Speed of Light

[pman]

As a demonstration, I'd like to be able to start at the sun and travel at the speed of light toward earth. It seems like this should be easy, but I haven't found it to be so. Any suggestions?

Thanks very much;
pman

[Verteiron]

Start Celestia. Press H to select the Sun. Hit G to go there. Now press 3 to select Earth (3=3rd planet). Now press F4 to change your velocity to c.

Now wait about 7.5 minutes

[Verteiron]

One thing I forgot, after you hit 3 to select earth, press C to center it. NOW you're all set.

[pman]

Thanks; I'll give it a try.

Next step is showing that Warp 10 isn't so hot when you're trying to get from one star system to another ...

Regards;
pman

[Trien]

Which scale?

IIRC on the 'new' scale, Warp 10 = infinite speed...

[pman]

There is only one scale.

So traveling from the sun to the earth at the speed of light, is there any way to swing around and view the sun receding? It appears you can only go in the direction you're heading.

Sorry for all the navigation questions; I'm still learning...

[ou8poop2]

All you need to do as you are traveling is to hit H again, and then C for center. that will place the sun in your field of view as you recede.

Don't worry about learning the different functions of Celestia; we ALL had to at one point!!

[pman]

Thanks to everyone for the help!

Looks to me like it's the combination of T and C that changes your view and direction. Traveling toward earth:

[H][C] turns you around and heads you back toward the sun;
[H][T][C] turns you around and lets you see the sun receding.

Way cool.

[Phule]

Start Celestia. Press H to select the Sun. Hit G to go there. Now press 3 to select Earth (3=3rd planet). Now press F4 to change your velocity to c.

Now wait about 7.5 minutes

When I do this, I get a zoom to Earth, then I zoom past Earth going at the speed of light.

I am running Celestia 1.25pre6. P4 2.0ghtz, 512mb, g4 ti 4400.

Correction:
When I do this, I get to the Earth in less than 3 seconds, then fly past the Earth.

[selden]

I think zooming past the Earth is correct. The two methods of changing your viewpoint (GoTo vs Spaceflight) are not the same. If you want your "spaceship" to stop at the Earth, you have to decelerate by typing "F1" (speed=0) as you go speeding by.

The equivalent command in a script would be "move", which does allow you to specify both duration and velocity.

See http://63.224.48.65/celestia/docs/scripting.html

[Verteiron]

One thing I have noticed using my technique above: yes, you will miss the earth. This is because during the 8 minutes or so of travel time at c, the earth has moved from where you last Centered on it!