Pushing past lightspeed is more than just pushing past lightspeed: it's pushing past the constraints of time. After all, there isn't really any point in giving Beyond Lightspeed its own post if we're only looking at going 1.01x or 1.25x or even double or triple. Beyond Lightspeed means you can jump into hyperspace and cross the galaxy in just thirty minutes (according to Star Wars, anyways), making the distance between worlds akin to the distance between your house and the local 7/11.

Honestly, that kind of thing has always bothered me in Star Wars. Starships are presumably massive investments that most farmers spend lifetimes saving up to buy, and hyperdrives doubly so - yet every measly outpost in the Rebel Alliance has dozens of hyperspace-compatible X-Wings ready to go at any moment. You hear about how the protagonist wants nothing more than to finally leave their stupid planet, and then suddenly gets their hands on ship after ship after ship throughout the story. The galaxy becomes tiny and limited: more like a city than a massive span of thousands of stars and worlds.

The Milky Way galaxy is over a hundred thousand light-years in diameter: 52,850 from the center out. There's probably still light from the Earth from the ice age that's finding its way to the other side right now. Going at five times the speed of light doesn't shrink the galaxy to the size of a city. Going at five hundred times the speed of light barely makes it feasible to cross with cryosleep and a ridiculous amount of investment. And at the point that you're saying you can go a million times the speed of light, then you'd literally be hitting so many stars on your way through - I can't even begin to express how dead you'd be.

So basically we come to the big question:

What's the best speed for FTL?

As I see it, there are several issues to take into account:

• How the heck are you supposed to navigate at significant FTL? The average distance between stars in the Milky Way is 5 light-years; at 3,000,000x you'd be hitting a star roughly every second, which is a quick and easy way to get yourself mcslain. Does that mean you can get up to 500,000x speed and navigate by the minute? How much energy is required to change the trajectory of a ship traveling at such speeds?
• How does one change directions at FTL? And in space, for that matter? The on-board computers in Star Wars chart out lightspeed paths automatically, creating a rough series of lines and stops to avoid death traps and reach destinations that can't be accessed by straight lines. They never bother to show the ship actually navigating itself through hyperspace though, which has always bothered me. Presumanly you'd have to make several stops mid-hypersepeed to avoid certain doom, jumping in and out at various locations to reach your destination.
• At what point does FTL become too slow? That is, how much faster than lightspeed does it have to be to effectively mitigate the problems of traveling at c? Going at 1.25x doesn't exactly open up the galaxy for a daytrip. What's the highest minimum speed for FTL to actually start working?
• Basically: What's the minimum speed and what's the maximum speed? And how do you navigate?

Bottoms Up: How Slow can you Go?

Once again, the average distance between stars is 5 light-years. That means at the speed of light, it's gonna take you five years to get from one star to another. This is not fun.

At roughly 500,000x the speed of light, it'll take you just minutes to get from one star to another. This probably isn't good for a minimum speed. At 100,000x speed it'll take you on average five minutes between each star; at 50,000x, ten minutes. These are all still quite large numbers, because - after all - lightspeed is pretty dang fast.

At less than 10,000x speed it'll take you an hour to get from star to star. At 5,000x you make a day of it. These are still big numbers. 1,000x it's a road trip, 500x you need to stop and get a hotel.

100x speed means it's a business week to get from one star to another. That means it'll take a month to cross through several districts and get to someplace more distant. In terms of the scale I've been writing for my sci-fi novel, this seems like a good model speed for the likes of business ventures and military expeditions. If time isn't a big constraint, then 100x is a good speed for saving money and getting stuff done. They'd be akin to voyages from England to the New World; longer ones would be like going from Europe to India.

It's effectively a step down from the industrial scale of Star Wars, which is akin to a galaxy-wide modern-day consumerist economy - think of it as how we can practically access the entire world at any given moment for enough money, and how it just takes days for Amazon to get us our stuff. In my particular story, space travel is still in a pre-industrial phase (even though it's still massively beyond the level of industrialism in reality). Many individuals do have access to massive FTL speeds, but for the most part it's significantly more cost-effective to just take your time on these things.

Obviously 100x wouldn't be the absolute absolute minimum speed. For local travel you could go at 1.01x - 1.25x and jump between planets to go hang out with your friends over the weekend, and perhaps if you don't have the money you could go at somewhere around 10x to spend a little over a month moving to the next star over. Regardless, at a practical scale, I think 100x makes for a very friendly number - so let's go with it.

Head over Heels: A Need for Speed.

30,000,000x speed is the right-away "too fast" bar, because at that speed you'd be hitting a star approximately every second.

We established earlier that roughly 500,000x will make star-to-star travel take about a minute each. I don't think that's a good high limit. If 100x speed is akin to an overseas voyage, then I want the maximum speed to be akin to an airplane ride. A jump from one star to another will take just an hour or two, while crossing the galaxy would take a day or two and multiple flights. It takes a commercial airliner to cross the globe in just under 48 hours, though that's around a globe rather than across a disk (I'll be going by radius rather than diameter to determine the max speed, then). 52,850 light-years is 19,191,700 light-days, so you'd have to go at roughly 9,595,850x lightspeed to cross it in a couple days.

That's obviously an issue - we'd still be hitting a star every few seconds. Clearly we need a different parameter.

Perhaps it's not a great idea to compare the galaxy to the globe. It's hard to express just how big it is. And besides - it's not like it's taking months for the 100x speed starships to cross the entire thing. Rather than looking at the galaxy as a whole, we should be looking at individual star-to-star travel in the same terms. From one star to another is like crossing an ocean: meaning for budget voyages it'll take a week or two, and for rich people trips just a few hours. It takes a plane roughly 3 1/2 hours to cross the Atlantic, so we'll set that to our goal for our top speed.

5 light-years times 365 = 1825 light-days, then times 24 makes 44760 light-hours. 8,760x speed would mean that you cross in just an hour, so our upper limit would be about 2500x.

So there we go. 100x - 2500x as our best average. The absolute slowest FTL would be just over 1.01x (for local system travel), while the absolute fastest would be upwards of 2900x (based on the fastest crossing of the Atlantic by plane coming out at about 3 hours).

Anyway

Navigation: How to Not Die in Space, For Dummies

So if you're going really fast, then it becomes remarkably easy to hit things - and in space, when you happen to hit things, you often wind up dying.

If you're going too fast, then there's really nothing you can do to avoid hitting space things. Yeah, there's a lot of space in space, and hitting things is kinda difficult - but it's like going on a windy mountain road in the middle of the night at fifteen over without your brights on. The chances of skidding over ice and hitting a deer just get higher and higher the fewer precautions you take - except in this case, the deer is an entire planet and the ice is a gravity well.

So how do you dodge a deer in space?

The faster you're going the harder it is to slow down - at least, that's how it works in normal physics. Fortunately for us, we aren't obeying the laws of normal physics at all - we're going upwards of 3000x the speed of light here. Clearly we're thinking with portals here.

Basically: if you can go past the speed of light and destroy all physics, then you can suddenly drop to speed 0 and destroy all physics.

So how do you know where the deer are in space?

Google maps, of course. We'd need to have charted the entire galaxy. All of it. The archives cannot be incomplete - this would be bad. In addition to having charted it, we'd need to have some way for every FTL-capable ship to access it all: a prospect that gets more and more complicated the more you have to consider.

Basically: we need some kind of supermapping supercomputer with really good FTL wifi.

What if there's a brand-new deer in space?

The last thing you want to encounter on your space daytrip is a rogue planet slamming into you mid-hyperjump. However, if there's FTL wifi, then it should stand to reason that there's also FTL radar. Your ship would likely be able to drop out of hyperspace in emergencies so that you don't hit any space deer.

Basically: space radar.

Hey, how are we doing FTL in the first place anyways?

Tune in next time for... uh.... the next thing!

Bye!

Whatever. This is what I'm thinking about right now, so this is what I'm going to talk about.

Artificial Gravity is a thing that exists. Or... well, rather, it doesn't. Not yet. It shows up time and again in science fiction without any explanation whatsoever, which is honestly fine by me. You don't have to explain to me why Obi-Wan Kenobi can jump into someone's starship wearing nothing but his jedi robes and stay glued to the floor - I'll just accept it as part of the universe. In some films (I'm thinking of Treasure Planet specifically rn) they'll have a generator for it, and I'll just be like "yeah sure that checks out."

But I was thinking about it last night because I've actually been writing a bit of this space opera story recently (yes, you'll be able to read it - eventually. Maybe. Probably. Perhaps). I have artificial gravity on the spaceship everybody's on board rn, but I've been quite the stickler for outer outer space rules (namely the "no sound" thing, so far) so I figured that if people can still float around outside then I should probably have a good reason for them to stay glued to the floor on the inside.

So here's...

Artificial Gravity - How to Do It and Why It's Important

Thing One: Why do we need gravity anyways?

Gravity is important because we've all grown up on planets chock-full of it. We developed our bodies over millenia of evolution to exist in this up-and-down world, evolving bones, muscles, skin, blood systems, organs, etc. They all work in gravity because that's what we've evolved them to be.

In space there's a lot less gravity than normal. When it comes to orbits what that means is that we send things going one direction really fast so that we counteract that gravitational force, meaning without an atmosphere things can kinda just stay up there for however long they want; but when it comes to deep space, there really isn't anything holding anyone down. You could be sitting completely still and still float around like a jellyfish. In many ways this is a good thing: it means we're no longer bound to two-dimensional travel, adding up and down to our repertoire of options.

But, of course, in many ways this is also a bad thing. Like I said, we evolved to exist in a gravity-filled environment, so without gravity our body starts to do some funky things:

• Bones begin to weaken. Without anything to hold up (because you're weightless), they get weaker and weaker over time.
• Same for muscles. They atrophy. There's a treadmill aboard the ISS for this reason.
• Some weird scud happens to our organs. Fluids don't do everything they oughtta in zero-g, leading to all kinds of problems.

Astronauts spending six months aboard the ISS can deal with this. It takes a decent amount of physical therapy and training protocols, but we've engineered our mission lengths to get the most out of each person without getting them permanently damaged. The ISS doesn't need artificial gravity. It's honestly fine.

It's when you get into much longer voyages that you start needing that kind of thing. Spending years in space could be irreversably damaging to your skeletal system, completely throwing your body for a loop. If you're living in my space opera galaxy, for example, and are taking a voyage from one star system to another without any form of >c travel, then dropping yourself off on the next planet could be really bad for your health.

So what're some methods to achieve this sort of thing?

Method Uno: The Halo Ring

The foremost candidate for artificial gravity in more "realistic" science-fictions is centrifugal (that's the one I'm going to use plz don't fight me) force. You live on the inside of a giant spinning ring, and the tangential force of its motion gives you a nice downward force throughout your body. "Gravity" in this sense is a directional force without the same acceleratory properities, but it hits all the main problems of actually creating artificial gravity, such as...

• Actually staying glued to the ground
• Having the force spread throughout your entire body
• Especially having the force spread throughout your fluid systems (in this case, primarily the fluid in your ears that maintain your balance)

Honestly, it's a great choice. Maybe the numbers they give you in the game aren't accurate or even realistic, but the principle holds out. However, this prospect comes with one major problem:

It looks stupid.

Who the heck wants to ride giant wheels careening through space? I sure don't. Imagine trying to have a space battle like that! Wheel versus wheel. People would be laughing their faces off in the theaters, because the most important part of any space opera is that your everything looks awesome.

So let's look at some other ideas:

Method Dos: Linear Acceleration

This one also somewhat speaks for itself. You put the spaceship sideways and have it rocked "upwards" through space towards its destination, pushing everything inside downwards. Simple, but effective. This gives the same effect as the Halo Ring, but without the necessity of making the whole thing just a really big circle.

However, this is a terrible idea, because it's incredible inhibiting to the spacecraft's maneuverability. In order to have a space battle with someong heading towards you, both ships would have to stop and turn off their gravity to shoot at each other. The only way to maintain the artificial gravity during a laser fight would be if both ships were riding parallel to each other, which would make space pirating a lot cooler, but completely defeat the purpose of things like surprise attacks and such.

This is a terrible idea.

Lemme dump some more on you.

Methods Tres through... Cinco, I think. I really should be going with french numbers, not spanish. All my spanish knowledge comes from Dora the Explorer.

• The Magic Generator: It  c a u s e s  g r a v i t y. Sure, sure.
• The Graviton Generator: Sorry Frustry, I already read your comment. No, I don't believe in gravitons. No, I will never use gravitons in anything I ever write. And no, nothing you could say would convince me that putting a massive particle accelerator in the floor of your spaceship would be cost-efficient enough to be worth having artificial gravity in the first place.
• Put a black hole in the floor: Build a sphere around a black hole. This is a terrible idea.

Kay, time for the idea that I'm electing to go with:

Method Six (but it's said "seez" because french): The magnet suit.

I came up with this out of nowhere last night and immediately began to consult the internet. The thought was simply "what if you just had magnet boots?", and I was somewhat disappointed to find that I was not the first to think of this. There's a whole page on Quora chock-full of the same answers shooting down this idea, kinda dropping my excitement from a hundred to five in about two minutes.

These were the main problems they highlighted:

• Magnet boots would not just keep you glued to the ground, but also make it really difficult to get back off of it. You'd have to awkwardly shuffle around rather than walk about.
• Magnet boots would not subject your entire body to the force of gravity. Your bones and muscles might not atrophy due to the new force, but your internal systems (namely your balance) would be just the same as they'd be in zero-g
• Maget boots would screw with the electronic systems on board.
• Literally everything we have ever put into space is made out of aluminum.

NASA apparently toyed with this idea for awhile, actually, but ran into all these issues and shot it down. Honestly, that's probably for the best: solving problems like those would not be at all feasible given our current level of space-ness.

But I'm doing a sci-fi, and I can do whatever I want.

So here are my solutions!

• To fix the shuffling problem, you'd need to make sure the boots are electromagnets with a computer worked into them. Given the fact that my sci-fi computers could probably run fifteen games of GTA V on a drone's battery screen, the idea that there'd be a way to detect how close your boots are to the "surface" and increase/decrease your magnetic output accordingly is totally feasible (I think). The magnetic force would be strongest while your foot is up off the ground to generate this gravity, and decrease significantly while it's on the ground so that you can pick your foot back up again just fine. Essentially, you'd always be feeling the same amount of force on you at all times.
• Add a whole suit to it! This is a terrible idea for modern astronauts (because who in the world would want to walk around in massive, bulky magnet suits all day?), but works just fine for my hyper-efficient space opera. If a computer can compute your foot's distance from the ground to output magnetic energy accordingly, then a lattice going across some underclothes exerting this force across your entire body is completely feasible. The only problem I can think of here is that your fluids wouldn't change at all, but.......... I'm going to ignore that so I can move on.
• It's a giant spaceship. It's thicc as hecc. All the systems would be feet beneath the floor, and probably shielded by aluminum and lead and everything anyways.
• It's a giant spaceship. It's thicc as hecc. The floor itself would not be made of aluminum.

I dub my new creation the Gravity Suit. Yes, it's a terrible name. Yes, it's incredibly on the nose. Yes, you can shut up now. It'd probably be made of some magical supermaterial like carbon nanofoam (which is, funnily enough, magnetic), and have a built-in computer system to exert gravity across your body without any real margin of error. What's more, this suit could even account for the problem of going from one planet to another with two different gravitational forces by subtly changing your own personal gravity over the course of the trip, and it could also allow you to walk up walls and across the ceiling to most effectively utilize the ship's space.

So... yeah.

That's that. If you hate it then I guess you can yell at me in the comments. I won't care because I'm probably not going to change my mind about this.

Cool luvya bye.

Should I make this a part two, maybe? Or is it a little late for that?

Screw it. If Incredibles can have a fourteen-year gap between the original and the sequel, then I can make a sequel after a long month or so.

Lightspeed and Beyond 2, Electric Boogaloo: Time Hijinks

We have a couple options here.

Option one is simple and effective, but makes for a terrible trip. Let's say, once again, that we want to get to our neighbor Alpha Centauri for a bit of terraforming and colonization. Apparently regular fusion could theoretically get a real spacecraft going at 10% the speed of light, which means that it'd be a forty-year trip to get there.

That is, as they say, an investment.

Fortunately, it's still well within the human lifespan. So as long as the ship is really big, contains lots of medical equipment (as well as, potentially, an onboard funeral home in case of something nasty happening), a person could totally make the trip. In order to maintain morale and general quality of life, it'd have to be a big ship. And a fancy ship. With, like... all the stuff. It'd literally be a big moving town, careening through space at a gazillion miles an hour.

We'd have to establish a spaceship government, a spaceship bill of rights, a spaceship constitution; spaceship citizenship, spaceship taxes, spaceship productivity. Some people would work in the algae racks to maintain CO2 levels; others would harvest the space plants and work the 3D food printers. You'd have engineers to check and double-check every single tiny thing, because there are no lifeboats on this puppy: if it's gone, it's gone. And everyone probably dies. 

A spaceship president, a spaceship head of engineering, a spaceship zip code manager, a spaceship communications guy. You'd have a whole bunch of folks working the food to keep things spiced up, a slew of guys maintenancing the maintainance robots, several forms of entertainment (theatre troupe, local band, video game devs), and probably a million other things that I haven't even thought of.

Eventually, a spaceship guy and a spaceship gal will be bonded for life by the power vested in the spaceship pastor, then go on to have spaceship babies to grow up in the spaceship. You'd have spaceship parks and spaceship dogs and spaceship youtube and spaceship everything.

(I've always wanted to manage a big cruise spaceship, by the way. I dunno if you've noticed).

That's option one. Just wait it out. However, it's far from guaranteed by any means: there's no telling if the spaceship crew will get angry at the spaceship captain and host a spaceship mutiny. There's no telling if the spaceship engineers get lazy and don't check up on the spaceship airlock and accidentally murders everyone.

So here's option two.

Dunno if any of you have seen Lightyear yet. If not... this probably isn't much of a spoiler. It's literally in the first fifteen seconds of the film or something.

TL;DR - Cryosleep.

It's entirely possible that the scientists and engineers and lucky youtuber guests wouldn't be all too stoked about sitting in the same spaceship for forty years straight, so an alternative option would be to put them under for the entire time in order to pass things by. The spaceship would be relatively small and unfurnished compared to what option one's might be, containing little more than enough chambers for everyone's cryosleep pods and probably some backup supplies just in case. Everything would be automated, which at this point means perfect.

I feel the need to remind you that AI and automation is only ever getting better, so in the next couple centuries, I imagine that automated spaceships would be way better than manned. Heck, it's like that already with airplanes and cars. Almost all accidents with such vehicles are due to human error, and several notable ones could've been easily avoided had the driver/pilot simply left the program in control. Currently, there's an uber-esque service that lets you get a ride in a driverless car, and that line has only seen nine total accidents: six of which were due to other cars doing something really stupid, three of which were when the car itself was freaking stationary and some idiots just walked into it

Here's the Veritasium video, in case you haven't seen it yet.

Of course, this opens up a whole 'nother social can of worms. You'd effectively be shutting yourself out of everything back from your home for about half your friggin life. I imagine that scientists would choose to either stay home or take their entire family, but that still leaves hundreds of friends and acquaintances to never see you again. In forty-four years they - old, tired, and cranky - will finally hear back from you, a servant of humanity sitll in the prime of their life. Each text message is going to take four years to send from Alpha Centauri, which makes things even worse.

But that's... ... ... ...fine... ...?

The Thing About Cryosleep

Let's open up our new science options to putting yourself under for a predetermined period of time, holding your body in a complete and total stasis until then. Suddenly, time becomes no object. An entire dimension of reality just won't apply to you for as long as you're under.

Which means, of course, that space exploration will change up a lot.

Let's say we want to colonize a distant star system, maybe several dozen light-years away. Perhaps even several hundred. You wouldn't just put a team of scientists and such on the ship: you'd have a massive population of regular working folk as well. They, as much as anyone else on any other kind of voyage, would be subjecting themselves to decades of cryosleep in order to continuate the human race. You, as the guy overseeing the voyage, would essentially be shipping an entire population of people to another planet. It would be a one-time investment, for the good of the species rather than your own wallet, as all outward shipments of resources and such would take just as long to get back.

But I really like this idea for an early interstellar story, actually. I think it could be really dang cool. Let's say that we figure out teleportation, first of all, but don't apply it to living beings because that's generally too dangerous. If you can dissolve materials into pure energy and beam it across the cosmos, then you'd essentially be opening up interstellar trade. This, of course, is what we call a "stimulated economy," and would become a massive venture opportunity for space company presidents.

Imagine you're the CEO of SpaceZ: a brand-new company that specializes in trade mediums (you're the middle man for interstellar trade, paying the worker costs and teleportation fees in order to reap the profits of people buying interstellar materials). Let's say it takes several years to build, prepare, populate, and launch an interstellar spaceship. You probably wouldn't oversee the whole thing, spending precious years of your life just waiting. Instead you'd put yourself under cryosleep, and even do so regularly. You would have literal time managers working for you that live out their lives normally, providing by taking care of your business during the down periods and reaping in profits for you. They would also be in charge of ensuring your cryosleep went on and off as intended, keeping your schedule so that you can oversee the big projects for a month or so before going back to sleep for another half a decade.

Cryosleep would be the new transportation of choice, eliminating all waiting time from whatever you might be doing. Imagine you're a regular businessman working for SpaceZ. Maybe you're completely used to getting put into cryosleep every few years or so to oversee colony construction. It's completely normal that your manager is never the same guy, that you never have any consistent friends and acquaintances. Or maybe you make a regular commute between Rigil Kentaurus and our own solar system (which needs a name, by the way), spending a month or so in either one before going back under for the ride back.

As it's likely a very precise science, it probably wouldn't be cheap. At best it would be affordable, meaning families could worry about their new life on Tau Ceti rather than the cost of getting there. As a businessman for SpaceZ, the regular commute would be covered by your boss, the same way plane tickets for working abroad are covered by companies now. But perhaps it gets more expensive the longer you hold it out for, making long-term or consistent cryosleep reserved for the wealthy. This is why SpaceZ's CEO can afford to pop in and out their own company every decade, keeping it in their grasp for hundreds and hundreds of years, all while the middle-managers just live out their lives as normal.

But overall, it's probably the best option for even if we could go at the speed of light, because no way under heaven are you gonna be making a regular four-year commute with nothing but a newspaper to look at. Time is the next dimension we have to conquer, and this is just how we'll do that.

Kay, now get us to this "beyond" stuff.

No.

Tune in next time for Part Three!

Dyson Sphere... system-wide production... extensive use of all immediately available resources...

Gotcha. Kay. We're back.

Stellar Engine! Left y'all hanging on that. It's a real piece of work, taking the power of a dyson sphere to do the unimaginable:

Move the solar system.

All the planets, asteroids, and stuff in our system are tidally-locked to our star: "the Sun" (as it is rather uncreatively named). Therefore, by moving the Sun, you can move the entire solar system.

How would we do this? Good question. The nitty-gritty engineering bits are all pretty foreign to me (check out Kurzgesagt's video if you're interested), but essentially you just need to make a massive booster using the Dyson Sphere as an engine. You plug it into the sun and fire it up, scooching our solar system along at a few thousand kilometers per hour or something.

The main reasons we would want to accomplish such a thing would be to avoid potential interstellar threats, like rogue stars and planets kareening into our solar system and throwing everything around like a furious toddler. Such threats would be apparent to us for thousands of years in advance, giving us plenty of time to move the solar system successfully out of the way.

Bear in mind, of course, a rather important thing: the solar system is heavy. While we'd be moving pretty fast compared to your old prius, this would be absolutely nothing on the scale of galaxies. Such movements would still be sufficient over long periods of time, as evidenced by space maneuvers used on smaller scales in real life currently (for example, one of the primary ways we move around satellites is by the use of mirrors. The minute amount of energy light puts into these things are enough to slightly change the movements of the satellites, which over the vast span between planetary bodies is all we really need).

Some concerns, addressed:

• But Faaaadrannnnnn, what happens if Earth swings around to where the engine is shooting its propulsion stuff?

Relax. We're not stupid. The engine would be facing downwards in relation to our orbit around the sun.

• But if it's facing downwards, then wouldn't we push ourselves out of the solar system?

First of all, you're really overestimating the overall power of this device, and second of all... no, actually! Our solar system is actually facing closer to perpendicular our galaxy's plane than parallel to it. The exact number is close to 60 degrees, I believe. So the engine would be blasting us more or less along the same plane.

• Would this even get us anywhere???

No. It would not.

Reminder: this is useful for minute changes in our solar system's placement for long-predicted threats. This wouldn't be any useful in a space battle or overall travel. If this sucker's moving at 20 m/s, it would take a million years to move 0.003 light-years. Proxima Centauri, our closest star, is 4.246 light years away. Crunching the numbers shows that it would take such an engine 1.415 billion years in order to get our system over there.

And also putting a solar system inside another solar system would be really stupid.

So, at the end of the day, while Stellar Engines are cool, they aren't exactly great. We need some real speed if we're going to be traveling from star to star, colonizing distant planets and meeting friendly aliens.

Which means now we're getting to the real numbers.

Sub-lightspeed

This isn't anything new. We go at less than the speed of light all the time! Such is perfectly normal behavior for literally anything that we can consider to be a "thing." The laws of physics dictate that in order to get things moving, you have to impart energy into it. Therefore, in order to make something go fast, you need a lot of energy.

Good thing we got a lot of energy, then.

Currently, the fastest human-controlled things are little neutrons and such, shooting about through massive particle accelerators to do... things, apparently (depends on how much of a conspiracy theorist you are)--and they go FAST. The numbers say they go at 99.9999991% the speed of light, then collide into each other to create MINI BLACK HOLES (depending, also, on how much of a conspiracy theorist you are). This is proof enough that it is within the boundaries of our current knowledge and technology to achieve such speeds, meaning that it's possible that we could do the same with larger objects.

Of course, it's not really that simple. Protons are really small and really light, so accelerating them to lightspeed is kind of a cinch. There was literally a boy scout who made a working one for his Eagle Scout project. When we kick up the mass a bit, though, things get more finnicky.

In order to understand this, you have to look at the fundamental laws of physics. The speed of light (or "C", as you might know from the famous equation E=MC^2) denotes the finite and immutable constant of a massless particle. A photon is the single smallest amount of energy you could possibly have: it is, essentially, your perfect "1" for the ultimate calculus of the universe. Therefore, if C is the speed it goes, then C is the fastest anything can go. Ever.

Which, of course, is a problem.

We can look at energy in another way, though, in its kinetic form: force. F=MA is Force equals Mass times Acceleration. If acceleration is C, then to move anything of literally any mass ever (let's say one kilogram. We'll be using SI units, as C is defined by the meter). Force would equal 1 X C, meaning you would have to have almost three hundred million joules of energy.

To move your car at the speed of light, you'd need about 390 billion joules of force. To get your massive party bus going that fast, it comes out to almost 5500000000000 joules.

So you can see now just how ludicrous that is. For comparison, the average annual consumption of energy on Earth is... uhh...

let's see... 580 million trillion joules... so to get your bus going that fast you'd need about 1/100th of the annual energy consumption...

Uh. wait. Hang on. That's global consumption, but by now we've colonized the entire solar system; not to mention the Dyson Sphere. It's ludicrous still, but...

Hold up.

Are you telling me that this is actually doable???

Alright, it'd take a LOT of energy to get your spaceship going at close to the speed of light--but by this point in time we'll have increased energy production and consumption by several factors. We've nearly tripled energy consumption since the industrial revolution, which was again triple the amount than humanity in late agricultural periods, which was again about triple(ish) the amount used in early agricultural periods.

That said, interstellar travel would be to a system-wide species as regular space travel is to us now. It would be incredibly expensive, but still doable. You'd likely have private investors and crazy gazillionaires funding private scientific and exploratory missions into the closest star systems. Such journeys would be decently long, spanning between five and twenty years. It's possible that by now humanity's life expectancy and quality would've drastically increased, so such time spans would be feel shorter comparatively; however, they'd still be incredibly long and arduous missions. Voyagers would have to take large amounts of supplies and perhaps live in more luxurious ships than what average planetgoers would usually use in order to maintain their mental states.

The Speed of Light

This is a problem.

You see, Einstein was at it again with his massive breakthroughs, learning about things like the fundamentals of space and time--y'know. The usual. I imagine he was driving a car when he came up with the idea of General Relativity: the basic philosophy of frames of reference and such. Let's say he was going at 60 mph on the local highway, then passed an older bloke going only 50. To the police officer watching for speeders from the side of the road, they are going 50 and 60 miles per hour, as he watches them pass. His frame of reference has, effectively, a speed of 0.

Einstein's car is going at a speed of 60 (gosh, miles; what have I done to myself?). However, he isn't constantly observing the speed of his car, as he is moving with it. Therefore, from Einstein's frame of refence, his speed is 0. That means to him, the old bloke is going at a speed of -10; the officer, -60. To the old bloke, Einstein is going at 10 mph, and the officer -50.

And then he crashes into the median because he'd forgotten something his mother had taught him ages ago: don't math and drive.

Of course, it's a lot messier in reality. The easy maths work well if you can't observe your own speed, which is a hard thing to do if you're rolling across a bumpy road during rush hour. The numbers would work better if there wasn't any resistance or external things to observe (like the Carmax ads or bridge overhead). If, say, Einstein was in a spaceship going through the cold vacuum of nothing--no friction, no gravity, no nothing--then these numbers work a lot better. Still, the concept remains.

Now we get into special relativity, which is a wonderful can of worms that I will gladly open here. Let's say Einstein drags himself out the burning wreckage of what was once his faithful prius and decides to take the trolley home instead. As he arrives at the station, though, it's just pulling out, forcing him to wait for the next one. Annoyed, Einstein watches all the happy passengers rolling out towards their destination through the window.

First, he observes Passenger One: a small child bouncing his toy up and down. To the boy, he's dropping the ball one meter down, and then the ball bounces one meter back up. Because he and the ball are moving with the trolley, he only observes two meters of overall movement.

However, to Einsten, he also observes the moving trolley. In the time it takes the boy to bounce his ball, the trolley also moves a meter away from its previous position. So while the boy observes a basic up-and-down, Einstein observes an angled down followed by an angled up, creating a sort of triangle. One meter up, one meter down, and one meter across: therefore, Einstein observes three meters of movement.

This is what general relatively says. We already went over this. Moving on.

Second of all, Einstein observes someone turn on the overhead lights to read the morning paper. However, the light reflects off the floor into the man's eyes, blinding him and making his spill his coffee everywhere. To the man, the light moved one meter down and one meter up (simplified, because I felt like it), meaning it moved two meters at a speed of yes. On Einstein's end, however, he saw it move three meters along with the trolley.

Here's where the problem is.

For the ball, the maths are simple. Speed is equal to distance over time: the distance was different, the time was the same - therefore, the only difference between the boy's and Einstein's observations was the speed. This makes sense, because the boy wasn't observing the additional motion of the trolley, but Einstein was. S = 2/1 for the boy, and S = 3/1 for Einstein.

But light has a constant speed. Always. ALWAYS. We don't actually know why this is, but it is THE RULE.

That means that we can't apply the rules of general relativity to the man who used to have a coffee and Einstein. If we did, then S = 2/[fast] for the man, and S = 3/[fast] for Einstein... this would mean a difference in speed, which is totally not okay.

Something that we also can't dispute is the distance covered, because the distance isn't a constant or randomly variable in any way. They have to remain at what each of them saw, or the law of general relativity wouldn't hold up, and suddenly traveling by car would get a whole lot weirder.

This, of course, leaves us with one thing we're allowed to mess around with:

Time.

If the distance is x and lightspeed is the constant, then time is the variable. 

Let's put Einstein back in his brand-new, top-of-the-line Prius Spaceship, then send him for a joyride out into the cold heart of space. As he passes other, inferior spaceshippers along the space highway, he observes them at varying speeds due to the law of general relativity. However, he also observes light from his headlights shooting forwards at their own speed: the speed - you guessed it - of light.

The way to conceptualize it is to remind yourself that frames of reference don't need to be human or animal or even alive at all. Literally everything is its own frame of reference: your shoe, your shoebox, the shoe store... even the old shoes left in your closet from years ago! This means that Einsten is in his frame of reference; the space prius is in its frame of reference; and the photons shot out from his headlights are their own frame of reference.

What are the implications of this?

Well, remember that light has its constant speed of roughly 300 million m/s, and from EVERY frame of reference, it must be going at this speed. That means that for Einstein, who is going at a speed of... let's say 500k m/s (it's a good prius and also in space), he sees the light shoot out from his car towards the rapidly-approaching Space Starbucks at 300m meters in a second. However, for the space highway cop waiting for something to actually happen, he sees the light go at 300m meters in a second... PLUS 500k meters. The difference in apparent spacialities is due to general relativity, as I explained earlier. Remember that Einstein is observing the rest of the universe moving towards and then zipping by him at the speed of his prius due to his frame of reference, while the cop is observing Einstein zip by at the speed of his prius from his own. That means when Einstein sees the light, he's seeing it move at 300m m/s away from him as apparent from his own reference frame of 0; while the cop observes light moving at this speed, but already effectively "pushed" by the prius's speed of 500k m/s.

Now there's only one thing left to do:

plug in the numbers and see how much time got dilated.

speed = distance / time. Distance covered for Einsten going to be 300m, as he observed over the course of one second. The speed of light, of course, is constant, meaning we can plug that in right away. 300m/s = 300m / x.  300m/s (x) = 300m - > x = 300m / 300 m/s. x = 1. Easy.

Now for the cop. He saw a distance of 300500000. 300000000 m/s = 300500000m / x. Do all the same stuff as above and you find a brand-new number: 1.006666666...7

So at a speed of 500k m/s, Einstein is experiencing time 1.007 times faster than a person sitting still and doing nothing.

Time travel is real, guys.

And we're doing it all the time.

The Kardashev Scale.

Theorized by Nikolai Kardashev back in the 1960s, likely as a supplement to the space race and whatnot. The scale is an early attempt at defining 'levels' of alien life and civilization, based on something very important to the universe: energy. All matter and forces can be traced back to the purest forms of energy, making it... pretty much the ultimate building block of everything. It makes stuff move, blow up, emit light... all that good stuff. And it's the foundational basis of all life as we know it.

I'm not going to get into biology much yet, but it shouldn't come as much of a shock that energy is a necessary requirement for life. You get all your molecules and stick 'em together to write up the code for your hampster, but nothing's going to happen if you don't give it a little jolt first. All life requires energy. In fact, death is literally just a body undergoing irreversable entropy (scientifically speaking, anyways). Thus, living things strive to acquire energy as a means of survival.

Why is that? Nobody knows. No biologist has ever managed to figure out where all these backwards things - things that actively avoid Newton's Second Law of Thermodynamics rather than ultimately striving towards it - came from. Neither do I, of course; so good thing that has nothing to do with what I'm talking about today!

As we understand it, large-scale evolution tends towards increasing energy consumption. Adaptation might increase energy efficiency and decrease usage, but if humanity stands for anything at all, then it's the constant increase of energy consumption.

 < - - that's what we science-minded folks call "a jump"

The Kardashev Scale reflects these massive jumps as tiers of societal complexity. A Type 0 civilization through to Type 1 represents all our time here on Earth. Initial jumps are from hunter-gatherers to agriculture, agriculture to industry, industry to automation, and so forth. Humanity as we know it is currently at the tail end of Type 1, meaning we've just about utilized all our planet's available resources and energy to maximum efficiency. Sure, we're doing it in the worst ways possible, but things like ethics and preservation aren't accounted for on this scale.

I started us into Type 2 civilization in the last post, detailing our usage of the local system as defined by our lovely home star. This post should hopefully detail all the way through to the end, taking us to about Type 2.5. This scale is logarithmic in nature, so I probably won't quite get to Type 3 anytime soon (consumption and utilization of the entire scudding galaxy).

Last time, we left off on the utilization of all the planets. However, there's still one celestial body left that's worth tapping into - and it's a big one:

The sun.

Ladies and gentlemen, allow me to introduce you to the Dyson Sphere. Apart from having one of the coolest names in scientific anything, the Dyson Sphere would be the first and greatest megastructure worth building for humanity. Put simply, it's a massive body of solar panels surrounding a star, designed to directly collect the sun's energy. Such a structure wouldn't actually take all that long: if we started now, the lot of us would probably even live to see the completion of it.

The most efficient method that them engineers have thought up is not, in fact, a big ol' dome surrounding the sun. That would be dumb, bad, and quite possibly disastrous (eternal night, MASSIVE resource costs; not to mention that a single weakness could send the whole thing careening into the star's surface to be consumed). The most efficient Dyson Sphere would actually be a Dyson Swarm: a HUGE array of satellites orbiting the sun in a lattice, harvesting the energy directly, then beaming it towards our collection points. This would essentially focus all the stellar output of the sun to where we need it, and completely eliminate a huge percentage of its energy that just goes... well, nowhere.

In terms of our current civilization, such a battery would complete negate any need for local energy sources. I can't imagine that big oil would be too happy about it, but you'd best believe that the rest of us certainly would be. Suddenly, energy production would be completely automated: we'd never have to worry about it again.

This is why a Dyson Sphere likely wouldn't be humanity's last step towards becoming Type 2; it would be a lot easier to make it humanity's first. The energy availability would make colonizing the solar system an absolute breeze, allowing us to shoot our distant interplanetary colonies with concentrated sunlight to supply them with all the necessary energy they could possibly need.

And it wouldn't stop there. A Dyson Sphere would certainly be the first megastructure; but it would be far from our only one.

The Matrioshka Brain

There are a number of frontiers that humanity has only just dipped its toes into; and if you've seen Tron, then you'd know that the Computational World is one of them. If we can't be sending people all across the universe for a week-long vacation, then we'll do the next best thing: create a whole new universe from here. What is the internet if not a massive new realm for us to explore and define? Built out of information, sprawling far and wide across the world--and all to the comfort of our iPhones and laptop computers.

Thus, just like energy consumption, humanity is going to improve efficiency; and also increase consumption. I don't think I need to tell y'all that internet has completely skyrocketed in recent time. The trends match our Kardashev Scale types, with increasing consumption and requirements.

^ ^ ^ that is the first personal computer ever built: the IBM PC. It's boxy, chunky, and has that whole massive array to it.

It could process a total of 5 Megabytes.

And this:

Is an apple watch. You can wear it on your wrist.

It can process 16 Gigabytes: 3200 times more than that chonky boi up there.

So what's your point? I hear you ask; and a good question, too. I haven't the leastest clue about data and software and stuff like that. Heck, I can barely screw up the HTML of a google page with the inspect tool! And, frankly, none of that really pertains to space travel.

Which is where the Dyson Sphere comes in.

Like anything else, storing and retrieving data requires energy. Your phone doesn't work if you never plug it in, and the more anime you stream, the faster it dies. It takes about 0.2 mJ to store a single bit of information. That's not much, but if you take the 175 Zettabytes of data (projected to be the amount in the so-called 'datasphere' by 2025), then that makes 280,000,000,000,000.03125 Megajoules of energy. That's in the trillions, so considering that our data usage is only ever going to go up, we're going to need something big for processing all that.

That's when, in 1997, Robert Bradbury proposed that we build a series of dyson swarms in layers to create the ultimate computational machine: the Matrioshka Brain. It would literally be a star-sized computer (the layers would be to capture all the waste heat coming off from the computation to fuel the next layer, minimizing energy loss).

After completing a Dyson Sphere, this would be the natural next step. Imagine outsourcing all your computations to this massive machine: it'd effortlessly take on any lag, bandwidth, and RAM, then simply stream the necessary images to flash up on your screen. Given optimizations and breakthroughs in internet technology, streaming the internet could become the next massive leap in humanity's journey through the Datasphere.

The Sunny Meal

I'm making this one up as I go along. I was considering other possible implications of a Dyson Sphere, then thought of this: a dyson-powered food factory.

Photosynthesis is the reverse process of Respiration: it takes carbon (usually in the form of CO2) and water (H2O), then combines them using the power of the sun to create a hydrocarbon, or ATP (for most plants, this is glucose: C6H12O6), with the added bonus of an Oxygen (O2) runoff. When plants are consumed by an animal (say, a cow), that cow converts that ATP into instant energy, and stores some of it for later use by building up fat and muscle. Then, when us humans ruthlessly murder that animal (say, the cow), we consume its flesh to soak up all the potential energy it had left; which also gets turned into instant energy... and also fat.

It all starts with the sun: our planet's ultimate energy source. So why don't we keep on using it?

Advancements are being made in artificially growing meat cells - for enough money, you can probably get yourself a 3D-printed burger right now. This, of course, is both more consistent and a lot more ethical than raising and killing animals in nasty meat farms. Imagine what we could do with this technology using the sun's power?

And that's not all: glucose, fructose, sucrose, and all the sugars in-between are what we science-minded folks call Hydrocarbons. Turns out they're actually the exact same thing we use to do stuff like fire. When you watch your marshmallow drip off your stick and plunge itself into the flame to be blackened and consumed, what you're seeing is the fire take in oxygen from the air to complete the exact same process that you use to make your own energy: respiration. Humans get the O2 by breathing, fire does it by... existing; it's combined with the hydrocarbons, then harvested by splitting the bonds (thereby releasing energy) to release H2O (usually in vapor form) and CO2.

What that means is that humanity has been powering its factories and cars by taking dead sugar and getting energy out of it using nothing but good ol' fashioned breathing... the whole time. Almost makes you wonder if fire is actually alive, and if we've just been enslaving it for our own benefit.

Eh. It's not exactly off-brand for us.

What I'm saying, ultimately, is that we could start making self-producing food. We make massive energy collectors using the Dyson Sphere (including a lot of CO2 and water), and include photosynthesizing machines to directly convert this energy into storable packets of ATP. These would sit around for a few weeks/days/hours, then ship themselves back to Earth and our other colonies to be manufactured into something more tasty. This could free up land to decrease agricultural requirements, allowing us to more efficiently use our real estate (for important things; like actually putting our massive population somewhere for once).

I have no clue if this'd be actually viable or even functional, but with all the crazy scientists adding their two cents to the Dyson Sphere thing... well, I thought I might add some of mine.

The Stellar Engine:

*Cough* looks like we're all out of time, folks! Make sure to like and subscribe, and hit that bell so you don't miss out on our next big article: Moving the Solar System Out of the Way of a Massive Incoming Asteroid So That We Don't All Die!

Railguns! Trebuchets! All methods we can use to traverse our local solar system. Things get complicated, though, when we try to look beyond. Halving the time it takes to get somewhere doesn't mean squat when we get to things like light-years.

Let's math this problem real quick. The closest start to us is Proxima Centauri (which I knew off the top of my head, btw; FEAR MY POWER). It's just over four light-years away, or 40,208,000,000,000 kilometers from Earth (on average, anyways). That presents a problem that - fortunately - someone already did the maths for. Skyhooks, as projected, would yeet you at approximately 26.7 thousand kilometers per hour into the cold heart of space. 

Which meaaaaaaaans we could be there in just about... 1501897916.66 hours.

Which meaaaaaaaans it'd take roughly... one hundred seventy-one thousand, four hundred forty-nine years.

This is, as scientists put it, an issue. Literally nothing of value could be gained from this. Interstellar colonization? No shot. Maybe if we put everyone into cryosleep or some scud like that we could save a tiny fraction of humanity from Earth's last flaming breaths, but... yeah. That won't do for conquering the galaxy.

Fortunately, we have other things to look at right now. If humanity is at all interested in colonizing other star systems, then it stands to reason that by now we've already colonized our own. Using up the available energy and resources to us in our system is a massive undertaking, but opens up all sorts of crazy things. Thus, I think it's worth taking a closer look at before we move along in humanity's grand journey.

Tier II - Our System

Let's take a closer look at all the cool things that us humans could do with our system given enough time and investment.

• Moon base: We're probably on the moon! Not even probably - almost definitely. It's not a particularly hostile environment, and there are precautionary measures we can take against the radiation and occasional meteor swarms - my favorite being "dig a hole." Most of humanity would probably live underground in massive reformed caverns, capable of creating massive structures with the lighter gravity. Entire ecosystems could be constructed within these habitats... and they'd have to, too. There really isn't any way to terraform the planet, as the gravity's too weak to maintain an atmosphere, and the electromagnetic field's too weak to protect everyone from nasty stuff like radiation. The 'outside' would have to be shielded using [something something  t e c h n o l o g y], and it's likely that people would have to get used to keeping space suits handy just in case.
• On the plus side, though, the moon gives us tons of opportunity for other things. First of all, its lighter gravity means that it's much easier to cast off from. It's tidally locked with the Earth, so it might be worth building a massive elevator on the dark side as a sort of makeshift tether and harness the moon's orbital momentum. However, it's also just as viable to build lots of regular skyhooks around the moon. We could build a bunch of railguns on the surface (which require far less energy), and make the moon a first-stop port to the rest of the solar system.
• Other stuff the moon has: resources! It's got plenty of metals, which can be used to maintain its own economy as well as being shipped abroad. Solar power could work decently well in smaller scales, but by far the greatest resource the moon has is H-3. The moon could become the first fusion-reactor-powered body in the solar system, and eventually ship out the stuff to other planets as a clean energy source.
• Mars Colonization: Let me make one thing clear. The reason everyone's talking about building a Mars base is because its close; not because it's viable. It has very little atmosphere (comprised almost entirely of CO2), no global magnetic field, a completely insane weather cycle, and nasty storms of electrically-conducting dust particles that get EVERYWHERE. There's no way to protect against all the space radiation, it's impossible to breath, long exposure to the lower gravity could cause permanent damage, and the literal dirt is toxic.
• But... it's free real estate.
• Now, I've never played any of those space terraforming games, so maybe y'all know more about this than I do. Just bear with me here. To first colonize Mars, you'd need to build small, cylindrical structures containing the bare necessities of life. There would be no windows, literally everything would have to be recycled, and the whole thing would be completely covered in dirt to shield the unhappy astronauts from the radiation. Any work that doesn't absolutely require human hands would be done by remotely-controlled drones so as to protect the astronauts from as much exposure as humanly possible. Mars suits would be incredibly bulky, with myriads more protection than required elsewhere. They'd need to undergo a rigorous sterilization process every time an astronaut returned so as to prevent the toxic microfibrous soil from entering the habitat, or potentially never even enter the habitat in the first place (such as by attaching to the outside).
• Colonizing Mars would be torturous. Fortunately, there are a few things we can do. Mars has plenty of natural resources that we can mine to build things, such as massive containment areas. By far the most viable option would be to construct large reinforced buildings on the surface. Making them airtight would allow us to completely control the conditions within, which means these could be the first viable human habitats for large groups of people. Domes seem decently doable, as they could balance out the pressure most efficiently. However, they'd need to be made with several layers of reinforcement so as to protect the structural integrity of the area. It would probably behoove the engineers to construct several independent airtight chambers within the area itself, so if a breach were to occur, they could protect the vast majority of the dome.
• Until we can come up with perfect insulation, building underground isn't an option. Any breach could allow the toxicity of the soil to seep into the habitat, which would be... y'know. Bad. There could potentially be emergency bunkers and such built there to evacuate people for short periods of time, but long exposure needs to be avoided at all costs.
• However, once the planet is colonized, we've really managed to open up the solar system. Its moons are very viable for large-scale skyhooks, and the abundance of natural resources (namely iron) would make it a hub for mining. It might even become a sort of temporary home to big resource mining industries (the habitats would allow you to stay and oversee operations, meaning the planet wouldn't have much or even any regular residency). It would become a industrial and infrastructural hub, and mark our first major step towards colonizing the solar system.
• ...
• ...
• ...
• ...Venus:
• Venus is hell. Let me make that ABUNDANTLY clear. VENUS. IS. HELL. The atmosphere is thick. The atmosphere is toxic. It is comprised almost ENTIRELY of carbon dioxide, with an average surface pressure of 1350 psi, or about 91.86 atm. Divers can survive up to 100 atm by not breathing - but, generally speaking, if you're a Venusian colonist, you're going to want to breathe. Not that it matters, of course, because the air here would kill you in instants! Did I mention the fact that it's toxic?? Or that it is literally made of CO2??? There are clouds made of sulfuric acid!!! The CO2 is supercritical!!! The greenhouse gas effect gives the planet an average temperature of 464 degrees Celsius!!! That means liquid lead. That means you won't have time for the supervolcanoes to kill you!!!!
• Venus is not conducive to colonization. Venus is conducive to death.
• *Pant* *Pant*
• ...But I hear you. "Fadran, what if we just terraform it?"
• Here is a link. It will take you to a Kurzgesagt video. They explain the process. I'm not going to go into it, because - frankly - this article is long enough already.
• You wanna hear my opinion? My brother just mentioned it, and I wholeheartedly agree. The place burns at gazillions of degrees, spits geothermal forces like a teen's first pimple outbreak, and soaks up sunlight like nothing else. That said, Venus is also the PERFECT thermal battery.
• We should turn hell into a battery.
• Mercury: Mining! Don't colonize here. It's either scalding hot or freezing cold, depending on what time it is. No atmosphere. Mining only. No humans allowed.
• Jupiter: The moons are all perfectly viable. Like, there's tons of them, and they're all pretty cool to boot! I don't have time to go into any of them, but I think they're all decently viable for bases and such akin to the ones on our own moon.
• Saturn: Prettyyyyyyy!!! Skip.
• Uranus: Did you know that its magnetic field is tipped away from its axis by 60 degrees? Cool, huh? Moving on...
• Neptune: We do not need two blue gas giants. Throw some ship names down below so we can finally combine them!
• Pluto...?: https://xkcd.com/473/
• Other Stuff: Asteroids! They're all pretty dang mineral-rich and mineable. Big ones could be viable for early interplanetary resource-gathering. Here's another Kurzgesagt video that goes into that.

So is that all? We've harnessed the solar system. And... it didn't really help us at all for interstellar travel. We can build... bigger skyhooks, maybe? There's... nothing left for us to use. Is interstellar travel impossible?

• The Sun:

...

Look forward to part two: Harnessing the power of the sun!

I dunno.

It took four days to get to the moon, and of the 110.6 meters of rocket that was launched initially, about ten or so actually held the astronauts. 15% by weight included the actual rocket, and less than 10% made up the bit that dropped Mr.'s Armstrong and Aldrin onto the lunar surface.

I don't think I should have to say that we can do better than that.

Step One: Railguns

Using the physics and engineering that we know and love, our beloved NASA scientists have come up with quite the solution to the whole "rockets suck" problem. All they need is two miles of train track, a cargo jet of X-Plane caliber, and enough power to run a small town.

Railguns use electromagnetism to propel objects. It's the same as any old magnet: you put south at south and they push each other apart. However, electromagnets can control for how much power this magnet has, meaning the more electricity you pump into it, the more force they push at each other with.

Thus, you put a massive coil thingy engine mcbobber (I'm no technician; I don't know the details) at the end of the track and stick your plane (called a Scramjet, apparently) right there full of its stuff. Then you fire up the electromagnet, and YEET the scramjet down the track. Two miles would give it more than enough time to get up to speed (mach four), and then hurls the jet off the end. The incredible air pressure ignites the fuel in the chamber required to get it higher in the air, eventually getting the scramjet up to Mach 10. At 20,000 feet, the jet can't continue flying ('cause there isn't any... y'know... air); so this is where spaceflight begins.

The scramjet fires its payload into space, then glides back down to Earth for reuse (it was projected that such a machine could be ready for use again in just twenty-four hours).

From here, NASA projected that the payload - in the example situation, it was a satellite of comparable mass to the moon lander - would be in orbit in just a day, and with the same railgun they could send men to the moon on the next.

But that's just the first step. Maybe that works for getting things off the ground, but that's nowhere near enough for a full-on space opera. You can't have incredibly epic space battles if it takes years just to reach the next planet over.

So this is where our next epic physics boi comes in.

Step Two: Trebuchets

 (hopefully the image actually does its thing)

This is a trebuchet. It uses the most basic physics to do the most awesome thing ever: yeet things. On one side, you have your payload, whether that be a boulder, a cow, or a flaming bag of dog poo. On the other side, you have a counterweight. You lock the thing in place to load up your boulder, then unlock it to have the weight heave down and catapult the boulder into enemy lines. What's more, the engineering of these things only ever improved, increasing accuracy, distance, and power.

So, naturally, we're gonna put one in space.

This is the Skyhook. It's a really, really long cord (made of yada yada 'super tough fiber') extending down into low Earth orbit. At one end is a hook thingy, and at the other is a counterweight.

The physics are really simple: spin.

So imagine you're a payload, having been yeeted into orbit by a railgun-powered x-plane. Now you're awaiting a years-long journey so you can drop off your brand-new rover on Mars or whatever.

But instead of just flying through space endlessly, you get caught by the end of a really long space rope. It's just dipped on down into Earth's atmosphere, but then continues its endless spin routine. When it was put into orbit originally, it was given a little push on one end so that it spirals in its path; and, as things tend to do in space, it continues in this spiral for time and eternity.

Then the tether continues spinning, spinning, spinning... you're dragged upwards and away from the Earth, approach the apex of the spin...

And then it YEETS you.

Skyhooks use basic parabolic physics to simply cast things around like rocks out of slings. You get all the wondrous momentum from rotation without any of the nasty gravitational pull stuff that Earth tends to do! So now you're zooming through space at intense speeds, with no need for fuel or steering. So as long as the computers calculated trajectories correctly (which they tend to do, being computers), you'll be landing on Mars in no time.

No time being, that is, about three to five months. Better than seven, though - or nine, if you're a human.

So now the solar system's much more local, but even then we can't have epic space battles with just that. So...

Step Three: What's Next?

First of all, these things will be used to colonize the solar system. It might be possible to build some really dang big skyhooks on Mars' moons. Being tidally locked, you could have two - one on either end - and have them act like an elevator. You latch onto the close end from Mars, beam yourself up, then yeet into space from the other side. Payloads coming in could catch onto the far end and travel back down into low Mars orbit to get down planetside. These would be the most massive and effective tethers possible in the solar system, and probably act as a major nexus for all local space travel.

Now, then, we do have a couple issues. What happens if something goes wrong? What if the calculations were off? What if something breaks? Could you send a luxury cruise of rich folks headed to Venus for vacation careening into the void for all eternity? Planes can make emergency landings, and boats can send out distress signals to get picked up. But in space? None of that will be any good.

Imagine trying to make an emergency landing on Jupiter.

Of course, there will always be a chance of things going horrendously wrong. Mid-air accidents happen and crash planes into mountains; sailors get stranded and die of starvation. What keeps people doing these things is the incredible infrustructure and technological redundancies that reduce the risk factor more and more and more. Planes never crash because just one thing got overlooked; it's always due to a myriad of errors stacking on top of each other and compounding to make things go horrendously wrong. Heck, every airliner actually has a minimum required maintenance level, meaning that a lot of planes you fly will actually have problems deemed negligible by the captain and crew to keep the thing flying.

So what things can we add to interstellar travel systems to ensure that nobody gets killed in the vacuum?

3.1 - More tethers

While there are eight and a half planets roaming around out there (Pluto? Hello?), they aren't the only things in space capable of maintaining tethers. If you can put a skyhook in orbit around the Earth, it stands to reason that you could put several in concentric orbits around the Sun as well. You could put them on asteroids, dwarf planets, or even each other (as dual counterweights) to create a massive network of tethers throughout the solar system. Think of it like gas stations: places you can go to refuel, buy a snack, or take an emergency pee break.

If something were to go wrong on a flight, you could correct your orbit by the necessary amount to grab hold of one of these intermediary tethers and readjust your trajectory. Or, heck, they could even be mandatory stops on a trip. Maybe a several months'-long voyage really isn't all that great for your craft, so you need to stop it somewhere for maintenance; or your departure doesn't line up with where Mars is at the time, so you need to transfer between a whole network of the suckers in order to line yourself up properly. And, of course, if you're threatened with the cold heart of space, you'd have several times as many points to save yourself than you would if Mars was the only place with a tether attached.

3.2 - Better engines

I think it goes without saying that we humans have had our fill of combustion. Hydrocarbons, I love ya to death... but us peoples really need to figure out an alternative already.

Fusion is the energy of the future. I say that unironically, because it clearly isn't the energy of the now. Fortunately, space really opens up that opportunity for us. The moon happens to have a lot of H-3: a Hydrogen isotope that works really well for cold(ish) fusion, and doesn't let off any radiation as a bonus. A clean, harvestable, and efficient energy source? Perfect for humanity!

Powerful and compact engines would allow for direct, on-board steering. Instead of correcting over the long term with minute, calculated thrusts, you could make more drastic and immediate corrections in real time. This would open up jobs such as  S P A C E   P I L O T S, meaning that we can finally get to -

Step Four: Epic Space Battles

...Okay, I'm not actually going to go into too much detail here. There are a LOT of thoughts for how to make a spaceship as effectively as humanly possible in combat, so I guess you could say that this step is more like... foreshadowing.

Fourshadowing.

How to leave a planet:

• Bad: Rockets (dumb, clunky, and inefficient)
• Good: R A I L G U N S (much better, but still require tons of energy)
• Good: Trebuchets (used in tandem with railguns to yeet stuff through space (i.e. the Skyhook))

How to enjoy a planet:

• Don't fill the atmosphere with CO2
• Don't fill the oceans with plastic
• Don't kill literally everyone else
• Constantly improve efficiency / recycle resources

Society:

• Eudaimonia...?
• Emergence - Ants, germs, and AIs
• Culture
  • Parts of a whole
  • God
• Kardashev Scale: Intelligence? Energy consumption? Numbers? Influence? Where does society come from?

Technology:

• Energy efficiency... but with a sample size of one
• Assuming war: explosives? Bigger explosives? What about planetary megastructures? Are bombs necessary?
• Assuming expansion: what kind of ships? We like railguns and trebuchets. What about dark matter and other physics?
• Assuming communication: Compression? Files? Light?

Biology:

• Why is everything always bipedal? We've found exactly one type of human so far. What makes Lucas think that humans evolved convergently?
• What other types of senses are there? There aren't only five. We know this. Is experience even something most organisms... do?
• WHERE THE HECK DID BIOLOGY COME FROM???
• Fire.