Spacescifi

So you are saying he would still look like a fireball? Why would he look like an orange or yellow fireball though? Are you saying thst when air is compressed and heated to a high degree it looks like a fireball regardless if any ablation of mass is taking place?

Curious... since the streak of fire seen on spacecraft during reentry is from the ablation of the craft's heat absorbent disposable surface. Superman does not ablate and neither does his costume, in fact he has his own kind of forcefield aura that not only keeps him clean from bugs gunking up his suit, but also from melting from heat. So if Superman goes supersonic in atmosphere, I imagine he would look like a blue whitish fireball. Why blue? Ionizing the air from the heat, and no mass is being ablated, just a lot of air being compressed and released really fast. Superman basically turned himself into a ramjet no? Flying low doing this will make people mad, since the constant sonic boom will shatter or crack windows as he passes overhead. So flying suborbital into space before reentry would be the ideal way for Superman to fly, but I suppose in desperate situations he might make exceptions. Curiously this is much the same scenario if a scifi ship with the classic forcfield bubble was hitting atmosphere and blocking it with the shield. The shield would not leave any sort of ablation streak unless it was actually ablating (and typically they don't since that's the whole point if having a forcefield). If flying fast enough I presume you would get a blue whiteish ionized plasma fireball streaking through the air here as well.

I wanted to design a scifi SSTO around the gimmick of being able to cancel the pull of gravity. I soon realized rocketry would be wastefull when I could just turbofan and coast into space. Sure it will take longer but not unbearably so, maybe an hour more. But it's worth it for not having to expend propellant. For space travel they would use a special vacuum reaction drive that pushes off space vacuum itself for thrust and won't work within thick atmosphere. Requires vacuum conditions to work.

I don't mind your feedback. Carry on or not as you wish. Telling a good story is what matters in the end. And there are different levels of SOFT scifi... theres Star Wars science fantasy that is soft as a marshmallow, and then there is Stargate SG1, which is like a jelly bean. A bit of thin candy hard science, but ultimately full of fiction in it's gòoey center.

Does not bother me. Possible solutions: 1. Access to unobtanium that specifically generates a zero gravity field when electric current is applied, which grows larger the more current is applied. Earth has none, or if it did once, was mined of all of it a long time ago by space aliens who use it. That's basically taken from Stargate, only a different function as opposed to naquadah. Can be found on select alien worlds. It also allows the excuse for not visiting Earth even though they know where it is (they have no unobtanium so nobody cares about Earth lol). 2. Bootstrapping alien tech so advanced you cannot retroengineer it (thus the turbofan). Yet claiming you made it to appear you're more technologically advanced than you really are (also from Stargate, Goauld loved doing this).

https://medium.com/@marek.janda.eng/nuclear-powered-jet-engine-is-there-a-case-for-reviving-this-idea-34954e20e31a Cool.

We make turbofans for flight on earth. Scenario: Attempt to fly a turbofan jet plane on: Mars: Nothing much happens right? No air. Jet engines need oxygen. Neptune: Same? Saturn: Same? Jupiter: Same? Conclusion: In theory you could bring liquid oxidizer but that just makes the plane weigh more and reduces flight range. Which leads to the conclusion that ductfans and propeller craft powered by electric power are the ways we know could work for flight virtually anywhere. Since all you need is atmosphere to react with. Anything requiring oxygen or any specific chemical is niche. Yes you could design aircraft specifically FOR Neptune or Saturn to exploit their specific chemicals in the air, but they would not be craft good for flying almost on any other planet with atmosphere. The foundation of modern industrial power began with mechanical power (pulleys, levers, etc), graduated with chemical power (gunpowder, dynamite, oil and gas, and rocketry), and has entered the age of electrical power, although we have not fully exploited it yet. Chemical power has limits based on chemical reaction power released. Electric only has limits based off heat and storage, and so far chemical beats it purely based on chemical storing more power. EDIT: I did not mention nuclear, because although you could make a nuclear turbofan... the nuclear part is the danger. Specifically the radiation. Although if you had no better alternative it would be perhaps a good alternative in any atmosphere where free oxygen is rare or nonexistent.

How about ductfans instead? They are more thrust efficient and make less noise. In practice how an OP spaceship would enter an atmosphere from space: 1 . Slow speed to geostationary orbit while in low orbit using vacuum reaction engines and gravity cancellation in tandem. Because normally you would be falling in a curved trajectory as the atmosphere slows you. Here you slow in space without falling. 2. Toggle gravity cancellation field off. The result is you fall straight down... only long enough for you to reach an optimal velocity that you know your ductfans can counter to avoid crashing into the ground. In practice this also means traveling to a planet's surface will take longer, I don't know how long. Maybe an hour or two? Good news is you no longer have to worry about ablative heat tiles, because you never go fast enough in atmosphere to need them. 3. Leaving an atmosphere likewise will take longer than it would with rocketry. So do proper reconaissance before you decide to fly down to a planet, because if there is an enemy airforce chances are high you will be a BIG sitting duck to them. 4. I don't know if ductfans can do reverse thrust, but I think so, as I have seen turbofans on jet engines do it, and all turbofans are is a ducted fan with a jet engine in the middle. Ductfans rely on electric power, something a scifi spaceship will have plenty of usually by default. Gravity cancellation helps as well, but I would also presume that scifi spaceships can store larger amounts of electricity than modern batteries do.

That won't work so well on planets like Mars with barely there atmosphere. Nor planets that don't have much oxygen (Saturn, Neptune, ect) unless you have an electrode jet, and those wear out with use. Plasma jets are a thing but thrust is kinda weak compared to normal air jets. To have something that will work anywhere you need rocketry.

Scenario: A star wars like setting with SSTO vessels with hyperdrives being common. Technology: All SSTOs possess gravity canceler tech, which allow vessels to float around as if in zero g despite gravity levels. Space propulsion: A special vacuum seemingly reactionless drive is used for outer space only propulsion. In actuality it reacts with the vacuum itself... a kind of vacuum propulsion akin to how air travel relies on the air itself. Main Question: Obviously rocketry is still used to reach space, but due to gravity cancelation tech, SSTOs are far easier to make. So the question now is... is there ANY legitimate reason NOT to use aerospike engines on SSTOs? Because I cannot think of one, and if I were an engineer in the setting I would propose slapping aerospike rockets onto every SSTO in the fleet I worked with. Obviously star wars is not science accurate, and they use the same rocket engines for taking off planets that they use in space.... even though practically in real life this virtually is never optimal, efficient, or safe. Star Wars also never seems to utilize aerospikes either... with perhaps a few rare exceptions. In the OP setting, special vacuum based non-rocket engines are used for outer space travel, which means you can afford to optimize your rocket engines purely for SSTO duty and RCS for steering in space. So once again... any good reason to use a cluster of traditional bell nozzles over a singular big truncated aerospike surrounded by a ring of combustion chamber outlets? Just to reach outer space? Since once there the vacuum space reaction engines take over for main thrust, and rocketry is only used for steering via the RCS.

Scenario: Pick the most capable Roman Emperor from the 1st century onward, and have him SUDDENLY know all of modern science and engineering know-how of how to make EVERY bit of modern technology in existence since the industrial age... plus knowledge of how the original timeline went. 1. Which emperor would you pick? 2. What are his odds of developing any technology? My analysis: Even if you picked a competent emperor how far they progress would be limited by the very nature of how power was in the Roman Empire. Emperors were assasinated all tye time, and who knows how much backing you could really get on your scientific endeavors. My guess is you would have to start with something, anything, that will reap rewards and fast, so folks could get behind supporting tye Emperor's mad quest for better industrial machinery. From there? Complexity until you can't or you get assasinated lol.

Oh I know... real life is like the classic old videogame asteroids... only in 3D and with all the real life physics installed for additional difficulty. I once played Oolite (based off the original Elite with a lot more mods), and even though it is essentially airplanes in space, there is a "dark laser" laser mod I installed where laser beams are invisible as they should be in vacuum. I can tell you space combat became much harder as I could no longer gauge where to fly to totally dodge the laser beams. At best I could dodge and pray.... worse yet was when I was tailing an enemy ship and I get hit by laser fire. I had a hard time knowing who shot me (ships often have both fore and rear lasers), as I did'nt know if the one I was chasing zapped me with rear lasers or if his "friends" came to his aid.

I was thinking about how we handle g-force better lying down on our backs, and how it probably would hurt a pilot's lower back in the sitting position when they pull a bunch of gees in a tight turn all of a sudden. Typically there is no reason to pull off such tight turns, but who knows? Maybe super manuverable jet fighterd will be made one day that can do that casually. Anyways... any merit in making standing seat jet fighters today or would the miltary industry just laugh at the idea if anyone presented it to them?

Often in science fiction scifi humanoids are either given pointy ears or odd colored skin as their sign to show their alien-ness. Personally, I favor more practical effects. Scenario: Like is common, their skin is some odd color, but beyond that their body appears human... only their hands are different. Instead of soft hands of flesh with endoskeletal bone, they are exoskeletal hands with whatever muscle/tendons working beneath it without bone. In addition to this, the hands have a small valve hole in the middle of each palm that can open or close. When open one hand can can squirt an orange liquid 70 feet (if sprayed along an arc path) while the other shoots a blue liquid. If the liquids come into contact they cause chemical combustion on contact. Humanoids have a limited reserve of these liquids but generate more daily, especially while sleeping. Reason: It's a designer humanoid race, designed specifically to have the ability to start fires without any tools required, which is also useful for self defense obviously besides combat. Main Question: How feasible is this according to physics? I think there is nothing in physics that says such a concept is impossible to exist. Also how practical would it be? I know exoskeletons are lethargic when molting and cannot be used as actively since they are softer, but according to youtube videos crabs only take about 30 minute to shed their exoskeleton and two days to fully harden up. With the OP humanoid race, it's only the hands, so the process should go faster I think. In practice I suppose work staff would be larger to substitute folks on their hand molt days off. Thoughts? Not sure about dexterity, but per scifi desire, I want dexterity to be on par with normal humans. They also have tiny hairs on the exoskeleton that allow a sense of touch.

What? How would that even look? No lens on laser? I always thought lasers would look like camera lenses, only instead of snapping pictures they burn you with concentrated photonic beams. And if you can go without a lens then why do atmospheric military shipboard lasers seem to use lenses?