Avengers: Infinity War, Iron Man
More info i
Credit: Marvel Studios

Examining the real science behind Avengers: Infinity War

Contributed by
May 7, 2018, 4:30 PM EDT

It's finally here!

I mean, half of it is. We kinda ended on a downer. But Marvel does have a problem with characters staying dead.

So while we're waiting for Infinity War 2: Electric Boogaloo, let's finish up this three-part series with some science from Avengers: Infinity War.

**SPOILER WARNING: This post contains spoilers for Avengers: Infinity War.**

First, I'm going to ask you a simple question:

What color is the sun?

If you just got to the title card of this movie — recently having witnessed Hulk take the Bifrost to Earth — you might answer "yellowish-orangeish."

You would, however, be wrong.

As is accurately portrayed when Thanos's fleet arrives to besiege Wakanda, the Sun is white. Just like we see it from the ISS:

NASA, space

Credit: NASA

If the Sun weren't white, objects we identify as white wouldn't look white in direct sunlight.

I mean, technically, had our star always been yellow, we'd just define that color as "white" and go from there. But say Thanos used the Reality Stone to change the Sun's hue. We all — or at least the half of us left alive — would see things as if they were being lit by sodium lamps.

As the color of a star is determined by how hot its surface is, there definitely /are/ stars that come in shades of yellow. Ours just isn't one of them.

So why do so many people think the Sun is yellow?

As that one Pink Floyd album cover teaches us, white sunlight is comprised of many colors. When those differently-colored photons enter our atmosphere, they slam into particles like nitrogen and oxygen molecules. This scatters the photons, but bluer ones get scattered way more than redder ones.

This is why the sky is blue during the day.

At sunrise/set, the light has to pass through more atmosphere before it reaches your eyeballs. This gives the blue light more opportunity to scatter, while the red (-ish) light keeps heading relatively straight for you.

As it's generally safer to look at the Sun at those early/late hours, you're more likely to see the Sun as yellow than white.

Astronomers are also partly to blame (As a non-practicing astrophysicist, I'm allowed to say this) because we classify the Sun as a "yellow, G-type star." That's because a bunch of dudes back in the 1950s decided to pick six "standard" stars and define /them/ as white, even though they would all look bluish-white to the human eye.

They also let pictures of the sun be published that look like this without specifying there's a filter that makes it look that color.

But there are filters that can capture the Sun's approximately-true color even from Earth. Behold.

You yourself could confirm that the Sun is white by staring at it when it's noon. Your retinas would burn out, but hey. Knowledge is power.

Speaking of science the MCU gets right sometimes, and then not in others…

Back in the first Guardians movie, Quill and Gamora survive exposure to the vacuum of space. Come Infinity War, Ebony Maw appears to instantly freeze to death when he flies out a hole in a spaceship Aliens (actually Alien) style.

While space is indeed cold — assuming you're not being boiled by the nearest star (the day side of the Moon can get up to 224 degrees Fahrenheit!) — you wouldn't instantly freeze. Yes, I saw Sunshine. And Mission to Mars. And that episode of The Magic School Bus where Arnold takes his helmet off on Pluto. Sometimes Hollywood gets things wrong, guys.

Heat can be transferred one of three ways: conduction (sticking your hand on a skillet), convection (sticking your hand in front of a fire), and radiation (sticking your hand out a window on a sunny day).

In outer space, conduction and convection can't really happen. There's neither direct contact with colder material nor fluid (e.g. air, water) to carry heat away. So, Maw's body temperature can only drop by emitting radiation. That takes a long time for a human-ish body.

We can't say with certainty when Mawpsicle time will come, but it's longer than it would take for a regular ol' human to die from lack of oxygen in space's vacuum, which is about 90 seconds.

Also, we didn't get to see his body balloon twice in volume (but not explode). Bummer.

Ebony Maw, Infinity War

Credit: Marvel Studios

Finally, I want to address Thanos' whole philosophy of balancing life and death — the reason he's seeking out the Infinity Stones in the first place. As explained in the comics:

Thanos, Death, Infinity Gauntlet Pt. 1

Credit: Marvel Comics

Obviously, it's impossible to know the exact population of lifeforms worthy of being considered for Death's cull. Do dogs count? They had better not. What about the microbiome — does Thanos know there at least as many cells in the human body that are actually other creatures?

And I can't answer the question of whether or not the number of living, sentient creatures on some far-off planet is greater than their dead…

But I can talk about humanity. And demography (I know, I know... it's a social science...).

While we don't know the exact number of homo sapiens that have existed since the dawn of the so-called "modern human," there have definitely been more people alive throughout history than there are alive at this very moment.

The Population Reference Bureau estimates that over 108 billion people have lived in the past 50,000 years. That number is certainly up for debate because researchers don't have the Time Stone to go back and actually count heads. But they aren't randomly guessing.

A lot of it has to do with infant mortality being more frequent in the past, and people being a lot more likely to die from war, disease, etc. before bearing children. That meant a lot of babies were needed to keep the population growing even a little bit.

Educated guesses are made in terms of the exact growth rate during different ages, so if you choose different trends than the PRB, you'll get a different number.

Arthur Westing calculated a smaller figure in 1981: 50 billion humans during the previous 300,000 years, which made the then-current population of non-dead only nine percent of the total.

Apparently, fears that the living outnumbered the dead showed up in the 1970s, but researchers have been debunking the myth for a while now. That news apparently never made its way into the Marvel Comics Universe.

In fact, 2001: A Space Odyssey author Arthur C. Clarke penned an accurate statement for the late 1960s when his book was published: "Behind every man now alive stand 30 ghosts, for that is the ratio by which the dead outnumber the living. Since the dawn of time, roughly a hundred billion human beings have walked the planet Earth."

This demographic error is less important in Infinity War since all Thanos really desires is population control. Sure, he offers up some quotes about balance (including props!), but I see right through those justifications, you giant purple man.

Avengers Infinity War, Peter Parker

Credit: Marvel Studios

And just so you know, Thanos, spiders aren't insects. They're arachnids. You probably meant it in a "look at this pathetic tiny creature I could smash beneath my boot" way, but you're from another planet so you might not actually be familiar with how we break down arthropods.