As I understand it (see: not at all), if you leave a spaceship with no suit on, you’d get baked like Marie Curie’s ovaries from the radiation. It’s mainly our atmosphere that protects us from most of the nastiest stuff. Would a giant cable reaching from Earth all the way to a platform outside the atmosphere become dangerously-radioactive over time? And if so, would that eventually cause the entire planet to get radioactive over hundreds of years? Kinda like if the hole in the Ozone layer were replaced with a Mario pipe.
And if that is the case, maybe we could forget the elevator aspect of it and just aim for a free eternal source of radioactive energy, like a really shitty Dyson sphere 👀
A recent Scott Manly video about radiation in space https://m.youtube.com/watch?v=DJcbevbBzsc.
Ada answered the question, but consider your question.
You said “leaving a spaceship with no suit”. If your idea is that something left in space becomes dangerously radioactive then any space station or space ship would itself become dangerously radioactive.
So the answer is, no, things in space don’t become dangerously radioactive. Also things in contact with radioactive substances don’t themselves become radioactive except under extremely specific circumstances. Your house didn’t become dangerously radioactive because of the radioactive americium-241 in the smoke detectors.
Any time you talk radiation, you need to be specific about what kind of particles, how much energy they have, and how much of it there is.
Most of the stuff in orbit is charged particles (electrons and small atoms) and low energy photons. Those get stopped by relatively thin layers of shielding, but if you’re not careful you’ll get cooked from raw heat.
Ionizing radiation like neutrons or x- and gamma-range photons can radioactivate materials, and take more shielding – think feet of water or a couple inches of lead. Nuclear reactors have that, but spaceships don’t. Fortunately unless you bring a reactor with you they’re rare enough that it’s not really necessary.
Substances become radioactive when they get hit by some kind of ionizing radiation and change into an isotope that itself emits radiation. Conducting radiation like a wick isn’t really a thing.
Electrons and small atoms are kinds of ionizing radiation when they’re flying around with enough energy. Also, it’s not the photonic type that makes something else radioactive (mostly). It’s the particles. Look up what neutrons are doing in nuclear reactors. They “contaminate” things that aren’t normally radioactive because neutrons ‘stick’ to their atoms and make the atom unstable because now it’s a different, most likely less stable isotope.
you need really spicy photons for activation to happen
in space you also have protons some with relatively high energy. most of these come from solar wind and also can cause activation
I think I read somewhere that we do have the technology to create a Dyson sphere but it would be too much of a massive undertaking time and labor-wise at our current level.
Not Dyson sphere (also a sphere is literally impossible), though maybe space elevator. If we weren’t already so close to Kessler Syndrome, anyways…
We do not. We can’t even move solar energy from earth orbit down to earth at any scale that would be economically viable or really even useful.
We lack the material science to build something that large but still light enough to be physically stable AND somehow collect and transmit energy.
We also lack the technology to stop it from being destroyed by space debris even if we could somehow build it.
There isn’t a requirement for a Dyson shell to transmit energy. You could just envelope the sun in habitats that use the energy they collect locally and that would meet the criteria of a Dyson shell (and a K2 civilization).
Sure but that’s even harder!
It requires more material and financial resources, but isn’t necessarily harder. Transmitting energy effectively to reduce heat, or managing the excess heat starts running into some pretty tough limits of physics. Most of the issues with spinning habitats are engineering problems within the capabilities of our current technology level and materials science. It’s just super expensive and has terrible ROI for now.
We have the technology to manufacture materials that could make up a Dyson Swarm. We are not even close to having the technology to make materials that would be sufficient to make a Dyson Sphere.
What we don’t have is the resources, logistics, energy supply and manufacturing base to implement either…
That’s the least of the worries facing the construction of a skyhook. I don’t think Heinlein’s Kenya Beanstalk is possible. It would have to stretch out so far to defeat gravity that it would hit so many satellites. That’s the first issue that pops to mind.
That’s not really much of a concern unless you aim satellites directly at it. There’s plenty of space in space.
Yeah, it’s not really satellites that are the problem. There’s so much debris in orbit from our space programs, it’s starting to form an entire layer around the planet. The risk of collision from this debris is constantly growing.
But there’s really not that much debris. Certain orbits can get packed but there’s plenty of availability. Also stuff in LEO deorbits pretty fast.
Kessler Syndrome. The worst part is that, at some point, the risk of collision becomes so great that the problem becomes self-perpetuating, further increasing the risk until we can’t leave Earth anymore.
Would it not be self-correcting in the end? The various bits of debris that form the Kessler cloud would collide so much that they would eventually fragment into little more than dust, or lose enough energy that they are no longer in a stable orbit?
There’s no appreciable drag up there, so if it’s in orbit it’s going to be in orbit for a while, regardless of how big or small it is. Is the amount of energy lost to ripping the debris apart enough to eventually de-orbit the object? I honestly don’t know. My immediate thought is no, barring outside factors, because if it did spacecraft would be torn apart during their de-orbit burns; but I honestly can’t get my brain around that well enough to be certain (maybe the longer time a spacecraft takes de-orbiting reduces the stresses that a piece of space junk suffers instantly).
The kind of crazy thing is that, if a 1,000kg satellite orbiting at an altitude of 36km and a speed of 11,000kph breaks into a thousand pieces, each of those 1kg pieces are still traveling at an altitude of 36km and a speed of 11,000kph.
Radiation isn’t water and the cable wouldn’t be absorbitant. 🤨
Compare that possibility to the radiation from sunlight. I wouldn’t worry about radiation, I would be more concerned about altering earths rotation, or damage caused if the space elevator were to collapse.
Yeah the
dearth ofdeath and destruction left by it falling would be insane. I assume it would have to be built along mainly west coasts to mitigate risks. But maybe it’s more important to be somewhere with less hurricane/cyclone risks, and with really stable bedrock obviously.Edited out some auto correct nonsense
By the necessities of its design a space elevator has to reach geostationary orbit, which would make it tall enough to wrap around the planet twice if it fell. Wouldn’t really matter if you built it on a west coast or not.
A geostationary orbit is ~35,000km from the surface of the earth. The circumference of the earth is ~40,000km.
Ah thanks, I was a dingus and looked up the diameter instead of the circumference. Still doesn’t really matter where you build it. No matter what it’s fucking up a a good portion of the equator if it falls.
It still can’t really fall. It’d be moving incredibly fast sideways. Fast enough to miss the Earth for a while. Geo stationary orbit is the point where orbital speed matches Earth’s rotational speed, so if it’s anchored at the ground, then it’s at orbital speed if at GEO. The higher the orbit, the slower the orbital speed. So using a higher orbit to maintain tension means it’d be traveling beyond escape velocity, held down by the cable. A break would release the mass into the solar system
I think that depends on how big the tether is tbh. It has to be usable as an elevator so it can’t just be a thin cable. And your scenario is assuming that it would be cut down near the base, if it’s damaged anywhere higher up anything below the cut will fall down to earth.
Yeah that’s kinda what I was envisioning, maybe half the tether zingin off into space when the other half fell into the pacific or desert, but even half is gonna be like 15,000km I guess.
Also wasn’t there a scenario like this in one of the Mars Trilogy books?
And not all would fall. Part of it would be launched outwards by inertia.
Actually, a good ways passed geostationary orbit if I remember correctly. It needs centrifugal force to keep the cable taut, since it won’t be supporting its weight from the surface.
Dearth means “a striking lack of,” as in “dearth of evidence.” (No evidence)
In fairness, if it fell, and somehow left no trace of its existence upon hitting the ground, that would also be insane, albeit in a different way.
It was supposed to say “death and” autocorrect had other ideas I guess.
Ooh, that makes more sense. Auto correct is getting shittier by the day. I’ve got a new conspiracy theory that it’s a push to get us to use voice to text more, to help train our robot replacements.
Its still funny to read this as you having a concern about the striking lack of distruction caused by space elevator collapse. Maybe the elevator debris all got thrown into orbit?
The trick with a space elevator is that the cable needs to be very thin. The material needs to be strong. That’s just two reasons why we’re still far from putting that to any real use.
I don’t think having a small line through our atmosphere will slowly poison us. The extra radiation that would make it through is probably a rounding error. The material would have to be such that it doesn’t attract radiation. And even if we discovered that this could be a problem, if we have become smart enough to build this space elevator, we’ll probably be smart enough to figure out a way to filter it out.
No extra radiation would make it through because that’s not how radiation works.
Induced radioactivity is mostly the result of contamination from radioactive materials. Whilst it’s possible to induce radioactivity from gamma rays directly, you’re talking “background noise” levels of radiation. Which is to say, the cable isn’t going to become notably radioactive, and even then, the part that does, will be the part that isn’t protected by the atmosphere. And for people to navigate those areas of space safely, we already need shielding to protect us from the suns electromagnetic radiation, so a small increase in radiation from the cable isn’t going to make much of a difference to anything.
I’m wondering what would keep the part in the atmosphere from building up a massive electrostatic charge.
