(via we-are-star-stuff)

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.” 

Watch more videos of ant mills here.

ucresearch:

Summer in the city can be especially hot and sticky, because urban heat islands exacerbate the warm weather. Researchers at Berkeley Lab are testing materials that battle that effect, making pavements cooler and safer.

Learn more about their research →

(via reillyinspace)

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. 

While it’s roots are easily understandable, considering the limited resources our ancestors had access to, you can now hopefully see why scientists, teachers, and science enthusiasts alike get upset when one mistakes astronomy for astrology and vice versa. With the ever advancing evolution of science, particularly astronomy, astrology became known as a “pseudo-science” of laughable proportions due to it’s archaic basis that did not evolve respectably over the course of history through solid scientific methods. Now that you know the difference, I hope you continue to improve your own personal methods of scientific thinking, questioning, and skepticism, as well as straying from taking pseudo-sciences such as astrology as seriously as many people mistakenly still do. 

(Source: thescienceofreality)

thatscienceguy:

Simple House Hold Science Trick: Borax Slime

This one I have personally done many times!

Needed;

• White Glue Paste (most different variations will work)
• 2 cups/bowls
• food colouring (optional)
• Borax Powder (available in most supermarkets, in the Laundry department)

Steps:

1. add one tablespoon of borax to half a cup of water, stir it well and then set it aside.
2. In the other cup/bowl add about 80ml (3oz or 1/3cup) with 20ml of water (3 table spoons)
3. add food colouring (Note* be careful using red, it comes out pink. I made that mistake… twice.) and stir.
4. add one tablespoon of the Borax/water solution to the entire Glue/water solution and stir.
5. Let it sit for about half a minute.
6. Have Fun! (if you have no other uses for the left over ingredients, try using different amounts to make different consistencies, or even multiply all the amounts evenly to make one giant blob!)

(via eatgeekstudy)

scienceisbeauty:

Potential flow around an airfoil, constructed with a Joukovski transform and inviscid, incompressible flow. Levels of blue represent pressure (darkest is highest).

By Thierry Dugnolle (Own work) [CC0], via Wikimedia Commons

biocanvas:

Light strikes the retina located in the back of our eyes, allowing us to see. Within the retina are neurons that transmit a signal to the brain when they are stimulated with light. Seen here is the surface of the retina from a mouse, with neurons converging towards the optic disc (bottom), the location where neurons exit the eye towards the brain.

Image by Dr. Alejandra Bosco, University of Utah.

nprfreshair:

Today’s guest and author of Gulp: Adventures on the Alimentary Canal, Mary Roach in Popular Science:

Taste is a sort of chemical touch. Taste cells are specialized skin cells. If you have hands for picking up foods and putting them in your mouth, it makes sense for taste cells to be on your tongue. But if, like flies, you don’t, it may be more expedient to have them on your feet. “They land on something and go, ‘Ooh, sugar!’ ’’ Rawson does her best impersonation of a housefly. “And the proboscis automatically comes out to suck the fluids.” Rawson has a colleague who studies crayfish and lobsters, which taste with their antennae. “I was always jealous of people who study lobsters. They examine the antennae, and then they have a lobster dinner.”

The study animal of choice for taste researchers is the catfish, simply because it has so many receptors. They are all over its skin. “They’re basically swimming tongues,” says Rawson. It is a useful adaptation for a limbless creature that locates food by brushing up against it; many catfish species feed by scavenging debris on the bottom of rivers.

I try to imagine what life would be like if humans tasted things by rubbing them on their skin. Hey, try this salted caramel gelato—it’s amazing.

Image by Emily Cavalier

ikenbot:

Memory Myths

As a lifelong user of human memory, you probably feel you’ve got a good idea of how it works, right? To test your understanding of memory, we compare several commonplace conceptions with insights from psychology.

by Christian Jarrett

Memory acts like a video recorder

In a US survey published in 2011, 63% of 1,838 respondents said they believed “strongly” or “mostly” that memory works like a video camera, “accurately recording events we see and hear so that we can review and inspect them later”. Memory is, in fact, a creative, fallible process, highly prone to suggestion and other distorting influences.

Some people have photographic memories

An extension to the memory as video recorder myth is the idea that some people have a “photographic memory”; that they can take a snap shot of a scene or a page in a book, and then bring it to mind whenever they want to.

It’s tempting to invoke such an ability to explain the achievements of celebrated memory champions such as Lu Chao. In 2005, he set a new world record (as recognised by the Guinness World Records) by reciting the first 67,890 digits of pi entirely from memory. However, studies of memory champions reveal that they depend on mnemonic devices and thousands of hours of practice.

A related concept is eidetic imagery, in which a person claims to “see” a detailed visual scene that is no longer visible. However, tests of “eidetikers” find their memory of images to be no more accurate than control participants. It seems they just feel as though the image is vivid and still “out there” rather than in their heads.

Forgetting occurs gradually

Some memory misconceptions have serious consequences for the way eye- (and ear-) witness testimony is treated in court. For example, many people, including psychologists (according to a recent Norwegian survey), believe that forgetting occurs gradually, as if memories decay like an ageing reel of film. In fact, most forgetting occurs immediately after an event.

Confidence is a reliable indicator of memory accuracy

While it’s true that accuracy and confidence can correlate within a single person’s repertoire of recollections, confidence is a poor marker of accuracy when judging a single act of recollection or when comparing across witnesses. One reason is that some factors, such as repeated questioning, can boost confidence without increasing accuracy. Also, we all vary in our baseline levels of memory confidence. So when judging a single witness, we don’t know if their confidence is high by their standards. In the legal system, when convicted people are exonerated by DNA evidence, confident testimony from an eye witness is the most common reason they were originally found guilty.

A related myth is that emotional events lead to more ingrained, accurate memories. Memories for dramatic events often feel more vivid and people feel more confident in these memories, but, in fact, they are just as prone to being forgotten as ordinary memories. Furthermore, if an event is stressful, this is likely to interfere with remembering details of that event.

Traumatic memories can be repressed and “recovered” years after they occurred

While subscribing to the erroneous idea that memories of emotive events are highly accurate, many people also often hold the somewhat paradoxical belief that traumatic memories, such as of abuse in childhood, are prone to repression. A related belief is that such memories can be “recovered” later in life, dug out with the help of a skilled therapist, or perhaps a hypnotist.

In fact, studies of child abuse victims suggest strongly that they usually do not forget their experiences. Moreover, research has shown that memories of abuse “recovered” in therapy are far less likely to be corroborated by third parties, or other evidence, than abuse memories recalled later in life outside of therapy, or never-forgotten abuse memories.

The consensus of the American Psychological Association on child abuse memories says that “most people who were sexually abused as children remember all or part of what happened to them, although they may not fully understand or disclose it”.

Hypnosis can be used to retrieve forgotten memories

Many people believe that hypnosis can be used to unearth not only past traumas but all manner of long-forgotten memories, including recollections way back to the womb or even to past lives.

In a way, it is a belief that is consistent with the “memory as a video recorder” myth; the mistaken rationale being that because everything we experience is stored, we just need to find a way to reach it. In fact, nearly all the evidence suggests that hypnosis fails to aid recall, but instead has the potentially harmful effect of increasing people’s faith in their memories, whether or not they are accurate recollections of events.

Amnesiacs forget who they are

A persistent myth is the idea that people suffering from amnesia have lost their long-term memory, including any recollection of their identity. In fact, amnesia caused by illness or brain damage typically manifests as an inability to lay down new memories. Specifically what is broken is the ability to convert short-term memories into long-term memories. An amnesiac will usually be able to tell you who they are and share stories about their earlier lives, but they won’t be able to tell you what they had for breakfast.

• Dr Christian Jarrett is author of The Rough Guide to Psychology. He blogs for the British Psychological Society at bps-research-digest.blogspot.com and is currently writing Great Myths of the Brain (Wiley-Blackwell). Follow him on Twitter at @Psych_Writer

• This article was corrected on 16 January 2012 because it said Hideaki Tomoyori set a new world record for reciting the first 67,890 digits of pi entirely from memory. Lu Chao set this record.

quantumaniac:

Introduction to How Marijuana Works

Marijuana is the buds and leaves of the Cannabis sativa plant. This plant contains more than 400 chemicals, including delta-9-tetrahydrocannabinol (THC), the plant’s main psychoactive chemical. THC is known to affect our brain’s short-term memory. Additionally, marijuana affects motor coordination, increases your heart rate and raises levels of anxiety. Studies also show that marijuana contains cancer-causing chemicals typically associated with cigarettes.

Marijuana plants contain more than 400 chemicals, 60 of which fit into a category called cannabinoids. THC is just one of these cannabinoids, but it’s the chemical most often associated with the effects that marijuana has on the brain. Cannabis plants also contain choline, eugenol, guaicacol and piperidine. The concentration of THC and other cannabinoids varies depending on growing conditions, plant genetics and processing after harvest. 

Marijuana in the Body

Every time a user smokes a marijuana cigarette or ingests marijuana in some other form, THC and other chemicals enter the user’s body. The chemicals make their way through the bloodstream to the brain and then to the rest of the body. The most powerful chemical in marijuana is THC (delta-9-tetrahydrocannabinol), which is primarily responsible for the “high” associated with the drug.

The most common way of using marijuana is smoking. Smoking is also the most expedient way to get the THC and other chemicals into the bloodstream. When the smoke from marijuana is inhaled, the THC goes directly to the lungs. Your lungs are lined with millions of alveoli, the tiny air sacs where gas exchange occurs. These alveoli have an enormous surface area — 90 times greater than that of your skin — so they make it easy for THC and other compounds to enter the body. The smoke is absorbed by the lungs just seconds after inhaling.

You can also eat marijuana. In this case, the marijuana enters the stomach and the blood absorbs it there. The blood then carries it to the liver and the rest of the body. The stomach absorbs THC more slowly than the lungs. When marijuana is eaten, the levels of THC in the body are lower, but the effects last longer

Marijuana and the Brain

THC is a very potent chemical compared to other psychoactive drugs. An intravenous (IV) dose of only 1 milligram can produce serious mental and psychological effects. Once in your bloodstream, THC typically reaches the brain within seconds after it is inhaled and begins to go to work.

Marijuana users often describe the experience of smoking marijuana as initially relaxing and mellow, creating a feeling of haziness and light-headedness. The user’s eyes may dilate, causing colors to appear more intense, and other senses may be enhanced. Later, feelings of a paranoia and panic may be felt by the user. The interaction of the THC with the brain is what causes these feelings. To understand how marijuana affects the brain, you need to know about the parts of the brain that are affected by THC. Here are the basics:

• Neurons are the cells that process information in the brain. Chemicals called neurotransmitters allow neurons to communicate with each other.
• Neurotransmitters fill the gap, or synapse, between two neurons and bind to protein receptors, which enable various functions and allow the brain and body to be turned on and off.
• Some neurons have thousands of receptors that are specific to particular neurotransmitters.
• Foreign chemicals, like THC, can mimic or block actions of neurotransmitters and interfere with normal functions.

In your brain, there are groups of cannabinoid receptors concentrated in several different places. These cannabinoid receptors have an effect on several mental and physical activities, including:

• Short-term memory
• Coordination
• Learning
• Problem solving

Cannabinoid receptors are activated by a neurotransmitter called anandamide. Anandamide belongs to a group of chemicals called cannabinoids. THC is also a cannabinoid chemical. THC mimics the actions of anandamide, meaning that THC binds with cannabinoid receptors and activates neurons, which causes adverse effects on the mind and body.

High concentrations of cannabinoid receptors exist in the hippocampus, cerebellum and basal ganglia. The hippocampus is located within the temporal lobe and is important for short-term memory. When the THC binds with the cannabinoid receptors inside the hippocampus, it interferes with the recollection of recent events. THC also affects coordination, which is controlled by the cerebellum. The basal ganglia controls unconscious muscle movements, which is another reason why motor coordination is impaired when under the influence of marijuana.

The “Munchies”

One peculiar phenomenon associated with marijuana use is the increased hunger that users feel, often called the “munchies.” Research shows that marijuana increases food enjoyment and the number of times a person eats each day.

Until recently, the munchies were a relative mystery. However, a recent study by Italian scientists may explain what happens to increase appetite in marijuana users. Molecules called endocannabinoids bind with receptors in the brain and activate hunger.

This research indicates that endocannabinoids in the hypothalamus of the brain activate cannabinoid receptors that are responsible for maintaining food intake.

Other Physiological Effects of Marijuana

In addition to the brain, the side effects of marijuana reach many other parts of the body, which include:

• Problems with memory and learning
• Distorted perception
• Difficulty with thinking and problem solving
• Loss of coordination
• Increased heart rate
• Anxiety, paranoia and panic attacks

The initial effects created by the THC in marijuana wear off after an hour or two, but the chemicals stay in your body for much longer. The terminal half-life of THC is from about 20 hours to 10 days, depending on the amount and potency of the marijuana used. This means that if you take one milligram of THC that has a half-life of 20 hours, you will still have 0.031 mg of THC in your body more than four days later. The longer the half-life, the longer the THC lingers in your body.

The debate over the addictive capacity of marijuana continues. Ongoing studies now show a number of possible symptoms associated with the cessation of marijuana use. These symptoms most commonly include irritability, nervousness, depression, anxiety and even anger. Other symptoms are restlessness, severe changes in appetite, violent outbursts, interrupted sleep or insomnia. In addition to these possible physical effects, psychological dependence usually develops because a person’s mind craves the high that it gets when using the drug.

Beyond these effects that marijuana has, marijuana smokers are susceptible to the same health problems as tobacco smokers, such as bronchitis, emphysema and bronchial asthma. Other effects include dry mouth, red eyes, impaired motor skills and impaired concentration. Long-term use of the drug can increase the risk of damaging the lungs and reproductive system, according to the U.S. Drug Enforcement Agency (DEA). It has also been linked to heart attacks.

Although marijuana is known to have negative effects on the human body, there is a raging debate over the use of medicinal marijuana. Some say that marijuana should be legalized for medical use because it has been known to suppress nausea, relieve eye pressure, decrease muscle spasms, stimulate appetite, stop convulsions and eliminate menstrual pain. Because of its therapeutic nature, marijuana has been used in the treatment of several conditions including: cancer and AIDS (to supress nausea and stimulate appetite), glaucoma (to alleviate eye pressure), epilepsy (to stop convulsions) and multiple sclerosis (to decrease muscle spasms).

Source: HowStuffWorks

(via decadentscience)