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Why do sunburns feel like burning flesh?

Well, it is because they are burning, but not in the sense you’d expect. When the UV rays affects and damage the cells of the outer layer of the skin the body starts pumping blood in that area to start the healing process. That healing process generates heat and will eventually heal the cells or allow them to be exfoliated.

Remember: the sunburns burn because the body reacts to the damaged cells by pumping blood and using other cells to rebuild the skin.

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NY Times: researches can now control appetite via fiber optics

Sorry for those mice, but the fiber optic control thing is incredible. It seems takes form SciFi movies. Scientist have determined what area of the mice’s brain controls appetite and they can start it or block using a switch.

These experiments allow researchers know more about what makes us eat that much and how we could control other processes that have been going out of control. Tampering directly with the brain in this manner is uncharted territory and can lead to unforseen consequences, however we need to take this step too if we want to learn more about humans and animals.

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The History of USB. Explaining USB 3.0

The USB, Universal Serial BUS, s a connector created to replace a ton of other ports for printers, mouses, keyboards and any other extra plug-in devices like game pads. USB is not in its third version and we will have soon enough an USB connector that can be inserted in the port upside down or the other way around and it will still work.

USB 1 had a transfer rate of 12 Mbps, USB 2 has a transfer rate of 480 Mbps and USB 3 allows you to transfer almost 5Gbps of data. Ars Technica has published an article about the History of USB. You should read it NOW!

FireWire or Thunderbolt are better than USB, but they cost more and require extra chips to make them work on any other motherboard. It seems that the USB reign is still a long one!

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Plastic from air? Not so fast

Thunderf00t has his chemistry sniper rifle aimed at the plastic from air hype that claims that a company called Newlight can create plastic from air. Since there is enough carbon dioxide in the air you could theoretically trap it, add water and then burn it to obtain CH2, a base molecule in plastics.

But Thunderf00t asks: if this were true, at what costs? He thinks that these guys don’t even get the carbon from the air int he first place. Most interestingly if they would get it from air, then the energy costs to obtain 1 kg of air plastic would lead to the consumption of 100 kg of fossil fuel used to generate the electricity to make the pump run.

Since we generate over 1kg of carbon each day, Thunderf00t asks why do they obtain so little amounts of plastic in the first place? Even if you would use methane from air, you would still consume way more energy than usual petrochemical processes to obtain that 1 kg of plastic.

If something sound too good to be true, then probably it is.

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The incredible story of blue: how painters colored the era they lived in

Nature Videos are thought provoking and often show a side of the culture of store we never knew existed. Why would we care about the blue color and how hard it was to come by? Why would we care about painters and their colors anyway?

Painters needed to use herbs and stones and whatever they could find to paint lively painting, vivid depictions of what they wanted to show us. An image is worth 1000 words, but a colored image is worth more.

Blue, among all colors, was hard to come by and Ashok Roy, from UK National Gallery, is presenting us the history of this color. UK’s National Gallery is showing off the exhibition called Making Colour between June 18th and September 8th in Trafalgar Square, London WC2N 5DN. When they wanted to paint something in blue they had to first use lapis lazuli, a mineral from NE Afghanistan which contains lazurite, then, after a long while, turned to cobalt blue. A long road to the colors we can use today.

From National Gallery:

Journey from lapis lazuli to cobalt blue, ancient vermilion to bright cadmium red, through yellow, orange, purple and verdigris to deep green viridian – in a series of colour-themed rooms. Finally, enter a dazzling central room devoted to gold and silver.

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Learn about 5 ancient medical treatments with Vsauce2

Interestingly enough, medicine have come a long way since the days of the shamans or of bleeding as a practice to treat whatever ailment you’d have. Kevin from Vsauce2 shows us 5 ancient treatments they used back then and how were they performed.

Bleeding was one of those methods and it stuck with the then-day doctors up until the 19th century. Regular people or kings, all were bled to death according to astrology calenders. You may find with some surprise that this was a highly valued method as bleeding was seen as a purifying method widely accepted. You can read more about such methods in the book called An Underground Education: The Unauthorized and Outrageous Supplement to Everything You Thought You Knew out Art, Sex, Business, Crime, Science, Medicine, and Other Fields of Human by Richard Zachs. Great book, read it, love it.

Other old ways to treat illnesses were:
– trepanning – drilling a hole into the skull to let the evil spirits out
– enema – doing rectal purges using animal parts as tubes
– smoking – was used during the London plague
– smelling foul gases – during the London plague was used to ward off the plague as they believed that bad gases brought it in the first place.

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Water: it shouldn’t even be a liquid [strange water facts]

Water has been the subject of countless studies and people are still wondering how on Earth could it exist and behave the way it does? I started learning a bit more about water when I stumbled upon Trends in bond angles for H2O and other substances on Chemistry Stack Exchange. The question begs and answer and it is best that we learn a bit of chemistry before falling into the traps of many sharlatans who sell you miraculous alkaline water that cures cancer and such.

Reading about water I spent a bit of time on Steve Lower’s website where you are taught about some basic chemistry things. In order to understand those things you may need a Table of Elements and a basic knowledge of electron orbitals or configurations.

Knowing that Oxygen has 8 electrons you then know how to calculate the orbitals: 1s2 2s2 2p4. Since the p suborbital should have 6 electrons, you can see that Oxygen can accept 2 new electrons from Hygron who is missing one from the s suborbital (it has 1s1 instead of 1s2).

Basic arithmetic for orbial levels (shells) and sublevels (subshells).
– there are 7 main orbitals : K, L, M, O, P, Q and each can have a max of 2n^2 electrons (n= 1,2,3…)
– there are 5 suborbitals: s, p, d, f, g and each suborbital can have a max of 2(2l+1) electrons (l= 0,1,2,…)

Oxygen has 8 electrons and that means that:
– it will have 2 electrons in the K orbital (2*1^2= 2) and 6 electrons in the L orbital (L has a max of 2*2^2 = 8 )
– it will have 2 electrons in the s subshell (1s2, s = 2 (2*0+1) = 2 ) and then 2 in the second s subshell of L shell 2s2 and then 4 electrons in the p subshell of the L shell 2p4 (p = 2(2*1+1)= 6 )

Now, some water facts:
– the bond angles in water should have been 109 degrees, but they are 104.5 degress and can never be changed. Read more on Stack Exchange and from Harvard PDF. The angles in bonds are calculates using a formula like cos( angle) = -1/ sqrt(li*lj), where li, lj are the number of outermost electrons in the hybrid molecular orbital. Like for sp3 there are 3 such electrons. The pdf will make that clearer, search for the Coulson’s Theorem.
– water should have been a vapour at room temperature as it should have become a gas at -70 degrees. See here more. The Hydrogen bonds which show up between the atoms of Hydrogen of one molecule and the Oxygen from another molecule. These bond last only for some picoseconds.
– from the same link above you will learn that water increases volume when is frozen below zero degrees
– water has the highest density at 4 degrees Celsius
– inserting salt into water will get the boiling point upper and the freezing point lower
– surface tension will keep a paper clip on the water
– you cannot get pure water, there will always be some forms of it depending on what type of Hydrogen you have in it (regular, deuterium, tritium)
– we lose about 1.5 litres of water per day from our bodies and most of it (800 mL) from breathing ( Loss through breath: 800 mL, Minimal sweat loss: 100 mL, Fecal loss: 200 mL, Minimal urine loss: 500 mL, Total: 1600 mL)
– water does NOT have memory and it does not get clustered
– the blue color is given by the hydrogen bonds

Read more about the strange properties of water from Martin Chaplin, Water structure and science and from Steve Lower, Water and its structure.

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TechQuickie: what is video compression

The guys at Techquickie create interesting videos on basics of different digital technologies and video compression of one of those techs. video compression is a great technical achievement of the digital world in which movies that would normally be 70GB in size are reduces to only about 70 MB.

Compression is a process in which you try to remember what parts on the same image are the same and then write down the information in this way: this type of pixel in these locations (X, Y,Z, T). Like in the video from above, there is a lot of white space behind the presenter. You can reduce all that space to only a couple of instructions and you saved a lot of space.

There is the compression which is done inside the frame or image, that is called intraframe compression or spatial compression. Usually you would use .jpeg compression (or codec) for that. Jpeg comes from Joint Photographic Experts Group.

And there is the interframe compression, the one done between the frames of the video, also called temporal compression. You would use the mpeg video format (or codec) for that. Mpeg stands for “motion jpeg”.

You can learn more about file compression from the video from below. It goes in more technical details:

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Hyperlapse: Microsoft’s take on first person videos is awesome

Microsoft Research has a super-project in which you take the videos someone is taking with their camera and then create a seamless time-lapse video. Hyperlapse is a time-lapse video in which the frames were created to flow continuously one form another in such a way that the camera swings are reduces to a bare minimum.

So, if you film a ton of stuff with your hand held camera and also shake it a lot, you can use Hyperlapse processes to create an ubercool looking time lapse video. Some things don’t stop to amaze me.

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The average face of Dr. Who

Now you would hear Dr. Who from season 5 in the new series done after 2005 played by David Tennant when he was very surprised: “What?! What?! What?! What?! What?!” In the video from above you will see the average Dr. Who face, which seems pretty close to David’s face. Pretty cool, eh?

Via Presurfer.