New answers tagged

13

No, they can't. To make a transistor you need to be able to smelt and refine to high levels of purity specific materials like Silicon, Germanium, Boron, Phosphorus and the like, and for some of them you even need a specific crystallographic set up. While Silicon and Phosphorus are easily found in their bound state, refining them is beyond the capabilities ...


0

You need a complete redesign, but a weapon firing plasma 'bullets' is feasible and was built (albeit on a larger scale) by the US military in the 90s. It also had one of my favourite acronyms: Magnetically accelerated ring to achieve ultrahigh directed energy and radiation for MARAUDER. The secret is forming the plasma into a vortex ring, essentially like a ...


1

It's pure handwavium... but it's not completely absurd. As noted in Christopher's answer, powerguns work via a hand-wavium reaction that generates plasma from a specially formed matrix of "stuff" (that probably qualifies as a metamaterial). Now... we've known how to achieve partial matter to energy conversion since at least World War II. We know there are ...


4

The "copper-cobalt charge" depends on a completely fictional phenomenon that converts those elements directly to energy. The mechanism was described in The Tank Lords: Weygand determined that metallic atoms of a fixed magnetic orientation could be converted directly into energy by the proper combination of heat, pressure, and intersecting magnetic fields. ...


0

Coincidentally I just watched a Scott Manley video on this topic published in May 2018. A small asteroid called 2015 BZ509, and a large gas giant named Jupiter have a resonance in their orbits which is self-correcting. Every time they approach, if the smaller body is too fast or too slow (that is, early or late) the influence of the larger body applies a ...


2

Short answer : Hormones and Chemicals Linked with our Emotion Everything you need should be found in that link, including any information you need to fine tune your description of the effects .. find the hormones most closely associated with effect you want then adjust your expectations of the pathology & symptoms to match their effects. Here's a ...


1

The general main challenges with fighting bacterial infections are: Don’t kill the good guys: First of all, you obviously do not want to kill the human host, but since bacteria are a completely different branch of life, there are lots of bacteria-specific angles of attack here. The bigger problem is that only a small fraction of bacteria is actually harmful,...


24

NASA recently discovered a very interesting resonant pair in two moons of Neptune, Naiad and Thalassa. Their orbits (nearly <2000km) intersect and have periods of 7 and 7.5hrs respectively. Even though they are quite close at nearest pass (<4000km) they never actually collide because of this ”unprecedented” 69:73 resonance. This resonance was ...


0

Let's make your planets more complicated: Each one is a hollow sphere, but with a sphere of inside it. Think tennis ball inside a softball, but probably closer in size. The shell then has the job of contain the atmosphere. This allows you do do some cool things: The visual distance in air at sea level pressure is 50-100 miles max. So if the space ...


30

You should have a look at Janus and Epimetheus. They are two moons of Saturn that exchange orbits every once in a while. This setup is probably not stable for more than a few billion years but it might do for what you want. Epimetheus orbits closer to Saturn, so has a shorter orbital period and eventually approached Janus from behind. As they get ...


2

Oh, maybe that is what the magic is about. Under normal circumstances, you can't have perfect synchronous orbits. Suppose the orbits are, to pick numbers, 1000 hours and 10,000 hours. That's about 40 days and about 400 days. So whatever is supposed to happen at the first coincidence might be off by some tiny amount. This tiny discrepancy grows for 400 ...


51

Ok, so you say 'Harmonic Orbits', but actual Space-Talking-Dudes call that 'orbital resonance', and it's the solution to your problem. We've got an example of something ALMOST exactly like what you're talking about right here in our own solar system with Pluto and Neptune. As puppetsock rightly points out, their orbits don't actually intersect because of ...


0

So the short answer is that any hollowed out object no matter how big will have zero gravity on the inside (even with an atmosphere on the inside). And no matter how distant the two structures are, over a LONG period of time, they will eventually impact each other. Thanks for you help.


0

1. It depends upon the the contents of the structure, but the shell will not exert any net force on objects inside. but as you go down towards the centre the gravitational force would decrease proportionaly. 2. If the bodies are stationary with respect to each other then there is no safe distance, it would just be a matter of time. That could even be ...


2

The people inside each hollow Earth will experience no gravity. This is due to the Shell Theorem. A non-hollow planet does not suffer this effect. In simple terms: in a non-hollow planet, as long as you are not on the mass center, there is always more mass pulling you to the mass center than otherwise. On a hollow, symmetrical planet, if you calculate the ...


1

You are talking about planets that are near each other somehow, so I'm going to draw your attention to this concept. A roche limit is the distance within which a celestial body, held together only by its own force of gravity, will disintegrate due to a second celestial body's tidal forces exceeding the first body's gravitational self-attraction. There's ...


0

According to the Shell Theorem, a spherically symmetric hollow sphere will always have zero gravity inside, so the people experience no gravity at all, unless they live on the outside or within the shell itself (where gravity will linearly fall off going inside). On the outside, gravity will be far below earth normal, because a hollow sphere of earth mass ...


3

You don't need to simulate the whole organism. Most bacteria don't "attack" as such, they just...are. That existence produces either waste products that are harmful (think botulism) or trigger the host into some response that is harmful. (think flu causing fever) So the problem with simulating a disease is not simulating a cell but figuring out what it is ...


4

It all depends on the accuracy and resolution of your simulation. Ultimately it’s not possible to create a perfect model of a pathogen due to the uncertainty principle operating at the lowest level of resolution in any model. That said an enormous amount can be learnt from simulations at all scales depending on what you are interested in. The secret is in ...


1

When gravitational waves reach Earth, they usually give a strain of $\delta L \over L$$=10^{-21}$. If we assume that they scale with the distance the same way electromagnetic waves do, thus following the inverse square law, we can get an estimate of the distance needed. LIGO detected the first merger of black holes at 1.3 billion light years away. If we ...


4

I think I can now answer my own question, having come across some decent references I hadn't found before asking it. I found the equation for the gravitational strain $h$ - the proportional change in length of an object due to gravitational waves from a mass $M$: $$h \approx {{GM} \over c^2} \times {1 \over r} \times {v^2 \over c^2}$$ (Source of formula) ...


6

TL;DR: Pretty unlikely. The objects are small (and hence faint), there aren't very many of them (astronomically speaking) and they're moving very fast so there isn't much time to spot them. Even if you knew they were coming, it might be tricky to catch a glimpse of them with today's technology. Basically, it would depend more on luck than judgement. If a ...


0

This answer comes from more of a video-gaming background than a physics background, but a pulsed particle burst typically means a heavy, punishing ball of particles that does a lot of instant damage. Usually those move at speeds comparable to conventional projectiles and you need to aim ahead. A beam particle weapon is typically continuous and hitscan (hits ...


0

At first, it may seem crazy, but yes. Alexander Bolonkin seems to have an idea on how to do this: http://vixra.org/pdf/1309.0200v1.pdf


2

Simply put, sane or not, if he were any scientist worth his salt, he'd understand that he cannot make a day any closer to the 86400 seconds that it currently is defined as. How precise can we be? The length of the year is ~365.2422ish days. This is the oft-cited duration of a tropical year, the "mean time between between vernal equinoxes", but is in fact ...


9

Lets first think about how much energy this needs. You've asked for spurious precision, but I'll save that til the end because no-one wants to see all the tedious decimal places in the workings (and if they do, they can repeat the process themselves). You want an orbit with a period of precisely 365 days, each 24 hours long. Via Kepler's third law, we can ...


3

The Earth is rotating too slowly for our scientist's liking, and it's also getting slower all the time due to gravitational tidal drag and other factors. This is currently happening at a rate of about $\mathrm{7.3×10^{−13} day/day}$, which is also the fraction by which the Earth's angular momentum needs to be topped up. Let's specify the propulsion system ...


4

Explosives on the Earth's surface, no matter their power level (short of ejecting significant chunks of the crust) will never change the Earth's rotation rate or orbit. Nor will a reaction drive of any kind -- with the exception that if its exhaust, after exiting the atmosphere, is still above Earth's escape speed, some tiny fraction of its thrust will act ...


2

This doesn't work around Sol, at the very least. You calculated that a mega-Jupiter (13 Mj) would have the right angular diameter at ~49M km, which is right around 1/3rd AU. For it to eclipse the sun (which needs to be 1AU away to have the correct angular diameter) then the mega-Jupiter would need to be orbiting the sun with a semi-major axis of only 2/3rd ...


2

I note that astronomical bodies are requested with diameters and distances that give them angular diameters of about 0.5 degrees. An object will have an angular diameter of about 0.5 degrees when it is at distance of about 114.59165 times it's diameter. The first thing that Overlord - Reinstate Monica should realize is: The length of seasonal cycles on ...


3

I'm pretty sure it can't be done with a gas giant. The problem lies in the stability of the habitable moon's orbit. An object's orbit around its primary is stable as long as it is within the Hill sphere of the primary (the region dominated by the primary's gravity), while being outside the Roche limit (the distance at which tidal forces will break the ...


6

TL;DR: maybe. Orbital stability is pretty borderline, and some fairly unlikely circumstances have to arise to produce something that looks like maybe it will fit your needs. Tidal effects and orbital resonances will mess with the figures below, so they're only approximate Lets start with a star the size of the sun, putting the orbit of the planet at 1AU. We ...


2

No, Even if the nano particles could retain their magnetic properties, what you would have done is released a bunch of particles that are free to orient themselves and connect with other particles. They would quickly collect into a mass and fall, raining out of the air. The further they had to fall, the larger they would become.


5

No, nanoparticles will not retain the magnetic properties of the bulk material, as they will lose their constructive force without being physically locked to the same polarity with regards to each other.


2

Why not just go down the modern route, and coat your drawn copper wire with cresol lacquer, derived from coal tar or creosote? These substances are reasonably commonly available, and have been known for thousands of years, from the pre-Christian era. Having worked (albeit briefly) in quality control at a factory producing copper transformer wire - exactly ...


1

You need a MIX of solutions. Your solenoid needs to have many windings, which means multiple layers. Traditionally, wax-paper was used between layers, and I believe still is. The next insulator is spacing. On your innermost layer, use a slightly larger diameter wire, not for conductivity, but to set the spacing of all subsequent layers. Now they won't be ...


18

There's actually a (beyond minuscule) loss of mass when fuel is burned. Your figures aren't much off for gasoline -- the extra mass comes from oxygen in the air. To oversimplify, let's assume gasoline is pure octane, C8H18 (molecular weight 114). To fully combust, it'll need 25 oxygen atoms (two for each carbon, and one for each pair of hydrogen), ...


6

Take assorted hydrocarbons from the gasoline. As the name suggests, they consist mostly of carbon and hydrogen, and by weight they are mostly carbon. Burn it, and one $C$ (carbon) atom bonds with two $O$ (oxygen) atoms from the air, forming $CO_2$. Each $O$ atom is about 1.33 times the weight of a $C$ atom, which means each $CO_2$ is only 27% carbon by ...


3

With the large amount of CO2 generated by the burning gas, there could be a multitude of uses. 1.A) Terraforming, specifically on planets with little/no atmosphere, could use the quick greenhouse gases(though not practical) 1.B) The military could use it to gas-out areas that are crucial to capture or to kill/capture the opposing forces.


2

Dredging through long-ago memories of my time in a laser lab... One critical reason for pulsed beams for cutting or weaponry lasers is to allow literal physical detritus to exit the beampath - there's a nontrivial outpuffing of small particles, splinters and fragments, and vapour of the target material at the beam impact point as the surface reaches a boil-...


2

Use varnish to coat the wire. You can get it from a cabinet maker. I've done this before and it works.


0

Send me the technical details of your temporal communicator and I'll make one and relay your message for you to your original time and they can send a rescue party to you with a spare solenoid... and it doesn't matter to you if it takes me a few years to complete the build as you'll still be rescued shortly after you send me the details! Alternatively, you ...


3

I think you could use grape juice thickened with flour. Both materials should be available in a medieval context (and long before that). It dries to a rubbery texture and you could run the wire through a trough of it a few times to ensure full coverage. To get an idea of the finished appearance, consider Georgian Churchkhela. You would want it thinner, of ...


2

If you remember televisions before they were flat, those had electron beams which created your picture. The secret to making the beam hit an extremely precise target on the screen was by shooting the beam in a vacuum. In any atmosphere, you won’t get a charged particle to go anywhere you want it to. It’s going to find it’s way to the nearest oppositely ...


-1

Accuracy. If you want to get all your electrons to arrive at the same place, you need to account for any interference from magnetic fields. Pulse would fire a discrete projection alike a burst. The accuracy would be better since the deviation from impact is stable. Now a beam would get whacky. A human has a pulse, which is why snipers are trained to fire ...


2

For a star of that mass, you are looking at a G0V to F9V main sequence star. It's luminosity, depending on age, is probably around 1.2 sol, from which you can calculate the bounds of the habitable zone. The inner edge of the zone is around 1.04 AU. The comfortable outer limit is around 1.5 AU. The maximum outer limit is around 1.86 AU. Your planet's moon,...


1

Since you want your world to be a habitable giant moon of a gas giant planet in another star system, an exomoon, you should look up some of the many previous questions about moons of gas giant planets on this site. for example, the most recent such question that I answered was this one: If Earth Were a Gas Giant's Moon1 And you should look up this ...


1

You can fabricate a crude form of cellulose acetate which is a form of thermoplastic. It can be created with cotton and other natural fibers and concentrated vinegar aka acetic acid. Both of these substances would be relatively easy to obtain. If the solenoid can be activated by mechanical means instead of electrical. That is moving the piston by another ...


4

Mentioned before leather. Intestines (small-large) best leather for a wire coating. Already a tube just pull it tight and let it dry. Smaller animals smaller tube.


3

Pitch and cloth or paper. the first widely used insulated wire was insulated with asphalt (pitch) soaked cloth. both materials are available in a medieval setting. pitch is widely used by shipbuilders and a dozen other trades and cloth is a bit expensive but not prohibitively so especially for how little you need. Cotton cloth is expensive but nearly and ...


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