Why do leaves turn yellow?

With the last days of summer and the beginning of autumn, I’ve decided to talk about trees. In particular, why they change colour as winter creeps closer.

Leaves are green because they have chlorophyll, a pigment that helps them absorb sunlight and photosynthesize. But chlorophyll is not the only pigment in plants, they also contain carotenoids, which colour them yellow, orange or red. 

  

Usually, chlorophylls is dominant, as it is the most efficient at absorbing the spectrum, but as winter approaches and the days grow shorter, photosynthesis is no longer as profitable. So to limit losses, plants stop producing chlorophyll and re-absorb that which is already in the leaves. As a result, for the short moment before they die and fall off, the carotenoids are revealed painting the trees red, orange and yellow.

References and additional reads:

Wonderopolis: Why Do Leaves Change Colour in Autumn?

WDNR: Why Do Leaves Change Colour?

ESF: Why Leaves Change Colour

USDA: Why Leaves Change Colour

Supernatural

In honour of the start of its eleventh season, we take a look at one of the longest running modern fantasy series: Supernatural.

The story is simple. There are monsters in the world, Heaven and Hell are real, witches are evil and a handful number of humans take the mantle of hunters, for one reason or another, killing the beasts and saving humanity. In this particular case, we follow the adventures of Sam, played by Jared Padalecki, and Dean, played by Jensen Ackles, Winchester and a changing cast of support characters. After the death of their mother, their father took to investigate what killed her, dragging the boys along into a life of fighting.

The acting is okay and the effects and fight scenes believable.

Supernatural is one of those dark, gritty series where nothing ever goes in the protagonist’s favour and someone always dies. Yet it never felt too heavy because of the humour, satire and very charismatic leads. Or at least it was such in its youth.

Eventually it turned into Gary and Larry Sue wacky adventures and gradual descend into incoherent or inconsistent storytelling. It’s still good. It was okay up until season five. But you can just feel the writers struggling to produce even a shred of creativity and originality at this point.

Overall, Supernatural is decent, check it out, but it has long ceded to alzheimers and is now slowly wobbling around on a tennis ball padded walking aid with the subtle stench of sour pie wafting in the air.

But nevermind that, let’s turn back to when Supernatural was still a toddler and barely released its Pilot episode. Watch out for spoilers on the road ahead.

The episode begins 22 years ago in Kansas. It’s night, and a spooky tree casts a shadow on a small family house. Inside, a woman is putting her sons to bed, and all seems fine until she’s thrown to the ceiling by a supernatural power and then set on fire, along with the house.

Right off the bat, nice build up, nice spooky mood in that opening sequence and solid and swift establishment of the backstory.

We then cut to present day Stanford university where Sammy, one of the boys, is studying. Everything is going well for him, good grades, a promising law school interview, sexy girlfriend, friends and parties, at least until his brother shows up for a visit.

Sammy isn’t happy about seeing his bad/play boy of a brother, but Dean is there on family matters. Their father has gone missing, and he needs Sam to help find him. We also learn that for years their father has been dragging them around, hunting whatever killed their mother and meanwhile slaughtering all kinds of monsters, a life Sam ran away from.

But gingerly, he agrees to help Dean, family first after all, as long as they’re back ‘first thing Monday.’ And then they’re off to California, the place where their dad was working on a serial disappearances case.

We move to location and a man who is talking on the phone with his girlfriend while driving along, until he sees a woman in white drifting about the road. He stops to ask if she’s okay, and she asks him to ‘take her home.’ She then gives him the doe eyes and asks him to go home with her. And so he zooms off into the distance, the girlfriend be damned.

They arrive at destination, a dark abandoned house. The man is understandably perplexed, ‘Who would even live there?’ He turns to ask her the address again, but she’s gone. It’s halloween so naturally he concludes it’s a bad joke. Still, instead of doing the sensible thing and leaving, he enters the house.

Or at least he tries to until a frantic bird sends him scurrying back to his car and driving off. Once he has gained enough distance, he looks in the back mirror, and there she is. He skids to a stop on the bridge, a muffled scream and blood splattered windows. Classic horror.

The next day Sam and Dean come across the crime scene as they enter town. Time for action. Dean grabs a fake badge and heads to ask the cops a few quick question. He learns the man has a girlfriend and moves on to talk to her. She and her friend brief Sam and Dean on the local legend. A girl disappeared hitchhiking, presumed dead. A short look into the library archives provides a slightly different story, a record of a suicide on the bridge where the men are going missing.

They arrive on location and see a woman in white jump off the bridge, just before their car tries to murder them.

After surviving the attack, they check into a hotel, and the receptionist recognizes the card informing them that someone else checked in with similar. The first real hint of their father. But it doesn’t seem like anyone has been around for a while in his room though he did leave them an extensive amount of research on the case.

Before they can confront the husband, find the grave, and burn the body to get rid of the ghost, the local cops catch onto their fake cards and badges. They arrest Dean to question him about his father. After finding an extensive journal on supernatural things the cops suspect the Winchesters are a family of murdering psychopaths.

And while the cops are entertaining Dean, Sammy visits the husband, asking him about their marriage, his wife and her demise.

Meanwhile, Dean steals a paperclip and escapes the police station.

Now they know that they’re dealing with a ‘woman in white,’ a wife who was wronged, killed her children in her insanity, then killed herself, and now haunts unfaithful men. The brothers get a lead on their father too, he left coordinates in his journal.

But no time for that now, out on the road Sammy has a very close encounter with the woman in white. She gets into his car and demands he takes her home. He refuses. She isn’t happy, locking the doors and manipulating the car into driving by itself.

Once again it stops in front of the old house, the woman mumbles that she can never go home and jumps on Sam, determined to make him unfaithful. But before she can rip out his heart, Dean appears to the rescue.

Now freed, Sam takes her home by driving the car into the house. There, the ghosts of her children drag her down into hell.

The ghost is vanquished, the day is saved, and Sammy goes home just in time to prepare for the interview. He enters the apartment, goes to the bedroom, looks up and sees Jess, his girlfiend, pinned to the ceiling the same way his mother was at the start. She bursts into flames and nearly takes him too but Dean drags him away.

And so begin the road trip adventures of Sammy and Dean, as they fight monsters, dramatize about brotherhood and family and spew one liners and clever exchanges.

The atmosphere the series manages to build is still its best quality, alternating between spooky and action packed, dark and sometimes goofy. A definite must watch for lovers of paranormal stories.

Why do we have seasons?

Have you ever wondered, as you watched the snow fall or basked in the summer sun, why is it that we have seasons? Why does water freeze into snowflakes at times while at others suffocates us with humid vapour.

What directs the drastic shifts in climate every spring or fall? No, it’s not because we revolve closer or further from the sun as many believe, the difference in the slightly elliptical orbit is not enough to cause heat changes.

We have seasons because our planet is tilted and at different times of the year the warm sunlight reaches the ground differently.

In the winter, not only are the days fleeting and short, but sunlight fall at an angle, failing to provide enough warmth to warm us up. Meanwhile, in the opposite hemisphere, light descends straight and the days are long and warm.

As for spring and fall, it is the time when the sun shines equally on both hemispheres, gifting us soft, temperate weather.

 

References and related reads:

SciJinks: Why does the Earth have seasons?

Woodland Junior School: Why do we have Seasons?

Nasa: What causes the seasons?

Everyday Mysteries: Why is it hot in summer and cold in winter?

Youtube: SciShow - Why do we have seasons?

Agents of S.H.E.L.D.

With almost equal zeal to DC, Marvel have been chugging out TV series after TV series about their most favourite heroes and universes. Because they couldn’t only dominate in the cinema, they had to take over TV too. Not that I am complaining.

So without further ado The Agents of S.H.I.E.L.D. The series meant to introduce the secret organization that keeps the world safe from superhuman terrestrial and extraterrestrial threats. And that’s the story, focusing around Coulson’s special team, the series follow Shield as it deals with a variety of threats usually revolving around getting, or retaking dangerous technology or dealing with unstable superpowered individuals.

I’ll say this from the start, I’m not a fan of the premise. The ideas behind some of the characters are not all that phenomenal either. The acting is alright though it can be awkward at times.

What really saves these series is the creators: Joss Whedon, Jed Whedon and Maurissa Tancharoen. Joss, in particular, is well known for his strong female leads, complicated intercharacter relationships, good fight choreography and really solid story that aims to innovate and surprise. And here, he does just that. The effects and choreography are excellent, the dialogue is clever, and the story is well plotted.

The show is decent, usually not something I would watch, kind of tired of the  government agency keeping the world safe premise. But I do watch it and it’s pretty high on my list.

A definite recommend, especially for fans of Marvel. Though be advised, you won’t be seeing any superheroes, at least not for now. The build up can be pretty slow though I found every episode pretty engaging and action packed.

But let’s move on to the Pilot and see how much promise the series shows in its opening. Needless to say, spoilers ahead.

We begin sometime after the events of The Avengers and the attack on New York with a woman narrating about how aware the world is now of heroes and monsters.

We then zoom in on a man buying a hotdog for his son. The kid isn’t too impressed with the food, he’s busy looking at action figures in the window of a store.

But no time for father-son bonding as the building next door explodes.

Well, at least we don’t have to beg for action.

The father leaves the son with a friend and rushes into the chaos to help. He hears a woman scream from a high window, and surprise, our character starts punching his way up the wall. He snatches the woman and jumps through the window. On the fifth floor.

Our superhero of the series you say… Nope, we don’t get to play with superpowered protagonists until way later on.

He doesn’t stick to answer any annoying questions or claim glory, but before he flees we meet our narrator and sort of protagonist Skye, played by Chloe Bennet, a young, expert hacker on a mission to expose all secrets the government hides.

The real action starts, however, with Agent Ward, played by Brett Dalton, who is on a mission in France to retrieve a mysterious package. He is promptly interrupted by “hostiles” and a short battle ensues. Naturally he wins and is whisked off in a helicopter.

The package, it turns out, is a piece of chitauri technology that he hands off to Avengers cameo Maria Hill, played of course by Cobie Smulders. And with this short sequence we are swiftly introduced to S.H.I.E.L.D. and its purpose: keep the world safe from threats and knowledge beyond people’s comprehension. And now after the grand alien exposure in New York and with information leaking networks such as The Rising Tide, a special team is formed under Agent Phil Coulson, played by Clark Gregg, who is now mysteriously alive after his inspirational demise in Avengers. Ward is not too happy about him being assigned to said team, he’s a solo player, but it doesn’t appear that he has a choice.

No time to dwell on that, we return to our young hacker now stalking the hero from earlier to warn him about the scary government agency S.H.I.E.L.D. and try to persuade him into taking up a hero’s mantle. Mike Peterson, played by J. August Richards, isn’t interested in her idea, nor happy about her pestering.

We move on to meeting member number three of the brigade, Agent Melinda May, played by Ming-Na Wen, now retired from field duty to push papers. She is rather reluctant about returning but Coulson works his awkward charm and promises he’s only taking her aboard as a pilot.

And oh look at the time, it’s the obligatory comic relief/tech nerd character introduction hour. In this case the Fitz/Simmons duo, played by Iain De Caestecker and Elizabeth Henstridge, a talented young engineer and his partner in science a biochem babe.

And then of course, the final member of the team: Lola, the flying car.

So with our team assembled the Shield plane departs on its first mission. Said mission being interrupting Skye from recording her next inspirational Rising Tide video. Bagged and tagged she’s brought on the plane for interrogation and while Ward and Coulson are playing good cop/bad cop the rest of the team is looking into the explosion.

Skye mockingly informs them about Centipede, a million dollar project no one at Shield seems to know about. Turns out that Mike Peterson is one of the test subject of said project where using alien technology they enhanced his strength in exchange of course for a really short temper. Great powers often come with great disadvantages.

The explosion, it turns out, destroyed a high tech lab working on Centipede.

Meanwhile, Mike argues with his ex-boss and loses control. After seeing the report about the savagely beaten man, Skye is finally convinced to share what she knows with Shield.

And again, surprise, surprise, Mike knows the woman he saved, she’s his doctor. She calmly explains to him that her bosses don’t like being exposed and that Mike Peterson needs to “disappear.”

Centipede, our protagonists meanwhile uncover, is a program aiming to create super soldiers, much like our beloved Captain America. And the first test subject raged so hard he exploded taking the whole lab floor with him.

After consulting with his doctor, Mike whisks off Skye from the scary men in black so she can make new identities for him and his son. Now convinced he needs help, she manages to hack into Shield’s network and broadcast her coordinates to Coulson.

His team moves to confront Mike and unsurprisingly negotiations don’t go smoothly. A short action chase scene ensues and in the end Mike is subdued by Fitz/Simmons new stun gun invention right before he explodes.

The day is saved, Mike is free from the explosive rage inducing contraption, he and his son are given a new home, and our special secret team is formed, now with a computer whiz on board.

Overall it was a stable beginning. The dynamic editing definitely helps the episode, keeping us on our toes with short spurs of action intertwined with brief introductions or exposition. The team itself can be quite clunky, but eventually the actors and their characters grow into their roles. Also, yes, I know, everyone hates Skye, but she does get better as the series progress.

The pop references can get quite old at times, but I do like the way they intertwined the series with the universe of the movies. I also found myself surprised or laughing in a good way more times than I expected.

So I’d give it a watch, premise wise it’s nothing really special, but the story gives it its zing.