42
votes
Accepted
35
votes
Accepted
Interstellar Image Effects
This was a fun question to answer, even considering that I know nothing about general relativity. It's all a matter of translating the equations presented in this paper by Oliver James, Eugenie von ...
- 67.3k
28
votes
Accepted
Interpreting Mathematica code on black holes
I managed to debug the code from KerrOrbitGRProject and reproduce the results for the Schwarzschild metric (figures on pp. 7-8)
...
- 42k
20
votes
Can I create a radar chart of sunrise/sunset times for a year
Download and learn Package for Radar Charts.
Import["http://tinyurl.com/ntmhkca"]
Load package:
Needs["RadarChart`"]
...
- 71.9k
14
votes
14
votes
Beautiful dance of the Earth and Venus around the sun
Here's something that is nowhere near the sophistication of the original, but might get you started.
The following assumes an orbital period for Venus of 225 days (thanks Michael!), and an average ...
- 65.8k
13
votes
What is the closest star to Earth other than the sun?
To clarify why it is that your command did not work, here is what your free-form input was translated to:
...
- 488
13
votes
Accepted
12
votes
Accepted
Extracting and displaying data from GW150914 hdf5 files
My first question is: is it possible that the import is discarding the
timestamp data?
The relevant timing data is contained in the attributes of the ...
- 136
12
votes
Accepted
Speed up NDSolve compared to Python (calls to LSODA)
First question.
I'm pretty sure that the difference is due to what happens with machine underflow. As of V11.3, underflow goes to machine zero instead of to arbitrary-precision numbers (as it does in ...
- 234k
11
votes
Accepted
Plotting how sunrise times change over the year
Importing and converting the data
Import the data (replace "path_to_the_downloaded_file.html" with the file path of the actual ...
- 4,644
11
votes
Processing images from NASA's Juno Jupiter Orbiter
You might find the functions ColorToneMapping and BrightnessEqualize useful, as well as modifying gamma in ...
- 13k
10
votes
Accepted
GeoGraphics - mapping the Moon
I think you are looking for the GeoCenter option to GeoGraphics.
...
- 65.8k
9
votes
How to speed up plotting with PlotPoints?
It's a listable expression, so you can plot it with a high precision fixed step size very quickly:
...
- 70k
9
votes
Accepted
Calculate moonrise
f[x_?NumberQ] := MoonPosition[DateObject[{2016, 9, 28, x}]][[2, 1]]
FindRoot[f[x], {x, 12}]
{x -> 17.5595}
...
- 23.7k
9
votes
Accepted
Does SolarEclipse only cover a limited date range?
When this data was originally curated, NASA was providing polygon data for a subset of the eclipses in their catalog.
Since then, NASA has changed their site, and they now give the Besselian ...
- 67.3k
9
votes
Accepted
N body simulation
Solving the problem requires high accuracy in determining the initial data. All parameters can be determined using ...
- 42k
8
votes
Composition: how to make a day and night world map?
Since version 10.0, the functions DayHemisphere[], NightHemisphere[], and ...
- 124k
8
votes
Beautiful dance of the Earth and Venus around the sun
With the caveat that it has zero physical meaning whatsoever, here you go:
...
- 15k
7
votes
The Orbit and Perigee of the Flamsteed comet
I've decided to write the "modernization" of my old code as a separate answer, to keep the previous answer (relatively) uncluttered. Overall, I've found the need for gymnastics related to ...
7
votes
Accepted
Orbit followed by a particle around Schwarzschild Black Hole
Solution 1
The equation can be solved with Method -> "StiffnessSwitching", together with a higher WorkingPrecision:
...
- 63.8k
7
votes
Accepted
Select Specific StarData
You can use:
StarData[
EntityClass[
"Star",
"DistanceFromEarth" -> Between[{Quantity[100,"ly"],Quantity[200,"ly"]}]
]
]
or:
...
- 130k
7
votes
Solar Power Calculations
This is because of the value of β becoming negative. If we replace the Arcβ definition with the following:
...
- 13k
7
votes
Accepted
Detect sub figures and split (automatically?)
ImageAlign should probably be at least part of the solution:
...
- 70k
6
votes
Solving the path of Earth around Sun
Eliminate the unnecessary force* variables, which forces NDSolve to use the DAE solver, and just solve it as an ODE. Then you ...
- 234k
6
votes
Series solution of the Lane-Emden equation
Here's a starting point (borrowing the notation from here):
...
- 124k
6
votes
Extracting and displaying data from GW150914 hdf5 files
TemporalData has a straightforward way of adding timestamps to data. Using your variables:
td = TemporalData[hlosc, {start, finish}]
Extracting a 5 second ...
- 1,848
6
votes
Accepted
Mass distribution in NDSolve
Because the Asteroid belt's mass is negligible (only 4% of the Moon's mass), it is not very efficient to include it in your simulations. However, if you still want to include it in your simulations, I ...
- 557
6
votes
Accepted
How to speed up plotting with PlotPoints?
Note that with n=1000 you have 500 revolutions.
MaxRecursion is the go to here, I tend to ...
- 8,557
Only top scored, non community-wiki answers of a minimum length are eligible