Post by: clueless on 07/09/2021 15:44:15
Post by: Janus on 07/09/2021 16:46:15
Jupiter, the next largest body would form a sphere ~1 km in radius.
Post by: yor_on on 08/09/2021 09:52:34
At a distance, please.
Post by: clueless on 08/09/2021 14:41:31
P.S. I am still having trouble of letting the hot-air balloon go, so if you can think of a certain astronomical body that would indeed (more or less) fit in a hot-air balloon, I'd be greatly appreciated.
Post by: Origin on 08/09/2021 14:53:30
P.S. I am still having trouble of letting the hot-air balloon go, so if you can think of a certain astronomical body that would indeed (more or less) fit in a hot-air balloon, I'd be greatly appreciated.You can figure it out yourself rather easily knowing that the density of a neutron star is
Post by: Janus on 08/09/2021 16:33:40
This is, actually, important, that is to say, I'm ambitiously writing a SF book; so please be precise, if You can do just that, or else I'll end up like Dan Brown who wrote The Da Vinci Code: rich and miserable. Yes. That is very interesting information about the Sun and the planet, and I'm thinking about using it; but - is it 100% authentic? How about at least 70%?The density of an atomic nucleus is 3e17 kg/m^3, So it is a simple matter to take the mass of any body, like the Sun, and work out its size if it had that density. Is it 100% accurate? No, it would actually be an underestimate in size. This is because the type of body that could physically form if you compressed the Sun down would be a neutron star, and the average density of it isn't quite as high as that of a nucleus.
P.S. I am still having trouble of letting the hot-air balloon go, so if you can think of a certain astronomical body that would indeed (more or less) fit in a hot-air balloon, I'd be greatly appreciated.
If we use the neutron star density value as given by Origin, and estimate the volume of a hot air balloon as being the equivalent of a sphere with a radius of 3m, then (roughly), the largest mass it could contain would be ~7e18 kg, There are a number of moons in our solar system that are smaller than that.
But now we come up against the practicality of such a venture. Even if you could compress a body of that mass down to a sphere 3m in radius, you now would have to deal with the fact that the surface gravity would be in the millions of g. If you tried to surround it with a hot air balloon, the material of the balloon would be crushed to the point that it would no longer maintain its molecular structure and would become part of the surface of the object itself.
Post by: Kryptid on 08/09/2021 16:34:17
You can figure it out yourself rather easily knowing that the density of a neutron star is
I'll go ahead and do that.
Radius of sphere from volume = 3√((3 x volume)/(4 x pi))
Mass of the Sun = 1.9885 x 1030 kilograms
vSun = (1.9885 x 1030 kilograms)/(1017 kilograms per cubic meter)
vSun = 1.9885 x 1013 cubic meters
rSun = 3√((3 x (1.9885 x 1013 cubic meters)/(4 x pi))
rSun = 16.807 kilometers
Mass of Jupiter = 1.8982 x 1027 kilograms
vJupiter = (1.8982 x 1027 kilograms)/(1017 kilograms per cubic meter)
vJupiter = 1.8982 x 1010 cubic meters
rJupiter = 3√((3 x (1.8982 x 1010 cubic meters)/(4 x pi))
rJupiter = 1.655 kilometers
Mass of Earth = 5.9724 x 1024 kilograms
vEarth = (5.9724 x 1024 kilograms)/(1017 kilograms per cubic meter)
vEarth = 5.9724 x 107 cubic meters
rEarth = 3√((3 x (5.9724 x 107 cubic meters)/(4 x pi))
rEarth = 242.5 meters
Mass of Moon = 7.342 x 1022 kilograms
vMoon = (7.342 x 1022 kilograms)/(1017 kilograms per cubic meter)
vMoon = 7.342 x 105 cubic meters
rMoon = 3√((3 x (7.342 x 105 cubic meters)/(4 x pi))
rMoon = 55.964 meters
Mass of Ceres = 9.3835 x 1020 kilograms
vCeres = (9.3835 x 1020 kilograms)/(1017 kilograms per cubic meter)
vCeres = 9.3835 x 103 cubic meters
rCeres = 3√((3 x (9.3835 x 103 cubic meters)/(4 x pi))
rCeres = 13.085 meters
Post by: Eternal Student on 09/09/2021 23:02:32
I'm ambitiously writing a SF book; so please be preciseWell how fantastic or science fiction do you want to go, in that book?
The earlier posts have talked about the most dense forms of matter we know about, e.g. Neutron stars.
However, there do seem to be objects in space that are over-dense Neutron stars or what could be described as totally collapsed objects. These things are of course, Black Holes.
Let's assume that to be remotely sensible, the surface of your balloon must be placed around the outside of the event horizon of a black hole. Then we just need to see how much mass we can fit into a black hole with that Schwarzschild radius.
We're going to assume a simple, non-charged and non-rotating black hole - A Schwarzschild Black Hole.
The Schwarzschild radius is given by:
Where G = universal gravitational constant; c= speed of light; M = a parameter that we can think of as the mass contained in the black hole (if we try to keep everything as simple as possible).
I would do the calculations but that would be just tedious. There's an online calculator tool you can use, here's the link to one of those:
https://www.omnicalculator.com/physics/schwarzschild-radius
I don't know if it's actually reliable, just that I'm too lazy to use my own calculator and a pencil.
Anyway, let's take the example Kryptid gave earlier, for an asteroid like Ceres, it would have a radius of 13m if we compressed it into a Neutron star. If we compressed it until a black hole formed, the Schwarschild radius would only be 0.000001 m, which is quite a bit smaller.
Conversely, if you allowed a balloon of radius 13m then we can stuff 8 x 1027 Kg into a black hole to have a Schwarzschild radius of that size. That's about 1010 objects like Ceres, or 4 planets like Jupiter.
Best Wishes.
Post by: Zer0 on 10/09/2021 15:15:13
But is there a possibility the Balloon could be made out of Dark Matter Fabric?
& Possibly propelled by Dark Energy?
Ps - Dark Matter has the Power of slowing down Galaxies.
Dark Energy has the Potential of ripping apart the Cosmos.
Why rely on lame matter, when you got exotic matter at your disposal.
Newyz, All thee Best!!!
👍
Post by: Janus on 10/09/2021 16:24:30
Hmm... perhaps a stoopid thought...Dark matter is "dark" because it doesn't interact electromagnetically (and thus doesn't interact with electromagnetic radiation.) You need electromagnetic interaction to make a tightly bound structure like a fabric. DM can't be made into "things" like balloons.
But is there a possibility the Balloon could be made out of Dark Matter Fabric?
& Possibly propelled by Dark Energy?
Ps - Dark Matter has the Power of slowing down Galaxies.
Dark Energy has the Potential of ripping apart the Cosmos.
Why rely on lame matter, when you got exotic matter at your disposal.
Newyz, All thee Best!!!
👍
Post by: clueless on 11/09/2021 18:33:12
Post by: Zer0 on 17/09/2021 20:34:33
😊
Mmm...but Dark Matter interacts with Normal Matter.
Like by providing it extra mass?
Why can't a balloon cloud of Dark Matter engulf a small solar system.
& Did that Chandra Yan from NASA really detect Dark Matter clouds interacting with it's ownself?
🤔
U know, i feel like the Universe in itself is like a balloon.
Won't Dare use the term GOD...
But sumthin or sumone seems to be really blowing hard onnit yaa!
🤭
(Wish the was an alternate hypothesis which could negate Dark matter & energy n just explain the Universe in a simpler format.)
Anyways, Thanks!
🍭
Post by: Halc on 17/09/2021 21:59:42
but Dark Matter interacts with Normal Matter.Dark matter does not provide anything with extra mass any more than a planet adds mass to the star it orbits. But the mass of the dark matter affects spacetime the same as ordinary matter, so all matter, dark or not, is attracted gravitationally to each other.
Like by providing it extra mass?
Quote
Why can't a balloon cloud of Dark Matter engulf a small solar system.Dark matter doesn't clump into clouds with local density. To do that it would need to have to slow down as it fell into its own gravity well, and it can't slow down if it can't interact. So the speed of any particular bit of dark matter tends to be greater than the escape velocity of any local object it happens to find itself in the vicinity of. The deeper the gravity well, the more likely that dark matter will enter but then leave it. Regular matter tends to remain behind because it is slowed by friction.
Quote
Wish the was an alternate hypothesis which could negate Dark matter & energy n just explain the Universe in a simpler format.Be glad it's complicated. The simple universes don't have complicated things like us in them.
Post by: Petrochemicals on 18/09/2021 10:40:47
https://www.nationalgeographic.com/science/article/110524-densest-matter-created-lhc-alice-big-bang-space-science
Quark gluon plasma is very dense but also quite hot.