Earth simulation games

We set the initial distance to be equal to the length of the astronomical unit AU , which is the average distance between the Sun and the Earth. The first time derivative of the distance, or the speed of the Earth, will be zero. Note that this is the speed of the Earth in the direction of the Sun, not the speed in the direction of the orbit. The initial conditions describe the system at the start of the simulation.

As time changes the Earth will move and the four parameters will change as well. Therefore, in our program we need to store the current state of the system, which is represented by the same four values: position, angle and their time derivatives, or speeds. We have set the initial conditions for the distance r and we know how it evolves from Equation 5. Now we can simply write this equation in our program as a function calculateDistanceAcceleration that computes the second time derivative of the distance r given the current state:.

Similarly, we write the second equation of motion Equation 8 for the angle as a function calculateAngleAcceleration :. For example, the method allows to compute the distance from speed. Similarly, it can give us the speed from the acceleration. Luckily, this is exactly what we need in our simulation.

Equations 5 and 8 give as the accelerations for the distance and the angle respectively. And by repeating the same trick again, we can find the distance and the angle from their speeds. To do this, we write a function called newValue.

It computes the new value of a physical property by using its derivative and the time increment deltaT :. In our program, the value deltaT will be a very small time increment, about 90 seconds, which will allow us to approximate the motion of the Earth with reasonable precision.

Now we are ready to bring all pieces together and write the code that computes the distance r from its second derivative. First, we use the function calculateDistanceAcceleration to calculate the acceleration r. There are very few people on the earth but you survived.

Escape and kill as many aliens as possible. Keep and eye on your radiation level and take anti-rad meds with X to reduce your rad count. Much fun! Flash Games. The Scale of the Universe 2. Bring the sun closer. By changing the display date, by default, the whole scene is redrawn and you can see the rotation of the earth with respect to the sun.

If you prefer, you can fix the earth on the camera and it will seem that the sun rotates around the earth, but you will not lose the current point of view. Fix earth. When drawing the universe, the earth, the sun and the moon are made according to the size of your browser window. If for some reason the size of the window changes you have resized the browser or rotated the device the display proportions may be lost. In this case, use the following option to redraw the entire content without having to refresh the page.

Total lunar eclipse May 26, Total solar eclipse April 8, Total solar eclipse August 12, All the solar eclipses of the 21st century. Total solar eclipses.