Husband & Dad, likes Python, good fiction & more
59 stories

5 Subtle Stretches You Can Do At Your Desk

1 Share

Desk stretches are a quick and easy way to boost mobility.Feeling tense at work? Step away from the keyboard, take your eyes off the screen, and spend a few moments focusing on your body. A quick stretching break could be just what you need to feel reinvigorated. In fact, studies have shown that taking a much-needed pause can help boost your productivity (and act as a great alternative to downing an extra cup of coffee when the afternoon slump hits). Perform all of the stretches below, or pick one or two, to target any part of your body that feels tight or out of whack.

Cat-Cow Stretch

The cat-cow stretch works well from a seated position.

Targets: back, chest
While this stretch is typically done on all fours, you don’t have to be on the ground to lengthen and contract your muscles. Perform a modified version of the same gentle, spine-stretching sequence from your desk to help ease your body back into proper posture.


  1. Scoot down towards the edge of your chair so that your back isn’t resting or being propped up by the back of the chair.
  2. With your hands resting on your knees, inhale and hinge slightly forward allowing a small arch in your lower back. This is cow pose.
  3. On your exhale, round your spine and tuck your chin into your chest. This is cat pose.
  4. Flow between those two poses, pressing your chest out and arching your back dramatically for the “cat” pose, and then breathing out and pulling your belly button in towards your spine as you arch your back into “cow.”


Trunk Rotation

Trunk rotation in chair.

Targets: obliques
You don’t have to be off the clock to make time to work your core. Squeeze in a seated oblique twist with this movement that engages your core while challenging your stabilizer muscles.


  1. Sit tall in your chair as you gently rotate your trunk and shoulders to one side. Grasp the outside of the corresponding leg to lean deeper into the pose.
  2. Hold, then repeat in the opposite direction. Each time, turn until you feel a slight stretch in your trunk.


Chest Stretch

Stretch your pecs with a seated chest stretch.

Targets: Pectoral muscles
Open up your chest with this chair stretch that also hits your arms.


  1. Sit on the edge of your chair with your feet hip-distance apart and firmly planted on the ground.
  2. Reach your hands back to grasp the back of your chair, palms facing you.
  3. With a straight back, draw your bellybutton in towards your spine. Press your chest forward and keep your gaze straight ahead.
  4. Hold this stretch for 30-60 seconds.


Shoulder Stretch

Shoulder stretch in chair.

Targets: deltoids (anterior, middle, and posterior)
This stretch keeps tension at bay by rolling your shoulders and mindfully relaxing your upper body.


  1. Sit up straight with your hands on your thighs.
  2. Roll your shoulders toward the front and then up to your ears, drawing them back and down while squeezing your shoulder blades together.
  3. Repeat for 10 repetitions before reversing direction.  


Neck Rotations

Neck rotations in chair.Targets: neck, trapezius
You don’t have to be in yoga’s “ragdoll” pose to experience the release that comes with letting your head weigh down and your neck roll. Help relieve neck and shoulder pain with this desk-friendly modification.


  1. Sit up straight with your hands resting on your thighs.
  2. With your head tilted back and gaze towards the ceiling, rotate your head clockwise.
  3. Continue until you’ve made a full rotation, dropping your chin to your chest at the halfway point.
  4. Repeat counterclockwise. That’s one rep. Repeat 10 times.

The post 5 Subtle Stretches You Can Do At Your Desk appeared first on Fitbit Blog.

Read the whole story
20 days ago
Share this story

How Exercise May Help the Memory Grow Stronger

1 Share
Stress weakens the brain’s ability to learn and retain information, but exercise may counteract those effects by bolstering communication between brain cells.
Read the whole story
25 days ago
Share this story

Tutorial: Creating the Fastest Hotkey-Based Web Search

1 Share

Some of the most useful workflows are the simplest.

In this post, you'll discover how to create a hotkey-based workflow which allows you to launch a web search for your current macOS selection or clipboard contents. It's an incredibly quick way of searching the web without re-typing your query, or manually launching a search.

First, let's take a look at my basic workflow.


Each of these two workflow streams consists of two objects; A Hotkey Trigger and a Default Web Search Action.

Taking a look at the first stream at the top, the hotkey is configured to pass the Selection in macOS as argument.


This means that, when text is selected in macOS, pressing the hotkey combination will pass this text on to the next object. In this instance, the next object is a Default Web Search, set to use Alfred's default Google Search and your default browser.

The Default Web Search object is left as default; Google web search, and default browser.


You've now created your first workflow stream, so select some text in macOS and press your hotkey combination to launch a Google search for that text in your default browser.

To create the second stream, select the first two objects, and copy and paste them below. Modify the Hotkey object slightly by setting a different hotkey combo, and choosing "Clipboard Contents" as argument. This hotkey will now trigger a Google search for the last text you copied to your clipboard!

Customising the Workflow

Now that you've created the workflow, you can add other streams and customise them as you need;

  • Change the Default Web Search to another search engine like Wikipedia, Amazon, IMDB, Twitter, Google Images, etc.
  • Use an Open URL Action with one of your own custom searches for your own work documentation or resources.
  • Open the results in a specific browser, rather than your default one.
  • Set the second object to be a different action like launching a custom URL where the argument becomes a {query} within your URL.
  • Passing the argument to an Output object like Large Type or Write File.

Take a look at how these hotkey-based workflows can save you time and clicks as you go through your day, and create your own variations.

Read the whole story
119 days ago
Share this story

Now Available: Three New AWS Specialty Training Courses

1 Share

AWS Training allows you to learn from the experts so you can advance your knowledge with practical skills and get more out of the AWS Cloud. Today I am happy to announce that three of our most popular training bootcamps (a staple at AWS re:Invent and AWS Global Summits) are becoming part of our permanent instructor-led training portfolio:

These one-day courses are intended for individuals who would like to dive deeper into a specialized topic with an expert trainer.

You can explore our complete course catalog, and you can search for a public class near you within the AWS Training and Certification Portal. You can also request a private onsite training session for your team by contacting us.




Read the whole story
235 days ago
Share this story

Thought Experiment: How Einstein Solved Difficult Problems

1 Share

“We live not only in a world of thoughts, but also in a world of things.
Words without experience are meaningless.”
— Vladimir Nabokov


The Basics

“All truly wise thoughts have been thought already thousands of times; but to make them truly ours, we must think them over again honestly, until they take root in our personal experience.”
— Johann Wolfgang von Goethe


Imagine a small town with a hard working barber. The barber shaves everyone in the town who does not shave themselves. He does not shave anyone who shaves themselves. So, who shaves the barber?

The ‘impossible barber’ is one classic example of a thought experiment – a means of exploring a concept, hypothesis or idea through extensive thought. When finding empirical evidence is impossible, we turn to thought experiments to unspool complex concepts.

In the case of the impossible barber, setting up an experiment to figure out who shaves him would not be feasible or even desirable. After all, the barber cannot exist. Thought experiments are usually rhetorical. No particular answer can or should be found.

The purpose is to encourage speculation, logical thinking and to change paradigms. Thought experiments push us outside our comfort zone by forcing us to confront questions we cannot answer with ease. They reveal that we do not know everything and some things cannot be known.

In a paper entitled Thought Experimentation of Presocratic Philosophy, Nicholas Rescher writes:

Homo sapiens is an amphibian who can live and function in two very different realms- the domain of actual facts which we can investigate in observational inquiry, and the domain of the imaginative projection which we can explore in thought through reasoning…A thought experiment is an attempt to draw instruction from a process of hypothetical reasoning that proceeding by eliciting the consequences of a hypothesis which, for anything that one actually knows to the contrary, may be false. It consists in reasoning from a supposition that is not accepted as true- perhaps even known to be false but is assumed provisionally in the interests of making a point or resolving a conclusion.

As we know from the narrative fallacy, complex information is best digested in the form of narratives and analogies. Many thought experiments make use of this fact to make them more accessible. Even those who are not knowledgeable about a particular field can build an understanding through thought experiments. The aim is to condense first principles into a form which can be understood through analysis and reflection. Some incorporate empirical evidence, looking at it from an alternative perspective.

The benefit of thought experiments (as opposed to aimless rumination) is their structure. In an organized manner, thought experiments allow us to challenge intellectual norms, move beyond the boundaries of ingrained facts, comprehend history, make logical decisions, foster innovative ideas, and widen our sphere of reference.

Despite being improbable or impractical, thought experiments should be possible, in theory.

The History of Thought Experiments

Thought experiments have a rich and complex history, stretching back to the ancient Greeks and Romans. As a mental model, they have enriched many of our greatest intellectual advances, from philosophy to quantum mechanics.

An early example of a thought experiment is Zeno’s narrative of Achilles and the tortoise, dating to around 430 BC. Zeno’s thought experiments aimed to deduce first principles through the elimination of untrue concepts.

In one instance, the Greek philosopher used it to ‘prove’ motion is an illusion. Known as the dichotomy paradox, it involves Achilles racing a tortoise. Out of generosity, Achilles gives the tortoise a 100m head start. Once Achilles begins running, he soon catches up on the head start. However, by that point, the tortoise has moved another 10m. By the time he catches up again, the tortoise will have moved further. Zeno claimed Achilles could never win the race as the distance between the pair would constantly increase.

In the 17th century, Galileo further developed the concept by using thought experiments to affirm his theories. One example is his thought experiment involving two balls (one heavy, one light) which are dropped from the Leaning Tower of Pisa. Prior philosophers had theorized the heavy ball would land first. Galileo claimed this was untrue, as mass does not influence acceleration. We will look at Galileo’s thought experiments in more detail later on in this post.

In 1814, Pierre Laplace explored determinism through ‘Laplace’s demon.’ This is a theoretical ‘demon’ which has an acute awareness of the location and movement of every single particle in existence. Would Laplace’s demon know the future? If the answer is yes, the universe must be linear and deterministic. If no, the universe is nonlinear and free will exists.

In 1897, the German term ‘Gedankenexperiment’ passed into English and a cohesive picture of how thought experiments are used worldwide began to form.

Albert Einstein used thought experiments for so of his most important discoveries. The most famous of this thought experiments was on a beam of light, which was made into a brilliant children's book. What would happen if you could catch up to a beam of light as it moved he asked himself? The answers lead him down a different path toward time, which lead to the special theory of relativity.

In On Thought Experiments, 19th-century Philosopher and physicist Ernst Mach writes that curiosity is an inherent human quality. We see this in babies, as they test the world around them and learn the principle of cause and effect. With time, our exploration of the world becomes more and more in depth. We reach a point where we can no longer experiment through our hands alone. At that point, we move into the realm of thought experiments.

Thought experiments are a structured manifestation of our natural curiosity about the world.

Mach writes:

Our own ideas are more easily and readily at our disposal than physical facts. We experiment with thought, so as to say, at little expense. This it shouldn’t surprise us that, oftentime, the thought experiment precedes the physical experiment and prepares the way for it… A thought experiment is also a necessary precondition for a physical experiment. Every inventor and every experimenter must have in his mind the detailed order before he actualizes it. Even if Stephenson knew the train, the rails and the steam engine from experience, he must have, nonetheless, have preconceived in his thoughts the combination of a train on wheels, driven by a steam engine, before he could have proceeded to the realization. No less did Galileo have to envisage, in his imagination, the arrangements for the investigation of gravity, before these were actualized. Even the beginner learns in experimenting than as insufficient preliminary estimate, or nonobservance of sources of error has for him no less tragic comic results than the proverbial ‘look before you leap’ does in practical life.

Mach compares thought experiments to the plans and images we form in our minds before commencing an endeavor. We all do this — rehearsing a conversation before having it, planning a piece of work before starting it, figuring out every detail of a meal before cooking it. Mach views this as an integral part of our ability to engage in complex tasks and to innovate creatively.

According to Mach, the results of some thought experiments can be so certain that it is unnecessary to physically perform it. Regardless of the accuracy of the result, the desired purpose has been achieved.

We will look at some key examples of thought experiments throughout this post, which will show why Mach’s words are so important. He adds:

It can be seen that the basic method of the thought experiment is just like that of a physical experiment, namely, the method of variation. By varying the circumstances (continuously, if possible) the range of validity of an idea (expectation) related to these circumstances is increased.

Although some people view thought experiments as pseudo-science, Mach saw them as valid and important for experimentation.

Types of Thought Experiment

“Can't you give me brains?” asked the Scarecrow.

“You do not need them. You are learning something every day. A baby has brains, but it does not know much. Experience is the only thing that brings knowledge, and the longer you are on earth the more experience you are sure to get.”
― L. Frank Baum, The Wonderful Wizard of Oz


Several key types of thought experiment have been identified:

  • Prefactual – Involving potential future outcomes. E.g. ‘What will X cause to happen?’
  • Counterfactual – Contradicting known facts. E.g. ‘If Y happened instead of X, what would be the outcome?’
  • Semi-factual – Contemplating how a different past could have lead to the same present. E.g. ‘If Y had happened instead of X, would the outcome be the same?’
  • Prediction– Theorising future outcomes based on existing data. Predictions may involve mental or computational models. E.g. ‘If X continues to happen, what will the outcome be in one year?’
  • Hindcasting– Running a prediction in reverse to see if it forecasts an event which has already happened. E.g. ‘X happened, could Y have predicted it?’
  • Retrodiction– Moving backwards from an event to discover the root cause. Retrodiction is often used for problem solving and prevention purposes. E.g. ‘What caused X? How can we prevent it from happening again?’
  • Backcasting – Considering a specific future outcome, then working forwards from the present to deduce its causes. E.g. ‘If X happens in one year, what would have caused it?’

Thought Experiments in Philosophy

“With our limited senses and consciousness, we only glimpse a small portion of reality. Furthermore, everything in the universe is in a state of constant flux. Simple words and thoughts cannot capture this flux or complexity. The only solution for an enlightened person is to let the mind absorb itself in what it experiences, without having to form a judgment on what it all means. The mind must be able to feel doubt and uncertainty for as long as possible. As it remains in this state and probes deeply into the mysteries of the universe, ideas will come that are more dimensional and real than if we had jumped to conclusions and formed judgments early on.”

― Robert Greene, Mastery


Thoughts experiments have been an integral part of philosophy since ancient times. This is in part due to philosophical hypotheses often being subjective and impossible to prove through empirical evidence.

Philosophers use thought experiments to convey theories in an accessible manner. With the aim of illustrating a particular concept (such as free will or mortality), philosophers explore imagined scenarios. The goal is not to uncover a ‘correct’ answer, but to spark new ideas.

An early example of a philosophical thought experiment is Plato’s Allegory of the Cave, which centers around a dialogue between Socrates and Glaucon (Plato’s brother.)

A group of people are born and live within a dark cave. Having spent their entire lives seeing nothing but shadows on the wall, they lack a conception of the world outside. Knowing nothing different, they do not even wish to leave the cave. At some point, they are lead outside and see a world consisting of much more than shadows.

“The frog in the well knows nothing of the mighty ocean.”

— Japanese Proverb

Plato used this to illustrate the incomplete view of reality most us have. Only by learning philosophy, Plato claimed, can we see more than shadows.

Upon leaving the cave, the people realize the outside world is far more interesting and fulfilling. If a solitary person left, they would want to others to do the same. However, if they return to the cave, their old life will seem unsatisfactory. This discomfort would become misplaced, leading them to resent the outside world. Plato used this to convey his (almost compulsively) deep appreciation for the power of educating ourselves. To take up the mantle of your own education and begin seeking to understand the world is the first step on the way out of the cave.

Moving from caves to insects, let’s take a look at a fascinating thought experiment from 20th-century philosopher Ludwig Wittgenstein. Imagine

Imagine a world where each person has a beetle in a box. In this world, the only time anyone can see a beetle is when they look in their own box. As a consequence, the conception of a beetle each individual has is based on their own. It could be that everyone has something different, or that the boxes are empty, or even that the contents are amorphous.

Wittgenstein uses the ‘Beetle in a Box’ thought experiment to convey his work on the subjective nature of pain. We can each only know what pain is to us, and we cannot feel another person’s agony. If people in the hypothetical world were to have a discussion on the topic of beetles, each would only be able to share their individual perspective. The conversation would have little purpose because each person can only convey what they see as a beetle. In the same way, it is useless for us to describe our pain using analogies (‘it feels like a red hot poker is stabbing me in the back’) or scales (‘the pain is 7/10.’)

Thought Experiments in Science

Although empirical evidence is usually necessary for science, thought experiments may be used to develop a hypothesis or to prepare for experimentation. Some hypotheses cannot be tested (e.g string theory) – at least, not given our current capabilities.

Theoretical scientists may turn to thought experiments to develop a provisional answer, often informed by Occam’s razor.

Nicholas Rescher writes:

In natural science, thought experiments are common. Think, for example, of Einstein’s pondering the question of what the world would look like if one were to travel along a ray of light. Think too of physicists’ assumption of a frictionlessly rolling body or the economists’ assumption of a perfectly efficient market in the interests of establishing the laws of descent or the principles of exchange, respectively…Ernst Mach [mentioned in the introduction] made the sound point that any sensibly designed real experiment should be preceded by a thought experiment that anticipates at any rate the possibility of its outcome.

In a paper entitled Thought Experiments in Scientific Reasoning, Andrew D. Irvine explains that thought experiments are a key part of science. They are in the same realm as physical experiments. Thought experiments require all assumptions to be supported by empirical evidence. The context must be believable, and it must provide useful answers to complex questions. A thought experiment must have the potential to be falsified.

Irvine writes:

Just as a physical experiment often has repercussions for its background theory in terms of confirmation, falsification or the like, so too will a thought experiment. Of course, the parallel is not exact; thought experiments…no do not include actual interventions within the physical environment.

In  Do All Rational Folks Think As We Do? Barbara D. Massey writes:

Often critique of thought experiments demands the fleshing out or concretizing of descriptions so that what would happen in a given situation becomes less a matter of guesswork or pontification. In thought experiments we tend to elaborate descriptions with the latest scientific models in mind…The thought experiment seems to be a close relative of the scientist’s laboratory experiment with the vital difference that observations may be made from perspectives which are in reality impossible, for example, from the perspective of moving at the speed of light…The thought experiment seems to discover facts about how things work within the laboratory of the mind.

One key example of a scientific thought experiment is Schrodinger’s cat.

Developed in 1935 by Edwin Schrodinger, Schrodinger's cat seeks to illustrate the counterintuitive nature of quantum mechanics in a more understandable manner. Although difficult to present in a simplified manner, the idea is

Although difficult to present in a simplified manner, the idea is that of a cat which is neither alive nor dead, encased within a box. Inside the box is a Geiger counter and a small quantity of decaying radioactive material. The amount of radioactive material is small, and over a period time, it is equally probable it will decay or not. If it does decay, a tube of acid will smash and poison the cat. Without opening the box, it is impossible to know if the cat is alive or not.

Let's ignore the ethical implications and the fact that, if this were performed, the angry meowing of the cat would be a clue. Like most thought experiments, the details are arbitrary – it is irrelevant what animal it is, what kills it, or the time frame.

Schrodinger’s point was that quantum mechanics are indeterminate. When does a quantum system switch from one state to a different one? Can the cat be both alive and dead, and is that conditional on it being observed? What about the cat’s own observation of itself?

In Search of Schrodinger’s Cat, John Gribbin writes:

Nothing is real unless it is observed…there is no underlying reality to the world. “Reality,” in the everyday sense, is not a good way to think about the behavior of the fundamental particles that make up the universe; yet at the same time those particles seem to be inseparably connected into some invisible whole, each aware of what happens to the others.

Schrodinger himself wrote in Nature and The Greeks:

We do not belong to this material world that science constructs for us. We are not in it; we are outside. We are only spectators. The reason why we believe that we are in it that we belong to the picture, is that our bodies are in the picture. Our bodies belong to it. Not only my own body, but those of my friends, also of my dog and cat and horse, and of all the other people and animals. And this is my only means of communicating with them.

Another important early example of a scientific thought experiment is Galileo’s Leaning Tower of Pisa Experiment.

Galileo sought to disprove the prevailing belief that gravity is influenced by the mass of an object. Since the time of Aristotle, people had assumed that a 10g object would fall at 1/10th the speed of a 100g object. Oddly, no one is recorded as having tested this.

According to Galileo’s early biography (written in 1654), he dropped two objects from the Leaning Tower of Pisa to disprove the gravitational mass relation hypothesis. Both landed at the same time, ushering in a new understanding of gravity. It is unknown if Galileo performed the experiment itself, so it is regarded as a thought experiment, not a physical one. Galileo reached his conclusion through the use of other thought experiments.

Biologists use thought experiments, often of the counterfactual variety. In particular, evolutionary biologists question why organisms exist as they do today. For example, why are sheep not green? As surreal as the question is, it is a valid one. A green sheep would be better camouflaged from predators. Another thought experiment involves asking: why don’t organisms (aside from certain bacteria) have wheels? Again, the question is surreal but is still a serious one. We know from our vehicles that wheels are more efficient for moving at speed than legs, so why do they not naturally exist beyond the microscopic level?

Psychology and Ethics — The Trolley Problem

Picture the scene. You are a lone passerby in a street where a tram is running along a track. The driver has lost control of it. If the tram continues along its current path, the five passengers will die in the ensuing crash. You notice a switch which would allow the tram to move to a different track, where a man is standing. The collision would kill him but would save the five passengers. Do you press the switch?

This thought experiment has been discussed in various forms since the early 1900s. Psychologists and ethicists have discussed the trolley problem at length, often using it in research. It raises many questions, such as:

  • Is a casual observer required to intervene?
  • Is there a measurable value to human life? I.e. is one life less valuable than five?
  • How would the situation differ if the observer were required to actively push a man onto the tracks rather than pressing the switch?
  • What if the man being pushed were a ‘villain’? Or a loved one of the observer? How would this change the ethical implications?
  • Can an observer make this choice without the consent of the people involved?

Research has shown most people are far more willing to press a switch than to push someone onto the tracks. This changes if the man is a ‘villain’- people are then far more willing to push him. Likewise, they are reluctant if the person being pushed is a loved one. In

In Incognito: The Secret Lives of The Brain, David Eagleman writes that our brains have a distinctly different response to the idea of pushing someone and the idea of pushing a switch. When confronted with a switch, brain scans show that our rational thinking areas are activated. Changing pushing a switch to pushing a person and our emotional areas activate. Eagleman summarizes that:

People register emotionally when they have to push someone; when they only have to tip a lever, their brain behaves like Star Trek’s Mr. Spock.

The trolley problem is theoretical, but it does have real world implications. For example, the majority of people who eat meat would not be content to kill the animal themselves- they are happy to press the switch but not to push the man. Even those who do not consume meat tend to ignore the fact they are indirectly contributing to the deaths of animals due to production quotas, which mean the meat they would have eaten ends up getting wasted. They feel morally superior as they are not actively pushing anyone onto the tracks, yet are still like an observer who does not intervene in anyway. As we move towards autonomous vehicles, there may be real life instances of similar situations. Vehicles may be required to make utilitarian choices – such as swerving into a ditch and killing the driver to avoid a group of children.

Although psychology and ethics are separate fields, they often make use of the same thought experiments.

The Infinite Monkey Theorem and Mathematics

“Ford!” he said, “there's an infinite number of monkeys outside who want to talk to us about this script for Hamlet they've worked out.”

― Douglas Adams, The Hitchhiker's Guide to the Galaxy


The infinite monkey theorem is a mathematical thought experiment. The premise is that infinite monkeys with typewriters will, eventually, type the complete works of Shakespeare. Some versions involve infinite monkeys or a single work. Mathematicians use the monkey(s) as a representation of a device which produces letters at random.

In Fooled By Randomness, Nassim Taleb writes:

If one puts an infinite number of monkeys in front of (strongly built) typewriters, and lets them clap away, there is a certainty that one of them will come out with an exact version of the ‘Iliad.' Upon examination, this may be less interesting a concept than it appears at first: Such probability is ridiculously low. But let us carry the reasoning one step beyond. Now that we have found that hero among monkeys, would any reader invest his life's savings on a bet that the monkey would write the ‘Odyssey' next?

The infinite monkey theorem is intended to illustrate the idea that any issue can be solved through enough random input, in the manner a drunk person arriving home will eventually manage to fit their key in the lock even if they do it without much finesse. It also represents the nature of probability and the idea that any scenario is workable, given enough time and resources.

To learn more about thought experiments, consider reading The Pig That Wants to Be Eaten, The Infinite Tortoise or The Laboratory of the Mind.

Sponsored by: Royce & Associates – Small Cap Specialists with Unparalleled Knowledge and Experience..

Read the whole story
271 days ago
Share this story

Behold the Liver, the Astonishing Blob That Runs the Body

1 Share
The underrated, unloved liver performs more than 300 vital functions. No wonder the ancients believed it to be the home of the human soul.
Read the whole story
271 days ago
Share this story
Next Page of Stories