Which planet is closest to Earth? If we look at a typical model of the Solar System with each planet neatly lined up, we can see that Venus approaches Earth closer than any other planet. However, this is only one interpretation of the question.
Technically, Venus is the planet that comes closest to Earth. However, as they do not orbit in synchrony, this approximation happens about once a year. At other times, Venus will orbit away from Earth and can go on the other side of the Sun, making the distance between Earth and Venus vast. In those times, Mars may seem like the next obvious choice to be closest to Earth.
But then again, Mars has the same issue where it and Earth are often on opposite sides of the Sun. Because of the nature of circular orbits, the distances between the planets swing and fluctuate, meaning that the real question should be:
Which planet is closest to the Earth most of the time on average?
The answer to this question happens to be Mercury. If we look at a “top-down” model of the Solar System, we can see that Mercury – being closest to the Sun – orbits rapidly around the Sun and often lies between Earth and the two other planets, Venus and Mars. If we plot the distance between each of these three planets and Earth, we can see that on average, Mercury is closer to Earth because the distance fluctuates less.
Interestingly, if we take this question further, we find that Mercury is also Mars and Venus’ closest neighbour on average. This is a property of the Solar System being formed of concentric circles, meaning that Mercury’s smallest orbit makes it average a closer distance to all of these planets.
Fascinatingly, if we go even further than that, we find that the same pattern holds for every other planet in the Solar System, despite the vast distance between Mars and Jupiter due to the Asteroid Belt. Even Pluto (not formally a planet anymore) with its massive elliptical orbit has Mercury as its closest neighbour on average compared to the other planets, due to the unique property of concentric circles.
No matter the distance, if you are orbiting the Sun, Mercury is the closest planet to you.
This video from CGP Grey explains it in a concise and informative way, complete with clean diagrams and animations!
Let’s say you have to organise a group dinner. With so many preferences, dietary restrictions and non-specifically fussy eaters, what is the best method to decide where to eat without starving to death while deciding?
The classic method relies on old-fashioned democracy, where people vote on their most desired place. However, the smaller the group size, the less reliable this method becomes as the results become more split. Furthermore, this method can make the minority unhappy as the majority choice may not even be the minority’s second or third choice. Lastly, it runs the risk of the “wolf and sheep” problem, where two wolves vote to eat the sheep and the sheep has no say because it is the minority.
A much better method is the approval voting system. Here, all you have to ask is for everyone to vote on every place that they are okay with going to. For example, let us say that 6 people have to vote between three potential options: burgers, dumplings and fried chicken.
In the old system, it could have been that 2 people voted on each option, making the vote useless. Or, 3 people may have voted dumplings when the other 3 hate it (but voted 2 burgers, 1 chicken), meaning half the group is unhappy with the final result.
With the new system, 3 people are okay with burgers, 3 people are okay with dumplings and 5 people are okay with fried chicken. Fried chicken wins the vote and a much greater majority of the participants are okay with the result, because the vote reflects some of their preference, even if it wasn’t what they most wanted.
The approval voting system also has the strength of accounting for people who are indecisive and vote on everything, or nothing. Voting on all the options essentially cancels out the ratio, so it counts as a null vote. This means that people have less power to swing the votes one way or another.
All in all, it is a simple but powerful tool to help decision-making in a group setting, which can be painfully frustrating when you are just trying to have fun together and relax.
Why do we get motion sickness when we are riding a moving vehicle?
Our sense of balance relies on an elaborate system. Our eyes give us visual information about head position and if it is moving in relation to our surroundings. Our inner ear contains delicate tubes (vestibular system) that act as gyrometers, indicating if our head is tilted or moving. Our brain synthesises the data from these two systems to know where we are in three-dimensional space and how we are moving within it.
The problem is that these two systems give conflicting information sometimes. For example, when you read in a car, your vestibular system senses that you are moving, but your eyes tell your brain that you are still. Conversely, when you watch a fast-paced action movie or playing a virtual reality game, your eyes will sense movement but your head will feel no movement.
When your brain receives conflicting information, it becomes confused; which information should it trust? The brain assumes that one of them must be wrong, possibly because you have been poisoned. The sensory mismatch results in nausea and you may start to vomit because the brain tries to get rid of whatever “poison” may be causing the problem.
In essence, motion sickness is caused by a mismatch between what the brain perceives and expects versus the reality.
Similarly, we can experience a form of “mental motion sickness“. Our brains are designed to predict the future, but the side effect of this is that we tend to form idyllic, simplified expectations. A good example is our tendency to hang our happiness on a future moment.
When we are unhappy or going through a hard time, we are prone to thinking that changing something will result in happiness. Some people change jobs or escape to another city (the “geographic solution“). Some people eagerly await for a holiday or for a deadline to be over. Some people start or end a relationship. We expect a drastic change in the future, even though the reality is that most things in life take time to change and happiness is not a switch you turn on, but a steady state that you build up to.
Eventually, when we realise that we are still unhappy, our brains become confused why reality is so different from our expectations. It makes us nauseated and want to reject our reality, frustrated that we are still miserable. But reality will not change just because we will it to.
The only solution is to manage our expectations. We need to accept that change happens gradually and that changing our environment will not necessarily change our headspace and perspectives. Our miseries will not disappear without us trying to improve our wellbeing. Instead of expecting a magical fix, we need to be mindful of our reality and find peace with the fact that it is okay not to always be okay.
We have evolved to improvise, adapt to and overcome changes and challenges. So instead of wallowing in self-pity that things did not turn out as expected, we must accept that things are as they are and keep fighting on to find our inner peace and happiness.
Pasta with homemade sauce is one of the best meals to cook at home, because it is often easy, makes a large portion and tastes delicious despite its simple recipe. It is also easily adaptable, such as this avocado pasta recipe which is an alternative to pesto, if avocados are in season and cheap.
When cooking pasta, remember to heavily salt the water (“as salty as the Adriatic Sea” as Italians might say) for extra flavourful pasta and to save 1-2 cups of pasta water for additional starchiness to the sauce.
Ingredients (serves 4):
2 avocados
2 cloves garlic
1/2 cup basil
2 tablespoons lemon juice
1/3 cup olive oil
1 cup cherry tomatoes
100-150g bacon/pancetta/chicken (optional)
350-400g pasta (any, but recommend fusilli or penne)
Cook pasta to preference (suggest 12-13 minutes in salted boiling water)
Chop avocados into medium-sized chunks to make it easy to process
Add avocados, peeled garlic, basil and lemon juice to the food processor
Season with salt and pepper to taste
Start blending all of the ingredients in the food processor and add olive oil in a slow stream (or intermittently and pulse)
Blend until all ingredients have fully emulsified with no pools of oil
Cut cherry tomatoes in half
If using bacon or pancetta, pan fry until lightly crisp
Tomatoes can be cooked in the bacon/pancetta oil if you prefer
If using chicken, cut into strips or cubes, season with salt and pepper, then pan fry until fully cooked
Combine pasta, avocado sauce, cherry tomatoes, meat and splash of pasta water (avoid making the mix too liquid)
The penis is an interesting organ that has the ability to harden, despite being made of spongy material. Contrary to the popular slang for erection (boner), the (human) penis contains no bone.
Instead, it is made of a pair of cylindrical, spongy tissue called the corpus cavernosa, and a smaller spongy tube that surrounds the urethra called the corpus spongiosum. An erection happens when the body redirects blood flow to fill these spongy tissues, engorging them with blood. As it expands, the corpora become rigid and tense as they are wrapped by a thick, dense tissue called the tunica albuginea. The tension compresses the surrounding veins, trapping the blood and keeping the penis erect. Once stimulation slows and less blood flows into the penis, the blood drains via the venous system and the erection withers.
A common problem with erections is that of erectile dysfunction (unable to become erect or sustain it), which is well-known to the lay person. However, a lesser-known, opposite problem is priapism.
Priapism refers to an erection that will not die down even when the stimulation has ended, or with no stimulation at all. Although this may not sound like a medical problem other than causing embarrassment, priapism can be a very painful condition and depending on the cause, the penis can become starved of fresh blood (ischaemic), resulting in permanent damage to the cells and tissue.
Priapism is named after the Greek god, Priapus. He was a minor god worshipped in rural Asia Minor as a god of fertility, livestock and gardens. Priapus is depicted as having a permanent erection to symbolise fertility, but ironically, was cursed with impotence by Hera while still in the womb. His massive, erect penis was a popular theme for Roman erotic art and can be seen in various pieces of ancient art.
Priapism can arise from various causes such as blood disorders, medications and spinal cord damage. The problem is usually due to blood being trapped in the penis, or the nervous system continuously stimulating blood flow into the penis. As the main issue is engorgement with blood, the acute treatment for priapism involves decompressing the penis by using a needle to aspirate (draw out) blood directly from the corpus cavernosa.
Imagine that you are an Olympic athlete. You have performed admirably and are stepping up to the podium to receive a medal for being one of the top three athletes at the game. Question: would you rather receive the silver or the bronze medal?
The logical answer would be that the silver medal is better, as second place is better than third. It is clear that the person who came second performed better and will also receive a more valuable prize. However, the opposite is true in reality.
In 1995, psychologists Victoria Medvec, Scott Madey and Thomas Gilovich studied video recordings and interviews of athletes from the Atlanta Summer Olympic Games. They studied facial expressions of medalists and noted a stark contrast between those who won gold, silver and bronze.
Obviously, the gold medalists were ecstatic and were not afraid to show this. By contrast, silver medalists rarely smiled immediately after their achievement, often showing flashes of sadness or contempt instead. They would usually smile on the podium as they received the medal, but compared to bronze and gold medalists, they were far more likely to show a fake smile rather than a Duchenne smile – a true, involuntary smile associated with happiness. Interestingly, those who won bronze looked far happier than the silver medalists.
This effect has been reported through other observational studies, such as a 2006 study that looked at athletes in the 2004 Athens Olympic Games. In fact, almost everyone will have had similar experiences where coming second place somehow feels worse than not doing well in a tournament at all. This is because of counterfactual thinking.
Counterfactuals are essentially “What if?” scenarios that we dream up in our heads. Being imaginative creatures, we are prone to thinking of what could have been, then proceed to have regrets or be disappointed by something that never even happened. The closer we get to our goals, the bigger the disappointment we have when we fail to achieve it.
We all fall victim to counterfactual thinking. We often wonder what would have happened had we taken action earlier, or did something slightly differently, then lament that the best case scenario did not happen. We compare our reality to a hypothetical situation and become frustrated.
Many studies have confirmed this in various settings, showing that objective achievement means nothing in the face of the subjective perception of the achievement. Even if you work hard and get an A- in an assignment, you could be sad and stressed that you did not get an A+.
A simple antidote to counterfactual thinking is turning it on its head. Instead of thinking that it is a shame that you didn’t achieve gold, be glad that you achieved such a high result. Instead of fretting that you did not get the best mark, imagine how bad it would had been if you had failed. Instead of lamenting that you had a bad day, be grateful that you did not have an ill fortune such as being hit by a bus or suffering a brain aneurysm rupture.
At the end of the day, the problem with counterfactual thinking is that it is based on our own imagination. We are creating stress in our own heads, actively choosing to be unhappy.
Because of our high expectations, we fail to enjoy the pleasures of life or appreciate the absolute value of our achievements. We forget that we don’t have to be the best or that we don’t have to win every game.
We live in a complicated world that constantly throws complex issues at us. Because it is impossible for one person to be an expert in every field, we have to employ different strategies and tactics to navigate through these issues.
A fascinating way that our brain tries to solve a current issue is the availability cascade. This is a self-reinforcing cycle, where an idea essentially “infects” a group of people, displacing individual thought and opinion and overwhelming critical thinking.
The way this happens was described and modelled by Timur Kuran and Cass Sunstein.
First, a new idea that seems to be a simple and elegant solution or explanation to the current issue starts to gain traction. People easily adopt and embrace this idea because it sounds plausible and because it is easy to process.
Secondly, people who adopt these ideas spread it themselves, making it more available in the social network. Particularly, nowadays we see this in both reported and social media.
Lastly, as the availability increases, more and more people are pulled in and the idea seems more credible, because “everybody” seems to think it. People do less research and have less individual thoughts or opinions about the matter because the group consensus is more appealing or acceptable.
The availability cascade as a platform can be very effective at raising awareness of issues and banding people together to fight a common cause, such as when the AIDS epidemic was starting. However, it is fraught with issues.
The availability cascade is mediated by a heuristic, which is essentially a mental shortcut. Heuristics are extremely useful in that it reduces our cognitive load and automates many of our decisions. However, because they are based on rule sets, they are not as effective for new, different situations.
We are less likely to think critically when using heuristics, meaning that we are more vulnerable to being manipulated. In this situation, people think “this is widely available information, therefore it must be important” and default to believing it (even if it is just to appear “current” and to fit in).
Because critical thinking is overwhelmed by the availability cascade, it can be extremely dangerous when misinformation spreads this way; or worse, disinformation – where people maliciously spread false information for their own gains.
A classic example is the anti-vaccination movement that spawned from a discredited, falsified article that claimed MMR vaccines increased rates of autism, despite mountains of evidence pointing towards the effectiveness and safety of immunisation. Subsequently, vaccination rates dropped and we now see outbreaks of illnesses such as measles, resulting in countless deaths and injuries that could have easily been prevented.
Information can be just as contagious and dangerous as an actual infection. Knowing about the existence of these cognitive biases and phenomena help protect us from falling victim to them.
You were on your way home when you died.
It was a car accident. Nothing particularly remarkable, but fatal nonetheless. You left behind a wife and two children. It was a painless death. The EMTs tried their best to save you, but to no avail. Your body was so utterly shattered you were better off, trust me.
And that’s when you met me.
“What… what happened?” You asked. “Where am I?”
“You died,” I said, matter-of-factly. No point in mincing words.
“There was a… a truck and it was skidding…”
“Yup,” I said.
“I… I died?”
“Yup. But don’t feel bad about it. Everyone dies,” I said.
You looked around. There was nothingness. Just you and me. “What is this place?” You asked. “Is this the afterlife?”
“More or less,” I said.
“Are you god?” You asked.
“Yup,” I replied. “I’m God.”
“My kids… my wife,” you said.
“What about them?”
“Will they be all right?”
“That’s what I like to see,” I said. “You just died and your main concern is for your family. That’s good stuff right there.”
You looked at me with fascination. To you, I didn’t look like God. I just looked like some man. Or possibly a woman. Some vague authority figure, maybe. More of a grammar school teacher than the almighty.
“Don’t worry,” I said. “They’ll be fine. Your kids will remember you as perfect in every way. They didn’t have time to grow contempt for you. Your wife will cry on the outside, but will be secretly relieved. To be fair, your marriage was falling apart. If it’s any consolation, she’ll feel very guilty for feeling relieved.”
“Oh,” you said. “So what happens now? Do I go to heaven or hell or something?”
“Neither,” I said. “You’ll be reincarnated.”
“Ah,” you said. “So the Hindus were right,”
“All religions are right in their own way,” I said. “Walk with me.”
You followed along as we strode through the void. “Where are we going?”
“Nowhere in particular,” I said. “It’s just nice to walk while we talk.”
“So what’s the point, then?” You asked. “When I get reborn, I’ll just be a blank slate, right? A baby. So all my experiences and everything I did in this life won’t matter.”
“Not so!” I said. “You have within you all the knowledge and experiences of all your past lives. You just don’t remember them right now.”
I stopped walking and took you by the shoulders. “Your soul is more magnificent, beautiful, and gigantic than you can possibly imagine. A human mind can only contain a tiny fraction of what you are. It’s like sticking your finger in a glass of water to see if it’s hot or cold. You put a tiny part of yourself into the vessel, and when you bring it back out, you’ve gained all the experiences it had.
“You’ve been in a human for the last 48 years, so you haven’t stretched out yet and felt the rest of your immense consciousness. If we hung out here for long enough, you’d start remembering everything. But there’s no point to doing that between each life.”
“How many times have I been reincarnated, then?”
“Oh lots. Lots and lots. And in to lots of different lives.” I said. “This time around, you’ll be a Chinese peasant girl in 540 AD.”
“Wait, what?” You stammered. “You’re sending me back in time?”
“Well, I guess technically. Time, as you know it, only exists in your universe. Things are different where I come from.”
“Where you come from?” You said.
“Oh sure,” I explained “I come from somewhere. Somewhere else. And there are others like me. I know you’ll want to know what it’s like there, but honestly you wouldn’t understand.”
“Oh,” you said, a little let down. “But wait. If I get reincarnated to other places in time, I could have interacted with myself at some point.”
“Sure. Happens all the time. And with both lives only aware of their own lifespan you don’t even know it’s happening.”
“So what’s the point of it all?”
“Seriously?” I asked. “Seriously? You’re asking me for the meaning of life? Isn’t that a little stereotypical?”
“Well it’s a reasonable question,” you persisted.
I looked you in the eye. “The meaning of life, the reason I made this whole universe, is for you to mature.”
“You mean mankind? You want us to mature?”
“No, just you. I made this whole universe for you. With each new life you grow and mature and become a larger and greater intellect.”
“Just me? What about everyone else?”
“There is no one else,” I said. “In this universe, there’s just you and me.”
You stared blankly at me. “But all the people on earth…”
“All you. Different incarnations of you.”
“Wait. I’m everyone!?”
“Now you’re getting it,” I said, with a congratulatory slap on the back.
“I’m every human being who ever lived?”
“Or who will ever live, yes.”
“I’m Abraham Lincoln?”
“And you’re John Wilkes Booth, too,” I added.
“I’m Hitler?” You said, appalled.
“And you’re the millions he killed.”
“I’m Jesus?”
“And you’re everyone who followed him.”
You fell silent.
“Every time you victimized someone,” I said, “you were victimizing yourself. Every act of kindness you’ve done, you’ve done to yourself. Every happy and sad moment ever experienced by any human was, or will be, experienced by you.”
You thought for a long time.
“Why?” You asked me. “Why do all this?”
“Because someday, you will become like me. Because that’s what you are. You’re one of my kind. You’re my child.”
“Whoa,” you said, incredulous. “You mean I’m a god?”
“No. Not yet. You’re a fetus. You’re still growing. Once you’ve lived every human life throughout all time, you will have grown enough to be born.”
“So the whole universe,” you said, “it’s just…”
“An egg.” I answered. “Now it’s time for you to move on to your next life.”
When an object from outer space enters the Earth’s atmosphere, it starts to burn up and creates a brilliant streak in the sky, which we call a meteor or shooting star. Contrary to popular belief, this is not due to friction with the air in the atmosphere.
An object entering the atmosphere is typically travelling at extraordinary speeds. Most meteors are travelling around 20km/s (or 72000km/h) when they hit the atmosphere. At these speeds, air molecules do not have a chance to move out of the way. The meteor will instead collide into the air molecules, pushing them closer and closer to each other, compressing the air in front of it.
As we know from physics class, compression increases temperature in gases as per the ideal gas law (PV=nRT). The impressive entry speed of these meteors result in so much air compression that their surface can heat up to 1650 degrees Celsius.
The heat boils and breaks apart the contents of the meteor, turning it into superheated plasma that gives off a glow. This is the streak of light that we see in the night sky when we wish upon a shooting star.
If you mix 1 part water to 1.5-2 part corn starch, you create a strange mixture called “oobleck“, named after a Dr. Seuss story. It is so simple to make, yet it exhibits some very strange properties that makes it a popular science experiment.
Oobleck is what is known as a non-Newtonian fluid, where the viscosity (or “thickness”) changes with how much stress it is under. If you press your finger gently into it, it will feel like water, but if you strike it with a hammer, it will behave as a solid. It will stiffen when you stir it, but run when you swirl it.
You can even run over a tub of oobleck as long as you change steps quickly enough to apply enough pressure to keep the fluid under your feet solid. This is because oobleck becomes very viscous under high stress, making it behave more solidly (shear thickening).
We can learn from oobleck not only some interesting physics principles, but also how to interact with people.
Much like a non-Newtonian fluid, people will tend to react stiffly and with more resistance if you apply stress or force. But if you apply gentle pressure and be assertive, you will find people generally react more softly and fluidly.
This simple change in your approach will lead to much better conflict resolution and constructive outcomes when dealing with other people.
