For Questions That Don't Merit Their Own Thread

[shynung]

1 hour ago, WinkAllKerb'' said:

how will being (including human) will react to long multigenerationnal space travel without a moon

From the gravity aspect, very little. Lunar gravity has little direct effects on earth life in general. it creates the tide cycle of the ocean, but that's about it as far as I know.

Radiation, almost nothing. The moonlight is vastly dimmer than the sunlight. About the only thing earthlings use it for are celestial navigation reference, and even then they can just use a visible star.

Frankly, the lack of surface gravity and radiation shielding will affect them more than the lack of a moon.

[RainDreamer]

On 24/04/2016 at 6:59 AM, KAL 9000 said:

Which is faster: a duck riding a bicycle, or a running horse?

Assuming the duck is indeed capable of operating a bicycle, it will be depending on the course. On a straight line, the horse will be faster due to its muscles size generating much more force to accelerate. On a course with a lot of turns though, the horse will be slower due to it higher mass, which means a lot of inertia, making it much more difficult to slowdown and turn compared to the lighter duck + bicycle.

6 hours ago, shynung said:

From the gravity aspect, very little. Lunar gravity has little direct effects on earth life in general. it creates the tide cycle of the ocean, but that's about it as far as I know.

Radiation, almost nothing. The moonlight is vastly dimmer than the sunlight. About the only thing earthlings use it for are celestial navigation reference, and even then they can just use a visible star.

Frankly, the lack of surface gravity and radiation shielding will affect them more than the lack of a moon.

I imagine nocturnal creatures that has evolved to use the moon in some ways might be slightly disoriented. But otherwise I guess they would be fine.

[WinkAllKerb'']

5 hours ago, RainDreamer said:

But otherwise I guess they would be fine.

well science people are no longer allowed to use any "asynchrone" stuff ; ) i guess they would be fine too ; ) anyway anyway just some thoughts ; )

[More Boosters]

If Mars is red because of all the iron oxide on its surface, can we spread whatever it is that you also need over it and then create the coolest thermite ever?

[Kryten]

3 minutes ago, More Boosters said:

If Mars is red because of all the iron oxide on its surface, can we spread whatever it is that you also need over it and then create the coolest thermite ever?

The oxide is mostly a thin layer of dust, you won't get much of a reaction. As shown by MSL, if you dig into it you get the grey of reduced iron.

[More Boosters]

31 minutes ago, Kryten said:

The oxide is mostly a thin layer of dust, you won't get much of a reaction. As shown by MSL, if you dig into it you get the grey of reduced iron.

Ah I really wanted a planet-wide inferno. Oh well.

[RainDreamer]

Following the theme of the previous questions: what happens when a superearth planet with pure oxygen atmosphere crashing into a hydrogen gas giant like Jupiter? 

[More Boosters]

6 hours ago, RainDreamer said:

Following the theme of the previous questions: what happens when a superearth planet with pure oxygen atmosphere crashing into a hydrogen gas giant like Jupiter? 

A pure oxygen atmosphere would probably be the product of life on the planet (that or it's a white dwarf) so I'm not sure what exactly would happen, but if a sapient race lives on that planet, they'll be very disappointed.

[KAL 9000]

14 hours ago, RainDreamer said:

Following the theme of the previous questions: what happens when a superearth planet with pure oxygen atmosphere crashing into a hydrogen gas giant like Jupiter? 

If there's lightning on one or both planets to make a spark... OH YEAH!!!

[Vanamonde]

15 hours ago, RainDreamer said:

Following the theme of the previous questions: what happens when a superearth planet with pure oxygen atmosphere crashing into a hydrogen gas giant like Jupiter? 

The chemical energy in the atmospheres would be tiny in comparison to the kinetic energy of the collision. Besides, whether some process like plant life is sustaining oxygen in the atmosphere or not, the process isn't making the oxygen, but merely freeing up oxygen that's already there. So a planet of the same size without an oxygen atmosphere would still contain about the same amount of oxygen, and wouldn't behave markedly differently during a collision. 

[Rakaydos]

Speaking of freeing up oxygen, whats a ballpark for how much oxygen is sequested in the surface Iron oxide of mars?

[JebKeb]

 Let's say there's about 1 cubic metre of soil for every square metre and the soil is around 30% oxygen. The surface area of Mars is roughly 150 million square kilometres, or around 150 trillion square metres. So that's about 50 trillion kilolitres, or 50 quadrillion litres. This is around the same amount of oxygen as in half of the water in the Atlantic ocean. 

oooOOOooo

Which is better for petrol (gasoline) production? The Fischer-Tropsch process, where hydrogen and synthesis gas is turned into naptha, diesel and kerosene but can be tweaked to provide petrol. Or the Mobil process, where methanol is dehydrated into dimethyl ether, then dehydrated again into an unrefined synthetic petrol.

If I only use the Fischer-Tropsch process there'll be less expense to build the plant, but, the tweaking might create unfavourable byproducts like methane.

If I also use the Mobil Process there'll be more expenses and complications, but it produces far more useful things (propane, ethane) and has been tested throroughly.

I'm swinging towards the Mobil Process.

Edited May 4, 2016 by JebKeb

[JebKeb]

There. Here's your picture.

[Wjolcz]

Can ion engine exhaust burn your hand?

[KerbonautInTraining]

5 hours ago, Veeltch said:

Can ion engine exhaust burn your hand?

Probably not. I'd be surprised if you could even feel it, as far as temperature and mass expulsion go. Remember, in the case of Dawn there's only 30 millinewtons of thrust being produced. Combine that with the massive specific impulse and there's essentially nothing hitting your hand. 

However, the engine is consuming many kilowatts of power and if more than a few percent of that makes it to your skin you'll definitely feel it 

[Break]

Why are most calculators limited to 8-10 digits? Would it be possible for an application to calculate irrational numbers to, say, 100 digits? I'm pretty sure any modern CPU could do it without breaking a sweat. Is it just a matter of brute forcing it or are there complications involving 32/64bit architecture? 

Edited May 4, 2016 by KerbonautInTraining
Added calculator question

[kunok]

1 hour ago, KerbonautInTraining said:

Why are most calculators limited to 8-10 digits? Would it be possible for an application to calculate irrational numbers to, say, 100 digits? I'm pretty sure any modern CPU could do it without breaking a sweat. Is it just a matter of brute forcing it or are there complications involving 32/64bit architecture? 

Hand calculators? The display is obviously the worse limitation. Also long numbers need more space in memory to do the calculations, and lots of more processing power. The processor itself is very limited. Think that a hand calculator doesn't know how to do a sin, only a few very basic operations, it makes an iterative process to calculate that, which is more demanding for every number you add. My casio fx-991es takes his time to solve some complex equations, and sometimes it doesn't end in the minute of processing that has of maximum, you can give another minute again but it will ask, and show you how big the iterative intervale is now, is useful because sometimes it just needs more than one minute but others is just not converging.

[KerbonautInTraining]

7 minutes ago, kunok said:

Hand calculators? 

I was referring to PC/phone based calculators.

[kunok]

8 minutes ago, KerbonautInTraining said:

I was referring to PC/phone based calculators.

There are lots of programs that can manage long numbers. Windows 10 calculator in the scientific mode can handle 32 digits.

The basic calculator programs are that, basic, so they simplifies the number storage, and making look "easier" showing less numbers.

Need ya a good math program? Say what need do you have, there is lot of people here using math programs, including myself

Edited May 4, 2016 by kunok
grammar

[insert_name]

Why does steel wool burn when you connect to it with a 9volt?

[StrandedonEarth]

22 minutes ago, insert_name said:

Why does steel wool burn when you connect to it with a 9volt?

The thin fibers of steel wool have high electrical resistance, which generates heat. The fibers are thin and light, and so heat up to red hot quite quickly. Red-hot steel likes to burn when exposed to oxygen; that's how oxy-acetylene cutting torches work (heat the work piece to red hot, then activate a high-pressure jet of pure oxygen). Hot-rolled steel forms a coat of black iron oxide. ANYTHING that's not already oxidized will burn if you heat it hot enough and expose it to oxygen, even diamonds.

[RenegadeRad]

How can mirrors be real if our eyes aren't?

[RainDreamer]

17 hours ago, RenegadeRad said:

How can mirrors be real if our eyes aren't?

Because it's now possible to bypass the eyes, even though they may or may not be real, using light sensors and sending the resulting electrical signals directly to the nerve cells behind it, which carry the information over to the brain for processing.

So, unless our brains aren't real which is another discussion, we are indeed capable of seeing light reflecting off a surface, such as a mirror, with or without eyes.

News about bionic eye:http://www.theguardian.com/society/2016/jan/05/woman-bionic-eye-joy-reading-clock-rhian-lewis

Edited May 6, 2016 by RainDreamer

[RenegadeRad]

*Mind Blown*

[Glaran K'erman]

Im curious, heard/read somewhere that most military satellites get launched directly into their orbits, thereby requiring different performance out of their launch vehicles.

A) If this is correct why is it so, and B) what would be the major differences in vehicle capability.

[Kryten]

39 minutes ago, Glaran K'erman said:

Im curious, heard/read somewhere that most military satellites get launched directly into their orbits, thereby requiring different performance out of their launch vehicles.

A) If this is correct why is it so, and B) what would be the major differences in vehicle capability.

Direct insertion offers the best payload mass from a given launch vehicle. Most commercial sats avoid it because they want flexibility; they don't want to be stuck on the ground if there's a problem with a specific launch provider or rocket, and they want greater choice than the few providers that could currently offer direct GSO insertion. Military sats are generally built from the ground-up to fit the capabilities of a specific launch vehicle from the same nation, so they go with the higher-efficiency option.

This doesn't apply 100% of the time; military sats based on commercial buses have used GTO, and some (all Russian IIRC) civilian and commercial sats have used direct GSO insertion.