Daily Archives: February 11, 2022

Applications for the CAD software extend far beyond medicine and throughout the burgeoning field of synthetic biology, which involves redesigning organisms to give them new abilities. For example, we envision users designing solutions for biomanufacturing; it's possible that society could reduce its reliance on petroleum thanks to microorganisms that produce valuable chemicals and materials. And to aid the fight against climate change, users could design microorganisms that ingest and lock up carbon, thus reducing atmospheric carbon dioxide (the main driver of global warming).

Our consortium, GP-write, can be understood as a sequel to the Human Genome Project, in which scientists first learned how to "read" the entire genetic sequence of human beings. GP-write aims to take the next step in genetic literacy by enabling the routine "writing" of entire genomes, each with tens of thousands of different variations. As genome writing and editing becomes more accessible, biosafety is a top priority. We're building safeguards into our system from the start to ensure that the platform isn't used to craft dangerous or pathogenic sequences.

Need a quick refresher on genetic engineering? It starts with DNA, the double-stranded molecule that encodes the instructions for all life on our planet. DNA is composed of four types of nitrogen basesadenine (A), thymine (T), guanine (G), and cytosine (C)and the sequence of those bases determines the biological instructions in the DNA. Those bases pair up to create what look like the rungs of a long and twisted ladder. The human genome (meaning the entire DNA sequence in each human cell) is composed of approximately 3 billion base-pairs. Within the genome are sections of DNA called genes, many of which code for the production of proteins; there are more than 20,000 genes in the human genome.

The Human Genome Project, which produced the first draft of a human genome in 2000, took more than a decade and cost about $2.7 billion in total. Today, an individual's genome can be sequenced in a day for $600, with some predicting that the $100 genome is not far behind. The ease of genome sequencing has transformed both basic biological research and nearly all areas of medicine. For example, doctors have been able to precisely identify genomic variants that are correlated with certain types of cancer, helping them to establish screening regimens for early detection. However, the process of identifying and understanding variants that cause disease and developing targeted therapeutics is still in its infancy and remains a defining challenge.

Until now, genetic editing has been a matter of changing one or two genes within a massive genome; sophisticated techniques like CRISPR can create targeted edits, but at a small scale. And although many software packages exist to help with gene editing and synthesis, the scope of those software algorithms is limited to single or few gene edits. Our CAD program will be the first to enable editing and design at genome-scale, allowing users to change thousands of genes, and it will operate with a degree of abstraction and automation that allows designers to think about the big picture. As users create new genome variants and study the results in cells, each variant's traits and characteristics (called its phenotype) can be noted and added to the platform's libraries. Such a shared database could vastly speed up research on complex diseases.

What's more, current genomic design software requires human experts to predict the effect of edits. In a future version, GP-write's software will include predictions of phenotype to help scientists understand if their edits will have the desired effect. All the experimental data generated by users can feed into a machine-learning program, improving its predictions in a virtuous cycle. As more researchers leverage the CAD platform and share data (the open-source platform will be freely available to academia), its predictive power will be enhanced and refined.

Our first version of the CAD software will feature a user-friendly graphical interface enabling researchers to upload a species' genome, make thousands of edits throughout the genome, and output a file that can go directly to a DNA synthesis company for manufacture. The platform will also enable design sharing, an important feature in the collaborative efforts required for large-scale genome-writing initiatives.

There are clear parallels between CAD programs for electronic and genome design. To make a gadget with four transistors, you wouldn't need the help of a computer. But today's systems may have billions of transistors and other components, and designing them would be impossible without design-automation software. Likewise, designing just a snippet of DNA can be a manual process. But sophisticated genomic designwith thousands to tens of thousands of edits across a genomeis simply not feasible without something like the CAD program we're developing. Users must be able to input high-level directives that are executed across the genome in a matter of seconds.

Our CAD program will be the first to enable editing at genome-scale, with a degree of abstraction and automation that allows designers to think about the big picture.

A good CAD program for electronics includes certain design rules to prevent a user from spending a lot of time on a design, only to discover that it can't be built. For example, a good program won't let the user put down transistors in patterns that can't be manufactured or put in a logic that doesn't make sense. We want the same sort of design-for-manufacture rules for our genomic CAD program. Ultimately, our system will alert users if they're creating sequences that can't be manufactured by synthesis companies, which currently have limitations such as trouble with certain repetitive DNA sequences. It will also inform users if their biological logic is faulty; for example, if the gene sequence they added to code for the production of a protein won't work, because they've mistakenly included a "stop production" signal halfway through.

But other aspects of our enterprise seem unique. For one thing, our users may import huge files containing billions of base-pairs. The genome of the Polychaos dubium, a freshwater amoeboid, clocks in at 670 billion base-pairsthat's over 200 times larger than the human genome! As our CAD program will be hosted on the cloud and run on any Internet browser, we need to think about efficiency in the user experience. We don't want a user to click the "save" button and then wait ten minutes for results. We may employ the technique of lazy loading, in which the program only uploads the portion of the genome that the user is working on, or implement other tricks with caching.

Getting a DNA sequence into the CAD program is just the first step, because the sequence, on its own, doesn't tell you much. What's needed is another layer of annotation to indicate the structure and function of that sequence. For example, a gene that codes for the production of a protein is composed of three regions: the promoter that turns the gene on, the coding region that contains instructions for synthesizing RNA (the next step in protein production), and the termination sequence that indicates the end of the gene. Within the coding region, there are "exons," which are directly translated into the amino acids that make up proteins and "introns," intervening sequences of nucleotides that are removed during the process of gene expression. There are existing standards for this annotation that we want to improve on, so our standardized interface language will be readily interpretable by people all over the world.

The CAD program from GP-write will enable users to apply high-level directives to edit a genome, including inserting, deleting, modifying, and replacing certain parts of the sequence. GP-write

Once a user imports the genome, the editing engine will enable the user to make changes throughout the genome. Right now, we're exploring different ways to efficiently make these changes and keep track of them. One idea is an approach we call genome algebra, which is analogous to the algebra we all learned in school. In mathematics, if you want to get from the number 1 to the number 10, there are infinite ways to do it. You could add 1 million and then subtract almost all of it, or you could get there by repeatedly adding tiny amounts. In algebra, you have a set of operations, costs for each of those operations, and tools that help organize everything.

In genome algebra, we have four operations: we can insert, delete, invert, or edit sequences of nucleotides. The CAD program can execute these operations based on certain rules of genomics, without the user having to get into the details. Similar to the "PEMDAS rule" that defines the order of operations in arithmetic, the genome editing engine must order the user's operations correctly to get the desired outcome. The software could also compare sequences against each other, essentially checking their math to determine similarities and differences in the resulting genomes.

In a later version of the software, we'll also have algorithms that advise users on how best to create the genomes they have in mind. Some altered genomes can most efficiently be produced by creating the DNA sequence from scratch, while others are more suited to large-scale edits of an existing genome. Users will be able to input their design objectives and get recommendations on whether to use a synthesis or editing strategyor a combination of the two.

Users can import any genome (here, the E. coli bacteria genome), and create many edited versions; the CAD program will automatically annotate each version to show the changes made. GP-write

Our goal is to make the CAD program a "one-stop shop" for users, with the help of the members of our Industry Advisory Board: Agilent Technologies, a global leader in life sciences, diagnostics and applied chemical markets; the DNA synthesis companies Ansa Biotechnologies, DNA Script, and Twist Bioscience; and the gene editing automation companies Inscripta and Lattice Automation. (Lattice was founded by coauthor Douglas Densmore). We are also partnering with biofoudries such as the Edinburgh Genome Foundry that can take synthetic DNA fragments, assemble them, and validate them before the genome is sent to a lab for testing in cells.

Users can most readily benefit from our connections to DNA synthesis companies; when possible, we'll use these companies' APIs to allow CAD users to place orders and send their sequences off to be synthesized. (In the case of DNA Script, when a user places an order it would be quickly printed on the company's DNA printers; some dedicated users might even buy their own printers for more rapid turnaround.) In the future, we'd like to make the ordering step even more user-friendly by suggesting the company best suited to the manufacture of a particular sequence, or perhaps by creating a marketplace where the user can see prices from multiple manufacturers, the way people do on airfare sites.

We've recently added two new members to our Industrial Advisory Board, each of which brings interesting new capabilities to our users. Catalog Technologies is the first commercially viable platform to use synthetic DNA for massive digital storage and computation, and could eventually help users store vast amounts of genomic data generated on GP-write software. The other new board member is SOSV's IndieBio, the leader in biotech startup development. It will work with GP-write to select, fund, and launch companies advancing genome-writing science from IndieBio's New York office. Naturally, all those startups will have access to our CAD software.

We're motivated by a desire to make genome editing and synthesis more accessible than ever before. Imagine if high-school kids who don't have access to a wet lab could find their way to genetic research via a computer in their school library; this scenario could enable outreach to future genome design engineers and could lead to a more diverse workforce. Our CAD program could also entice people with engineering or computational backgroundsbut with no knowledge of biologyto contribute their skills to genetic research.

Because of this new level of accessibility, biosafety is a top priority. We're planning to build several different levels of safety checks into our system. There will be user authentication, so we'll know who's using our technology. We'll have biosecurity checks upon the import and export of any sequence, basing our "prohibited" list on the standards devised by the International Gene Synthesis Consortium (IGSC), and updated in accordance with their evolving database of pathogens and potentially dangerous sequences. In addition to hard checkpoints that prevent a user from moving forward with something dangerous, we may also develop a softer system of warnings.

Imagine if high-school kids who don't have access to a lab could find their way to genetic research via a computer in their school library.

We'll also keep a permanent record of redesigned genomes for tracing and tracking purposes. This record will serve as a unique identifier for each new genome and will enable proper attribution to further encourage sharing and collaboration. The goal is to create a broadly accessible resource for researchers, philanthropies, pharmaceutical companies, and funders to share their designs and lessons learned, helping all of them identify fruitful pathways for advancing R&D on genetic diseases and environmental health. We believe that the authentication of users and annotated tracking of their designs will serve two complementary goals: It will enhance biosecurity while also engendering a safer environment for collaborative exchange by creating a record for attribution.

One project that will put the CAD program to the test is a grand challenge adopted by GP-write, the Ultra-Safe Cell Project. This effort, led by coauthor Farren Isaacs and Harvard professor George Church, aims to create a human cell line that is resistant to viral infection. Such virus-resistant cells could be a huge boon to the biomanufacturing and pharmaceutical industry by enabling the production of more robust and stable products, potentially driving down the cost of biomanufacturing and passing along the savings to patients.

The Ultra-Safe Cell Project relies on a technique called recoding. To build proteins, cells use combinations of three DNA bases, called codons, to code for each amino acid building block. For example, the triplet 'GGC' represents the amino acid glycine, TTA represents leucine, GTC represents valine, and so on. Because there are 64 possible codons but only 20 amino acids, many of the codons are redundant. For example, four different codons can code for glycine: GGT, GGC, GGA, and GGG. If you replaced a redundant codon in all genes (or 'recode' the genes), the human cell could still make all of its proteins. But viruseswhose genes would still include the redundant codons and which rely on the host cell to replicatewould not be able to translate their genes into proteins. Think of a key that no longer fits into the lock; viruses trying to replicate would be unable to do so in the cells' machinery, rendering the recoded cells virus-resistant.

This concept of recoding for viral resistance has already been demonstrated. Isaacs, Church, and their colleagues reported in a 2013 paper in Science that, by removing all 321 instances of a single codon from the genome of the E. coli bacterium, they could impart resistance to viruses which use that codon. But the ultra-safe cell line requires edits on a much grander scale. We estimate that it would entail thousands to tens of thousands of edits across the human genome (for example, removing specific redundant codons from all 20,000 human genes). Such an ambitious undertaking can only be achieved with the help of the CAD program, which can automate much of the drudge work and let researchers focus on high-level design.

The famed physicist Richard Feynman once said, "What I cannot create, I do not understand." With our CAD program, we hope geneticists become creators who understand life on an entirely new level.

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Quantum Holograms Dont Even Need to See Their Subject - IEEE Spectrum

image:The Bs0 mesons oscillate between the material form composed of the strange quark s and the beautiful antiquark b bar, and the antimatterial form composed of the beautiful quark b and the strange antiquark s bar. (Source: IFJ PAN) view more

Credit: Source: IFJ PAN

We think of matter and antimatter as being as opposite as fire and water. There are, however, particles that can behave as representatives once of the world of matter, once the world of antimatter. An international group of scientists working onexperiments at the LHCb detector have reported their measurement of the extreme speed of oscillation of these sorts of particles between the two worlds.

Like a child on a swing, moving back and forth, there are particles that can change their properties many times with incredible speed, acting as representatives of the world of matter at one moment only to behave like antimatter in the next. Oscillations of particle properties between matter and antimatter are considered to be one of the most fascinating phenomena of quantum mechanics. Inthe case of the mesons known as Bs0, these oscillations have been measured with unprecedented accuracy. The results of this unusual measurement were reported by a group of scientists carrying out experiments in the LHCb detector at the Large Hadron Collider. An article describing their work has appeared in Nature Physics.

The first measurement of the Bs0 meson oscillation was carried out back in 2006, as part of the CDF experiment at the US Fermilab laboratory. We have now managed to improve the accuracy of the original measurement by as much as two orders of magnitude!, says Dr. Agnieszka Dziurda from the Institute of Nuclear Physics of the Polish Academy of Sciences (IFJ PAN) in Cracow. Dr.Dziurda leads the international team of physicists who carried out this research.

The constituents of matter that make up the visible Universe are mainly up and down quarks, electrons and electron neutrinos. Inside the Standard Model, a complex theoretical tool that describes the world on atomic and subatomic scales, these particles are grouped into one generation. It is known that two other generations exist. Both contain particles with similar properties to the first generation, only that they become more and more massive in subsequent generations.

In the Standard Model, every particle of matter has its counterpart in the form of an antiparticle that differs mainly in the sign of its electric charge (in the case of electrically neutral neutrinos, other quantum properties are important). Quarks do not like loneliness and always combine with others into particles. The simplest of these are mesons, i.e. pairs made up of a quark and an antiquark (not necessarily of the same kind).

Mesons may carry an electric charge, but they do not have to. Those devoid of electric charge, referred to as neutral, exhibit an intriguing feature they oscillate between matter and antimatter forms. We focused on analysing the oscillation frequencies of neutral mesons Bs0 containing athird-generation beauty quark b and a second-generation strange quark s, explains Dr. Dziurda.

As unstable particles, mesons decay quickly. It is no different with Bs0 mesons, whose life in the experiment in question ended after a single picosecond (that's a fraction of a second with 12 zeros after the decimal point). During this time Bs0 mesons covered a distance of about one centimetre and, as it turned out, they oscillated several times.

From a technical point of view, measuring a phenomenon of such high frequency proved to be extremely difficult. In particular, it required a deep understanding of the experimental techniques used in the detector, as these could have distorted the measurement. Only with this knowledge physicists were able to precisely reconstruct the trajectory of the recorded mesons and identify the particles into which it decayed.

Quantum mechanics predicts that the decay products of the Bs0 meson must be different depending on whether it was in a state of matter or antimatter at the time of the decay. Thus, only after recording and identifying the decay products of a given meson we could determine whether it decayed as a representative of the matter or antimatter world. Combining this knowledge with information about the nature of the particle at the time of its production allowed us to measure the oscillation frequency, explains Dr. Dziurda.

The data analysed concerned Bs0 mesons created in proton-proton collisions with a total energy of 13 teraelectronvolts, recorded at the LHCb detector between 2015 and 2018. Ultimately, the researchers were able to determine that Bs0 mesons oscillate between matter and antimatter three trillion times per second, which is 300 times faster than the oscillation of a typical atomic clock built using caesium.

The result obtained by physicists from the LHCb experiment is not an empty encyclopaedic curiosity from the exotic world of quanta, but a measurement of wider significance. On the one hand, it agrees with the predictions of quantum mechanics at a new level of accuracy and is its beautiful illustration. On the other hand, the measured oscillation frequency of Bs0 mesons significantly narrows the search areas for particles undescribed by the Standard Model, including those suggested by many theorists to explain the anomalies observed in recent years. Perhaps traces ofthis new physics can be detected when the upgraded LHCb detector resumes recording collisions in 2022.

The Henryk Niewodniczaski Institute of Nuclear Physics (IFJ PAN) is currently one of the largest research institutes of the Polish Academy of Sciences. A wide range of research carried out at IFJ PAN covers basic and applied studies, from particle physics and astrophysics, through hadron physics, high-, medium-, and low-energy nuclear physics, condensed matter physics (including materials engineering), to various applications of nuclear physics in interdisciplinary research, covering medical physics, dosimetry, radiation and environmental biology, environmental protection, and other related disciplines. The average yearly publication output of IFJ PAN includes over 600 scientific papers in high-impact international journals. Each year the Institute hosts about 20 international and national scientific conferences. One of the most important facilities of the Institute is the Cyclotron Centre Bronowice (CCB), which is an infrastructure unique in Central Europe, serving as a clinical and research centre in the field of medical and nuclear physics. In addition, IFJ PAN runs four accredited research and measurement laboratories. IFJ PAN is a member of the Marian Smoluchowski Krakw Research Consortium: "Matter-Energy-Future", which in the years 2012-2017 enjoyed the status of the Leading National Research Centre (KNOW) in physics. In 2017, the European Commission granted the Institute the HR Excellence in Research award. The Institute holds A+ category (the highest scientific category in Poland) in the field of sciences and engineering.

CONTACTS:

Dr. Agnieszka Dziurda

Institute of Nuclear Physics, Polish Academy of Sciences

tel.: +48 12 6628086

email: agnieszka.dziurda@ifj.edu.pl

SCIENTIFIC PUBLICATIONS:

Precise determination of the $B_s^0 - bar{B}_s^0$ oscillation frequency

LHCb Collaboration

Nature Physics, 2022

DOI: https://doi.org/10.1038/s41567-021-01394-x

LINKS:

http://www.ifj.edu.pl/

The website of the Institute of Nuclear Physics, Polish Academy of Sciences.

http://press.ifj.edu.pl/

Press releases of the Institute of Nuclear Physics, Polish Academy of Sciences.

IMAGES:

IFJ220209b_fot01s.jpg

HR: https://www.euvolution.com/prometheism-transhumanism-posthumanism/wp-content/uploads/2022/02/IFJ220209b_fot01.jpg

The Bs0 mesons oscillate between the material form composed of the strange quark s and the beautiful antiquark b bar, and the antimatterial form composed of the beautiful quark b and the strange antiquark s bar. (Source: IFJ PAN)

VIDEOS:

IFJ220209b_vid01.mp4

HR: http://press.ifj.edu.pl/news/2022/02/09/IFJ220209b_vid01.mp4

The Bs0 mesons oscillations. (Source: IFJ PAN)

6-Jan-2022

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From matter to antimatter, to and fro trillions of times a second - EurekAlert

Few science experiments are as strange and compelling as the double-slit experiment.

Few experiments, if any, in modern physics are capable of conveyingsuch a simple ideathat light and matter can act as both waves and discrete particles depending on whether they are being observedbut which is nonetheless one of the great mysteries of quantum mechanics.

It's the kind of experiment that despite its simplicity is difficult to wrap your mind around because what it shows is incredibly counter-intuitive.

But not only has the double-slit experiment been repeated countless times in physics labs around the world, but it has also even spawned many derivative experiments that further reinforce its ultimate result, that particles can be waves or discrete objects and that it is as if they "know" when you are watching them.

To understand what the double-slit experiment demonstrates, we need to lay out some key ideas from quantum mechanics.

In 1925,Werner Heisenberg presented his mentor, the eminent German physicist Max Born, with a paper to review that showed how the properties of subatomic particles, like position, momentum, and energy, could be measured.

Born saw that these properties could be represented through mathematical matrices, with definite figures and descriptions of individual particles, and this laid the foundation for the matrix description of quantum mechanics.

Meanwhile, in 1926,Edwin Schrdingerpublished his wave theory of quantum mechanics which showed that particles could be described by an equation that defined their waveform; that is, it determined that particles were actually waves.

This gave rise to the concept of wave-particle duality, which is one of the defining features of quantum mechanics. According to this concept, subatomic entities can be described as both waves and particles, and it is up to the observer to decide how to measure them.

That last part is important since it will determine how quantum entities will manifest. If you try to measure a particle's position, you will measure a particle's position, and it will cease to be a wave at all.

If you try to define its momentum, you will find that behaves like a wave and you can't know anything definitive about its position beyond the probability that it exists at any given point within that wave.

Essentially, you will measure it as a particle or a wave, and doing so decides what form it will take.

The double-slit experiment is one of the simplest demonstrations of this wave-particle duality as well as a central defining weirdness ofquantum mechanics, one that makes the observer an active participant in the fundamental behavior of particles.

The easiest way to describe the double-slit experiment is by using light. First, take a source of coherent light, such as a laser beam, that shines in a single wavelength, like purely blue visible light at 460nm, and aim it at a wall with two slits in it.The distance between the slits should be roughly the same as the light's wavelengthso that they will both sit inside that beam of light.

Behind that wall, place a screen that can detect and record the light that impacts it. If you fire the laser beam at the two slits, on the recording screen behind the wall you will see a stripey pattern like this:

This is probably not what you might have been expecting, and that's perfectly rational if you treat light as if it were a wave. If the light was a wave, then when the single wave of light from the laser hit both slits, each slit would become a new "source" of light on the other side of the wall, and so you would have a new wave originating from each slit producing two waves.

Where those two waves intersect causes something known as interference, and it can be either constructive or destructive. When the amplitude of the waves overlaps at either a peak or a trough, it acts to boost the wavelength in either direction by adding its energy together. This is constructive interference, and it produces these brighter bars in this pattern.

When the waves cancel each other out, as when a peak hits a trough, the effect neutralizes the wavelength and diminishes or even eliminates the light, producing the blacked-out spaces in between the blue bars.

But in the case of quantum entities like photons of light or electrons, they are also individual particles. So what happens when you shoot a single photon through the double slits?

One photon alone reacting to the screen might leave a tiny dot behind, which might not mean much in isolation, but if you shoot many single photons at the double slits, those tiny dots that the photon leaves behind on our screen actually show up in that same stripey interference pattern produced by the laser beam hitting the double slits.

In other words, the individual photon behaves as if it passed through both slits like it was a wave.

Now, here's where things get really weird.

We can set up a detector in front of one of the slits that can watch for photons and light up whenever it detects one passing through. When we do this, the detector will light up 50% of the time, and the pattern left behind on the screen changes, giving us something that looks like this:

And to make things even wilder, we can set up a detector behind the wall that only detects a photon after it has passed through the slit and we get the same result. That means that even if the photon passes through both slits as a wave, the moment it is detected, it is no longer a wave but a particle. And not just that, that second wave emerging from the other slit also collapses back into the particle that was detected passing through the other slit.

In practice, this means that somehow the universe "knows" that someone is watching and flips the metaphorical quantum coin to see which slit the particle passed through. The more individual photons you shoot through the double slit, the closer that photon detector comes to detecting photons 50% of the time, just as flipping a coin 10 times might give you heads 70% of the time while flipping it 100 times might give you tails 55% of the time, and flipping it 1 billion times gives you heads 50.0003% of the time.

This seems to show that not only is the universe watching the observer as well, but that the quantum states of entities passing through the double slits are governed by the laws of probability, making it impossible to ever predict with certainty what the quantum state of an entity will be.

The double-slit experiment actually predates quantum mechanics by a little more than acentury.

During the Scientific Revolution, the nature of light was a particularly contentious topic, with manylike Isaac Newton himselfarguing in favor of a corpuscular theory of light that held that light was transmitted through particles.

Others believed that light was a wave that was transmitted through "aether" or some other medium, the way sound travels through air and water, but Newton's reputation and a lack of an effective means to demonstrate the wave theory of light solidified the corpuscular view for just shy of a century after Newton published hisOpticks in 1704.

The definitive demonstration came from the British polymath Thomas Young, who presented a paper to the Royal Society of London in 1803 that described a pair of simple experiments that anyone could perform to see for themselves that light was in fact a wave.

First, Young established that a pair of waves were subject to interference when they overlapped, producing a distinctive interference pattern.

He initially demonstrated this interference pattern using a ripple tank of water, showing that such a pattern is characteristic of wave propagation.

Young then introduced the precursor to the modern double-slit experiment, though instead of using a laser beam to produce the required light source, Young used reflected sunlight striking two slits in a card as its target.

The resulting light diffraction showed the expected interference pattern, and the wave theory of light gained considerable support. It would take another decade and a half before further experimentation conclusively refuted corpuscles in favor of waves, but the double-slit experiment that Young developed proved to be a fatal blow to Newton's theory.

Young wasn't lying when he said, "The experiments I am about to relate...may be repeated with great ease, whenever the sun shines, and without any other apparatus than is at hand to everyone."

While it might be a stretch to say that you can use the double-slit experiment to demonstrate some of the more counterintuitive features of quantum mechanics (unless you have a photon detector handy and a laser that shoots individual photons), you can still use it to demonstrate the wave nature of light.

If you want to replicate Young's experiment, you only need as large a box as is practical with a hole cut in it a little smaller than an index card. Then, take an Exacto knife or similar blade for fine cutting work and cut two slits into a piece of cardboard larger than the hole in your box. The slits should be between 0.1mm and 0.4mm apart, as the closer together they are, the more distinct the interference pattern will be. It's better to create cards for this rather than cut directly into the box since you might need to make adjustments to the spacing of the slits.

Once you're satisfied with the spacing, affix the card with the double-slit in it over the hole and secure it in place with tape. Just make sure sunlight isn't leaking around the card.

You'll also need to create some eye-holes in the box so you can look inside without getting in the way of the light hitting the double-slit card, but once you figure that out, you're all set.

To accurately diffract sunlight using this box, you will need to have the sunlight more or less hitting the double-slit card dead on, so it might take some maneuvering to get it properly positioned.

Once it is, look through the eye holes and you can see the interference pattern forming on the inside wall, as well as different colors emerging as the different wavelengths interfering with each other change the color of the light being created.

If you wanted to try it out with something fancier, get yourself a laser pointer from an office supply store. Just like you'd do with a viewing box, create cards with slits in them, and when properly spaced, set up a shielded area for the card to rest on.

You'll want to make sure that only the light from the laser pointer is hitting the double-slit, so shield the card however you need to. Then, set the laser pointer on a surface level with the slits and shine the laser at them. On the wall behind the card, the interference pattern from the slits should be clearly visible.

If you don't want to go through all that trouble, you can also use Photoshop or similar software to recreate the effect.

First, create a template of evenly spaced concentric circles. Using different layers for each source, as well as a background later, position the center of the concentric rings near to one another. On a 1200 pixel wide canvas, a distance of 100 pixels between the two centers should do nicely.

Then, fill in the color of each concentric ring, alternating light and dark, with an opacity set to about 33%. You may need to hide one of the concentric circle layers while you work on the other. When you're done, reveal the two overlapping layers of circles and the interference pattern should jump out at you immediately, looking something like this:

Of course, if you want to dig into the quantum mechanics side of things, you'll need to work in a pretty advanced physics lab at a university or science institute, since photon detectors aren't the kind of thing you can pick up at the hobby store.

Still, if you're compelled to try the heavier stuff out for yourself, you wouldn't be the first person to get drawn into a career in physics because of the weirdness of quantum mechanics, and there are definitely worse ways to make a living.

Original post:

What is the double-slit experiment, and why is it so important? - Interesting Engineering