Comments on: Beyond The Cold

By: K.J.

K.J. — Mon, 15 Aug 2016 20:05:21 +0000

You are correct…landing on a Neutron Star will break the ship down to neutrons itself and become part of the star. Thanks for adding that, i appreciate it.

By: Jean Tate

Jean Tate — Sun, 14 Aug 2016 21:38:44 +0000

Pretty good. The surface gravity of a neutron star and a white dwarf are similar, some 10^11 times that here on Earth (the neutron star’s is greater, but only by a factor of a few).

Landing on a neutron star you and your spaceship would be reduced not only to a pancake, but the atoms and their nuclei would be reduced to (mostly) neutrons. On a white dwarf, atomic nuclei would retain their identity. One difference is that a white dwarf has (or can have) a stable atmosphere (albeit a rather odd one), whereas a neutron cannot (well, without getting really nitpicky about the definition).

By: Jean Tate

Jean Tate — Sun, 14 Aug 2016 21:31:05 +0000

If you use a particular definition of temperature, to do with how populated each accessible energy level is, in a system, then negative temperatures are possible; they occur when there is a ‘population inversion’. Such population inversions occur in lasers, so when the lasers in your CD drive fire up, they produce negative temperatures! :O

@C.R. Because the way the definition of temperature is written, getting below 0 K is impossible (except for the population inversion systems I mentioned above). This is more easily understood by considering that temperatures are ‘really’ logarithms, so just as you cannot get to infinity (or minus infinity), so you cannot get to 0 K (the log of 0 is …). Units in physics aren’t usually so ornery 😉

By: Brian Koberlein

Brian Koberlein — Sun, 14 Aug 2016 20:32:06 +0000

There would be some energy lifting it, but in terms of the thermodynamic energy it wouldn’t matter. If white dwarfs were made of matter in a classical arrangement, then it could get colder than absolute zero. There’s a similar issue with black holes, in that quantum theory seems to save the day.

By: C.R.

C.R. — Sun, 14 Aug 2016 15:31:59 +0000

Also true ‘Absolute Zero’ would be when all atomic (and sub-atomic) movement stops. How can anything be ‘less than stopped’? (Turns to antimatter?).

By: C.R.

C.R. — Sun, 14 Aug 2016 14:51:15 +0000

If a chunk of cold neutron star could be lifted off the star’s surface to a point that it would then expand, would it not be gaining much potential energy? (Think a rock on the bottom of a hill then lifted to the top of a hill). Further, once the neutron matter was no longer confined, would not the ‘expansion’ be a tremendous explosion with much friction? This seams to be at least two sources of energy to prevent the cold chunk from any possible tendency toward a colder temperature, and likely the opposite – toward much higher temperature.

By: K.J.

K.J. — Sat, 13 Aug 2016 15:14:38 +0000

It depends on how dead the star is, and what type of star it once was 🙂

– A stellar Black Hole is a dead star. You know what happens if you set course towards one with your spaceship
– A Neutron Star is a dead star. Land there and you and your spaceship will become as flat as a few atoms thick…a mega pancake spread over its surface
– A White Dwarf is a dead star. I never calculated its gravitational force and tidal forces, but i guess the outcome is simular to the Neutron Star
– If they are real, a Quark Star is a dead star. Even worse for your spaceship as the Neutron Star. (It might be an in-between Neutron Star and Black Hole object)
– Smaller stars that die, might cool down enough and have survivable gravity. But a star is roughly 75% hydrogen, 25% helium, and at most 1 or 2 percent heavyer elements (metals). Do not add up the percentages i mentioned to 101 or 102, i said “roughly” :-). The ship would have no surface to land on…simular to Jupiter

If i made errors or forgot an object we could consider a dead star, someone pls correct. Thanks in advance
Regards

By: rob krol

rob krol — Sat, 13 Aug 2016 14:52:19 +0000

in many old SF story is idea that spaceship landing on the dead cool stars is that posible?