# 6 Everyday Things That Happen Strangely in Space



## qubit (May 30, 2011)

Here's two of them to get you going:



> *You Can't Burp Beer*
> 
> Because no gravity means no buoyant force, there's nothing pushing gas bubbles up and out of carbonated drinks in space. This means carbon dioxide bubbles simply stagnate inside sodas and beers, even when they're inside astronauts' bellies. Indeed, without gravity, astronauts can't burp out the gas — and that makes drinking carbonated beverages extremely uncomfortable.



Yes, can you imagine what all that trapped wind would feel like?! 



> *You Sweat More*
> 
> As explained in the context of candle flames, zero g's means there's no natural convection. This means body heat doesn't rise off skin, so the body constantly perspires in an effort to cool itself down. Even worse, because that steady stream of sweat won't drip or evaporate, it simply builds up. All this makes for a pretty moist journey to the beyond.



Ewww! Nuff said.

Read the rest at space.com


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## wahdangun (May 30, 2011)

wtf.

Body heat transfer didn't rely on gravity, and isn't astronaut suit have cooling system in it.


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## lilhasselhoffer (May 30, 2011)

wahdangun said:


> wtf.
> 
> Body heat transfer didn't rely on gravity, and isn't astronaut suit have cooling system in it.



Convection is the flow of lower density air, pushed by higher density air.  This flow is counter to that of gravity, because lower density fluids have less particles for gravity to exert a downward force on.  In space there is no "down," thus lower density and higher density fluids can exist in pockets.

You generate large amounts of heat, thus you require convection currents (driven by density changes and gravitational forces) to cool yourself.  

Additionally, they don't wear space suits inside the capsules.  Space suits actually generate forced convection (like you'd find in an oven) using fans or pumps (in the case of liquid cooling) to generate pressure variances.


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## qubit (May 30, 2011)

I didn't agree with their explanation that a flame (item 2) only rises on earth due to the incredibly tiny difference in atmospheric density due to gravity within a space of one inch though. :shadedshu

The reason this happens is because the flame is _damn hot!_ and is burning in the presence of gravity. Hot air is less dense than cold air, therefore, it sets up a convection current, where cold falls around the hot air, to the bottom. Where it's close to the flame, it then gets heated and rises and the process continues until the flame runs out of fuel. Heck, just think of an electric room heater or electric kettle heating water. Exactly the same convection currents occur here and there's no flame at all, just a temperature difference.


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## cheesy999 (May 30, 2011)

qubit said:


> The reason this happens is because the flame is damn hot! and is burning in the presence of gravity. Hot air is less dense than cold air, therefore, it sets up a convection current, where cold falls around the hot air, to the bottom. Where it's close to the flame, it then gets heated and rises and the process continues until the flame runs out of fuel. Heck, just think of an electric room heater or electric kettle heating water. Exactly the same convection currents occur here and there's no flame at all, just a temperature difference.



yeah, and without gravity the less dense air expands in all directions instead of upwards


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## qubit (May 30, 2011)

cheesy999 said:


> yeah, and without gravity the less dense air expands in all directions instead of upwards



Exactly, giving the ball flame shown in the picture. They didn't explain this in the article, but zero-g flames are also cooler, because the convection currents are absent.


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## Thatguy (Jun 3, 2011)

cheesy999 said:


> yeah, and without gravity the less dense air expands in all directions instead of upwards



theres no gravity in space ? wow, how the hell does the earth orbit the sun then ?


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## Thatguy (Jun 3, 2011)

qubit said:


> Exactly, giving the ball flame shown in the picture. They didn't explain this in the article, but zero-g flames are also cooler, because the convection currents are absent.



convection currents are present, they aren't as asymetrical as they are on the planet due to the lower  force of gravity.


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## qubit (Jun 3, 2011)

Thatguy said:


> theres no gravity in space ? wow, how the hell does the earth orbit the sun then ?



I think you're missing something. An object in orbit feels no gravity, other than tidal forces. That's why you see the astronauts float around the space shuttle. Cheesy is right in this context.



Thatguy said:


> convection currents are present, they aren't as asymetrical as they are on the planet due to the lower  force of gravity.



Since gravity is negligible in orbit, the convection currents are effectively zero. It's weird, but true.


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## Kreij (Jun 4, 2011)

I want to see popcorn popping in zero-G. Seriously.


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## qubit (Jun 4, 2011)

Kreij said:


> I want to see popcorn popping in zero-G. Seriously.



Yeah, me too. It would fly everywhere!


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## Thatguy (Jun 4, 2011)

qubit said:


> I think you're missing something. An object in orbit feels no gravity, other than tidal forces. That's why you see the astronauts float around the space shuttle. Cheesy is right in this context.



  objects in orbit experince gravity. The reason for the lack of apparance is likely due to the balance of gravity between the earth and the sun cancelling each other. Without gravity between the earth and the sun the earth would fly right the fuck out of its orbit. 



qubit said:


> Since gravity is negligible in orbit, the convection currents are effectively zero. It's weird, but true.



  convection has nothing to do with gravity. convection occurs when a high pressure area moves into a low pressure area.


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## qubit (Jun 4, 2011)

Thatguy said:


> objects in orbit experince gravity. The reason for the lack of apparance is likely due to the balance of gravity between the earth and the sun cancelling each other. Without gravity between the earth and the sun the earth would fly right the fuck out of its orbit.



Yes, you're _definitely_ missing the point.  You don't appear to have understood what I've said. It's not possible to put it any more clearly, so I won't bother trying to explain it any further to you. All I can suggest, is that you carefully reread cheesy's and my posts again.



Thatguy said:


> convection has nothing to do with gravity.



To put it politely, that's rubbish. :shadedshu You don't appear to have a very good grasp of physics.

Here's a nice handy explanation from Wikipedia:



> *Natural convection*, or *free convection*, occurs due to temperature differences which affect the density, and thus relative buoyancy, of the fluid. Heavier (more dense) components will fall while lighter (less dense) components rise, leading to bulk fluid movement. Natural convection can only occur, therefore, in a gravitational field. A common example of natural convection is a pot of boiling water in which the hot and less-dense water on the bottom layer moves upwards in plumes, and the cool and more dense water near the top of the pot likewise sinks.
> 
> Natural convection will be more likely and/or more rapid with a greater variation in density between the two fluids, a larger acceleration due to gravity that drives the convection, and/or a larger distance through the convecting medium. Convection will be less likely and/or less rapid with more rapid diffusion (thereby diffusing away the gradient that is causing the convection) and/or a more viscous (sticky) fluid.



As you can see, convection most certainly does have everything to do with gravity.


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## BrettRuthnam (Jun 17, 2011)

Thatguy said:


> objects in orbit experince gravity. The reason for the lack of apparance is likely due to the balance of gravity between the earth and the sun cancelling each other. Without gravity between the earth and the sun the earth would fly right the fuck out of its orbit.



Yes objects in orbit experience "gravity" although it's more an "attractive force" due to the mass of the objects, just look at Newtons law of universal gravitation. 


You know what's sad when we talk about stuff in space?
When you realise we are nothing but particles that can communicate, move around (most of the time at will), bla bla blaa ......etc etc.


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