Posts by HDE 226868
How far and how well will sound travel through the sea? First, we need to figure out exactly what the sea is made out of. You've indicated that it's sulfur, but what kind of sulfur? Lopes & Wi...
I was rereading The Restaurant at the End of the Universe, the sequel to The Hitchhiker's Guide to the Galaxy, and I came across an interesting passage: Flare riding is one of the most exotic a...
That's no planet! Let's say that the radius is $18R_{\oplus}$, where $R_{\oplus}$ is Earth's radius. The volume will then be $$\frac{4}{3}\pi(18R_{\oplus})^3\bar{\rho}=5832\left(\frac{4}{3}\pi R_{...
So . . . modeling the space near two close black holes is actually a really, really tough task. Numerical relativity is extremely challenging; a good example is the intense computations it took to ...
Consider a short-period comet (specifically, Comet Encke). Pros: Very short-period comets can have orbital periods of only a few years, with approaches relatively close to Earth ($\sim0.1\text{ ...
I can give you a Newtonian analysis of the situation, which may or may not be correct. If you want a Newtonian universe, then great. If you want a general relativistic one, you'll need something mo...
The best way to study water waves of many sizes is to use Airy wave theory (see also here), a mathematical model using several simplifications that nonetheless produces reasonable results. The line...
Let's look at the two extremes: $\Delta T=15^{\circ}\text{F}$ and $\Delta T=40^{\circ}\text{F}$. In the first case, I'll say $T_{\text{min}}=50^{\circ}\text{F}$ ($283.2\text{ K}$) and $T_{\text{max...
Have you ever heard of the Einstein-de Haas effect? Take a large piece of iron, cylindrically shaped. Now, put it in an external magnetic field. The bar should become magnetized. Given that magnet...
Although astronomers have considered this phenomenon in the past, the data indicates that this isn't how stars are born. That said, yes, your premise works. Here's how you make a star, in a nutshe...
I'm considering a story where an exploration is devised to explore a binary system containing a black hole; the choice is Cygnus X-1, with its companion supergiant star HDE 226868. It would likely ...
Asimov's laws of robotics are not technical laws; they're societal laws, imposed by humans to ensure that robots don't destroy mankind. You can make a robot that breaks any of them, still using or...
This has indeed been investigated. I found a thesis by Daniel Jontof-Hutter (2012) that did a stability analysis of particles in rings orbiting, among other bodies, Saturn. One important quantity h...
Try radiometric dating. Accuracy: $\pm0.11\%$. Radiometric dating - see also the excellent USGS page - uses the decay of radioactive isotopes of elements to determine the age of a sample. It works...
I recently finished reading the Kim Stanley Robinson novel 2312 - set, of course, in the year 2312. Part of the background to the political negotiations and ongoing terraforming in the outer Solar ...
The change in pressure below the ocean is approximately $$\frac{dp}{dz}=\frac{1\text{ atm}}{10\text{ m}}$$ where $z$ is measured from the surface of the water downwards. We also have to add in the ...
When will the planet break apart? A solid body will break up if the centrifugal force at a point is equal to the gravitational force. At Earth's equator, the equation becomes $$\frac{GM_{\oplus}}{...
I came up with some basic ideas before posting the question: Space weather Radiation problems can severely damage a spaceship's instruments, making navigation and flight severely dangerous or imp...
This is, for the record, the same universe as in Is space piracy orbitally practical? and How can I prevent Kessler Syndrome among space stations?. In my world, circa 2100, space stations orbiting...
I'd suggest that they may lose at least partial immunity to a decent extent within a decade or two of leaving Earth. According to Smith et al. (2014) (explained for us laypeople here), the number ...
Give it a circumstellar cloud of oxygen. Some planetary nebulae, such as NGC 6826, appear green because of ionized oxygen. Image in the public domain. Yes, this is a true-color image. I see no...
Let's imagine that the hottest part of the apparatus is the barrel, so to speak, which is cylindrical with length $l$, radius $r$ and temperature $T_b$. We can surround it with a fluid of temperatu...
They could still tell the difference. A non-inertial frame involves acceleration of some sort, i.e. non-uniform velocity. Such a frame can certainly have uniform speed, but the direction of motion...
In a world I'm building - the same one as in Is space piracy orbitally practical? - there are many space stations in low Earth orbit, used as orbital spaceports, each about ten times the size of th...
Note: This answer assumes that those going to Mars have a high IQ (which I believe the OP intended), and that IQ is indeed a fairly good measure of intelligence. Yes. I think the question of th...
