The Africans:


There is a Zebra hidden in their clothes.


Fly Fishing Trip:

This painting depicts a man on a fly fishing trip. If this guy knew what else there is to be seen in this forest, he probably wouldn't be fishing though ...
The rock in the river are shaped like a naked woman

Hidden Lion:

Can you find the lion. You'll have to admit this is really cool.

The Hidden Tiger:

Can you find ... The hidden tiger ? Not the very obvious one, of course.
The sentence The Hidden Tiger is written in the tiger stripes.

Love:

Can you see what is hidden in this picture ?
The seagulls spell out the word LOVE.

Hidden Orchestra:

Mr. Rust has hidden an orchestra in plain sight! But where ?
In the mountains.

Music:

The statue on the left of the painting is obvious. But there is also another person playing music. Where is he, and what musical instrument is he playing?
A Saxophone player in front of the right pillar.

Lost Tiger:

Start looking at this image with your nose to the screen. You'll see puzzle pieces, some in the shape of animals. Now keep increasing your distance from the screen until you can see the lost tiger!

Dreams:

Something is hidden in the barn. Can you find it ?
The barn door shows an antique car.

Valley of the Tiger:

From a distance this is the painting of a tiger. In close-up it's a grassy landscape with some small rivers and two tigers. This is one of the best ambiguous images around because it works so well on both levels.



The waterfall looks like a group of horses standing next to each other.



The hill on the left gives the illusion of the head of a fox (or wolf).



There is a tiger hidden in this picture. Look closely at the centre of the picture and you can spot the tiger.



There are 3 wolves waiting to get hold of the deer! Cant spot them??
Look at the mountains.



The region between the two trees look like the face of a human.



Water, good ol’ H2O, seems like a pretty simple substance to you and me. But in reality, water - the foundation of life and most common of liquid - is really weird and scientists actually don’t completely understand how water works.

Here are 5 really weird things about water:

1. Hot Water Freezes Faster Than Cold Water
Take two pails of water; fill one with hot water and the other one with cold water, and put them in the freezer. The hot one would be frozen before the cold one. But wait, you say, that’s counterintuitive: wouldn’t the hot water have to cool down to the temperature of the cold water before proceeding to freezing temperature, whereas the cold one has “less to go” before freezing?

In 1963, a Tanzanian high-school student named Erasto B. Mpemba was freezing hot ice cream mix in a cooking class when he noticed that a hot mix actually froze faster than a cold mix. When he asked his teacher about this phenomenon, his teacher ridiculed him by saying “All I can say is that is Mpemba’s physics and not universal physics.”

Thankfully, Mpemba didn’t back down - he convinced a physics professor to conduct an experiment which eventually confirmed his observations: in certain conditions, hot water indeed freezes before cold water*.

Actually, Mpemba was in good company. The phenomenon of hot water freezing first, now called the “Mpemba effect” was noted by none other than Aristotle, Francis Bacon and René Descartes.

But how do scientists explain this strange phenomenon? It turns out that no one really knows but there are several possible explanations, including differences in supercooling (see below), evaporation, frost formation, convention, and effects of dissolved gasses between the hot and cold water.

*In reality - of course - it’s much more complex than that: hot water freezes first (it forms ice at a higher temperature than cold water), whereas cold water freezes faster (it takes less time to reach the supercooled state from which it forms ice)

2. Supercooling and “Instant” Ice
Everybody knows that when you cool water to 0 °C (32 °F) it forms ice … except that in some cases it doesn’t! You can actually chill very pure water past its freezing point (at standard pressure, no cheating!) without it ever becoming solid.

Scientist know a lot about supercooling: it turns out that ice crystals need nucleation points to start forming. These nucleation points could be anything from gas bubbles to impurities to the rough surface of the container. Without these things, water would continue to be a “supercooled” liquid well below its freezing point.

When nucleation is triggered, then a supercooled water would “instantly” turn into ice, as this very cool video clip by Phil Medina of MrSciGuy shows.

Note: Similarly, superheated water remains liquid even when heated past its boiling point.

3. Glassy Water

Quick: How many phases of water are there? If you answer three (liquid, gas, and solid) you’d be wrong. There are at least 5 different phases of liquid water and 14 different phases (that scientists have found so far) of ice.

Remember the supercooling we talked about before? Well, it turns out that no matter what you do, at -38 °C even the purest supercooled water spontaneously turns into ice (with a little audible “bang” no less). But what happens if you continue to lower the temperature? Well, at -120 °C something strange starts to happen: the water becomes ultraviscous, or thick like molasses. And below -135 °C, it becomes “glassy water,” a solid with no crystal structure. (Source)

4. Quantum Properties of Water
At a molecular level, water is even weirder. In 1995, a neutron scattering experiment got a weird result: physicists found that when neutrons were aimed at water molecules, they “saw” 25% fewer hydrogen protons than expected.

Long story short, at the level of attoseconds (10-18 seconds) there is a weird quantum effect going on and the chemical formula for water isn’t H2O. It’s actually H1.5O! (Source)

5. Does Water Have Memory?

In the alternative medicine of homeopathy, a dilute solution of a compound can have healing effects, even if the dilution factor is so large that statistically there isn’t a single molecule of anything in it except for water. Homeopathy proponents explain this paradox with a concept called "water memory" where water molecules "remember" what particles were once dissolved in it.

This made no sense to Madeleine Ennis, a pharmacologist and professor at Queen’s University in Belfast, Northern Ireland. Ennis, who also happened to be a vocal critic of homeopathy, devised an experiment to disprove "water memory" once and for all - but discovered that her result is the exact opposite!


In her most recent paper, Ennis describes how her team looked at the effects of ultra-dilute solutions of histamine on human white blood cells involved in inflammation. These “basophils” release histamine when the cells are under attack. Once released, the histamine stops them releasing any more. The study, replicated in four different labs, found that homeopathic solutions - so dilute that they probably didn’t contain a single histamine molecule - worked just like histamine. Ennis might not be happy with the homeopaths’ claims, but she admits that an effect cannot be ruled out.

So how could it happen? Homeopaths prepare their remedies by dissolving things like charcoal, deadly nightshade or spider venom in ethanol, and then diluting this “mother tincture” in water again and again. No matter what the level of dilution, homeopaths claim, the original remedy leaves some kind of imprint on the water molecules. Thus, however dilute the solution becomes, it is still imbued with the properties of the remedy.

You can understand why Ennis remains skeptical. And it remains true that no homeopathic remedy has ever been shown to work in a large randomised placebo-controlled clinical trial. But the Belfast study (Inflammation Research, vol 53, p 181) suggests that something is going on. “We are,” Ennis says in her paper, “unable to explain our findings and are reporting them to encourage others to investigate this phenomenon.” If the results turn out to be real, she says, the implications are profound: we may have to rewrite physics and chemistry. (Source)

So far, other scientists failed to reproduce Ennis’ experimental findings (throughout, Ennis herself was skeptical of the result’s interpretation that water has a “memory” but maintained that the phenomenon she saw was real).

More recently, a team of scientists at the University of Toronto, Canada, and Max Born Institute in Germany, studying water dynamics using fancy multi-dimensional nonlinear infrared spectroscopy did find that water have a memory of sorts - in form of hydrogen bond network amongst water molecules. Problem for homeopathy was, this effect lasted only 50 femtoseconds (5 x 10-14 seconds)!

Bonus: Ice Spikes

Ice spikes are, well, spikes that grow out of ice cube trays. They look like stalagmites found in caves, and you can make ‘em yourself using distilled water. Kenneth G. Libbrecht of SnowCrystals explains:

How do Ice Spikes Form?

Ice spikes grow as the water in an ice cube tray turns to ice. The water first freezes on the top surface, around the edges of what will become the ice cube. The ice slowly freezes in from the edges, until just a small hole is left unfrozen in the surface. At the same time, while the surface is freezing, more ice starts to form around the sides of the cube.

Since ice expands as it freezes, the ice freezing below the surface starts to push water up through the hole in the surface ice (see diagram). If the conditions are just right, then water will be forced out of the hole in the ice and it will freeze into an ice spike, a bit like lava pouring out of a hole in the ground to makes a volcano. But water does not flow down the sides of a thin spike, so in that way it is different from a volcano. Rather, the water freezes around the rim of the tube, and thus adds to its length. The spike can continue growing taller until all the water freezes, cutting off the supply, or until the tube freezes shut. The tallest spike we’ve seen growing in an ordinary ice cube tray was 56mm (2.2in) long. (Source)

Bonus 2: Make Instant Snow with Boiling Water
What do you get when you throw boiling water to the air in subzero weather? Instant snow. Interestingly, it only works with boiling hot water : Watch here

These aren’t the only things weird about water. We didn’t talk about how water density changes with temperature (ice, for instance, is less dense than water so it floats - a key property of water that made life possible in the oceans and lakes). Nor did we talk about the weirdly strong surface tension of water, ordered clustering of liquid water, and so on. If you are interested, check out the Anomalous Properties of Water article by Martin Chaplin.




Original article here.

High speed, or "flash" photography is an art, widely used in scientific research, which also has a dedicated following among those wanting to "blow things apart" in the most elegant way possible. It's not easy to come up with a perfect shot... consider 1200ft/sec average speed of a bullet, plus a synchronizing laser, hi-tec flash setup and a fancy camera-work. The following is "the best of" gallery from a few masters of the genre.

Stefan, a.k.a. Fotofrog has a gorgeous set, where fruits and some vegetables get blown to smithereens, together with some tableware:
























(images credit: Stefan - Fotofrog)

Crayons from Spyzter:

(image credit: Khuong)

Shattered glass lamp:

("Shattered Glass" by Raniel)

Peeled banana (and more from Jasper Nance)


Antibacterial soap bar:


Unfortunate doll:


Hot tomato:

(images credit: Jasper Nance)

Bullet through a bottle:

(image credit: Johnny Lee)

"Pulsetronics" is UK company specializing in high-speed photography, mostly for science research. They also have a few artistic gems there:










Full Magnum Force:

(image credit: Arya Abidi)

Two spherical shock waves are visible on this "schlieren image" (an interferometric technique used to study the distribution of density gradients within a transparent medium). A serious weapon with considerable force, but nothing a good solid bottle of beer couldn't do:

Any time you feel dumb, don't worry. Check out the following excerpts from a "Wall Street Journal" article by Jim Carlton. Lots of people are dumber than you.

1. Compaq is considering changing the command "Press Any Key" to "Press Return Key" because of the many calls asking where the "Any" key is.

2. AST technical support had a caller complaining that her mouse was hard to control with the dust cover on. The cover turned out to be the plastic bag the mouse was packaged in.

3. Another Compaq technician received a call from a man complaining that the system wouldn't read word processing files from his old diskettes. After trouble-shooting for magnets and heat failed to diagnose the problem, it was found that the customer labeled the diskettes by rolling them into a typewriter to type on them.

4. Another AST customer was asked to send a copy of her defective diskettes. A few days later a letter arrived from the customer along with Xeroxed copies of the floppies.

5. A Dell technician advised his customer to put his troubled floppy back in the drive and close the door. The customer asked the tech to hold on, and was then heard putting the phone down, getting up and crossing the room to close the door to his room.

6. Another Dell customer called to say he couldn't get his computer to fax anything. After 40 minutes of trouble-shooting, the technician discovered the man was trying to fax a piece of paper by holding it in front of the monitor screen and hitting the "send" key.

7. Another Dell customer needed help setting up a new program, so a Dell tech suggested he go to the local Egghead. "Yeah, I got me a couple of friends," the customer replied. When told "Egghead" was a software store, the man said, "Oh, I thought you meant for me to find a couple of geeks."

8. Yet another Dell customer called to complain that his keyboard no longer worked. He had cleaned it by filling up his tub with soap and water and soaking the keyboard for a day, then removing all the keys and washing them individually.

9. A Dell technician received a call from a customer who was enraged because his computer had told him he was "bad and an invalid". The tech explained that the computer's "bad command" and "invalid" responses shouldn't be taken personally.

10. An exasperated caller to Dell Computer Tech Support couldn't get her new Dell Computer to turn on. After ensuring that the computer was plugged in, the technician asked her what happened when she pushed the power button. Her response, "I pushed and pushed on this foot pedal and nothing happens." The "foot pedal" turned out to be the computer's mouse.

11. Another customer called Compaq tech support to say her brand-new computer wouldn't work. She said she unpacked the unit, plugged it in, and sat there for 20 minutes waiting for something to happen. When asked what happened when she pressed the power switch, she asked "What power switch?"

We yell for the Government to balance the budget, then take the last dime we have to make the down payment on a car that will take 5 years to pay off.

We demand speed laws that will stop fast driving, then won't buy a car if it can't go over 100 miles an hour.

We know the line-up of every baseball team in the American and National Leagues but mumble through half the words in the "Star Spangled Banner."

We'll spend half a day looking for vitamin pills to make us live longer, then drive 90 miles an hour on slick pavement to make up for lost time.

We tie up our dog while letting our sixteen year old son run wild.

We whip any enemy in battle, then give them the shirt off our backs.

We will work hard on a farm so we can move into town where we can make more money so we can move back to the farm.

We run from morning to night trying to keep our "earning power" up with our "yearning power."

We get upset we're spending over a billion dollars for education, but spend three billion dollars a year for cigarettes.

In the office we talk about baseball, shopping or fishing, but when we are out at the game, the mall or on the lake, we talk about business.

We're supposed to be the most civilized Christian nation on earth, but we still can't deliver payrolls without an armored car.

We have more experts on marriage than any other country in the world and still have more divorces.

We're the country that has more food to eat than any other country in the world and more diets to keep us from eating it.

The EMBRIO Advanced Concept is a one-wheeled recreational and commuting vehicle for the year 2025, designed by the Canadian company Bombardier Recreational Products. Although the riding position is similar to that of a motorcycle, the vehicle uses sensors and gyroscopes to balance up to two passengers on a large single wheel whilst driving.
Specifications and pictures of this weird motorcycle are showed below:



TECHNICAL SPECIFICATIONS

MODEL NAME: EMBRIO Advanced Concept
DEVELOPED BY: Bombardier Recreational Products
STATUS: Concept
YEAR: 2003
DRIVE SYSTEM: Fuel cell electric
FUEL: Hydrogen
LENGTH: 1,240 mm (48.8 in)
WIDTH: 700 mm (27.5 in)
HEIGHT: 1,200 mm (47.5 in)
WEIGHT: 164 kg (360 lbs)
SEATING CAPACITY: 2





Although the vehicle will also remain stable when motionless, with two small front wheels deployed at speeds below 20 kilometres per hour (12.5 mph). To move forward, the rider activates a trigger on the left handlebar. At a speed of 20 kilometres per hour (12.5 mph) the front wheels or “landing gear” retracts so the rider is balancing on the large single wheel. To turn the rider leans to the left or right. The brake is activated by a trigger on the right handlebar. Fuel cells running on hydrogen provide electricity for the electric motor which drives the single wheel.


Five Flower Lake in Jiuzhaigon National Park, China, is known for its crystal
turquoise waters. The floor of the lake is littered with ancient fallen trees
from the surrounding forests.


Another view of Peyto Lake in Banff, demonstrating how light reflection can
drastically alter the colour of water.


This amazing shot was taken near Uyuni, Bolivia. The dark green waters are so
calm the mountains are reflected perfectly.


Wise Lake turned green from overhanging trees at Congaree National Park
in South Carolina.


A cleverly placed sunglasses lens in front of the camera turns
Kournas Lake in Crete an interesting green colour.


A lime green colored lake at Mill Hollow in the Unita Forest
is actually named Yellow Lake.


Wonderful shot of a large salt lake, Uyuni, Bolivia. The red colour is caused by
astronomical numbers of microscopic, unicellular organisms living in the water and salt crust.


Deep red tones over Lake Michigan at dusk.


A deep red lake at Sanetsch Pass, Switzerland.


Purple and blue skies at sunset over Lake Tahoe, California/Nevada.