If there’s one thing space is good  at, it’s posing for pretty pictures.

Here, I’ll prove it. Aren’t they just  beautiful?

There’s just so many colors. But that makes me wonder:  what was the first color? What was the color of the Big Bang? [♪ INTRO] Let’s start by setting some ground rules.

We’ll pretend a human could survive a  trip to the beginning of the universe, and define color based on  what a human eye can perceive. As opposed to, like, dog eyes. We all good here?

Ok. So step number one in figuring  out the color of the Big

Bang: In order to see anything at  all, we’re gonna need photons. Those little packets of light hitting our eyes is the first step in how we perceive color. So if we’re hanging out at the beginning of time, we’ve gotta wait until  photons come into existence. But luckily, we don’t have to wait long.

This incredibly early point in our  universe’s timeline is wildly hard to study. We don’t actually have data from that time, just models based on more recent data that  scientists then extrapolate backwards. So when our writer reached out to some  experts to pin down exactly when the first photons popped into existence, the  timelines weren’t in perfect agreement.

One expert said they “appeared  no later than 10^-34 seconds.” And another would only say that  they appeared sometime between 10^-43 seconds and 1 second into  the existence of everything. But an official CERN website went  with that 10^-43 seconds value, so for the sake of ease, we’ll go  with that for our number crunching. And now that we have a time,  we can estimate a temperature.

Which might sound like I’m going off on a  tangent to get to color, but stay with me. The temperature of the early universe  was very closely tied to its age. Specifically, as the universe  got older, it got bigger.

And as it got bigger, it cooled down. At 10^-43 seconds, the temperature  was roughly 10^26 Kelvin… which is about as hot as 17 sextillion Suns. But that’s only half as hot as my laptop gets when I’m just trying to lay in bed  late at night and watch Youtube videos.

Now as for what the temperature  of the universe has to do with the color of the universe, well  it’s actually pretty straightforward: The temperature controls the color. This is the basic principle of Planck’s law. Coined by the physicist Max Planck  in the 1900s, it basically says that the only thing that determines the  color of a blackbody is temperature.

Not chemical makeup, nothing  else, just temperature. Temperature corresponds to energy, and particles at different  energies emit different colors. And to answer that question you  almost definitely have swirling around in your brain right now, a blackbody  is an object that emits its own light, but completely absorbs any and all  light that tries to reflect off of it.

So nothing in existence is a true blackbody, but it’s a pretty good approximation  for things like stars. Or the Big Bang. If you want an example of how all this  works, just take a look at our Sun.

No, don’t literally look at the Sun. Unless, of course, you are wearing our  SciShow eclipse glasses to specifically look at a solar eclipse like the one that  will be visible from North America in 2024. For the purpose of this video,  just look at this image of our Sun.

So it looks white, right? Well it’s really a smushed  together rainbow of colors, and the amounts of each color it  emits are governed by Planck’s law. Here’s the profile of colors  emitted by a blackbody with the same temperature as our Sun’s surface.

And that peak right there tells us our Sun emits more green light than any other color. The Big Bang has its own blackbody  curve, too, but if you plug 10^26 K into the equation for Planck’s law,  you get a peak that is way over yonder in the gamma ray part of the  electromagnetic spectrum. But even though the peak is over there,  the curve never actually drops to zero.

The Big Bang would have also emitted  light that’s visible to the human eye. And most of that light would have been violet, followed by blue, then green, and so on. But before we can smooch all that light  together to get a single perceived color, I just need to take a quick moment  to thank our sponsor, Brilliant.

Brilliant is an online learning  platform with thousands of interactive lessons in science,  computer science, and math. And their course Beyond the Nutshell  was created in collaboration with fellow YouTube channel, Kurzgesagt. So you know it has great visuals and explanations to make complicated space science  a little bit less complicated.

Over eight lessons, this course explores  the big questions of astrophysics and cosmology, along with smaller  concepts like the limits of humanity. So for one of the most efficient  ways to totally blow your mind, you can try Brilliant for free for  30 days at Brilliant.org/SciShow or by clicking the link in  the description down below. That link will also give you 20% off an  annual premium Brilliant subscription.

And now, let’s get back to figuring  out the color of the Big Bang. So we’ve figured out the photons,  but now we have to address the nuances of human vision…and  of computer monitors. For one thing, every individual  person experiences color differently, but in general, humans are better  at seeing blue than violet.

So the Big Bang might look bluer  than it otherwise “should”, given the actual number of violet  and blue photons being emitted. And no two people may agree on the exact shade of periwinkle their  brains wind up processing. But even acknowledging all of that, I  still can’t show you a definitive color.

Because whatever I’m trying  to share with you has to be translated into something  your computer understands, and then tries to replicate with whatever  technology it’s rocking inside of its screen. And I don’t know what kind of device  you’re using to watch this video, let alone the color profile  settings that you’ve gone with. If you’ve got one of those blue  light remover apps turned on, this isn’t going to work at all.

So, bearing all of that in mind, this is a rough approximation of the color of the Big Bang. This image is based on numbers crunched by a few people trying to find  the color of “infinitely hot”. It’s not our exact 10^26 Kelvin  temperature, but it’ll do.

However, it’s worth noting that the  guy who first did this calculation has a disclaimer to not “take  any of this as very accurate.” According to him, there’s a  lot of nuance in converting a temperature into a perceived color,  so there’s a lot of room for error. But that’s the end of the story, right? We’ve got a hypothetical color of  the Big Bang!

Should we have a party? Maybe design some merch? I mean, I could  go for a periwinkle t-shirt for sure.

Maybe not so fast with that  because I’ve got some bad news: If you went back in time to watch the  Big Bang, you would see nothing at all. It turns out the universe was completely opaque until around 380,000 years  after it came into being. At 10^-43 seconds, you wouldn’t be able to see your hand in front of your face,  let alone a pretty periwinkle.

And by the time you could actually see stuff, the universe would have cooled  down to a balmy 3000 Kelvin. Which, at that point, the universe would look a lot more like a medium-toned  household light bulb than a summer sky. Which for a make-believe time traveler,  is probably a pretty big bummer.

But, ya know, I’m content to sit back and admire all the colors that the universe  has made in the intervening eons. Cause, ya know, they’re pretty nice, too. [♪ OUTRO]