# Tag Info

## New answers tagged physics

5

Iron fusion. Fusing light atoms is exothermic. Fusing iron and heavier atoms is endothermic. https://www.as.utexas.edu/~chris/stardatearticle.pdf The fusion reactions that make elements heavier than iron are endothermic — that is, they use up more energy than the reaction gives off. So “when you get an iron core,” Sneden says, “it sucks energy in and ...

0

Using Goliath to move David: If I'm following your system, you create a sort of artificial gravity in simulations of miniature solar systems. So if this is how your magic system works, can't you use it to create a simulated solar system with one of the "planet" nodes as a ship? This would allow your ship to essentially undergo a slingshot effect ...

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The first uses that come to mind would just basically be to use the clay to make models and simulations to better understand gravity and the solar system and stuff. Uses outside of that requires interpretations of the limits of the system. Assuming that the gravity from the clay and star only influences only the clay, and if the magic person can choose ...

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The one thing in terms of movement i think everyone forgot is how large this creature is. If it manipulates its mass just right then it can probally physically change its mass in specific ways to effect its own gravity. By shifting its body the right way it could probally create literal gravity sinks and use the gravity to accelerate its body. If it does ...

1

I think a half-baked idea I was having the other day might apply here. In relativity, there is no absolute reference frame. If there was a clock at every point in space they would all read differently. But presumably, the clocks were all wound at the same time: the "Big Bang". I think you could justify that the soul field is the "place" ...

0

I don't have the scientific understanding to answer your question in the physics jargon in which you've asked it. For example, at my IQ-level, "Frame of Reference" refers to the cultural and philosophical biases which a person might bring into a situation. It's a characteristic of the person experiencing the universe rather than an aspect of that ...

1

The spaceship landed perfectly normally, it just was using Apple Maps, and was setting up for a soft landing at 3200 ft ground altitude, when it discovered that actual ground altitude was 3250 ft. That's a gentle but devastating crash, much like parking your car 30 feet into your 25-foot long garage.

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Bad FTL exit One issue that you might want to consider is that the spaceship could be noticeable well before hitting the planet. Most forms of propulsion are highly visible, so if the spaceship needs to decelerate before hitting the atmosphere then any NASA-like agencies would be likely to notice it. Douglas Adams humorously presented another problem people ...

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As someone with more than 300+ hours in Kerbal Space Project, I can tell you that there is a lot of potential for catastrophic failure of a landing during its final moments. To take an example from real life, check the Soyuz TMA spacecraft, which the IIS crew uses to return to Earth. In its final descent it uses parachutes to slow down to ~7m/s (24 feet per ...

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Soft, stealthy landing at orbital speed The alien ship has a surface capable of reacting at very high resolution. It models the incoming atoms in real time, focuses an electron emission array at them to ionize them, and guides them into channels that pass through its infrastructure to the other side, where the electrons are removed and they are sent on ...

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Your shipped turned out to have soft landed on a small comet. That comet unfortunately then crashed into the Earth. After the fire ball stage of re-entry the spacecraft fell off what ever was left of the comet. People will assume it was just some bit of the comet. What remains of the comet continues on wards and crashes a long way away. Thus when people go ...

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For reference, here's a Progress launch, just a small cargo capsule, viewed from the ISS: https://www.youtube.com/watch?v=ouBfzCgXHgk The booster engines make it a bright, easily visible moving light from the moment it leaves the ground, and at around 36 seconds, the reentering booster makes that look dim, actually noticeably illuminating a large patch of ...

4

Crash it earlier The main character doesn't need to see the crash, unless it's for further plot reasons. The ship can have crashed years or decades ago. That is why it looks functional but old. It's late The time can reduce the amount of people seeing it. It can ve so early in the morning that next to no one sees it, or is clear enough to pinpoint a crash ...

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Perhaps the crash was during a thunderstorm and/or a meteor shower, so the sound and light show were less distinct (and sensible people were home in bed anyhow). And in fact maybe the thunderstorm and/or meteor shower contributed to the crash.

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The ship crashed during a heavy snowstorm, your character was out hunting/finding a lost sheep/a more nefarious reason and got caught in the storm. No one else was dumb enough to be out and so your character was the only one to see the crash.

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If crashes are a regular occurrence, because the orbit of the planet is/was being used as a breakers' yard and, if still active, low value hulks/components are often allowed to degrade in their orbit until they crash, or if inactive because the whole yard is slowly crashing out. Or there was a space battle in the system at some point and the debris has been ...

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There are a couple different things that make a mess when a spaceship lands: the fireball that streaks through the sky, the engine firing/parachutes deploying, the smashing into the ground. The most noticeable of them is the fireball, which is a ball of plasma that creates sonic booms as it goes by. Getting through this violent process is why spaceships have ...

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Why does the crash have to be a fiery comet from space? The ship could have safely landed due to a medical issue with the pilot. The ship might have sucked a duck into the engine intake while hovering and fallen a short distance. The ship may have landed automatically after the crew got wiped out by a radiation blast. The ship's AI may have vented atmosphere ...

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It all depends on the reentry trajectory: if it happens over oceans and scarcely populated areas there will be not so many eyes seeing it. Keep in mind that the "glowing" part of the atmospheric reentry takes place in the upper layer of the atmosphere, when the landing site is still far away. Then there is the supersonic bang which can be mitigated ...

0

An octagonal concrete wall will some decorations on it, but no windows. It may have some cameras to allow residents to look what is happening outside. The light for the apartments would come from the courtyard in the centre. If the ratio of the base size to the height is big enough the external perimeter wall won't have to be too thick. To reduce the sense ...

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One-kiloton nuclear surface burst at 500 meters is not that bad From the blast wave perspective, it does not look as bad as a category 5 hurricane - and residential buildings in some municipalities, like Miami, are already built to withstand that. Of course if the charge detonates closer, or it is more powerful, then the situation would change, but if we ...

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You are looking at a piece of real estate that was specifically built with the expectation of taking a hit, the building is simply too expensive to justify if you don't have a reasonable expectation of it being nuked, and has several rather odd and expensive extra features that you'd never bother with (mainly because of the fallout not the blast): It will ...

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It would have next to zero impact on any present day nuclear fission technology To oversimplify, in order for a neutron to cause a fissile atom to fission, it needs to be whizzing past the nucleus of that atom close enough to be captured via quantum mechanical processes. We measure the probability of capture by a value called "cross section" where ...

3

Nope! In fact, it would be very useful for getting them to happen more controllably and reliably! It would inhibit some types of nuclear reactions, because some types of nuclear reactions do in fact require fast neutrons to happen efficiently. But different isotopes have different neutron interactions cross section curves, with peaks at different energies, ...

1

You linked a good answer. Will such a situation affect ICBM's - yes. (No) Will it prevent delivery of pieceful(peaceful) freedom nukes - no. I refer to that 5% percent chance, meaning 1/20 penetration, so as ICBM are not the only way to deliver, so as it is relatively easy to fix ICBM's to increase chances(changing delivery trajectories, using booster ...

0

Sure but you run the risk of dimming the the sun with mining debris and possibly crashing the planetary ecology. If your mining throws off waste dust and excess material, especially if it is sulfur or carbon rich, that material has the potential to change the chemistry of the upper atmosphere. If you make one miscalculation it gets worse because you're going ...

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According to an article about "Neutron Shielding Materials", the half-thickness (thickness that absorbs half the radiation) of water against neutrons is 5.4 cm (page 8). 10 inches ~ 25 cm, so a water-filled mattress this thick would actually absorb 96% of incoming neutrons. A problem may be that such a mattress that ia 2 m long and 1 m wide would ...

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From this paper https://aip.scitation.org/doi/10.1063/1.1698304 Threshold detectors (In115, Ag107, and C12) were used to determine the relative intensities of neutrons at various distances inside a large water tank. Neutrons with energies up to 30 Mev were produced by (d, n) reactions. At distances in the water >20 cm the half‐thickness'' of water was ...

2

Two potential ideals: Absorb mass by sucking in: In a sand desert environment you could imagine an animal that sucks sand into a body cavity / 'sand bladder' This was already suggested by another answer. (Dry) sand has the advantage, that it can quickly be sucked up. Absorb Mass by chemical reactions: Looking at @FluxFlowFreq answer: Any oxydation, that ...

1

I think this'll work: Theoretical biological mechanism - Spontaneous Osteogenic Response. Just a fictional mutation This mechanism could be defined as the abrupt growth of bone cells in response to outside stimuli which would explain the gaining of mass. (Osteo - bone, genic - growth). You could manipulate the wording to dictate that the creature have ...

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I am assuming a terrestial creature rather than one in water. The creature would either use compressed air, but that is a lengthy task, or it could simply have the stomach to eat whatever is nearby. Scoop up all the sand nearby and you just gained weight. Swallow some rocks, a heavy plant etc. Another option is to use claws to dig into something like a tree ...

1

Fugu fish can consume water and air quickly to become much bigger. During inflation process, fugu consumes water, and her mass gradually increases. Mainly because mass of water she consumed is added to her own mass. This is video showing fugu inflating to protect herself from fisherman https://www.youtube.com/watch?v=L8-IFdxXW4w

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While it is hard to gain weight, your creature could have something like momentum wheels ready to accelerate to high velocities. Momentum wheels rotating at high speed make the creature more resistant against angular momentum against its axis, which gives the benefit of better stabilization. A crude example of this effect is seen with bikes, at higher speeds ...

4

In addition to existing answers that mention venting swim bladders and compressing air to reduce buoyancy: The sperm whale's blunt head is filled with oil plus a network of blood vessels and nasal passages. The sperm whale uses this to vary its buoyancy, by passing cold water though the nasal passages to cool the oil when it wants to dive, and increasing ...

3

Swim bladders Image via Wikimedia commons Many bony fish have swim bladders. These are gas-filled internal organs that help the fish maintain neutral buoyancy and rotational stability, so that they do not have to expend energy maintaining a constant depth or staying upright. The bladders are designed to extract gases from the bloodstream, which are in ...

1

You can't see out of this armor because nearly all light is reflected away. If you can see out of the armor, your eyes or sensors still get cooked by the energy beam. The first bit of dust/dirt/rain that gets on the armor gets heated into a plasma by the incoming energy beam, physically blasting a tiny pit into the armor. This imperfection is, of course, ...

1

Your creature appears to be composed of mundane atomic/molecular matter. However, swimming around him are thousands or even millions of tons of exotic, weakly-interacting particles. When necessary, these particles can be caused to decay back into the regular sort of matter, and it results in an apparent (but not true) gain of mass. This process is reversible,...

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Compressed Air If you compress gas, its density increases and effectively increases the weight of a vessel containing it. For example, a filled scuba tank can weigh several pounds more than an empty one. So in terms of an organism, what you need is an organ for storing air (kind of like an air bladder in fish) with two properties: rigid and sturdy enough to ...

4

Spoilers The spoiler on a racecar is designed for exactly the purpose you describe - the downward force of air hitting it it increases the apparent weight of the vehicle, increasing the amount of friction between the tires and the road, and allowing the car to take corners faster or more tightly. Since it only increases apparent but not actual weight, it has ...

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Dark matter is responsible for temporal refraction of photons: while for ordinary refraction we see the beam of light slightly changing its direction of propagation in space, for temporal refraction we would see changing its propagation in time, meaning that we would either see the beam appear from nowhere or disappearing without any sign. The disappearance ...

3

Another option is "hiving": several creatures can emerge into a bigger thing (via glue-like skin coverage that is exposed as a reaction on dangerous situations). That naturally leads us to a condition the creatures are not lone wolfs and live by colonies/communities like sea gulls etc.

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They can have jaws big enough to promptly consume a dozen of surrounding turf and elastic belly (like deep-water fishes) to accommodate it. Then, just eject the turf back if it's not required anymore. So, the idea is close to gators eating stones to adjust their weight/volume ratio. To be more realistic, that creatures may habit only places where the turf is ...

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This is entirely possible for an aquatic or partially aquatic creature, by the simple expedient of ingesting a large volume of water, and is readily reversible by ejecting the ingested water. In fact, puffer-fish rely upon this mechanism to inflate their bodies and erect their defensive spines. Squids and octopi also rely upon this mechanism as a source of ...

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To change your effective weight in Earth gravity and atmosphere, you need to add or reduce lift force. Mechanical lift is easiest to achieve, so the most realistic answer to your question is: birds! They "gain weight" when they land. For other kinds of lift you can design different kinds of animals, all of whom are very much fictional and less than ...

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