List Of Free Science Books

What’s Up for May 2016?

What’s Up for May? Two huge solar system highlights: Mercury transits the sun and Mars is closer to Earth than it has been in 11 years.

On May 9, wake up early on the west coast or step out for coffee on the east coast to see our smallest planet cross the face of the sun. The transit will also be visible from most of South America, western Africa and western Europe.

A transit occurs when one astronomical body appears to move across the face of another as seen from Earth or from a spacecraft. But be safe! You’ll need to view the sun and Mercury through a solar filter when looking through a telescope or when projecting the image of the solar disk onto a safe surface. Look a little south of the sun’s Equator. It will take about 7 ½ hours for the tiny planet’s disk to cross the sun completely. Since Mercury is so tiny it will appear as a very small round speck, whether it’s seen through a telescope or projected through a solar filter. The next Mercury transit will be Nov. 11, 2019.

Two other May highlights involve Mars. On May 22 Mars opposition occurs. That’s when Mars, Earth and the sun all line up, with Earth directly in the middle.

Eight days later on May 30, Mars and Earth are nearest to each other in their orbits around the sun. Mars is over half a million miles closer to Earth at closest approach than at opposition. But you won’t see much change in the diameter and brightness between these two dates. As Mars comes closer to Earth in its orbit, it appears larger and larger and brighter and brighter. 

During this time Mars rises after the sun sets. The best time to see Mars at its brightest is when it is highest in the sky, around midnight in May and a little earlier in June. 

Through a telescope you can make out some of the dark features on the planet, some of the lighter features and sometimes polar ice and dust storm-obscured areas showing very little detail.

After close approach, Earth sweeps past Mars quickly. So the planet appears large and bright for only a couple weeks. 

But don’t worry if you miss 2016’s close approach. 2018’s will be even better, as Mars’ close approach will be, well, even closer.

You can find out about our #JourneytoMars missions at mars.nasa.gov, and you can learn about all of our missions at http://www.nasa.gov.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

How Tattooing Really Works

1. Tattooing causes a wound that alerts the body to begin the inflammatory process, calling immune system cells to the wound site to begin repairing the skin. Specialized cells called macrophages eat the invading material (ink) in an attempt to clean up the inflammatory mess. 

2. As these cells travel through the lymphatic system, some of them are carried back with a belly full of dye into the lymph nodes while others remain in the dermis. With no way to dispose of the pigment, the dyes inside them remain visible through the skin. 

3. Some of the ink particles are also suspended in the gel-like matrix of the dermis, while others are engulfed by dermal cells called fibroblasts. Initially, ink is deposited into the epidermis as well, but as the skin heals, the damaged epidermal cells are shed and replaced by new, dye-free cells with the topmost layer peeling off like a healing sunburn.

4. Dermal cells, however, remain in place until they die. When they do, they are taken up, ink and all, by younger cells nearby so the ink stays where it is.

5. So a single tattoo may not truly last forever, but tattoos have been around longer than any existing culture. And their continuing popularity means that the art of tattooing is here to stay.

From the TED-Ed Lesson What makes tattoos permanent? - Claudia Aguirre

Animation by TOGETHER

Harvard has a pigment library that stores old pigment sources, like the ground shells of now-extinct insects, poisonous metals, and wrappings from Egyptian mummies, to preserve the origins of the world’s rarest colors.

A few centuries ago, finding a specific color might have meant trekking across the globe to a mineral deposit in the middle of Afghanistan. “Every pigment has its own story,” Narayan Khandekar, the caretaker of the pigment collection, told Fastcodesign. He also shared the stories of some of the most interesting pigments in the collection.

Mummy Brown

“People would harvest mummies from Egypt and then extract the brown resin material that was on the wrappings around the bodies and turn that into a pigment. It’s a very bizarre kind of pigment, I’ve got to say, but it was very popular in the 18th and 19th centuries.”

Cadmium Yellow

“Cadmium yellow was introduced in the mid 19th century. It’s a bright yellow that many impressionists used. Cadmium is a heavy metal, very toxic. In the early 20th century, cadmium red was introduced. You find these pigments used in industrial processes. Up until the 1970s, Lego bricks had cadmium pigment in them.”

Annatto “The lipstick plant—a small tree, Bixa orellana, native to Central and South America—produces annatto, a natural orange dye. Seeds from the plant are contained in a pod surrounded with a bright red pulp. Currently, annatto is used to color butter, cheese, and cosmetics.”

Lapis Lazuli “People would mine it in Afghanistan, ship it across Europe, and it was more expensive than gold so it would have its own budget line on a commission.”

Dragon’s Blood “It has a great name, but it’s not from dragons. [The bright red pigment] is from the rattan palm.”

Cochineal “This red dye comes from squashed beetles, and it’s used in cosmetics and food.”

Emerald Green “This is made from copper acetoarsenite. We had a Van Gogh with a bright green background that was identified as emerald green. Pigments used for artists’ purposes can find their way into use in other areas as well. Emerald green was used as an insecticide, and you often see it on older wood that would be put into the ground, like railroad ties.”

Source

The hairstyle of this small girl, cut short and topped with a ribbon bow, seems to date this advertisement from the early 1950s. The printer is believed to be Whitcombe & Tombs, because the poster came to the Library with other material printed by that company.

[Whitcombe & Tombs Ltd?] :Goodness! that’s tempting. Weet-bix [ca 1954?]

Eph-C-FOOD-Whitcombe-2-03

Top 10 Most Uncomfortable Physics Facts

While physics can show us amazing things about our universe, it doesn’t always agree with how we think things should work. Sometimes, physics can be very counter-intuitive, and often unsettling. So, here’s my list of physics facts that can be a bit unnerving.

10: Weight doesn’t matter

If it wasn’t for air resistance, everything would fall at exactly the same speed. If you let go of a hammer and a feather from the same height at the same time  on the Moon, they would hit the ground simultaneously. 

9: Gyroscopic precession

It doesn’t matter how much you know about physics; gyroscopes are weird. The way they seem to defy gravity makes you rethink everything you know about physics, despite being fairly simple toys. Still, it’s all just Newton’s laws of motion.

8: Neutrinos and dark matter

We like to think that we can interact with most of the world around us, but this couldn’t be further from the truth. Neutrinos and dark matter are passing through your body right now, as if you weren’t even there. The fact that 65 billion neutrinos pass through each square centimeter of your body every second is weird enough, who knows what we’ll learn about dark matter.

7: Photons are particles

Light travels like a wave, but can only interact like a particle. It can interfere and have a frequency, but it can only take and give energy in discrete quantities. It behaves like nothing else in our macroscopic world, and can be very difficult to imagine.

6: Electrons are waves

We’ve established how photons act like waves and particles, but surely massive particles act normally. Nope! Even electrons have wave-like properties. In fact, everything acts like a wave! Except these waves come in discrete quantities, which we’ll call particles. This won’t get confusing.

5: E=mc^2

Einstein’s most famous contribution to physics states that matter is simply another form of energy, which has very profound consequences. A wound-up Jack-in-a-box would weigh ever so slightly more than a released Jack-in-a-box, due to the potential energy stored within.

4: Time is relative

The core of special relativity states that time passes differently for different observers. If you took a trip to Alpha Centauri at 99% the speed of light, everyone on Earth would see the trip take 4.4 years, while you would only experience 7.5 months. Time travel is real!

3: The (not so empty) vacuum

Something can be created from nothing, as long as it goes right back to being nothing quickly. In seemingly empty space, particles pop in and out of existence all the time as a result of the uncertainty principle. Not to mention, space is inflating at an accelerated rate due to “dark energy”. To the vacuum, the law of conservation of energy is more of a suggestion.

2: c is the fastest speed

Another important point in special relativity is that nothing could ever go faster than light. This doesn’t sit well with a lot of people, but the math doesn’t lie. To even get something with mass to travel at the speed of light would require infinite energy. Even if you somehow get around this, there are just too many mathematical problems with superluminal travel. Like it or not, the universe has a speed limit.

1: The cat is dead and alive

How could it not be this? The nature of quantum mechanics allows for objects to take on two seemingly contradictory states in a ‘superposition’. An electron can be in two places at once, or in a more extreme example, a cat can be both dead and alive. Of course, this weird property goes away once someone makes an observation. It’s as if there are tiny physics trolls messing with nature whenever we’re not looking.

Of course, there’s plenty more unsettling physics facts, like the space-bending nature of general relativity, or the “spooky action at a distance” that is quantum entanglement, but these are my top 10. I’d like to hear any unsettling physics facts you think I’ve missed, though!

File Format Posters

By Corkami, “Reverse engineering & visual documentations”

The collection of images includes all kinds of formats — GIF, ZIP and WAV are all represented, but it even gets into some real esoterica — DOLphin format executables are here if you’re a total GameCube fanatic. Each poster breaks down the format into parts, such as the header, metadata and descriptor sections, and come in a variety of formats themselves — most available in SVG, PDF and PNG.

(via Hackaday)

On this day, 13th February 1743, Sir Joseph Banks was born.

Sir Joseph Banks was a British botanist and naturalist who sailed with Captain James Cook on the Endeavour voyage of 1770.

Joseph Banks was born on 13 February 1743 in London. His passion for botany began at school. From 1760 to 1763 he studied at Oxford University, during which time he inherited a considerable fortune. In 1766, Banks travelled to Newfoundland and Labrador, collecting plant and other specimens. The same year he was elected a fellow of the Royal Society.

In 1768, he joined the Society’s expedition, led by Captain James Cook, to explore the uncharted lands of the South Pacific. The expedition circumnavigated the globe and visited South America, Tahiti, New Zealand, Australia and Java. Banks collected an enormous number of specimens on the way and, on his return, his scientific account of the voyage and its discoveries sparked considerable interest across Europe.

The journal kept by the then 25-year-old Joseph Banks on board HMS Endeavour is one of the State Library’s most significant manuscripts. It records the first Pacific voyage of Captain James Cook from 1768 to 1771. Following the Endeavour’s return to England in 1771, Banks was hailed as a hero. 

The State Library’s Sir Joseph Banks collection includes correspondence, reports, invoices, accounts, maps and watercolour drawings which document the far reaching influence of Banks on the colony. This significant archive containing over 7,000 pages has recently been digitised and now needs to be transcribed. Once fully transcribed the archive will be keyword searchable which will enhance discovery and access to the collection and increase the research potential in this significant archive.  

Find out more about how to transcribe the Banks Papers

Fructose alters hundreds of brain genes, which can lead to a wide range of diseases

A range of diseases — from diabetes to cardiovascular disease, and from Alzheimer’s disease to attention deficit hyperactivity disorder — are linked to changes to genes in the brain. A new study by UCLA life scientists has found that hundreds of those genes can be damaged by fructose, a sugar that’s common in the Western diet, in a way that could lead to those diseases.

However, the researchers discovered good news as well: An omega-3 fatty acid known as docosahexaenoic acid, or DHA, seems to reverse the harmful changes produced by fructose.

“DHA changes not just one or two genes; it seems to push the entire gene pattern back to normal, which is remarkable,” said Xia Yang, a senior author of the study and a UCLA assistant professor of integrative biology and physiology. “And we can see why it has such a powerful effect.”

DHA occurs naturally in the membranes of our brain cells, but not in a large enough quantity to help fight diseases.

“The brain and the body are deficient in the machinery to make DHA; it has to come through our diet,” said Fernando Gomez-Pinilla, a UCLA professor of neurosurgery and of integrative biology and physiology, and co-senior author of the paper.

DHA strengthens synapses in the brain and enhances learning and memory. It is abundant in wild salmon and, to a lesser extent, in other fish and fish oil, as well as walnuts, flaxseed, and fruits and vegetables, said Gomez-Pinilla, who also is a member of UCLA’s Brain Injury Research Center.

Americans get most of their fructose in foods that are sweetened with high-fructose corn syrup, an inexpensive liquid sweetener made from corn starch, and from sweetened drinks, syrups, honey and desserts. The Department of Agriculture estimates that Americans consumed an average of about 27 pounds of high-fructose corn syrup in 2014. Fructose is also found is in most baby food and in fruit, although the fiber in fruit substantially slows the body’s absorption of the sugar — and fruit contains other healthy components that protect the brain and body, Yang said.

To test the effects of fructose and DHA, the researchers trained rats to escape from a maze, and then randomly divided the animals into three groups. For the next six weeks, one group of rats drank water with an amount of fructose that would be roughly equivalent to a person drinking a liter of soda per day. The second group was given fructose water and a diet rich in DHA. The third received water without fructose and no DHA.

After the six weeks, the rats were put through the maze again. The animals that had been given only the fructose navigated the maze about half as fast than the rats that drank only water — indicating that the fructose diet had impaired their memory. The rats that had been given fructose and DHA, however, showed very similar results to those that only drank water — which strongly suggests that the DHA eliminated fructose’s harmful effects.

Other tests on the rats revealed more major differences: The rats receiving a high-fructose diet had much higher blood glucose, triglycerides and insulin levels than the other two groups. Those results are significant because in humans, elevated glucose, triglycerides and insulin are linked to obesity, diabetes and many other diseases.

The research team sequenced more than 20,000 genes in the rats’ brains, and identified more than 700 genes in the hypothalamus (the brain’s major metabolic control center) and more than 200 genes in the hippocampus (which helps regulate learning and memory) that were altered by the fructose. The altered genes they identified, the vast majority of which are comparable to genes in humans, are among those that interact to regulate metabolism, cell communication and inflammation. Among the conditions that can be caused by alterations to those genes are Parkinson’s disease, depression, bipolar disorder, and other brain diseases, said Yang, who also is a member of UCLA’s Institute for Quantitative and Computational Biosciences.

Of the 900 genes they identified, the researchers found that two in particular, called Bgn and Fmod, appear to be among the first genes in the brain that are affected by fructose. Once those genes are altered, they can set off a cascade effect that eventually alters hundreds of others, Yang said.

That could mean that Bgn and Fmod would be potential targets for new drugs to treat diseases that are caused by altered genes in the brain, she added.

The research also uncovered new details about the mechanism fructose uses to disrupt genes. The scientists found that fructose removes or adds a biochemical group to cytosine, one of the four nucleotides that make up DNA. (The others are adenine, thymine and guanine.) This type of modification plays a critical role in turning genes “on” or “off.”

The research is published online in EBioMedicine, a journal published jointly by Cell and The Lancet. It is the first genomics study of all the genes, pathways and gene networks affected by fructose consumption in the regions of the brain that control metabolism and brain function.

Previous research led by Gomez-Pinilla found that fructose damages communication between brain cells and increases toxic molecules in the brain; and that a long-term high-fructose diet diminishes the brain’s ability to learn and remember information.

“Food is like a pharmaceutical compound that affects the brain,” said Gomez-Pinilla. He recommends avoiding sugary soft drinks, cutting down on desserts and generally consuming less sugar and saturated fat.

Although DHA appears to be quite beneficial, Yang said it is not a magic bullet for curing diseases. Additional research will be needed to determine the extent of its ability to reverse damage to human genes.

Scroll of Esther, Venice, 18th century

This Venetian eighteenth century Scroll of Esther is enclosed within an elegant tubular scrolled filigree case. The cylindrical case of delicate silver filigree is beautifully decorated with floral motifs, with a gilded, flower-shaped element on top. In contrast to its richly ornamented case, the parchment scroll is very simple and has no decorations around the handwritten text. 

U. Nahon Museum of Jewish Italian Art Gift of Mrs. Zaban in memory of her parents, who were murdered in Auschwitz. Trieste, 1987 

This week, we’re taking a look at manuscripts having to do with health, medicine, and human physiology specifically focusing on how bodies are displayed in manuscript illuminations or diagrams across different cultures.

LJS 389 shown above, is a 14th century Chinese treatise on the anatomy, physiology, and pathology of blood vessels titled Shi si jing fa hui. The manuscript is made from bamboo paper and the diagrams and kaishu script are written with black ink. Focus on the diagrams of the bodies and stay tuned this week to see not only how the details and forms of these depictions change from culture to culture, but also the mediums with which these manuscripts are created.

The full LJS 389 manuscript filled with more diagrams can be found on Openn: http://openn.library.upenn.edu/Data/0001/html/ljs389.html

and Penn In Hand: http://hdl.library.upenn.edu/1017/d/medren/4824235