Surreal Georgia

Is Water Always Wet?

It seems as if my experimental period is still not over now.

• Is water always wet?
• Does fabric always gets wet when you dip it into a fluid?
• Does rain always make leaves wet?
• What do detergents do?
• Does a sponge soak up every kind of fluid?
• Why does chalk stick on a a chalkboard? Why not when the chalkboard is greasy?

All these questions have in common, that there are several kinds of material that come into close contact.

There are adhesive forces that are responsible for different things sticking together. Between all materials there are such forces, but they are stronger or less strong depending on what materials get in contact.

There are also forces between the molecules of the same kind, kohesive forces. They are less or more strong depending on which material it is. They are responsible for the fact that fluids form drops, when they are poured on the ground. 

Lets make an example!

Put a drop of water on a desk or on glass. It looks like this. Well, It's Cola I poured on my desk.

If you put some mercury on a desk or on a plate of glass it looks like this:

Can you spot the difference?

It's the angle between the drop and the material the drop is in contact with:

If it is bigger than 90° the kohesive forces are stronger than the adhesive. The fluid does not get much in contact with the material, because the stronger the adhesive forces the more it gets the shape of an orb and an orb touches the base in only one small point. If the angle is smaller than 90° the cohesive forces between the fluid and the base is stronger and therefore the fluid covers the base. Such fluids are called wetting fluids.

The smaller the angle the wetter the fluid makes the base, because it covers a big area. The bigger the angle is the dryer stays the base, because the fluid covers only a small area.

And this is already the answer: Only wetting fluids can make something wet! If you would try to wash your shirt in mercury (who would do so!?), it wouldn't even get wet.The mercury would simply drip of. A sponge of course would never soak up a non wetting fluid. Chalk sticks on a chalkboard, because the adhesive forces are stronger than the koherent forces, but it's different when the base changes. A greasy chalboard makes the adhesive forces much smaller. So the chalk wouldn't write on such a chalkboard. By the way, a prominent joke of pupils, cleaning the chalkboard with some kind of detergent. The chalk won't stick any more on this chalkboard.

This leads us to the question, what detergents do. Mixed with water they diminish the kohesive forces, so that the water gets more wetting and can therefore resolve more dirt than before. But detergents on a chalkboard make it sort of greasy and therefore they diminish the adhesive forces.

Because it depends on both, the kind of fluid and the base, it is possible that leaves can't get wet although water is poured over them:

They stay dry! The leaves do this by a very special structure of their surface. This effect is well known as the lotus effect, but not only lotus plants do this, also this lupine.

So water is not always wet.

Because water always contains resolved minerals and dirt, surfaces that can't be wetted by water stay clean much longer. Ceramic in bathrooms and glass is sometimes  finished with nano particles which cause this lotus effect. You need not clean them as often as normal ceramic or glass.

The wettest fluid I know is fluid helium. If it is extremely cold, shortly above absolute zero (0 K or - 273°C or -459° F) it nearly has no kohesive forces any more. And because there are only adhesive forces between the fluid helium and the vessel it is in, it starts to creep up the vessel and gets out of it this way. It's sort of superfluid at that temperature.

Thank you for hearing my short lecture in phyics. ;o)

I need a coffee now and you too, I guess! I'm glad that it's not wetting enough to creep out of my cup!

Traffic Signs (Photo Challenge)

OK, I'm Queen Scatterbrain when there are special topics in our Challenge. But I can't stop my brain getting connotations which might be unusual. I'm an urban geographer and my daughter is studying town planning. So traffic signs are not only traffic signs but represent models like the car friendly town by Sir Colin Buchanan or the German architect Hans Reichow. Your cities in the USA are very car friendly, so are our cities. It's an old concept with many, many problems. I think you all experienced these problems yourself. European and German town planners are retreating from this principle and try to find new concepts for town renewal. Car friendly towns are "human unfriendly" and urban life does not take part between these oversized highways which are cutting up neighborhoods and avoid communication and street life. Well, it's a topic that could fill hundreds of books, but these few sentences are enough for a photo challenge.

I thought it would be nice coming with me and looking through the car window as if you were the driver. Come with me and look how a typical German car friendly town looks like. And of course you will see traffic signs!

I must confess, that I did these pictures not today, but last October. But I'm ill today and can't go outside. So I hope it counts.

Here we start!

 

This is my home village: Notice the traffic signs! Check! The yellow sign says: Here is a village, you aren't allowed to drive faster than 50 km/h. The sign with the red and white stripes says: Dangerous bend!

 

At first we drive on normal state roads, which use to have two lanes. In the background you see the outline of an old volcano which is dominating the landscape.

Then we use the autobahn, which usually has at least 4 lanes, but sometimes also up to 8 lanes. This here is near an expressway interchange, so there are more lanes. On the autobahn you are allowed to drive as fast as you want. On my opinion there should be a speed limit!

If you are tired and need a break you can stop at one of the motor houses. But I can't suggest it, because the restaurant is very expensive and very bad. You only get fast food. Even using the toilets is expensive. Not to talk about fuel...

Big ring roads take you from the autobahn to the next city. The lanes are often divided with concrete obstacles and the crossing traffic drives upon road bridges.

This is an underground station. Notice the traffic sign: 70! You are allowed to drive 70 km/h. In towns it is usually only 50 km/h, but on these big roads you mostly can drive faster. The bridge is only for pedestrians who had to cross the road to get the underground.

Sometimes these urban highways are so wide, that pedestrians can't cross them. This is another pedestrian bridge. 

When you are closer to the city the ring roads cross each other and there are very ugly intersections. In the outskirts of the town there are big business parks like this here, where people can also go shopping. More and more people do their shopping here, because it takes too long to drive into the city and find a free parking lot there.

Here we are in the old quarters which were constructed at about 1880 to 1920. The old houses are mostly not in good condition, there are no gardens and only few green plants. It's loud and dusty. The shops which were formerly in the first floor are mostly abandoned or there are shops for poor people or special ethnic groups of the population (Turkish, African, Russian,...shops). These are quarters for the lower classes.

This is shortly before we arrive at the border to the old Medevial town. Here are parking garages (blue sign with P on it), hotels and a lot of office buildings.

Here you see the pedestrian zone in the city. This was the area of the medevial town, but during WW II most of the old buildings were destroyed and so you find a lot of new ones like the "Kaufhof", a department store, which was constructed in the 60ies. An imporant principle of the car freindly town is, that other kinds of traffic like pedestrians and bikerider are banned on special lanes and special zones, so that the cars can drive with high speed. Outside these pedestrian zone the pedestrians and bikeriders had to wait very long at the crosswalks until they are allowed to cross a 6 lane road in 15 seconds! As a pedestrian you aren't allowed to be old or sick! You have to hurry, because the cars have to drive. And where there are no crosswalks there are tunnels, which are stinking after human excrements or bridges, which are pretty steep for old people for example or those who are hampered.

This is also a residential quarter for lower classes, mostly of German origin. There are six apartments in each apartment building and blocks of garages. Well, it's pretty dreary. The road collects the traffic from the smaller residential streets and has got usually two lanes and parking lots beside it.

There are also multi-storing buildings at the smaller residential streets. These tenants don't have garages, but only parking lots. The lawn is not planned for playing on it or sitting outside, it's just lawn. Most of the apartments have balconies. It's not desirable to live here. It's a bit like in a battery farm.

This is a small shopping center in one of these quarters. It consists of a supermarket, a hairdresser, another supermarket with very cheap food and a bakery. People can get there what they need daily.

More outside the town there are endless quarters with homes of different age. This quarter is constructed in the 80ies. These quarters look different, which depends on the different age of the houses. But I think this is the same in the USA. These are the quarters for the middle classes.

I prefer to leave the town. I love the country. - The sign on the left side says: You are now allowed to pass again. Outside of towns and villages you are allowed to drive 100 km/h, which is pretty fast.  

 

Oh, we also have got Mac Donalds (Do you see the sign?) 

 Night is coming!

Home again in our small village.

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 Photo Challenge!

http://margareetaville.blogspot.com/

http://bustershouse.wordpress.com/

http://jayahrsblog.blogspot.com/

 

Today - 95 Years Ago

Today I want to remind you to Victor Franz Hess, who was born on June 24, 1883 at Schloss Waldenstein in Austria and died on December 17, 1964, at New York.

(Picture: Stamp with portrait of Hess)

Hess got the Nobel Prize for Physics in 1936 for his discovery of the Cosmic Rays. I want to remind you today, because it was on August 7, 1912, when he let fly a balloon near Vienna which measured the Cosmic Rays for the first time. Hess published this discovery in the newspaper „Physikalische Zeitschrift“ No. 13 of 1912.

Hess has been working on radioactivity and on the exploration of Radium in Vienna. During WW I he was the leader of an X-Ray-department of a sick bay. In 1919 he became a professor at the University of Graz and a short time later he went to the USA for two years, where he worked on the medical use of Radium. In 1931 he went to the University of Innsbruck, where he led the new Institute for Radiology. In 1936 he got the Nobel-Prize together with Carl David Anderson because of the investigation of the Cosmic Rays.

Graz, old university (the red building)

Innsbruck, part of the oldest town with the Golden Roof and the Alps in the background

From 1937 on he again worked at the University of Graz. Hess rejected National Socialism and his wife was Jewish. So the Nazi-Regime tried to opress him: After Austria had joined the German „Reich“, he was arrested for a short time and in May 1938 he was set into retirement at the age of 55 and in September 1938 he was fired without any claim for a pension.

Still in 1938 he immigrated to the USA, where he worked on at Fordham University. In 1944 he became an American citizen. After WW II he traveled several times to Vienna and Insbruck, but he never came back.

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• If you want to find out more about Cosmic Rays, read: http://en.wikipedia.org/wiki/Cosmic_ray
• More about Hess: http://nobelprize.org/nobel_prizes/physics/laureates/1936/hess-bio.html
• And last but not least more about Fordham University: http://en.wikipedia.org/wiki/Fordham_University

Pictures: Public domain

Old Like a Whale

Whalers had found the spike of a more than 100 year old harpoon in a bowhead whale, which they had killed near the shores of Alaska. The 13 centimeter long piece of metal stuck in a bone near the shoulder blade. The US-magazine „Standard Times“ reported last Wednesday that this whale is probably older than 130 years.

Picture: Bowhead whales on a stamp

John Bockstoce, curator of the museum of New Bedford, claimed that the spike was from a kind of harpoon, which was produced before 1885. The spice has a little metal cylinder, which was filled with explosive, which could be fired a little bit delayed. The whalers wanted to kill the animals with such weapons before they could dive under the pack ice. This harpoon has hit the whale, but hadn’t killed it. A specialist for Arctic history said that there had been also earlier similar founds in killed whales, but this time the age of the harpoon can be deduced very exactly: This harpoon must be fired about 1890. He knows this, because it’s known when special harpoons were used in Alaska for the first time. So the whale must be older than this piece of a harpoon.

Picture: Differents types of harpoons used at whale hunts

Picture: Whale hunt about 150 years ago

About 130 years – this is a high age, but already chemical analyzes of the eyes of whales had shown that a lot of animals become 100 years and older and also a 200 year old whale was found.

An Inuit of Alaska had killed the whale on May 16, 2007, and he gave his found (the spike in the bone, not the whale) to the Museum of Bedford, which iss specialized of whales and whale hunt. This Inuit comes from one of the ten villages in Alaska, which have a special permission on hunting whales, because they need the whales for food.

Picture: Cooked whale meat (my personal Opinion: yuck, sorry.)

Bowhead whales only live near the pack ice in the arctic. They become 15 meters long and weigh 60 – 80 tons. Today there are only 11,000 animals left.

Picture: Populations of several species of whales

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Source: t-online

Pictures:

• Whale meat: This Wikipedia and Wikimedia Commons image is from the user Chris 73 and is freely available at http://commons.wikimedia.org/wiki/Image:Whale_meat_on_dish.jpg under the creative commons cc-by-sa 2.5 license.
• All other pictures: Public domain

WiTricity

Wireless – this is the dream of the future. There are already telephones, cell-phones, laptops all wireless, but most electrical devices still need wires and an electrical outlet.

Picture: German electrical outlet and plug

Already Nikola Tesla (picture) dreamt of a completely wireless technique more than 100 years ago and tried to transmit electricity via radio. The problem was, that the electromagnetic waves spread all over and therefore their efficiency is very small.

Now scientists believe that this dream could become true: Marin Soljacic and his colleagues (Cambridge) could provide a light bulb with electricity from a distance of 2 meters. The efficiency was about 40 percent. In this experiment efficiency is till too low at the moment, but the scientist hopes that he will manage to increase it. Soljacic managed to transmit electricity by two huge copper spirals. In one of these spirals electric current flows with a frequency of about 10 Megahertz. The other copper spiral taps this energy and runs the light bulb. However, to use this electromagnetic resonance you have to be very near to the primary copper spiral. Only distances of a few meters work.

The scientists claim that the electromagnetic field wouldn’t cause any health-risks for humans or pets. Electromagnetic fields with such deep frequency wouldn’t penetrate too deeply into the body. Also credit cards, cell phones and other electric devices haven’t been affected by the electromagnetic fields during the experiments. But all effects still have to be investigated the scientists said. Well, I’m sceptical about the ineffectiveness of such intensive electromagnetic fields  on health and physical comfort. But this is my personal opinion.

Soljacic calls this new technique „WiTricity“ (Wireless Electricity). So good-bye jack?

Map: Types of electrical outlets all over the world

Picture: American B-plug and electrical outlet

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Source: t-online

Pictures: Public domain

1.3 Billions of Jumping Chinese

No joke but a serious question: What would happen if all 1.3 billion Chinese would jump up and down at the same time? Would there be an earthquake?

Picture: German rock festival "Rock am Ring"

This morning Birger Luehr from the German Potsdam-Geo-Investigation-Center made an experiment that should answer this question. Today there was a rock concert, a huge open-air festival, which is called "Rock am Ring". The band „Wir sind Helden“ (this is the name of the band; translated: We are heroes) invited the audience jumping up and down to the rhythm of the song. Several ten thousands of fans participated and caused oscillations of the ground. Near the stage the ground moved clearly but less than a millimeter up and down. Also in one-kilometer distance from the stage a seismograph still recorded the oscillations. But the main problem was getting such a huge number of people into a synchronous movement. If all these people aren’t 100 percent synchronous the oscillations blanket each other and the amplitude of the oscillation would be weakened.

Picture: The band "Wir sind Helden"

So the amplitude of the oscillation during the rock festival was a bit disappointing. But at least the earth was shaking. And there was also recorded another oscillation, which was much stronger than this one the jumping people caused. This stronger oscillation came from the bass guitars. It was ten times stronger.

Picture: Seismogram of the atomic explosion at the Mururoa-Atoll

Picture: Seismogram of the Tsunami Christmas 2004

But back to the question in the beginning: If 1.3 billions of Chinese would jump up and down 100 percent synchronously this would be energy of 10,000,000,000,000 Joule. This would be the energy of an earthquake of the magnitude 1 – nothing extraordinary. Those earthquakes are nothing unusual and only measurement devices could notice them. People can notice only earthquakes of magnitude 3 or higher. So even if 1.3 billions of Chinese would jump tomorrow at the same time the world wouldn’t notice it.

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Source: t-online

Pictures: Public domain

Official Website of the band: http://www.wirsindhelden.de/

Who Brought the Chicken to America?

How did chickens come to America? Of course by the Spaniards, who brought their chickens on their ships to America! Nope!

An international team of scientists found out by DNA-analysis of fossil chickens from Chile Domestic fowls came about 100 years earlier than the European immigrants. Probably the chickens came with people from Polynesia, which is a group of over 1000 islands in the Pacific.

Picture: Comparison of a European Chicken (left side, white Leghorn) and the American Araucana Chicken

The Spaniard Francisco Pizarro investigated that chickens were already a part of the Inca-heritage, when he arrived at Peru in 1532. Alice Storey and her colleagues now proved this deliverance. The team examined fossil chicken bones and came to the result that these bones were from the 14th century. So the first chickens on the American continent are about 600 – 700 years old. The team also compared their DNA with those of living chickens in Polynesia and experienced that their DNA was very similar. So these ancient Chilean chickens must have been originally from Polynesia.

But on the other hand it might be that chickens have been brought several times to America, also European chickens. Until today there are two stems of chickens, Polynesian and European chickens, which didn’t blend.

Picture: The wild Bankiva-Chicken

And where from came the first chickens in the world? Our Domestic fowls descend from the Bankiva-Chicken, which only produces only about 20 eggs a year. Today this kind of chicken still lives in India and Indonesia. It became a domestic animal later and changed its appearance. Maybe domestication has taken part in China about 8000 or 9000 years ago. Founds of old chicken bones seem to suggest this. Later first proved verifications are from the Indus-Valley about 2500 B.C., so it seems that domestic fowls spread first over South and East Asia. First European founds are younger: For instance in Switzerland domestic fowls lived there not before about 500 years B.C. Chickens spread all over the continent not before the Romans, who began breeding chickens for producing meat and eggs in huge stables.

Picture: Magnificent rooster

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Sources: t-online, Wikipedia

Pictures: Public domain

Cellulite: An Invented Disease?

It's becoming summer and a lot of women are afraid wearing short skirts or shorts because of their cellulite. There is nothing they don’t have trie getting rid of those unbeautiful buckles on their legs and butt. And magazines are full of good tips how to combat against cellulitis.

So you can read the following advices:

• Caffeine rises fat burning! OK, this is right, but only if you exercise directly after you have drunk a lot of coffee. Creams or lotion with caffeine however don’t show much effect. So save your money and don’t buy this expensive crap!
• Shower alternating with hot and cold water! Um, yes it stimulates your circulatory, but doesn’t help against cellulitis. Just the opposite, it additionally stresses your connective tissue.
• Avoid crossing your legs! It is not proved that this prevents cellulitis. But it’s healthy, because it avoids blood congestion in your legs.
• Low heels avoid cellulite. Nope, but it’s healthy wearing them from time to time.
• Salt poultices tighten the skin. Hmmm, the salt peels the upper layers of the skin and the intense massage raises the blood circulation, but it doesn’t help against cellulite. The buckles will remain.
• Massages help against cellulite. No again! It’s the same like with the salt poultices. It’s healthy, but doesn’t help against cellulite.
• Sports and healthy nutrition help. Nope. The cellulite will survive! But doing sports will help to shape the form of the body, so the unbeautiful cellulitis will be less eye-catching, but it will stay your most devoted friend.
• Slim women don’t have cellulite. This is also wrong, also very slim women can have it!
• Cellulite is a disease. No, it’s the most normal thing in the world and it is jut the opposite of a disease.

Cellulite is an adipose tissue the body of women needs for pregnancy and the later time of breast-feeding. Hormones control this supply, because women need an enormous amount of calorie during these times and therefore the evolution preferred women who are able to save fat in this special adipose tissue. So cellulite is useful and normal and nothing bad. It belongs to women like for example their bust.

Most men wouldn’t think of hiding their beer bellies or baldheads. So why do women think cellulite would be bad!? For my opinion let other people think whatever they want and show your cellulite by wearing proudly your shorts! And save all the money for remedies, which don’t help. As far as I know there is only one thing that would really help: A very radical diet, because this adipose tissue we call cellulite, is the last adipose tissue our body loses when we make a diet. But I can’t suggest doing this, because such radical diets also reduce your muscles and cause cardiac insufficiency. – Another argument for showing our cellulitie with pride. Hey, we are women and this damned cellulite is totally normal!

Cellulite is an invented disease - for me, which has a lot to do with our ideal of youth and beauty. In ancient times there have been other ideals of beauty and so nobody thought of cellulite like a disease.

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Sources:

• t-online.de;
• Wikipedia;
• http://www.figurelicious.com/articles/fitness/cellulite-invented-disease
• Beolingus dictionary translated the German word Cellulite into Cellulitis. Anyway  you know, that I mean the ugly (?) buckles on the legs and butt...

Pictures: Public domain

Dark Matter

Two gigantic galaxy-systems collided and a lot of mysterious dark matter came into being and formed a big ring. “Mother nature is making an experiment for us, we can’t do in our labs”, said James Jee, a scientist of the John-Hopkins-University in Baltimore. The space telescope Hubble found the strongest argument for the mysterious dark matter until now. In a 5 billion light years away pile of galaxies scientists discovered a ring of this substance. The European Hubble-Center at Garching near Munich reported this last Tuesday.

Picture: A warp which might be caused by dark matter

The group of scientists around James Jee examined the piles of galaxies ZwCl0024+1625 in the sign of the zodiac Pisces. First they discovered aberrations. The analysis of these strange warps showed that the reason was the gravity of a ring of dark matter. “Although this invisible dark matter has also found in other piles of galaxies, it is never before found separated as much from the galaxies and the hot gas of them.” Jee said.

Scientists suppose that dark matter is five times more frequent than normal matter, which stars and planets consist of. The dark matter can’t be watched directly, because it doesn’t send out light or other radiation. The only way to find dark matter is looking for warps caused by the gravitation of the matter. Matter and its gravitation attract light. So light is diffracted by gravitation and this causes the warps, which the scientists noticed in the pictures of Hubble. Until now it is not known of what substance dark matter consists. And it is not finally proved that it really exists. Without it’s existence Newton’s law of gravitation would be wrong. If this is enough to believe that there is really dark matter?

In Wikipedia you can also read about another understanding of the dark matter problem:

"A proposed alternative to physical dark matter particles has been to suppose that the observed inconsistencies are due to an incomplete understanding of gravitation.”

Well, I think you don’t need to know all these complex theories, which try to explain the universe without dark matter. For me as a non-astronomer they are mostly unintelligible like the theories that use dark matter for their explanations about the universe.

But another example would suggest being careful with such ideas: In the late 19th century scientists postulated the so called Luminiferous Aether, a substance which would fill all the empty space in the universe. They needed it to declare why electromagnetic waves could go through the universe. From other wave like water waves it was known that they all needed a substance like a fluid, a gas or rocks (earth quakes) for propagation. Later theories including special relativity were formulated without the aether concept, and today the aether is considered to be a superseded scientific theory.

So let’s see if scientists can really prove dark matter or not. I’m curious.

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Sources: t-online.de, Wikipedia (dark matter, Luminiferous Aether)

Picture: Public domain

Bad Breath

Beans defend themselves: caterpillars, which eat leaves or other parts of beans, get bad breath! And other plants can recognize the danger of greedy caterpillars by this bad breath. This is no joke, but the result of a study of American scientists published in the magazine “Plant Physiology”.

How does it work? After eating parts of bean plants the caterpillars’ spittle contains a chain of eleven amino acids, which comes into being when the caterpillars digest the parts of the bean plant, which contains a special protein. The product of the digestion is this chain of eleven amino acids, which produces a scent, which can warn other plants. If other bean plants notice a caterpillar with such bad breath they produce substances, which cause stomach pains for the caterpillars, and they produce other scents, which also warn the neighboring plants.

And what do these caterpillars with bad breath teach us? Scientists hope that they can use this knowledge to protect food crop better against varmints.

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Pictures: Public domain