At work.

(April 14, 2019 at 6:54 pm)Gawdzilla Sama Wrote:

(April 14, 2019 at 6:39 pm)Peebo-Thuhlu Wrote: Actually, some one of a physics bent could probably work that kind of thing out.

Of course, the numbers would have a deal of 'Error' since we don't know specifics such as Alderan's mean density or composition.

Don't forget that 'Solar sails' are a thing. So... if you have a laser beam... you can push such a sail all the same.

Cheers.

And that's on the receiving end, the light beams impact with the sail and impart kinetic energy. There's no thrust at the origin end.

Uhm.... wait? What?

Lets work through this image again and together.

So... the innitial idea is for the photons cascading off Sun (And up, out of the Sun's gravity well) to be 'Caught' and their momentum harnessed to 'Push' a vehicle.

The advantage is the solar power is an effectivly 'Free' byproduct of stellar fusion. The down side is 'Inverse square law' (?) As you receed from the sun. The amount of radiant power (Photon scatter ?) drops off at a rapidly reduced rate.

So, to 'Push' a solar sail out of the planetary system and not just move around the inner system
You need to build a focussed photon array (A laser) to keep the craft accelerating out into the void.

NOW, of course, we get to the fun part of physics.

If I have a power generator hooked up to a laser then the very act of photons leaving the array will impart a force on said array in the other direction. So, kind of, photon rocket science.

We currently do this the working 'Ion drives' that a couple of little probes are using to move about in our solar system (With Xenon being the operating medium).

I'm pretty sure Scott Manley has a naffy series that covers this side of our discussion when he talks about "So what is rocket fuel?"

Hope that all helps.

Rocket fuel isn't a laser. The rocket engine pushes in all directions. The exhaust goes out the rear end, but the thrust is applied to the rocket itself. And the nozzles focus that thrust. Completely different case.

'Rocket fuel' is actually 'Reaction mass'.

It's the actual action of the mass leaving the vehicle that imparts the motion to move in the other.

An astronaut with a pistol/gun would be under the same eftect. As the bullet and gases go one way the astronaut and gun go the other.

The same (Just different acceleration velocities) with a power supply + laser going the opposite direction to the photons leaving the lens.

Please, go and check out Scott Manly's vids. He can explain it much more entertaingly (And with pictures!) than I.

You need more than one source to get this clear.

(February 12, 2019 at 7:50 pm)Gawdzilla Sama Wrote: If they keep making money they'll keep making them.

I think that it has turned into a space General Hospital; whether it continues to make money remains to be seen.

(April 15, 2019 at 9:18 am)Jehanne Wrote:

(February 12, 2019 at 7:50 pm)Gawdzilla Sama Wrote: If they keep making money they'll keep making them.

I think that it has turned into a space General Hospital; whether it continues to make money remains to be seen.

Too bad it's not Sector General.

(April 15, 2019 at 11:54 am)Gawdzilla Sama Wrote:

(April 15, 2019 at 9:18 am)Jehanne Wrote: I think that it has turned into a space General Hospital; whether it continues to make money remains to be seen.

Too bad it's not Sector General.

Ha!  That is so funny!!  (Seriously.)  Maybe an idea for a children's cartoon?

You liked my joke? Very White of you.

(April 14, 2019 at 9:14 pm)I Peebo-Thuhlu Wrote: 'Rocket fuel' is actually 'Reaction mass'.

It's the actual action of the mass leaving the vehicle that imparts the motion to move in the other.

An astronaut with a pistol/gun would be under the same eftect. As the bullet and gases go one way the astronaut and gun go the other.

The same (Just different acceleration velocities) with a power supply + laser going the opposite direction to the photons leaving the lens.

Please, go and check out Scott Manly's vids. He can explain it much more entertaingly (And with pictures!) than I.

Indeed.


Also, the amount of energy it takes to actually blow a earth sized planet apart, as in blowing a planet apart with more energy than the planet’s mass can absorb with its own gravity, not just sterilize it or melt it, is actually mind blowingly huge.    It’s about 10E32 joules.   It’s roughly equal to the total energy earth’s sun puts out in a week.

Death star’s superlaser seems to deliver that energy in one second or less.  So Death star’s peak power output when firing on a planet must be at least 10e32 watts (that’s roughly a million times the peak power output of the sun for those of you counting)

Now, how much thrust does firing photos at a total power 10e32 watts generate?

I believe the formula is F=P/c.   So recoil force of Death Star’s super laser at the moment of firing is 3.33e24 newtons.   That’s equal to, oh, like, one quintillion times (like a trillion times, but a million times more) the thrust of the Saturn 5 rocket that launched Neil Armstrong to the moon.

So I would say the Death Star would shake and rattle.

Now for added ludicrousity, calculate how many Gs the Death Star would experience if pushed by such a recoil thrust.  Hint, grand moff Tarkin would be a sticky paste on the deck of the Death Star.

(April 16, 2019 at 6:32 pm)Anomalocaris Wrote: Also, the amount of energy it takes to actually blow a earth sized planet apart, as in blowing a planet apart with more energy than the planet’s mass can absorb with its own gravity, not just sterilize it or melt it, is actually mind blowingly huge.    It’s about 10E32 joules.   It’s roughly equal to the total energy earth’s sun puts out in a week.

Death star’s superlaser seems to deliver that energy in one second or less.  So Death star’s peak power output when firing on a planet must be at least 10e32 watts (that’s roughly a million times the peak power output of the sun for those of you counting)

Now, how much thrust does firing photos at a total power 10e32 watts generate?

I believe the formula is F=P/c.   So recoil force of Death Star’s super laser at the moment of firing is 3.33e24 newtons.   That’s equal to, oh, like, one quintillion times (like a trillion times, but a million times more) the thrust of the Saturn 5 rocket that launched Neil Armstrong to the moon.

So I would say the Death Star would shake and rattle.

Now for added ludicrousity, calculate how many Gs the Death Star would experience if pushed by such a recoil thrust.  Hint, grand moff Tarkin would be a sticky paste on the deck of the Death Star.

Of course, Star Wars is a space fantasy rather than proper science fiction, as are most of such movies.