How Instant Photography Works

Instant cameras were a real revolution in the world of photography. Their invention made it possible for people to take a picture and hold the actual photograph in their hands only a few seconds later. How does that work? The film inside the camera is a plastic base coat with particles of silver compounds that are sensitive to light. Color films, such as those in instant cameras, have three layers of silver compounds – the top layer is sensitive to blue light, the middle layer to green and the bottom layer to red light. Underneath each layer, there is a developer layer containing dye couplers. All these layers sit on top of a black base layer and underneath the image layer, the timing layer and the acid layer. When exposed to light, the sensitive particles at each layer react to light of that color, forming metallic silver at that layer. The developing process is then started by the reagent. It is a mix of light blockers, alkali and white pigment. It is collected in a blob at the white bottom of the film sheet, away from the light-sensitive material to keep the film from developing before it has been exposed. After taking a picture, the film sheet passes out of the camera through a pair of rolls. The rolls help spread the reagent out in the middle of the film sheet where it reacts with other chemical layers in the film. The opacifier material stops the light from filtering onto the layers below. The reagent then dissolves the developer dye so it begins to diffuse up toward the image layer. Only the dyes from the unexposed layers will reach the image layer. The acid layer in the film reacts with the alkali and opacifiers in the reagent, making the opacifier become clear. The timing layer slows the reagent down on its way to the acid layer, to give the film time to develop before it is exposed to light. When the film sheet gets out of the camera you are actually able to see the last chemical reaction, namely the acid layer clearing up the opacifier in the reagent and making the image visible.

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Zombie attack abstract

An epidemic of a certain disease has a root with a positive real part. It follows that, in a short outbreak, everyone will probably be infected. The purpose of this academic article is to inform about such a scenario. Instead of naming a particular disease, zombies were taken as an example. First, the basic model is explained: susceptible, zombie and removed. Secondly, the model with the latent infection analyses how the susceptible individuals become infected before the outbreak of the disease. Thirdly, the model with quarantine focuses on the contagious individuals and how they are removed from the population and set in quarantine in order not to infect the still healthy individuals. The treatment model takes in consideration that a cure can be found but it would not provide immunity for the body, hence a repeated infection could be possible. The last method strategically focuses on destroying the disease at such times that our resources permit. Giving the disease a latent period of infection, it will again take over the population. Putting individuals in quarantine would only solve the problem for a short period of time and would not impact the system as a whole. Although the method with treatment would provide a cure, some would still die because of repeated infection. The outbreak of an epidemic is most likely to be disastrous for humans, unless extremely aggressive tactics are employed against the virus and the infected individuals.

(238 words)

XOXO A.

CAJ #5 - Graphene abstract

The aim of this journal is to inform about graphene, one of the newest and most promising materials in the world. Graphene is the thinnest, lightest and most transparent material known to mankind. Its possibilities seem endless because of its many properties that are only exploited when graphene is combined with other materials, including gasses, metals, and sources of carbon. The methodology used for bringing forth the amazing possibilities of graphene includes reading various scientific papers and websites. Watching videos on YouTube that explain everything regarding graphene was also a very helpful tool in getting a better understanding of the true value and importance of graphene. Although graphene holds the solution to many problems, it is still in an early phase of research. The uses of graphene range from solar panels and smart phones to biological engineering and ultrafiltration. The price of graphene is linked to its quality, and not all applications require superb material quality. Mechanically exfoliated graphene comes in small, high-quality flakes that are incredible expensive, costing several thousand dollars per flake. The application of graphene in everyday appliances will therefore take some time. Graphene is bound to change our lives, to change the world we live in. Although it is currently facing certain problems, such as its cost, it still has a bright future ahead of itself because of it limitless application.

(227 words)

XOXO A.

How to prevent time travelers from killing Hitler?

How to prevent time travelers from killing Hitler?

You will need:

1)    1)  A time machine

2)    2) A laptop

3)    3)  Computer knowledge or someone with computer knowledge

4)    4)  History knowledge

5)    5)  Money

Estimated time: depends on your skills

1.     1. Find a time machine. You are most likely to find one at the museum of future technology. Maybe you will have to pay to use it.

2.      2. Check out the time machine and look for the “date changing“ option.

3.   3. Set the date on the time machine back to the time when Hitler lived.

4.    4. Take out your laptop and connect it to the time machine via WiFi.

5.     5. Use your laptop to hack into the time machine's system.

6.   6.  If you do not know how to hack into a system call a friend or someone who knows how to do it.

7.   7. Once you have hacked into the system, read all the encrypted codes from the previous time travelers such as the time they went back to, their intentions, what they changed and when they returned.

8.      8. Gather all the data and create a computer program of your own.

 

9.     9. Make sure that the computer program also includes the time span from when Hitler was born until his death. Again, if you do not know when Hitler was born and died, google it or find someone who is familiar with Hitler’s biography.

10. 10. Turn the computer program into a virus. If you do not know how to do that, call someone who has some sort of computer knowledge.

11.   11. Configure the virus so that it can prevent all future time travelers from travelling to any point in time during Hitler’s life.

12. 12.  Connect to the global time travelers’ network and send out the virus to all time machines. If you do not have an account, please sign up. Do not worry, it is free of charges.

13. 13.  Congratulations, you managed to stop every future time traveler from traveling back in time and killing Hitler.

(330 words)

How to make a camera lucida?

The instructions “How to make a camera lucida”, written by Tim Hunkin, are very vague.

They do not not fulfill their task to explain how to build a camera lucida. Many important elements of an effective instructional text are missing. At the beginning the author does not provide a  list of items that are needed for the project. Constructing something without a list of what is required can be hard. However, the author tries to illustrate the process of building the camera by providing pictures that show measurements for the materials. Another important element missing is the estimated time for the project. Further on, what is really noticeable when looking at the how-to-guide, is that there are no numbered steps. It is challenging to follow the instructions as they are divided into paragraphs. Although the author explains how to build the camera lucida, he does not provide information on how to build the construct on which the camera should be fixed if used for drawing purposes. Despite containing pictures that could be helpful while building the camera lucida, the instructional text is complicated and makes it hard follow the steps since they are not numbered.

[195 words]

CAJ #4 - Introducing graphene video

While googling my CAJ I came across really interesting uses of graphene that I would like to share with you. However, before I do so, we should repeat what we have learned so far. Since YouTube is a great source for visual learning I typed “graphene” into the search bar and looked for some videos that could help me and you to understand what graphene is all about and how it was discovered. Below is a really amazing video that explains in just two and a half minutes what I have written about so far. Take a look at it. You will not regret it, believe me. Even my brother liked it and that means something since he is usually not so interested in the things I do for university.

XOXO A.

CAJ 3 - How was graphene discovered?

Phillip R. Wallace was the first to study graphene. In 1947 he studied graphene as a limiting case for theoretical work on graphite. The earliest TEM (transmission electron microscope) images of few-layer graphite were published by G. Ruess and F. Vogt in 1948.

Gordon Walter Semenoff, David P. DeVincenzo and Eugene J. Mele discovered in 1984 that the electric current could be theoretically carried by effectively massless charge carries in graphene.

S. Mouras is the first to mention the name graphene in 1987.

In 2004 graphene crystals were first isolated by two University of Manchester scientists, Andre Geim and Konstantin Novoselov.

(Andre Geim and Konstantin Novoselov)

Geim and Novoselov were trying to make graphite as thin as possible using lab equipment. They were struggling for months as they could not  make it thinner than 10,000 layers. After their work the lab surfaces were often covered in graphite and they would use scotch tape to clean it. Most of the time they would just look at the scotch tape to see what was happening to the graphite but would then throw in into the trash can. One day, instead of throwing it away, they decided to look at it under the microscope. They saw transparent pieces of graphite – graphene.

It is a true miracle that Geim and Novoselov continued their research on graphene because they wanted to give up on it since they overheard that other scientist at the university also use Scotch tape to clean graphite before putting it under the lens.

(a TEM image of the porous graphene)

The two scientists were first very surprised by their discovery because their physics intuition told them that this material should not exist since we live in a 3D world and graphene is a 2D material. However, they found a way of transferring the ultra-thin flakes of graphene from Scotch tape to a silicon wafer. After succeeding, they were able to examine the electrical properties of graphene.

Andre Geim and Kostya Novoselov were awarded the 2010 Nobel Prize in physics for their work and experiments regarding graphene. They continue to research graphene and other related two dimensional crystal materials.

The Nobel committee was not just blown away by the discovery the two scientist had made but also by the way they did it. The playfulness the two scientists showed while experimenting with graphite was the key to their success. “A playful idea is perfect to start things but then you need a really good scientific intuition that your playful experiment will lead to something, or it will stay as a joke for ever,” Novoselov says. Geim is known in the scientific community for his playful experiments. In 1997 he levitated a frog to demonstrate his work in magnetism.

XOXO A.

P.S. Many great discoveries that changed the world were accidental. It seems that sometimes the only thing standing in the way of a great discovery is a little bit of luck.

Isaac Newton was supposedly sitting in his garden when he discovered gravity. He saw an apple fall straight down from a tree. He wondered why they apple never falls upwards or off to a side. Newton soon discovered that all things fall straight down and that there is an attractive force pulling them down. Twenty years after that the published his theory of gravity.

In 1927 Fleming was experimenting with the properties of staphylococci. Before leaving his laboratory in August for holiday with his family, he had stacked all his cultures of staphylococci on a bench in a corner. After he returned, he noticed that one culture was contaminated with a fungus, and that the colonies of staphylococci immediately surrounding the fungus had been destroyed. Other staphylococci colonies farther away were normal. Fleming then grew the fungus in a pure culture and found that it produced a substance that killed a number of disease-causing bacteria. He identified the mold as being from the Penicillium genus, hence calling it penicillin.