Skyler4856

For Questions That Don't Merit Their Own Thread

Recommended Posts

20 minutes ago, ARS said:

If that's the case, then it is possible to obtain similar or higher power density than LBCFR with an added advantage of better cooling due to high-temp gas cooled reactor allowing a larger coolant fraction in the core (due to the low number density of gas coolant)

It seems like an unexploited niche. Apparently there are advantages to a DC electric motor, at least in azipod design, and handily, an MHD produces DC while also achieving much higher efficiency.

At least on paper.

And it's not a big step. Aside from the French, it is my understanding that even the Yasens have a turboelectric mode for silent running.

Share this post


Link to post
Share on other sites

Is it possible for a planet that's formed outside of goldilocks zone (either closer or farther towards the sun compared to earth) to contain Oxygen as one of the main component of it's atmosphere (doesn't have to be at breathable concentration) from the gases that forms the atmosphere of the planet (as in, a planet with oxygen content in it's atmosphere with no plants whatsoever)?

Share this post


Link to post
Share on other sites
1 hour ago, ARS said:

Is it possible for a planet that's formed outside of goldilocks zone (either closer or farther towards the sun compared to earth) to contain Oxygen as one of the main component of it's atmosphere (doesn't have to be at breathable concentration) from the gases that forms the atmosphere of the planet (as in, a planet with oxygen content in it's atmosphere with no plants whatsoever)?

Yes and no. Oxygen is very reactive and can't stay around for long without constant replenishment.

On the other hand, every icy body in the outer Solar System has a thin 'atmosphere' of oxygen from water-dissociated water. Including Pluto.

Share this post


Link to post
Share on other sites
1 hour ago, ARS said:

Is it possible for a planet that's formed outside of goldilocks zone (either closer or farther towards the sun compared to earth) to contain Oxygen as one of the main component of it's atmosphere (doesn't have to be at breathable concentration) from the gases that forms the atmosphere of the planet (as in, a planet with oxygen content in it's atmosphere with no plants whatsoever)?

One option is an atmosphere with mostly oxygen. This require water and solar radiation who split the water molecules into hydrogen and oxygen, hydrogen escapes. 
Think this require an large and hot star? Or did this happen on Venus? 
An large and hot star will not live long, but might live long enough to produce life who produce oxygen. 
This is an reason why O2, is not an perfect bio signature.

Share this post


Link to post
Share on other sites
8 hours ago, DDE said:

Oxygen is very reactive and can't stay around for long without constant replenishment.

You frighten me...

(Starts gathering empty PET cans to store the oxygen while it's around.)

***

Afaik, iron deoxidation in the upper layers of the planet core will cause massive flow of oxygen, which will raise to the surface (because the underlying minerals are already oxidized, mostly).
And hundreds millions of years later, at the end of the gravitational differentiation, when all original iron oxides split into iron (core) and this oxygen, this will cause significant raise of oxygen concentration in atmosphere, killing  primitive remains of life on the Earth.

(Just in case: this doesn't relate to the water and UV in any form, it's reduction of the iron oxides).

So, probably any Earth-like rocky planet enough massive to hold the atmosphere will have some period of oxygen-rich atmosphere.
Lesser ones will loose this oxygen as any other gas.
Bigger ones have a lot of hydrocarbons and so on to fully oxidize it with this oxygen, and turn it into the water and carbon dioxide.

Edited by kerbiloid

Share this post


Link to post
Share on other sites

Weather condition plays a vital role in aviation where it determines the flight of aircraft, whether it's safe to fly or not. What about spaceflight? Does the weather plays a vital role too? Especially during the ascent phase (even if it's brief). What's the weather parameters that must be checked before declaring it's safe for launch? I am particularly interested with space shuttles, since it's arrangement and assembly is different than regular rockets (being a plane strapped to giant fuel tanks with strap-on boosters instead of towers of stacked fuel tanks and engines of regular rockets)

Share this post


Link to post
Share on other sites
24 minutes ago, ARS said:

What's the weather parameters that must be checked before declaring it's safe for launch? I am particularly interested with space shuttles...

https://www.nasa.gov/centers/kennedy/news/releases/2003/release-20030128.html

Post Columbia, there may have been additional rules to visibility.

Edited by razark

Share this post


Link to post
Share on other sites
3 hours ago, ARS said:

Weather condition plays a vital role in aviation where it determines the flight of aircraft, whether it's safe to fly or not. What about spaceflight? Does the weather plays a vital role too? Especially during the ascent phase (even if it's brief). What's the weather parameters that must be checked before declaring it's safe for launch? I am particularly interested with space shuttles, since it's arrangement and assembly is different than regular rockets (being a plane strapped to giant fuel tanks with strap-on boosters instead of towers of stacked fuel tanks and engines of regular rockets)

SpaceX fandom has a meme for that scrub reason.

 

Share this post


Link to post
Share on other sites
5 hours ago, DDE said:

SpaceX fandom has a meme for that scrub reason.

 

First stage recovery makes weather much more of an issue. If you don't plan to land its more like artillery than aviation. 

Share this post


Link to post
Share on other sites
9 hours ago, magnemoe said:

more like artillery than aviation

Ah, the big internal battle that cost the Soviets the Moon.

Share this post


Link to post
Share on other sites

Is a generation ship ethical? 

Share this post


Link to post
Share on other sites
2 hours ago, zeilden said:

Is a generation ship ethical? 

No, it is technological.

What you should have asked is whether it's moral. At which point you end ho walking in circles because morals, as studied by the science of ethics, are a very disagreeable subject.

i?id=b99cdb5f94f4a54a49621d4c450c1710&n=

Welcome to the forum anyway!

Share this post


Link to post
Share on other sites
1 hour ago, zeilden said:

Is a generation ship ethical? 

Short answer:

In their currently imagined form (ie: severe restrictions, deficits and difficulties of many different kinds, even in the most optimistic of scenarios, when compared to living on Earth)? No. With near-infinite resources (see: Shkadov thruster) maybe.

But it may be relatively ethical compared to say, allowing humanity to become extinct. Or if living conditions changed on Earth, the balance of morals/ethics could change.

I think everyone would agree that generation ships are among the the least desirable forms of space travel. By some significant definitions, it cannot even be regarded as "travel", in a human sense, since nobody who boards the ship gets off, and nobody that arrives at the destination has ever existed at the origin.

Share this post


Link to post
Share on other sites
Spoiler

i?id=b99cdb5f94f4a54a49621d4c450c1710&n=

5 suicidal maniacs vs 1 ?

And what is that man with a vacuum cleaner doing near the rails? He is not sure to which party join?

 

 

 

Share this post


Link to post
Share on other sites

I have a question:

Why does/did it say "United States" on the side of NASA rockets and also airforce ICBMs?

(actually, especially ICBMs, since basically nobody ever really saw them apart from the staff who physically built them and delivered them to the silos)

I cant think of a single reason.

I mean, theres no reason why not....but its a bit like tattooing my own name into my armpit.

Edited by p1t1o

Share this post


Link to post
Share on other sites
19 minutes ago, p1t1o said:

I have a question:

Why does/did it say "United States" on the side of NASA rockets and also airforce ICBMs?

(actually, especially ICBMs, since basically nobody ever really saw them apart from the staff who physically built them and delivered them to the silos)

I cant think of a single reason.

I mean, theres no reason why not....but its a bit like tattooing my own name into my armpit.

On orbital rockets it makes some sense at least during the cold war, SpaceX rockets has spaceX on them. 
However it don't looks like its painted on ICBM, they tend to have the US Air Force on them, and this tend to be either test launches or static displays both are seen.
images?q=tbn:ANd9GcTDoCXlQCcBRHOhrfMI7tY

Goggled this and it don't looks like missiles in silos has it. They might have the air force emblem because tradition. it might also be to mark them as US rockets because warplanes has to be marked as so. 
No its not very relevant for an ICBM and tactical rockets are not marked as I know 

Share this post


Link to post
Share on other sites

Maybe there is "Property of the Government of the" written with smaller and darker font.

And "All rights reserved" after that.

Share this post


Link to post
Share on other sites
23 minutes ago, kerbiloid said:

Maybe there is "Property of the Government of the" written with smaller and darker font.

Nah, that's a one-inch round sticker, printed blue on a silver background.

Share this post


Link to post
Share on other sites

So... I had a few questions. I found this formula for converting the relative humidity into absolute humidity. The problem is, it only shows the T (temperature), and rh (relative humidity). What's the number represents for? Is it constants? Can anyone explain?

ah1.jpg

source: https://carnotcycle.wordpress.com/2012/08/04/how-to-convert-relative-humidity-to-absolute-humidity/

Share this post


Link to post
Share on other sites
1 hour ago, ARS said:

So... I had a few questions. I found this formula for converting the relative humidity into absolute humidity. The problem is, it only shows the T (temperature), and rh (relative humidity). What's the number represents for? Is it constants? Can anyone explain?

ah1.jpg

source: https://carnotcycle.wordpress.com/2012/08/04/how-to-convert-relative-humidity-to-absolute-humidity/

Why is that a problem? Those are the most important variables. Atmospheric pressure also has a smaller effect.

If you are talking about an atmosphere other than Earth's, then those constants would be different.

Share this post


Link to post
Share on other sites
33 minutes ago, mikegarrison said:

Why is that a problem? Those are the most important variables. Atmospheric pressure also has a smaller effect.

If you are talking about an atmosphere other than Earth's, then those constants would be different.

No, I just want to know what the numbers represents

Share this post


Link to post
Share on other sites
37 minutes ago, ARS said:

No, I just want to know what the numbers represents

273.15 is a conversion to Kelvin temperature, so it implies T is supposed to be in deg C for that equation. I am pretty sure the rest are derived from the ideal gas laws and physical constants associated with water and dry air.

I mean, you know what relative humidity is, right? It's a measure of the saturation pressure of water vapor compared to the partial pressure of water in the air. When the partial pressure of water exceeds the saturation pressure, then water will start to condense as liquid. That is 100% relative humidity.

If you want a full derivation, I'm sure you can look this up just as easily as I can.

Edited by mikegarrison

Share this post


Link to post
Share on other sites
10 minutes ago, mikegarrison said:

273.15 is a conversion to Kelvin temperature, so it implies T is supposed to be in deg C for that equation. I am pretty sure the rest are derived from the ideal gas laws and physical constants associated with water and dry air.

I mean, you know what relative humidity is, right? It's a measure of the saturation pressure of water vapor compared to the partial pressure of water in the air. When the partial pressure of water exceeds the saturation pressure, then water will start to condense as liquid. That is 100% relative humidity.

If you want a full derivation, I'm sure you can look this up just as easily as I can.

Thanks! now that clears something up. I just getting some school project that involves measuring absolute air humidity, which makes me confused since I'm not familiar with this matter before before

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.