you know what’s more freeing than killing yourself? running away to a small town and getting a job as a waitress. buying a cheap car and sticking a bed in the back and driving southwest. adopting a cat. learning a new instrument. moving apartments. visiting a friend in another city. chopping all your hair off.
you can kill your current life without dying. you can kill this version of you and make a new one.
maybe I’m just a bipolar sucker for rebirth but sometimes that thought is all that keeps me alive
pulling a wholesome gone girl > actually killing yourself
Weird things I do instead of studying: wonder how much energy fictional wizards would need to cast a spell and if it would physically possible to do it. As in: “Okay, once we assume I wield a power that allows me to act on the environment around me without physically touching it, how much energy do I need to, idk, stop my friend from falling to their death? How many spells can I cast before I run out of energy? Should fictional wizards be always chubby/fat so that they always have a lot of stored energy in case of a fight?”
I mean… physics wise it depends on what you’re trying to do. Are you getting the energy from your own body? Are you getting the energy from your surroundings? Are you getting the energy from some mystical source that isn’t on this plane of existence? And how do you judge how much energy you need? Do you need to calculate the speed of your friend so you can send a precise amount of energy to stop their fall, because if you get that wrong they’re still going at best terminal velocity and you won’t be able to save them, or can you handwave it and the magic does the maths for you? If you send you much energy as a force opposing their fall, they will decelerate too quickly, which will be just as bad as hitting the earth… if you send too little they won’t slow down enough before hitting the ground. This also doesn’t take into account how long the spell takes to cast, the time it requires for it to take effect, other potential factors such as how close your friend is to the ground and if there is anything impeding your magical efforts to break their fall…
I’m a mathematician I could go on about this for hours…
Okay, I’ve got some free time, I’m going to science the shit out of this!
So…
How many cheeseburgers do I need to cast Feather Fall?
(Disclaimer: I am a mathematician, not a physicist. If I use a formula wrong somewhere, feel free to let me know and we can politely debate science)
Assumptions:
We have a friend, let’s call him Mike (sorry anyone reading this who is named Mike) who is falling at terminal velocity. We’re assuming gravity is the same as on earth (because we’re lazy) and we’re rounding it to 10
m/s²
(because we’re lazy- it’s actually 9.807 m/s² but that would mean i need to go get out a calculator so 10 it is!).
So.
To get the force that Mike is experiencing, we need to multiply his acceleration (10 m/s²) by his mass (which we’re assuming is about 70 kg, the average mass of a person). So the force he’s experiencing is 10*70 = 700 Newtons of force on Mike. We need to counter this force if we want Mike to stop falling towards the ground. We also ideally want to slow him down enough so that he is not falling at terminal velocity when he hits the ground, because that would kill him. Terminal velocity on earth is about 54 m/s; with a parachutethis goes down to about 7-8 m/s, which is what we’re aiming for. If we decelerate at 10 m/s² we can achieve this in about 5 seconds. A human can withstand acceleration of about 49 m/s²; bear in mind that we’ve got to take existing gravity into account. We could decelerate at 39 m/s², which slows us down in a couple of seconds, but that is going to push the limits of what Mike can withstand. It depends how close he is to the ground as to how fast we want to decelerate- if he’s too close, we might not have the time to slow him down fast enough without killing him anyway.
We’re going to assume he’s about 500 metres up in the air; he’s high up enough that we’ve got time to slow him down, but he’s going to hit the ground in about 10 seconds if we don’t do something about it. Time for some maths!
How much energy does it take to stop gravity?
Now, we want to know the potential energy related to Mike’s current fall, because this will tell us how much energy we need to counteract this. He’s currently got 700 Newtons of force pulling him down; this means that for every metre he falls, it releases 700 Joules of potential energy. This means that, to stop the force of gravity from making him accelerate any faster, we need to send 700 Joules of energy to push him in the other direction- and this is the amount we need to send every second while he’s up there, because gravity does not have an off switch.
So, 700 Joules per second to start with. Air resistance is going to deal with this until we start slowing his fall, but once we start slowing him down we are going to need to keep up the 700 Joules per second until he hits the ground, otherwise he will start to accelerate again. That’s already going to be quite a lot of energy; we certainly don’t want to leave Mike suspended in midair for a long time.
How much energy do we need to slow his fall?
So, the 700 Joules per second means that Mike is no longer moving any faster towards the earth. We still need to deal with getting our speed of 54 m/s down to 7 m/s so that Mike won’t die when he hits the ground.
If we decelerate at 10 m/s² for 5 seconds (bringing us down to 4 m/s because a. slower is better and b. I’m too lazy to fetch the exact number of seconds we need) (ignoring what we’ve already done to take out the effects of gravity), we will use 3500 Newtons of force. In that time we will fall (54^2 - 4^2)/2*10 = (with the help of a calculator)
145 metres. Then we can calculate the work done, which is force * distance = 3500 * 145 = 507500 Joules.
Putting it all together
So, we have an initial output of energy to slow down Mike, for 507500 Joules, and we need a good 145 metres of space before he hits the ground to do this. Then while we’re doing that we need to expend 700 Joules per second to counteract the effects of gravity, which will be happening for at least 5 seconds while he’s decelerating, possibly longer once he’s slowed down and not at the ground yet.
Because Mike is our friend and we’re very conscious about the fact that we don’t want to accidentally wait too long before we slow the fella down, we’re going to start slowing Mike down now. We have an initial output of 507500 Joules to slow him down, plus another 700 * 5 = 3500 Joules for counteracting gravity while he decelerates. that’s 510100 Joules so far for anyone keeping score at home.
So Mike is now floating down at a leisurely 4 metres per second. He’s still 500-145 = 355 metres up in the air, so he will be travelling down for another 89 or so seconds. That’s another 62,300 Joules of energy to stop gravity while he’s decelerating, making our grand total to be 572400 Joules to get Mike safely to the ground.
Where are we getting this energy?
We’ve been working in Joules, but most foods are defined in KiloJoules, so let’s convert: we have to find 572.4 kJ to stop Mike from hitting the ground. For context: a cheeseburger has about 3000 kJ, so we can reliably save 5 Mikes on a happy meal (assuming we eat something as well- your body needs fuel too!) (this also says something about how insanely weak the force of gravity is).
Of course, this essay doesn’t take into account what energy requirements you need to project energy, or send energy that far, but here’s a comforting thought; Mike is going to live, thanks to you!
Fin.
BONUS: Accio Parachute!
Okay, what about if we instead conjure up a parachute for Mike to use? That means we don’t need to concentrate on slowing him down for a minute and a half, we can just let the parachute do the heavy lifting, right?
(This of course assumes that Mike knows how to operate the parachute you summon for him, and that he has enough time to put it on/use it before he hits the ground)
We can create mass out of energy, using Einstein’s famous equation:
E=mc²
Where E is our energy, m is our mass, and c is the speed of light. Ignoring the fact that this mass needs to be in a functional parachute shape: we need to create about 11 kg of mass for a beginner’s parachute (which should give Mike the best chance depending on his skill level). The speed of light is about 3 * 108 m/s, squared is 9 *
1016 ,which means we need 99*
1016
Joules or 99 * 1013 Kilo-joules to summon a parachute. So you would need 33 *
1010 cheeseburgers to summon a parachute for Mike… better just stick to feather-fall.
aka why tf am i procrastinating on The Thing (more like a flowchart, actually)
lots of people who have executive function difficulties worry about whether they’re procrastinating on a task out of laziness/simply wanting to be a jerk or mental struggles. this checklist might help you figure out which it is at any given time! (hint: it’s almost never laziness or being a jerk.) (obligatory disclaimer: this is just what works for me! something different might work better for you.)
1) do I honestly intend to start the task despite my lack of success?
yes: it’s a Brain Problem. next question
no: it’s shitty to say one thing & do another. better be honest with myself & anyone expecting me to do the task.
2) am I fed, watered, well-rested, medicated properly, etc?
yes: next question
no: guess what? this is the real next task
3) does the idea of starting the task make me feel scared or anxious?
yes: Anxiety Brain. identify what’s scaring me first.
no:next question
4) do I know how to start the task?
yes:next question
no: ADHD Brain. time to make an order of operations list.
5) do I have everything I need to start the task?
yes: next question
no: ADHD Brain lying to me about the steps again, dangit. first task is ‘gather the materials’.
6) why am i having a hard time switching from my current task to this new task?
i’m having fun doing what i’m doing: it’s okay to have fun doing a thing! if task is time-sensitive, go to next question.
i have to finish doing what i’m doing: might be ADHD brain. can I actually finish the current task or will I get trapped in a cycle? does this task really need to be finished?
the next task will be boring/boring-er than the current task: ADHD brain. re-think the next task. what would make it exciting? what am I looking forward to?
I might not have enough time to complete the task: ADHD brain wants to finish everything it starts. (if task is time-sensitive, go to next question)
i just want to make the person who asked me to do it angry: sounds like anxiety brain trying to punish itself, because I know I’ll be miserable if someone is angry at me. why do i think I deserve punishment?
no, I seriously want to piss them off: okay, i’m being a shithead
7) have I already procrastinated so badly that I now cannot finish the task in time?
yes: ADHD brain is probably caught in a guilt-perfection cycle. since I can’t have the task done on time, i don’t even want to start.
reality check: having part of a thing done is almost always better than none of a thing done. if I can get an extension, having part of it done will help me keep from stalling out until the extension deadline. i’ll feel better if I at least try to finish it.
no, there’s still a chance to finish on time: ADHD brain thinks that I have all the time in the world, but the truth is I don’t.
reality check: if i’m having fun doing what I’m doing, I can keep doing it, but I should probably set a timer & ask someone to check on me to make sure I start doing the task later today.
8) I’ve completed the checklist and still don’t know what’s wrong!
probably wasn’t honest enough with myself. take one more look.
if I’m still mystified, ask a friend to help me talk it out.
hope this helps some of you! YOU’RE DOING GREAT SWEETIE DON’T GIVE UP ON YOU
Ooh, this is a really lovely (and kind-hearted) guide for ADHD, executive dysfunction issues, or just plain ol’ brain fog! Should help with misplaced guilt, too.
