#informativefacts

See the world through the eyes of a cat. By Shaunacy Ferro | PopSci | Image Credit: Nickolay Lamm

An awesome, disorienting look at kitty vision.

What does the world look like through a cat's eyes? The basic structure of feline eyes is pretty similar to what humans have, but cats' vision has adapted to very different purposes, so the world they see looks familiar, but isn't quite the same as ours. As predators, they need to be able to sense movement well in very low light. To make that work, they have to sacrifice some of the finer detail and color perception that humans have.

Artist Nickolay Lamm, who has previously brought us visualizations of urban heat islands and sea level rise projections, took a look at the world through kitty eyes for his latest project. Lamm consulted with ophthalmologists at the University of Pennsylvania's veterinary school and a few other animal eye specialists to create these visualizations comparing how cats see with how humans do. How we see things is represented on top; how a cat standing next to us would see the same scene appears below. 

Some of the cat-eye facts he took into account: The blurry edges of the pictures represent peripheral vision. Humans have a 20 degree range of peripheral vision on each side. Cats can see 30 degrees on each side. Their visual field overall is just bigger—they see 200 degrees compared to our 180 degrees.

Cat vision isn't so great at a distance. What we can see sharply from 100 feet away, they need to see at 20 feet. From what researchers can tell, cats can see blue and yellow colors, but not red, orange or brown, which is why all the images look a little washed out. Your kitty sees in Instagram, it seems. Not so good for looking at far-away, lush landscapes.

But the last image above shows how much better cats' night vision is.

Cats can see some six to eight times better than us in the dark, partially because they have more rods, a type of photoreceptor in the retina. Their elliptical pupils can open very wide in dim light, but contract to a tiny slit to protect the sensetive retina from bright light. And like other animals that evolved to hunt at night, cats have a tapetum lucidum, a reflective layer of tissue that bounces light that hits the back of the eye out through the retina again for a second chance to be absorbed by the rods. It's also what gives them those terrifying glowing eyes in pictures.

The Science of Flaming Farts. By Esther Inglis-Arkell | io9 | Image Credit: Gif made by The Science of Reality, video via Youtube.

You know you've always wondered why farting on a lighter causes a brief burst of flame. Believe it or not, there is rarely any methane in farts, and so methane is not what’s burning when farts are ignited. Find out what does, and why some farts ignite and others don’t.

It’s a commonly-held belief that farts contain methane, which is why they smell and they can ignite. And this would be true, if people were cows. Actually, the gut bacteria of humans generally don’t produce methane. There are certain kinds, which live in a certain percentage of the population, that do produce methane, but it’s far from in the majority of farts.

What actually makes it through your body will depend on many things, including what you put in. Eggs, cauliflower, and meats are often more sulfur-rich and so add a little hydrogen sulfide to the final, ah, product. As for the rest, the largest component is often nitrogen, which is already a good portion of the atmosphere, and so doesn’t ignite all that readily.

What will? Mostly it’s the hydrogen in the hydrogen sulfide that’s released. Occasionally, if the person does have the lucky gut that produces methane, it will burn along with the hydrogen. In order to get the most flammable fart, people will generally eat sulfur-rich foods. It’s not a good idea to hold them in and store them up, as to those who have tested the technique a held-in fart is less likely to catch fire.

A typical breakdown of the chemical composition of farts via About.com's Chemistry section:

Nitrogen: 20-90%

Hydrogen: 0-50% (flammable)

Carbon dioxide: 10-30%

Oxygen: 0-10%

Methane: 0-10% (flammable)

Oh, but don’t go for the matches just yet. About a quarter of the fart igniters get burned in the process. There is no way to stress how little anyone likes to get burned in that area. Worse, the ignition of the released fart can ignite gasses higher up the intestinal tract, and sometimes, high in the intestinal tract, there will be swallowed oxygen. Oxygen is swallowed daily, but generally doesn’t make it out of the body because it is so readily absorbed into cells.

Oxygen is also likely to ignite explosively if heated, and this has happened during surgical procedures carried out in the intestinal area – though there is no record of it happening when someone tried to ignite their farts. Still, it’s a bad idea to take even the most remote chance on an internal Hindenburg. Just let this knowledge seep into your mind, and keep your downstairs area well clear of it.

Elements in Fireworks via Milky way scientists via About.com  By Anne Marie Helmenstine, Ph.D.

Fireworks are a traditional part of many celebrations, including Independence Day. There is a lot of physics and chemistry involved in making fireworks. Their colors come from the different temperatures of hot, glowing metals and from the light emitted by burning chemical compounds. Chemical reactions propel them and burst them into special shapes. Here's an element-by-element look at what is involved in your average firework:

Aluminum - Aluminum is used to produce silver and white flames and sparks. It is a common component of sparklers.

Antimony - Antimony is used to create firework glitter effects.

Barium - Barium is used to create green colors in fireworks, and it can also help stabilize other volatile elements.

Calcium - Calcium is used to deepen firework colors. Calcium salts produce orange fireworks.

Carbon - Carbon is one of the main components of black powder, which is used as a propellent in fireworks. Carbon provides the fuel for a firework. Common forms include carbon black, sugar, or starch.

Chlorine - Chlorine is an important component of many oxidizers in fireworks. Several of the metal salts that produce colors contain chlorine.

Copper - Copper compounds produce blue colors in fireworks.

Iron - Iron is used to produce sparks. The heat of the metal determines the color of the sparks.

Lithium - Lithium is a metal that is used to impart a red color to fireworks. Lithium carbonate, in particular, is a common colorant.

Magnesium - Magnesium burns a very bright white, so it is used to add white sparks or improve the overall brilliance of a firework.

Oxygen - Fireworks include oxidizers, which are substances that produce oxygen in order for burning to occur. The oxidizers are usually nitrates, chlorates, or perchlorates. Sometimes the same substance is used to provide oxygen and color.

Phosphorus - Phosphorus burns spontaneously in air and is also responsible for some glow-in-the-dark effects. It may be a component of a firework's fuel.

Potassium - Potassium helps to oxidize firework mixtures. Potassium nitrate, potassium chlorate, and potassium perchlorate are all important oxidizers.

Sodium - Sodium imparts a gold or yellow color to fireworks, however, the color may be so bright that it masks less intense colors.

Sulfur - Sulfur is a component of black powder. It is found in a firework's propellant/fuel.

Strontium - Strontium salts impart a red color to fireworks. Strontium compounds are also important for stabilizing fireworks mixtures.

Titanium - Titanium metal can be burned as powder or flakes to produce silver sparks.

Zinc - Zinc is used to create smoke effects for fireworks and other pyrotechnic devices.

Learn more about fireworks by clicking the following links:

History of Fireworks

How Fireworks Work

The universally acknowledged Irish mascot that is the three-leafed clover is also known as trifolium repens, which hints at the rarity of the phenomenon of the very existence of a clover with four leaves. The first half of it's scientific name, trifolium, in layman's term means three-leafed. Statistically it's estimated one out of about every 10,000 clovers is four-leafed. 

This mis-interpreted symbol of luck is more of a genetic rarity than a bringer of good fortune. Scientists from the University of Georgia studied the DNA of the white clover in 2010, the same plant that is symbolically related with St. Patrick's Day, and not only discovered previously-unknown genes, but revealed one of the newly-observed genes was the very genetic mutation that caused the phenomenon of the "lucky" four-leaf clover. The scientists also revealed the reason four-leaf clovers are rare is because the very gene that causes the growth of an extra leaf is, more times than not, closeted by a different gene that regulates the three-leafed trait. The published work of these scientists is available here in the journal Crop Science.

Even more surprising is that the genetic rarity of extra-leaf-growth doesn't stop at four. There have been known instances of people finding five-leaf clovers, there's even a  Guinness world record for a clover with the most leaves, which just so happens to be 56, which was discovered by Shigeo Obara in Hanamaki City, Japan in 2009. Even better, Shigeo is a retired crop researcher, with a focus on breeding clovers, specifically, which means he had mutually impressive previous world records of abnormally leafed clovers. In 2008 he revealed his 21-leaf clover, which trumped his 18-leaf clover from 2002. 

The Science of Ant Mills aka Death Spirals.

"Imagine a complex society that can accomplish amazing things, but also has an error in its programming that, occasionally, causes many of its members to run amok and die tragically. This is the situation faced by some species of ants, and the behavior is called a death spiral or an ant mill. You can see several examples in the videos below. The ants seem to have gone insane, walking in an endless circle together.

Ant Death Spiral:

Beebe (1921) described a circular mill he witnessed in Guyana. It measured 1200 feet in circumference and had a 2.5 hour circuit time per ant. The mill persisted for two days, “with ever increasing numbers of dead bodies littering the route as exhaustion took its toll, but eventually a few workers straggled from the trail thus breaking the cycle, and the raid marched off into the forest.”

The cause of this behavior is the technology ant societies use for ground navigation. They follow pheromone trails on the ground laid down by other ants, or they simply follow other ants visually. The system works well normally. A scout ant goes out and finds something. Other ants go back to get more by following the scent trail, or by following each other. However, if a loop gets created, the ants will march blindly, sometimes circling until they die.

You can see an ant pheromone trail being formed in this video: Fire ant pheromone." 

The Merriam-Webster Dictionary defines astronomy as "the science of objects and matter beyond the Earth's atmosphere", and astrology as "divination based upon the supposed influence of the stars upon human events". Now let's break this down below, not too much, but enough for you to see, through pure language, how obvious the difference is. 

Astronomy: "The science"[also defined as "an area of knowledge that is an object of study", or "knowledge covering general truths or the operation of general laws especially as obtained through the scientific method". Scientific method is, to put very simply, "finding and stating a problem, the collection of facts through observation and experiment, and the making and testing of ideas that need to be proven right or wrong."] "of objects and matter beyond the Earth's atmosphere."  So, to generally state, astronomy is a science based off of facts and findings, that are continually tested until proven true or false, concerning very real and solid objects and matter within the universe outside of our own planet. 

Astrology: "Divination" [defined as "the art or practice of using omens or magic powers to foretell the future"] "based upon the supposed" [with supposed defined as "mistakenly believed"] "influence of the stars upon human events." Which is very simply stated as practicing with superstitious and immensely exaggerated "magic" and/or "omens" to make generalized, and baseless, predictions for universally microscopic humans depending on our perceived position[s] of the [annual and daily] stars, constellations, and "heavenly bodies" of our night skies/celestial sphere.

In comparison, on one hand you have a science concerning the stars, and other celestial bodies, outside of Earth's own atmosphere and how they exist and coexist within their respected "systems". On the other hand you have an "art", of sorts, based upon superstitious and fallible predictions of individual human lives that are assumably determined by the stars and planets in relation to their positions within our skies. 

In ancient times astrology was so commonplace during the beginnings of astronomy that astronomers and astrologers were usually one in the same, and "well versed" in both subjects and practices. Although nowadays, thanks to the continuous advancements of  the science world and our growing knowledge of the universe, astrology may seem a bit silly and childish, but it's quite easy to understand, when looking into the origins of astronomy, why astrology was originally so popular and quickly accepted by our ancestors. 

The sun and moon in our sky clearly influence our lives in many ways, from determining seasons to causing the tides, as well as determining the daily amount daylight and darkness. The lunar phases even happen to coincide with many biological cycles, such as crops. Of course, when looking into the night sky, our ancestors observed the planets alongside the plethora of stars, including our own, and to them it seemed reasonable to assume they influenced our lives in just as many ways, if not more. Unbeknownst to them, their initial assumptions were correct, aside from positions of stars and planets directly effecting the social/personal aspects of human life, and would remain undiscovered for many years until our understanding of our solar system, and astronomy itself, evolved on many levels. 

Now we recognize the ideas of things like energy and gravity that explain the influences of our Sun and Moon, which also prove, with modern science, that the other planets are too far from us astronomically to have any significant infleunce on our own planet, or anything biological including ourselves and our lives. The data is shown below via this post here:

ON THE GRAVITATIONAL EFFECTS OF THE PLANETS, FROM NASA’S WEBSITE:

Here is a table of tidal forces of the Sun, Moon, and Planets. With the Sun’s tidal force equal to 1.00, the following values are given in Thompson (1981):

Moon: 2.21

Sun: 1.00

Venus: 0.000113

Jupiter: 0.0000131

Mars: 0.0000023

Mercury: 0.0000007

Saturn: 0.0000005

Uranus: 0.000000001

Neptune: 0.000000002

Pluto: 0.0000000000001

ON THE MAGNETIC EFFECTS OF THE PLANETS, FROM WIKIPEDIA:

Others have proposed conventional causal agents such as electro-magnetism within an intricate web of planetary fields and resonances in the solar system. Scientists dismiss magnetism as an implausible explanation, since the magnetic field of a large but distant planet such as Jupiter is far smaller than that produced by ordinary household appliances.

Astrology has fallen by the wayside and has become a children's topic compared to modern scientific endeavours and achievements. With the constant testing and re-testing associated with true science, astrology fails to meet the constantly-questioning requirements of scientific thinking and skepticism. 

Ever wondered how food tastes in space?

"Canadians have a well-known love affair with maple syrup. So, naturally, when Canadian astronaut Chris Hadfield took the reins as commander of the International Space Station, it was only a matter of time until the matter of Canadian cuisine came up. But what does food taste like in space? One student from Airdrie, Alberta asked that question during a "Let's Talk Science" event sponsered by the Canadian Space Agency. And Commander Hadfield has the answers.

The most interesting thing to take away from this video -- other than the endless pleasure of watching objects float around in zero gravity -- is Hadfield's description of what sounds like an outer space-induced head cold. The human body is so used to the pressures of gravity that it is constantly working to keep blood in the upper part of the body. But in space, the lack of gravity means blood is free to flow in any direction, something the body has to adjust to, resulting in excess fluids in the head. The result is stuffy sinuses and food that, "doesn't taste like anything."