For Questions That Don't Merit Their Own Thread

[kerbiloid]

The highest jump ever - 39 km.

sqrt((80 000 - 39 000) * 9.8 * 2) ~= 900 m/s, without air drag.

So, the person should survive a 3-4 Mach aerobraking.

K-36DM maximum = 2.5 Mach (and the pilot is packed and protected with chair).

So, neither Earth, nor Kerbin look survivable, unless using some heatproof inflatable raft.

Edited September 5, 2019 by kerbiloid

[mikegarrison]

38 minutes ago, DDE said:

Picture a suborbital mission with an apogee of barely above 100 km.

At apogee, the pilot exits the vehicle, and never gets back in.

Is the parachute jump from near space survivable?

Does the situation change if were's talking 80 km above Kerbin?

Is the pilot Jeb? Then yes.

[DDE]

1 hour ago, mikegarrison said:

Is the pilot Jeb?

Well, crap, that wasn't a variable I was planning to introduce yet.

I'm charting a rather realistic roleplay fanfic, but the first suborbital mission is planned to be this loony. I'm not sure who was the first to come up with the idea of a detachable command pod... so there won't be one!

You know who the pilot will be, of course.

Edited September 5, 2019 by DDE

[ARS]

3 hours ago, DDE said:

You know who the pilot will be, of course.

You don't even need to ask him. Jeb will gladly jump on the first seat of the craft you made, before it's construction even finished on the hangar!

[kerbiloid]

5 hours ago, DDE said:

I'm charting a rather realistic roleplay fanfic,

The first two hours they are watching White Sun of Desert.
Then put on spacesuits, get out of the hotel room, put their signatures on the door, and go by bus to the launchpad to have a (liquid) on its wheel.
(That's already a double-time pilot episode of the future sci-fi series . To be continued soon... )

5 hours ago, DDE said:

but the first suborbital mission is planned to be this loony.

He can cut off a piece of insulation from the ship and use it as a heatshielding raft to slow down to 2 Mach.
Just don't forget to forget a machete in the cabin.

P.S.
Reminds me of Inheritance ("Наследство") by A.Clarke, about suborbital rocket hopping

Edited September 5, 2019 by kerbiloid

[ARS]

Is it possible for a black hole to have their own system? Is it gonna be a stable system? For example, when a rogue planet is being caught within black hole's gravitational field. Considering that black hole's tendency to devour the stars, much less a planet

[kerbiloid]

Sgr A* contains even a star in a close orbit.
As well, it can contain planets.

[DDE]

8 hours ago, ARS said:

Considering that black hole's tendency to devour the stars, much less a planet

Black holes are not quick eaters. The stars get siphoned off bit by bit over the course of a very large period of time.

Edited September 8, 2019 by DDE

[Nightside]

On 9/7/2019 at 10:07 PM, ARS said:

Is it possible for a black hole to have their own system? Is it gonna be a stable system? For example, when a rogue planet is being caught within black hole's gravitational field. Considering that black hole's tendency to devour the stars, much less a planet

The orbit would have to remain outside the event horizon though, right?

[StrandedonEarth]

1 hour ago, Nightside said:

The orbit would have to remain outside the event horizon though, right?

I don’t see why something could not have an extremely fast orbit (probably have to  go plaid) inside the event horizon, IF it can withstand the ludicrous tidal forces. But we would never know it’s there, since not even light can escape the event horizon. But I’m not an astrophysicist. 

[kerbiloid]

8 hours ago, Nightside said:

The orbit would have to remain outside the event horizon though, right?

Probably, it would remain even outside the ergosphere.

6 hours ago, StrandedonEarth said:

I don’t see why something could not have an extremely fast orbit (probably have to  go plaid) inside the event horizon

Shocked...

https://physics.stackexchange.com/questions/365969/are-stable-orbits-within-the-event-horizon-of-a-black-hole-possible
https://arxiv.org/abs/1103.6140

And if remember that Schwarzschild radius of the visible Universe almost matches its visible size...
https://en.wikipedia.org/wiki/Schwarzschild_radius#Parameters

Edited September 10, 2019 by kerbiloid

[mikegarrison]

By it's nature, we really don't know for sure what it is like inside an event horizon. It's all just math with no way to prove it.

Also, it is expected that matter would be seriously distorted by tidal forces. https://en.wikipedia.org/wiki/Spaghettification

[Guest]

32 minutes ago, kerbiloid said:

And if remember that Schwarzschild radius of the visible Universe almost matches its visible size...
https://en.wikipedia.org/wiki/Schwarzschild_radius#Parameters

that's... oddly similar to something else...

Edited September 10, 2019 by Guest

[Spacescifi]

 

If we had a machine that could increase the strength of the strong force (holds atoms together), could we power it with a nuclear reactor?

Or would it require massive amounts of electricty that an antimatter/matter reactor could give but we do not have it?

 

I guess I am asking just how much energy it takes for an atom to hold itself together, since I will use that as a gauge to figure how much energy is needed to increase it.

Applications? Rocket nozzles and nuclear reactors that won't melt while propellant is superheated. Thus nuclear SSTO's would possible with s higher TW ratio.

Edited September 11, 2019 by Spacescifi

[AngrybobH]

6 hours ago, Spacescifi said:

could we power it with a nuclear reactor?

You can power anything with anything. You could power a scifi FTL drive with a coal furnace. Scale is all that matters.

If going into scifi materials, I much prefer materials made from quad- or penta-quark particles. If you could get those to be stable, who knows what kind of properties they would have. And, if you could make those with the needed properties, they would not need continuous energy usage to hold the material together(or maybe they would if that is how they are stabilized).

I could not tell you specifically about the energy required to hold an atom together but wikipedia does say this about the strong nuclear/colour force:

... At the range of 10⁻¹⁵ m (1 femtometer), the strong force is approximately 137 times as strong as electromagnetism, a million times as strong as the weak interaction, and 10³⁸ (100 undecillion) times as strong as gravitation.^[1] The strong nuclear force holds most ordinary matter together because it confines quarks into hadron particles such as the proton and neutron. In addition, the strong force binds neutrons and protons to create atomic nuclei. Most of the mass of a common proton or neutron is the result of the strong force field energy; the individual quarks provide only about 1% of the mass of a proton.

So it seems increasing the strong force(if even possible) would increase mass. That is, if I understand that correctly. Particle physics is not something I would consider myself more than a basic amateur.

Edited September 11, 2019 by AngrybobH

[Spacescifi]

8 minutes ago, AngrybobH said:

You can power anything with anything. You could power a scifi FTL drive with a coal furnace. Scale is all that matters.

If going into scifi materials, I much prefer materials made from quad- or penta-quark particles. If you could get those to be stable, who knows what kind of properties they would have. And, if you could make those with the needed properties, they would not need continuous energy usage to hold the material together(or maybe they would if that is how they are stabilized).

I could not tell you specifically about the energy required to hold an atom together but wikipedia does say this about the strong nuclear/colour force:

... At the range of 10⁻¹⁵ m (1 femtometer), the strong force is approximately 137 times as strong as electromagnetism, a million times as strong as the weak interaction, and 10³⁸ (100 undecillion) times as strong as gravitation.^[1] The strong nuclear force holds most ordinary matter together because it confines quarks into hadron particles such as the proton and neutron. In addition, the strong force binds neutrons and protons to create atomic nuclei. Most of the mass of a common proton or neutron is the result of the strong force field energy; the individual quarks provide only about 1% of the mass of a proton.

So it seems increasing the strong force(if even possible) would increase mass. That is, if I understand that correctly. Particle physics is not something I would consider myself more than a basic amateur.

Thanks.

The energy required seems like it would be more efficiently powered with an antimatter/matter reactor. A nuke reactor may take too long to generate the desired energy levels.

Or perhaps not,  at any rate it may not be possible to power it unless the energy powering it is more than the amount of energy that is being absorbed by the solid that the device is strengthening.

So a nuclear reactor might be able to strengthen a rocket nozzle to survive the heat of over 7000 kelvin metallic hydrogen exhaust. But it would take hours to build up that amount of force I imagine using nuclear reactors.

With antimatter it would not take near as long.

[kerbiloid]

Lemme guess the next thread title.
"How can we build a strong force engine?"

[Spacescifi]

21 minutes ago, kerbiloid said:

Lemme guess the next thread title.
"How can we build a strong force engine?"

 

No. I only wanted to know the power levels involved to give me clue as to what it takes to power it. How to make one matters not... not for fiction anyway.

[ARS]

Does VTOL jet fighter has any advantage compared to conventional jet fighter when they come into dogfight?

[kerbiloid]

Only if they fight next to the carrier, and the conventional jet is nearly out of fuel and must hurry up.

[Spacescifi]

1 hour ago, ARS said:

Does VTOL jet fighter has any advantage compared to conventional jet fighter when they come into dogfight?

 

Assuming neither side used missiles (seldom the case in the modern era) the answer is probably not.

Since VTOL aircraft are probably heavier than normal fighter craft are due to extra equipment. Which would negate any advantage in combat.  VTOL is for VTOL. Not combat.

 

Assuming you made a craft weigh the same as a normal craft the answer is just a maybe.

Dogfights require slower speeds, and most nowadays kill at high speed with missiles.

[AngrybobH]

On 9/14/2019 at 10:31 PM, ARS said:

Does VTOL jet fighter has any advantage compared to conventional jet fighter when they come into dogfight?

The real answer is, it depends on many different factors. If you look up the combat tactics of the Sea Harriers in the Falklands war, you can learn a bit about successful VTOL use. Typically, like @Spacescifi said, missiles kill planes from over the horizon in modern warfare. Doesn't really matter what kind of plane you have. Terrain and refueling opportunities can give large advantages to VTOL but I believe, if both planes are fully fueled and armed and they are in gun range, a dedicated fighter plane would easily best a VTOL.

[DDE]

15 hours ago, AngrybobH said:

Terrain and refueling opportunities can give large advantages to VTOL

One of the rather overhyped scenarios is a roving pack of 16 F-35Bs and 4 V-22s full of fuel and ammo.

[kerbiloid]

Kinda those quadrocopters from the youtube I've posted before.

[magnemoe]

On 9/16/2019 at 8:32 PM, AngrybobH said:

The real answer is, it depends on many different factors. If you look up the combat tactics of the Sea Harriers in the Falklands war, you can learn a bit about successful VTOL use. Typically, like @Spacescifi said, missiles kill planes from over the horizon in modern warfare. Doesn't really matter what kind of plane you have. Terrain and refueling opportunities can give large advantages to VTOL but I believe, if both planes are fully fueled and armed and they are in gun range, a dedicated fighter plane would easily best a VTOL.

This, note that the Falklands war was over ocean something who benefit long range missiles, harriers still worked pretty well. Mountains especially if both parts has long ranged SAM will force this to become pretty weird.