A Question About Pulsars

[Hannu2]

16 hours ago, magnemoe said:

Yes, however its an high chance that an close flyby would mess up the physic a lot.

There could be minimum altitude which would destroy the craft like Kerbol does. Official explanation could be radiation or magnetic field. Limit would be set so that physics do not break. I think that there are no good reason for more than couple of hundreds of km/s orbital velocities. Everything above that would be just huge numbers in mod's code.

[ThiccRocketScientist]

It is extremely hard for tidal forces to effect things on the small scale like humans, because in orbit one part of you must be going faster than the other part for your atoms to be torn from one another (in the case of a neutron star or black hole) somewhere on Earth, a few feet is very little difference in terms of velocity, but I suppose on a black hole or neutron star a foot could be a few tens of meters per second? Am I thinking of this right?

[Hannu2]

Compact stars are insanely extreme objects. Gravitational acceleration is a = GM/r^2. Derivation gives change of acceleration per length da/dr = -3*GM/r^3. If we assume solar mass and orbit with radius of 1000 km, da/dr = 400 (m/s^2)/m. So, if astronauts height is 2 m his head is ripped apart from his toes at 800 m/s^2, which would certainly be fatal. But probably radiation and magnetic fields would have killed him far before tidal forces in real life.

[kerbiloid]

We should never forget that "near" a neutron star or a star-mass black hole means "deep inside" a regular star of the same mass. The hell stays on its own place, but got transparent.

[monophonic]

9 hours ago, kerbiloid said:

We should never forget that "near" a neutron star or a star-mass black hole means "deep inside" a regular star of the same mass. The hell stays on its own place, but got transparent.

No, worse actually at least from a gravity point of view. See shell theorem. Pressurewise things might be harder if actually inside a star.

[kerbiloid]

7 hours ago, monophonic said:

No, worse actually at least from a gravity point of view.

Usually deep inside a star not the gravity is a problem, but multimillion temperature of electromagnetic chaos.

[MichaelPoole]

On 19. 1. 2017 at 4:57 PM, p1t1o said:

Whatever combination works best with KSP physics.

It could even have full-blown planets orbiting it, SOIs would be much smaller, yes I can see it being an interesting environment to add to KSP.

Question: what is the luminosity of a neutron star like? Would it shine like a sun or be more a dull glow? Or even dark?

The surface of neutron stars is millions of degree high, so a bright dot.

By the way, try Universe Sandbox 2. A pulsar at a range of several thousand kms will not just tear humans apart, but super-Jupiter sized planets will start to break apart in seconds. Earth would be literally destroyed in seconds by the heat and tidal forces, when I put it like 10 000 km from the Crab pulsar it went up to 20 000 degrees Celsius in a few seconds.

If you were in a spaceship really close to it, you would probably experience the fastest death possible for a human being. Your neurons would be plasma before you registered anything.

That being said, due to their small size, they are not unthinkably bright. PSR B1257+12 for example has planets around it and a luminosity of 5.2 Solar, much of which is gamma and X rays. If Kerbol was in a binary system wirh the pulsar being in the Oort cloud, it would probably not be disruptive and would be seen as just a random suspiciously bright blue star in the sky. At that distance the ionising radiation would be very weak too, courtesy of inverse square law. The reason why it is more destructive than the Death Star from close up is because it would be like approaching Sun's core at a lesser distance than between New York and Tokyo.

That being said, I am not sure how complex life on Kerbin survived the supernova explosion that made this pulsar.

Edited January 24, 2017 by MichaelPoole

[tomf]

Unfortunately I'm pretty sure KSP uses the distance to the COM to calculate gravity so you aren't going to get any tidal/spaghettification effects. Which is a pity, because apparently orbits around extremely dense, small objects are pretty interesting.

https://what-if.xkcd.com/68/

 

[magnemoe]

29 minutes ago, tomf said:

Unfortunately I'm pretty sure KSP uses the distance to the COM to calculate gravity so you aren't going to get any tidal/spaghettification effects. Which is a pity, because apparently orbits around extremely dense, small objects are pretty interesting.

https://what-if.xkcd.com/68/

 

Yes, KSP uses center of mass, this can be exploited, have an long ship in orbit pointing away from Kerbin or other body, pump all fuel to top of ship, this moves COM upward, rotate ship so fuel is closest to Kerbin and repeat this, to raise orbit. 
With an rotating setup and automated pumping you can even make an working reactionles drive. This does not work in real life. 

[kerbiloid]

Instead of a tidal breaking pulsar, in KSP one can implement its close analog: krakulsar.
A small sphere with many-many polygons. Once a ship gets close to it, it (ship) immediately bursts apart.

Upd: btw it makes relativistic effects, too. The closer you are - the more FPS drops down.

Edited January 25, 2017 by kerbiloid