Black Body Radiation – Heat dissipation in Space

This just in, today’s train of thought has derailed somewhere in left field. The authorities are urging everyone to remain calm while their team of engineers work to get things back on track.

I was making my usual patrol around the reddit and came across the type of question I like to see.

Explain Like I’m 5: why is it freezing in space if there is no matter in the vacuum to transfer body heat into?

Now I was already aware of the vague idea that heat dissipated really slowly in space. Heat transfer as us earthbound people think of it is from one object to another. From a heating element to a pot, from a radiator to the air around it, and so on. In the vacuum of space though, there really isn’t much matter to transfer heatΒ to.

The top comment from a user called afcagroo said this:

The other mechanism is radiation. Your body is constantly radiating infrared light, carrying away heat energy. (This is known as ‘black body radiation’.) Black body radiation isn’t all that fast, so freezing in outer space will take a bit of time.

This gave me a couple of things. First off, it gave me a solid concept to hang the phrase “black body radiation” on. I mean, I’d heard the phrase used before, but I’m not a physicist and didn’t have anything specific to relate it to.

It also returns later to make me do some quick internet research that I’m not qualified to really comprehend. I wandered off on a weird tangent for a while but I eventually came back to this idea. I thought, Elite Dangerous has a heat mechanic, and it’s about space ships with a slight bent toward the realistic, did they actually consider this or just hand waive it?

I started with trying to determine how much “heat” an ship has in the game. Honestly it’s expressed as a percentage in the game and bad things start happening around 100%, but that’s not really a useful number. I decided then that 100% should be about 90c, figuring that’s around the temperate that modern microprocessors start having issues. Everything on the internet about this was using Kelvin so I rounded it off to 360k, which is really 86.85c but I’m just ballparking an idea anyway. I vaguely remember one of my ships running at 32% most of the time, my vulture probably, and went with that. 115.2k or -157.95c for anyone interested.

After some math involving the general volume and density of a diamondback explorer how long would it take to get from 360k to 115.2k? Over a month. That’s a super rough number with a lot of problems, but it answers the initial question of how close to reality heat dissipation in Elite is. It isn’t.

Now, I must admit, I expected this answer, but you never know. Having ruled that out it occurred to me that I couldn’t possible be the first person to ask this question, so I googled it. Sure enough it’s mentioned on the wiki. Ah well, it’s just a game anyway. Let’s face it, sitting around a system for a month waiting for your ship to cool down from a single jump wouldn’t be very much fun. We play games to escape reality, not recreate every frustrating detail.

So that’s what I did this morning. Ran around the internet with a calculator and google converting units of measure back and forth and approximating the size, density, and temperature of a hypothetical ship just to sate my own curiosity.

3 thoughts on “Black Body Radiation – Heat dissipation in Space

  1. Hehe. Interesting thing. Though, I think that black body radiation is not the only way ships in ED loose heat. Just use your outside camera and go for ship control. Then use high heat weapons or shield cell batteries and see what happens. πŸ™‚

    That being said, the game has plenty of aspects which are not realistic. I still find it very nice to know that several ships of the game would need to apply downward thrust to land on Earth. The density (means, mass in relation to volume) is lower than of air, so those ships would actually float on Earths atmosphere. πŸ™‚

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    1. My coworker saw me do gown that rabbit hole and he was thinking you’d just put a heat sink on it. I had to explain that while the heat sink absorbs the heat, you’d have to physically eject it or it would just sit in the heat sink. Also told him how crazy effective heat sinks were in Elite.

      I wondered about that though, I actually have a cell bank on my Vulture, I’ll check that out at some point. It did occur to me that some sort of particulate matter in the heat vents could store heat and be released which would certainly speed the procedure up. I mean, surely they could figure out something in 1000 years. Even running water through it and venting the steam would make a huge difference.

      Well, just having looked up the density of air, I’m happy to report my estimate was at least more dense than that. It was super rough though. I used the dimensions of the ship which is a, um, okay there isn’t a pretty word for a 3D rectangle, but I’m aware that the volume of that space is technically higher than the volume of the actual ship. It was a fun rabbit hole to go down though.

      Also now I’m trying to visualize a landing pad that has to physically clamp the landing gear down so the ship doesn’t float away and what it looks like if they forget.

      “Dangit Dave, I told you, YOU HAVE TO LOCK THE LANDING GEAR! That’s your third anaconda this week!”

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      1. Actually what ED shows effectively is just light emission. I interpret this as a form of lasercooling. (https://en.wikipedia.org/wiki/Laser_cooling in ED it looks like this: https://www.youtube.com/watch?v=QiKt0i2WLfY )

        Of course, they don’t just focus on cooling one atom down, but use is on bigger scale.

        So yes, there’s some “fuuuture” aspect to it. But at least for me, that’s fine enough. πŸ™‚

        As an unrelated sidenote: hmm. I liking something requires me to dig out my old WordPress account and password. Have to look into that occasionally. πŸ™‚

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