journaliste scientifique, Pierre Kohler suit depuis longtemps particulièrement les sujets liés à l'espace. Les astronautes lui ont fait de nombreuses confidences, sauf sur un thème tabou d'outre-Atlantique à l'Oural : le sexe en orbite.

Toutes les agences spatiales sont pudiques sur cette question. Aux Etats-unis, les demandes d'entretien sur le sexe sont systématiquement rejetées et les principaux intéressés répondent par un sourire ambigu.

Bonnie Dunbar, astronaute et épouse d'astronaute, affirme n'y voir que des rumeurs. Parce qu'il y a des caméras partout ! se défend-elle, en oubliant de préciser que ces appareils indiscrets peuvent être coupés.

Interrogée à son tour, sa collègue russe Elena Kondakova a affirmé "ne pas avoir bien compris" la question : "Voulez-vous parler de gens mariés ou de la vie dans l'espace en général ?"

Dès 1982, le séjour d'une ex-Soviétique, Svetlana Savitskaïa, à bord de l'ancienne station Saliout-7, en compagnie de quatre hommes, donna lieu à des rumeurs sur de possibles "expériences" mais, il est improbable, estime Pierre Kohler, que la cosmonaute, déjà mariée, ait accepté de se livrer à des ébats, fût-ce au nom de la science. Svetlana est aujourd'hui mère de deux filles, nées bien après son vol.

En 1991, l'Anglaise Helen Sharman, alors célibataire et âgée de 28 ans, a avoué avoir vécu à bord de Mir de "fantastiques expériences". "Nous nous sommes bien amusés en sa compagnie", ont confirmé ses co-équipiers russes, Sergueï Krikalev et Anatoly Aserbatski. Certes, cela peut vouloir dire tout simplement qu'elle fut facile à vivre. Une séquence vidéo tournée dans Mir montre la jeune Anglaise évoluant en apesanteur, vêtue d'une nuisette rose...

A en croire un document référencé "NASA n 12-571-3570", cité par Pierre Kohler, une expérience confidentielle de rapports sexuels sans équivoque aurait bien été menée, après simulation informatique, lors de l'un des quatre vols de navette réalisés en 1996 avec des présences féminines à bord.

Sans doute en prévision de futurs séjours de longue durée, il s'agissait de déterminer les meilleures positions pour des ébats en microgravité. Sur les dix modes testés, six auraient fait appel à une ceinture et un tunnel gonflable destinés à maintenir les partenaires serrés l'un contre l'autre, alors que dans les quatre positions restantes, le couple devait s'en remettre à a seule force musculaire.

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2) T-shirt anti-portables (Aout 2000)

Une société japonaise nommée Gunze vient de mettre au point un tee-shirt qui protégerait ses utilisateurs des ondes émises par les téléphones portables. Nouvelle lubie japonaise ou véritable moyen d'atténuer les effets (encore mal connus) de ces ondes.

On se souvient encore du tollé médiatique provoqué par un communiqué de presse du gouvernement anglais : celui-ci, alors que les enchères pour les licences UMTS venaient à peine de se terminer, mettait en garde la population (et principalement les enfants, jugés plus vulnérables) contre les effets dangereux des portables, alors qu'aucune étude scientifique n'a établi à ce jour la véracité de ces propos (ni le contraire d'ailleurs).

Les inventions pour se prémunir des radiations électromagnétiques rivalisent désormais d'ingéniosité : la société française AESD a ainsi mis sur le marché un étui transparent nommé Teddy comportant une plaque métallique qui s'adapte à la forme de l'appareil et qui refoule la plus grande partie de l'intensité vers l'arrière de celui-ci et devrait ainsi réduire l'exposition du visage aux ondes électromagnétiques.

Cet étui, vendu au prix de 150 F, reste bien moins onéreux que le tee-shirt- proposé par Gunze au prix de 1600 F : cependant, ce dernier a été spécialement conçu pour dévier 92 % des ondes électromagnétiques en provenance du téléphone mobile utilisé ou des téléphones mobiles environnants. Idéal donc pour ceux qui portent des pacemakers et qui sont entourés en permanence de téléphones portables.

Ce qui s'avérera fortement utile au Japon où l'on compte 50 millions d'abonnés au téléphone mobile pour 125 millions d'habitants.

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5) Canettes (Juin 2002)

Une legende urbaine AVEC (chose rare) son propre dementi!!!:

COCA-COLA, SPRITE, ORANGINA, BIERES ...ETC

Article paru sur Caducée, source d'information professionnelle dans le secteur médical ( MESSAGE DE SANTE PUBLIQUE ) :

Une personne est morte récemment dans des circonstances absurdes. Elle était partie en bateau avec des amis, un dimanche, et avait mis des canettes de boisson dans le réfrigérateur du bateau. Le lendemain, lundi, elle était internée au CHU pour en ressortir le mercredi, morte. L'autopsie a révélé qu'il s'agissait d'une Leptospirose fulgurante

L'examen des canettes a confirmé qu'elles étaient infectées par de l'urine de rat et donc de Leptospiras. La personne en question n'a probablement pas nettoyé la partie supérieure de la canette avant de la boire et celle-ci était contaminée par de l'urine de rat sèche, qui contient des substances toxiques et mortelles, dont la leptospiras, qui provoque la leptospirose.

Les boissons en canettes et autres aliments de conditionnement similaire sont stockés dans des entrepôts qui sont souvent infestés de rongeurs et sont ensuite transportés jusqu'à leur lieu de vente sans faire l'objet d'un quelconque nettoyage. Chaque fois que vous achetez une canette, lavez consciencieusement la partie supérieure avec de l'eau et un détergent avant de la mettre au réfrigérateur.

Suivant une étude réalisée par INMETRO (Espagne), le couvercle des canettes de boissons sont plus contaminées que les toilettes publiques. L'étude montre que la quantité de germes et de bactéries sur les couvercles des canettes est telle qu'il est indispensable de bien les nettoyer avec de l'eau et un détergent.

Reçu de la Direction des ressources humaines de l'Hôpital cantonal de Genève.

* la leptospirose a une période d'incubation de 4 à 19 jours (donc mort en 4 jours ça paraît un peu rapide...), et en plus elle se soigne assez facilement grâce aux antibiotiques.

* le site Caducée dément être la source d'une telle information.

C'est encore un hoax...

Alors vu la température d'aujourd'hui, n'hésitez pas à vous taper une canette bien fraîche !

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6) Métro Parisien (Septembre 2003)

Bienvenue dans le Métro de Paris ! !

Si vous êtes un voyageur régulier du Métro Parisien, voici des faits qui vont vous faire regretter de l'avoir pris !

Durant l'automne 2000, une équipe de scientifiques a déplacé une rangée de sièges d'un wagon du Métro de la ligne Centrale pour effectuer une analyse de propreté. Malgré les protestations de responsables du Métro de Paris, comme quoi l'intérieur des trains sont d'une propreté tout à fait normale, les scientifiques ont fait des découvertes alarmantes.

L'analyse ayant été poussée jusqu'au plus petits détails. Voila ce qui avait été trouve à la surface des sièges :

* 4 sortes différentes de poils: d'humain, de souris, de rat et de chien

* 7 sortes différentes d'insectes, dont la grande majorité était des puces, et dont la plupart étaient vivantes

* du vomit provenant d'au moins 9 personnes différentes

* de l'urine humaine provenant d'au moins 4 personnes différentes

* de l'excrément humain

* de l'excrément de rongeur

* du sperme humain

Lorsque les sièges ont été déplacés, ils ont aussi trouvé :

* les restes de 6 souris

* les restes de 2 gros rats

* un type de moisissure/champignon inconnu

Il a été estimé qu'en tenant un des accoudoirs, vous transférez à votre corps, les huiles naturelles et ainsi que la transpiration d'environ 400 personnes différentes. Il a été estimé qu'il est généralement moins toxique de fumer 5 cigarettes par jour que de voyager durant une heure dans le Métro Parisien. Il est beaucoup plus hygiénique de se laver les mains à l'intérieur d'une cuvette de toilette tirée avant de manger que de s'essuyer les mains sur un des sièges du métro avant de manger. Il a été estimé que, dans Paris, il y a plus d'arrêts de travail pris à cause de germes attrapés durant un transport dans le métro que pour quelques autres raisons (y compris l'alcool).

MORALITE : Laissez votre place aux personnes âgées, et garder vos mains dans les poches !!!

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In English

1) Microwave and water controversy (February 2000)

2) Gross story (February 2000)

3) Research (October 2001)

4) Idiots (August 2003)

1) Microwave and water controversy

Subject: Microwaving Water to Heat it Up

I feel that the following is information that any one who uses a microwave oven to heat water should be made aware of. About five days ago my 26-year old son decided to have a cup of instant coffee. He took a cup of water and put it in the microwave to heat it up (something that he had done numerous times before). I am not sure how long he set the timer for but he told me he wanted to bring the water to a boil. When the timer shut the oven off, he removed the cup from the oven. As he looked into the cup he noted that the water was not boiling but instantly the water in the cup "blew up" into his face. The cup remained intact until he threw it out of his hand but all the water had flew out into his face due to the buildup of energy. His whole face is blistered and he has 1st and 2nd degree burns to his face which may leave scarring. He also may have lost partial sight in his left eye.

While at the hospital, the doctor who was attending to him stated that this a fairly common occurrence and water (alone) should never be heated in a microwave oven. If water is heated in this manner, something should be placed in the cup to diffuse the energy such as a wooden stir stick, tea bag, etc. It is however a much safer choice to boil the water in a tea kettle. Please pass this information on to friends and family.

Regards

Mike J Tucker

Safety/Security Officer

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Urban legend or not?

Here is a discussion about it:

>Somebody here (a chemist) says it's not necessarily bull shit. liquids can reach a metastable temperature above their fusion temperature, say water at 120C and then any littel agitation will brake the equilibrium and spend the whole energy at once, vaporating brutally.

Please describe this mechanism in detail as applied to this situation. I challenge you to provide a defendable physical explaination. :-}

> On an oven the temperature gradient creates a flow in the liquid that makes it impossible to reach the unstable equilibrium. But in a microwave it would be possible. In some chemical experiments involving heating for long periods of time, they put stones at the bottom of the flask for this purpose, stones move and release gas bubbles, hence impeding this undesired equilibrium to take place.

This is to prevent "bumping," the effect where few nucleation sites are present and the bubbles which form due to boiling are large enough to swish some of the material being boiled out of its container as they rise. Bubbling stops very shortly after something is removed from a source of heat.

> Nevertheless, an urban legend is a kind of story, with a certain style, describing something that might or might not have happenned, so this one qualifies anyway...!!!

This is like putting a carbonated beverage into a perfect container... only then will you not receive and fizzing. Besides, there is plenty of motion in water in a microwave. Let me remind you of beer's law of radiative absorption in matter. This is exponential. This means the outside will heat more rapidly than the inside, causing a temperature differential and hence a convective-type motion.

I dislike these type of myths because people seem to gobble them up not thinking about it in detail. Challenge it! We're all scientists here! Science is not done on anecdote!

> you have some good points. However, metastable equilibrium exists, no?

Oh yes, I won't begin to argue that. I just have a hard time believing in exploding cups of water. A supersaturated solution of salt is a good example, of course. But my point is just TRY to make it successfully... it is quite difficult! Same deal with the almost perfect conditions that would be needed in a microwave to make exploding water. I would like to know a mechanism in any sense because I sure can't think of one. It is more acceptable to me to have cold liquid water...

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Here is another "explanation":

http://rabi.phys.virginia.edu/HTW/microwave_ovens.html

There is a story circulating by email about a 26 year old man who heated a cup of water in a microwave oven and had it "explode in his face" when he took it out. He suffered serious burns as a result. Is this possible and, if so, how did it happen? -- JJ, Kirksville, Missouri

Yes, this sort of accident can happen. The water superheated and then boiled violently when disturbed. Here's how it works:

Water can always evaporate into dry air, but it normally only does so at its surface. When water molecules leave the surface faster than they return, the quantity of liquid water gradually diminishes. That's ordinary evaporation. However, when water is heated to its boiling temperature, it can begin to evaporate not only from its surface, but also from within. If a steam bubble forms inside the hot water, water molecules can evaporate into that steam bubble and make it grow larger and larger. The high temperature is necessary because the pressure inside the bubble depends on the temperature. At low temperature, the bubble pressure is too low and the surrounding atmospheric pressure smashes it. That's why boiling only occurs at or above water's boiling temperature. Since pressure is involved, boiling temperature depends on air pressure. At high altitude, boiling occurs at lower temperature than at sea level.

But pay attention to the phrase "If a steam bubble forms" in the previous paragraph. That's easier said than done. Forming the initial steam bubble into which water molecules can evaporate is a process known as "nucleation." It requires a good number of water molecules to spontaneously and simultaneously break apart from one another to form a gas. That's a rare event. Even in a cup of water at several degrees above the boiling temperature, you might have to wait minutes before such a rare event occurred. In reality, it usually occurs at a defect in the cup or an impurity in the water--anything that can help those first few water molecules form the seed bubble. When you heat water on the stove, the hot spots at the bottom of the pot or defects in the pot bottom usually assist nucleation so that boiling occurs soon after the boiling temperature is reached. But when you heat pure water in a smooth cup using a microwave oven, there is virtually nothing present to help nucleation occur. The water can heat right past its boiling temperature without boiling. The water then superheats--its temperature rising above its boiling temperature. When you shake the cup or sprinkle something like sugar or salt into it, you initiate nucleation and the water then boils violently.

Fortunately, serious microwave superheating accidents are unusual--this is the first injury I've ever heard about. You could minimize the chance of this sort of problem by deliberately nucleating boiling before removing the cup from the microwave. Inserting a metal spoon or almost any food into the water should trigger boiling in superheated water. A pinch of sugar will do the trick, something I've often noticed when I heat tea in the microwave.

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Here is another version of the story:

"I am a 44-year-old man who was injured by exploding water. Here is how it happened:

I was boiling about two cups of water for tea in my microwave in a clear Pyrex-type measuring cup, and when I didn't see it boiling, cranked up the microwave for another few minutes. I somewhat absent-mindedly did this SEVERAL TIMES, and when it never boiled, figured there must be something wrong with the oven. Thankfully, it crossed my mind that I should be cautious, and reached in for the cup with my face away from the door; because the water literally exploded out of the cup. It instantly covered from half of my hand to midway up my upper arm -- and I'm six and a half feet tall. Only a few drops of water were left in the cup.

I called the emergency room, I called the Optim Nurse Line, and I called a friend who I knew had an aloe vera plant. I ended up self-treating with fresh-squeezed aloe juice several times a day, followed with clean bandages, but it was very painful for quite a while. I ended up with just a little blistering, and a reddish tint that faded over a few months' time.

I'm sure that my experience was not "reported." In fact, I didn't talk about it much, because it was so weird and incredible. Some people looked at me like they weren't sure they believed me, so I shut up. I am very glad I found some validation for my experience, so I can show it to them. It could be that many cases of this occur but go officially unreported.

I'm also glad that I ran across your scientific explanation, because it totally baffled me and the few I asked about it.

If it is of any interest to you or anyone else, I will put you in contact with people who saw my burns and helped me treat them, and I will gladly give you my address, etc."

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Another answer from a chemist friend:

> This is to prevent "bumping," the effect where few nucleation sites are present and the bubbles which form due to boiling are large enough to swish some of the material being boiled out of its container as they rise. Bubbling stops very shortly after something is removed from a source of heat.

The effect of the stone is also to create lots of nucleation sites inside the boiling water. When you try to distillate a mixture of liquids, you have to put stones in it, or the mixture can reach a temperature above the evaporation temperature, and be in a metastable state. If you forget the stone, and try to put it in once the mixture is already hot, the entire material can be swish out of its container and explode. This is an experiment confirmed by the Director of the Chemistry Department of the Ecole Normale Superieure, Christian Amatore.

> Besides, there is plenty of motion in water in a microwave. Let me remind you of beer's law of radiative absorption in matter. This isexponential. This means the outside will heat more rapidly than the inside, causing a temperature differential and hence a convective-type motion.

I don't think that the 'epsilon' factor in the Beer-Lambert's law of radiative experiment is significantly high, so my opinion is that there is no temperature differential between the inside and the outside of water in the glass.

The same phenomenon happens when you freeze a glass of water and don't touch it once in the freezer. Its temperature can be negative, but the water is still liquid. If you touch the glass, the water freezes instantly. I even met some microwave oven where it is said on purpose that you do not have to boil water in it, but should put a small object, like a spoon (not an iron one, of course!) or a tea-bag in the glass. This is still to create nucleation sites for the bubbles, because there are few nucleation sites on the surface of a well-washed glass...

I can even find an article where the size of the Champagne bubbles are correlated to the washing of the glass with an appropriate detergent...

That's why I think the story MIGHT happen.

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2) Gross story (February 2000)

Susy DeLucci and the Miracle of Life.

One morning around 5am 22 year old Susan DaLucci of Kittery Maine,woke up with a painful need to urinate. At first she thought she had diarrhea, but when she stood up out of bed, she realized that it was urinary pain. It was very similar to the feeling of having diarrhea, just out the wrong hole. She wobbled to the toilet and upon sitting on it, her vagina erupted into the most horrific messy farting noise anyone has ever heard.

In paralyzing pain, Ms. DeLucci for the next few minutes continued to push and squirt out of her vagina a burning tide of wretch and filth while she gripped the sides of the toilet, white-knuckled. She was screaming wildly, and the neighbors called the police. When medics arrived they found Ms. DeNucci unconscious lying on the floor of her bathroom wearing nothing but her bath robe. Running down her leg, was a stream of brown and green syrup.

The medic had to transfer her to a stretcher, so he grabbed her left leg which was bent crossing her other leg, to straighten her out. She was lying there all twisted up. When he lifted her left leg to straighten her body out, he exposed her vagina at which point a creature, no larger than the tip of a finger wormed its way out of her genitals and landed on the floor with a wet popping sound. Shocked, the medic stared at the creature that was lying on the tile bathroom floor in a casing of mucous. It was a tiny mud shrimp and it sat there on the cold floor gasping for water while flipping itself back and forth.

The horrified medic turned to the toilet as he felt the nausea setting in. When he put his face down into the toilet to puke what he saw was so horrific that to this day he cannot look into a toilet without convulsing. The entire toilet bowl was boiling with baby brown mud shrimp flipping and splashing at a furious pace.

If you think that is bad - wait until you hear how it happened: Ms. DeLucci official death was the result of a combination of shock and severe head trauma. She stood up over the toilet in pain and when she saw what she had done, she went into shock and fell, smashing her head on the toilet and then on the floor.

It is believed by medical police that on two nights before the accident she had purchased a live lobster at a fish market. While lying in a tub, she gently inserted the creature's tail into her vagina to derive pleasure. At that point, she held a lighter under the creature's face causing it to flip its tail in a violent snapping motion. The medics found a lesbian XXX video in the VCR and the TV was positioned on a table in front of the tub. The lobster was found in the kitchen garbage can wrapped in a paper bag. Traces of Ms. DeLucci's DNA were found on the lobster along with pubic hairs that had wedged themselves between the lobster tail joints. The lobster's face was lightly burned with the same fuel used in lighters. The lobster's digestive track and colon were found to be full of mud shrimp egg casings. Doctors believe that the lobster had eaten them (they are common in the water at fish markets and are usually harmlessly boiled to death) and the lobster had crapped them out into Ms. DeLucci when she was torturing it. Maine mud shrimp only take two days to gestate and Ms. DeLucci was only four days away from getting her period, doctors believe that at that point of her menstrual cycle, her womb was the perfect PH balance to grow these mud shrimp which are a much larger version of the popular "Sea Monkey" pets sold throughout the US. Overnight the eggs had hatched and the mud shrimp began doubling in size every ten minutes. You can imagine the pain she was in when she woke up that morning and gave birth to well over 1,000 mud shrimp in her toilet.