8

This is a frame challenge. Sure, you can extend the life of a star if you have unlimited supplies of matter and energy... but why would you want to? What's the point? If you already have unlimited energy, you don't need a sun. If yours is wearing out, just discard it. You could build an artificial replacement... but even that is more effort than it's worth....


8

According to your link: The process can work with any level of carbon dioxide concentration, Wu says -- they have tested it all the way from 2 percent to 99 percent -- but the higher the concentration, the more efficient the process is. The atmospheric concentration of carbon dioxide is .0391%. That's well under 2%. This would not work well at ...


8

You can’t use carbon dioxide as fuel, and that’s not what the article you cite is about. You can turn carbon dioxide (plus hydrogen or water) into fuel, but the process will need more energy than you will later release by burning the fuel, so you’ll need to get that energy from somewhere. But yes; if you get the energy without burning fossil fuels and you ...


7

It is technically possible to burn carbon dioxide, but not in a practical way. The reason burning carbon produces energy is that the total potential energy of carbon and oxygen is minimized by the CO2 configuration. Splitting them up into carbon and oxygen again requires an addition of energy. Therefore, in order to burn carbon dioxide, you need to find ...


7

In open battle, yes And the answer takes two vital components - speed and strength. Your idea of weapons for these deinos revolve around human ones. But that's not the correct approach, it's talons. Large, wicked sharp talons that the deinos have on their feet which gives them better reach. They would attack humans by leaping in the air and landing on them, ...


5

So you have a small, man-portable device capable of providing electrical power in any quantity desired. Daniel Thomas Shipstone would be proud! Brushless electrical motors are commonly used to provide lift and momentum in airborne drones which operate very similarly to helicopters. The great challenge in creating a load-bearing drone is not the weight of ...


4

It looks internally consistent but you may simply get a large bang, stars are, complicated. In theory if you have energy-matter conversion, and infinite energy, you can pump hydrogen into a star to sustain fusion beyond the normal life of the star. But stars are always a balance between the outward force created by photon pressure and the gravity from the ...


4

TLDR: Your hunch is correct. Shorter wings. You ask, "does such aircraft actually need normal wings at all?" The answer is an emphatic no. In fact, aircraft on Earth don't even need traditional wings. Check out the X-24. You still need control surfaces, but in a high pressure environment you don't necessarily need wings. It would be helpful to find a ...


4

As has been stated already, these creatures weapons and strategies would build upon their physiology. Those tails could power slings, while accuracy is hard to judge since its a matter of eye-tail coordination, in mass they could be quite dangerous. Their basic shape would engender the use of the atlatl-like tools, held in their jaws. They could then ...


4

Recently planted trees are likely to have troubles getting enough water. That is because their root system has very likely been cut off quite considerably when they were taken out of their previous habitat. The root systems of trees are incredibly complex structures, that often live in symbiosis with funghi mycelia and in interaction with the soil around ...


3

I don't have the time it would take to dissect your map in detail (especially when your map is of the significant continent but fails to include the entirety of the world), and it doesn't help that even zooming in the picture fails to make the color key or the distance scale easily legible, but I can highlight some problems that leap out at me from an ...


3

All the fossil evidence we have indicates that dinosaurs were the precursor species to modern birds, which are most certainly homeothermic. So, we can presume that this mesothermy is such that the dinos need not bask in the sun to maintain body temperature. Mesothermy has nothing to do with endurance. In fact, the relationship may actually be inverted: ...


3

Your preference is for initial observation by Mr. Average Joe. We can see how plausible this is by creating some categories of how likely Average Joe is to have access to certain vantage points. From most plausible to least plausible (list is not exhaustive): Surface of Earth - very easy, just walk outside Low Earth Orbit (hudreds of km up) - not as easy ...


2

We do have a telescope observing the Earth from beyond the Moon, the Deep Space Climate Observatory. It orbits itself at Earth-Sun L1 point. When moon aligned right it already captured the moon's far side, potentially revealing any objects above it or at Earth-Moon L2. However, 10000 square metres means diameter of about 100 metres. This is roughly 0,00005 ...


2

I just got a crazy idea reading at people answers. What if a meteorite or comet is about to pass really close to the Earth (and thus, the Moon), and, as so many people are looking at it, they detect the shadow of the alien starship when it goes between the Sun and the meteorite? I know is pretty impossible that it just happen to align for the shadow to hit ...


2

Over a period of many tens of thousands of years, possibly. It takes something in the range of 100,000 years for heat from the core of a star to get to the surface. So if a star has used up its fuel, or "the pilot light has gone out" or something, then it takes that long for the surface to start to cool. And similarly that long for it to start to heat up ...


2

Lean but strong Realistically these characters would be like hunter / rangers Monsters are naturally stronger than humans so they'd kill them using arrows and/or traps. Evil overlords have more men and are better armed and armoured so again it would be ambushes, traps and arrows from afar. You don't want bulky muscles because it's extra weight hiking back ...


2

There isn't one. Beyond the fact that they would be in reasonably physical shape different people will have different forms and appearances based on the sorts of training they have done. For example some people will favour agility and speed. Others brute strength. Wizards probably don't spend much time lifting weights. People (particularly in a standard ...


2

Amber is transformed resin by application of heat and time. It's not particularly hard (scores a 2/10 on Mohs, compare to iron which is 4/10), nor is it made from any particularly rare elements. Amber is made from resin, resin is mainly made from turpenes, which can be derived from isoprene formulas (that is, a multiple of C5H8). It's just carbon and ...


2

You have functionally unlimited amounts of electricity? Just use electric-powered jet engines. Jet engines have four stages, only one of which, the combustion chamber, is chemically-powered, and the burning jet fuel is primarily used simply to increase the temperature of the air in the combustion chamber. With unlimited electricity, you can simply use ...


1

Where do you think fossil fuels came from? CO2 that was removed from the atmosphere by plants (converted into the carbohydrates &c that the plants were composed of), then captured underground by various geological mechanisms. The obvious problems with using this process to address global warming are 1) The process takes tens to hundreds of millions of ...


1

Yes, but not from the link in the question. According to the link in the question, Carbon Dioxide can be used to produce an energy storage medium in a rudimentary way, a bit like the chemical production of alcohol out of sugars by yeast or even sugars out of CO2 sunlight and water. In all these cases the net energy output is less than the energy put into ...


1

It doesn't matter. Your only listed requirement is cardio (long hikes). You can have a strong heart and be any size and shape. 300 lbs people run marathons. 70 lbs people can't do a single push up or walk more than 5000 steps without becoming exhausted. So it really doesn't matter what someone looks like, it is what is inside that counts.


1

I see 4 issues Packing problem (why tails are a problem in close order combat) Human formations can be very dense. In a phalanx, troops can be placed less than a foot behind the line in front of them. They can still effectively use their spears to strike. They can support each other and bring a large number of weapons to bear. Raptors have these long ...


1

The effectiveness of our dinos directly correlates with a tactical acumen. But before we look at the best tactics we should look at how to arm them. Because of their physiological make-up, they are pretty much cavalry without any further need for anything but a lance. Due to being armed with natural claws, additional hand to hand weapons are not needed, ...


1

Easily, by working together more effectively. An army of 100,000 D-men will slaughter 5,000 humans. By having superior organisation and, crucially, not always fighting among themselves while sowing discord among their human foes, the D-men can overcome any minor physiological disadvantage they might have. Nobody says the Romans won because they were bigger ...


1

I think the sudden gravitational influence of a very large ship would impact the stability of every geostationary satellite orbiting the Earth. Since these satellites have limited maneuvering fuel for correcting minor perturbations to their orbit, the corrections are applied very judiciously. So, a sudden perturbation to every satellite would cause people ...


1

I don't think this works, because it would effect the gun as much as the bullets. You would feel no recoil because the gun can't gain more momentum than the bullet does. So there isn't much preventing you from using a gun with large bullets. If you needed 10x as much mass as a normal bullet to be lethal, but also felt 1/10th the recoil, every soldier ...


1

Pay a visit to any semiconductor manufacturer and the answer will slap you right in the face: cleanliness. There's a darn good reason why all the fab workers wear moon suits, and they won't let you anywhere near the shop floor without one. So what if you contrive a situation whereby creating a sufficiently clean environment is impossible? Or the required ...


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