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Heat of the Sun?

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posted on Jul, 15 2012 @ 01:37 PM
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Originally posted by jiggerj

Originally posted by bigfatfurrytexan

Originally posted by epsilon69
So the shuttle would continue to heat up in direct sunlight. How does the shuttle cool itself down in a vacuum environment? It's not like it can spread the heat to molecules surrounding it since it's in a vacuum. So does it need to be in a shaded area (like behind the Earth) in order to radiate heat fast enough for the temperature to drop?


The side that faces the sun would heat up, while the side that is away from the sun would cool down. I would suspect that a combination of it being small enough to dissipate the heat internally, combined with how absolutely cold it would be on the dark side, combined with the use of novel materials and creative designed, would prevent total catastrophe.


Wait a minute, wait a minute! lol We just made clear that there aren't enough atoms in outer space to radiate heat. So, if the atoms of the shuttle heat up, that heat energy has to go SOMEWHERE. If not in the space surrounding the shuttle then where does it go before it literally boils the shuttle?


Yes. It dissipates into the cooler parts of the shuttle. Simple thermodynamics. The atoms that are there (i.e., the shuttle and its inhabitants" dissipate the heat. The energy is basically lost to the colder parts of the vessel.




posted on Jul, 15 2012 @ 01:42 PM
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space is a vacuum and has little to no atmosphere. planets form atmospheres due to rotation of inner and outer core materials. The suns rays get amplified by the atmosphere and that in turn is what your feeling, a type of transduction if you will.



posted on Jul, 15 2012 @ 01:53 PM
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reply to post by bigfatfurrytexan
 


What happens when the shuttle runs out of cooler areas to warm? Now we have the entire shuttle heated and the only way to lose heat is in the form of infrared radiation or other forms of electromagnetic radiation since thermal convection and conduction are already ruled out because we are in a vacuum.

Correct me if I'm wrong but that would mean the shuttle would have to reflect and radiate the incoming energy or it's temperature would slowly increase, right? Even 1% more energy in than out would mean a temperature increase albeit a very slow one. So that's why i assumed that the shuttle needed the shadow of the Earth to regulate it's internal temperature because being in constant sunlight would mean an increase in energy until equilibrium. What i mean by that is until the shuttle starts glowing and emitting just as much energy as it is absorbing. Please feel free to correct me if i am wrong.



posted on Jul, 15 2012 @ 01:58 PM
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wow, triple post!
edit on 15-7-2012 by bigfatfurrytexan because: (no reason given)



posted on Jul, 15 2012 @ 01:58 PM
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See, i mean it. Triple post. It must be a record!
edit on 15-7-2012 by bigfatfurrytexan because: (no reason given)



posted on Jul, 15 2012 @ 01:58 PM
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Originally posted by epsilon69
reply to post by bigfatfurrytexan
 


What happens when the shuttle runs out of cooler areas to warm? Now we have the entire shuttle heated and the only way to lose heat is in the form of infrared radiation or other forms of electromagnetic radiation since thermal convection and conduction are already ruled out because we are in a vacuum.

Correct me if I'm wrong but that would mean the shuttle would have to reflect and radiate the incoming energy or it's temperature would slowly increase, right? Even 1% more energy in than out would mean a temperature increase albeit a very slow one. So that's why i assumed that the shuttle needed the shadow of the Earth to regulate it's internal temperature because being in constant sunlight would mean an increase in energy until equilibrium. What i mean by that is until the shuttle starts glowing and emitting just as much energy as it is absorbing. Please feel free to correct me if i am wrong.


Well, we can discuss supposition all day. But it will never really matter so long as there is only 1 sun in our solar system, and reality remains 3 dimensional. Since the sun is only on 1 side, there will always be a cooler space.

Since there is no air, there is nothing external to insulate the shuttle. Heat is not tangible, it is nothing more than the disturbance imparted to matter as energy moves through it. The matter takes up a higher amount of energy, and its heat rises. As it loses the energy, its heat dissipates and it cools. Heat is not tangible. It is a by product of energy. A disturbance. It is why superconductors don't create a lot of heat. They pass through without resistance (the measurment we call "Ohms") and don't create heat. It is why your computer has a fan, and why "quantum computing" and other ideas are so attractive. The biggest impedement to faster computing is heat dissipation. As the electricity runs along circuits, the resistance creates heat. Heat is a disturbance, and causes noise in communication. It is why heat on the nanoscale is called a "phonon". It is "noise" in the signal (energy).
edit on 15-7-2012 by bigfatfurrytexan because: (no reason given)



posted on Jul, 15 2012 @ 02:04 PM
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reply to post by bigfatfurrytexan
 


I found this page on NASA's website talking about the space stations heat exchange systems. They use a combination of reflective Mylar fabric and a liquid heat exchange system that radiates the heat off into the space protected by the shadow of the station. Here's the link to the website science.nasa.gov...
edit on 15-7-2012 by epsilon69 because: grammar



posted on Jul, 15 2012 @ 02:11 PM
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Originally posted by bigfatfurrytexan
As it loses the energy, its heat dissipates and it cools. Heat is not tangible. It is a by product of energy. A disturbance.


Heat may not be a very useable or useful form of energy but it is still a form of energy. Heating water up to create steam; to drive a turbine as primitive as it sounds is still the main way we power our society. Heat can still be transformed into higher forms of energy, but it must be done so extremely inefficiently.



posted on Jul, 15 2012 @ 02:25 PM
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The fundamental, scientific, and mathematical definition of temperature is based on the speed of collision between the atoms and molecules that compose a substance.

Normally, atoms and molecules are in ballistic motion and strike their neighboring atoms and molecules--rebounding and continueing in perfectly elastic collisions. Temperature is a measure of how fast the atoms and molecules move and how hard they hit and rebound. Hot substances contain atomic particles moving relatively fast and cold substances contain particles moving relatively slowly. At absolute zero the particles in a substance no longer move or collide, they remain in whatever arrangement they had when the temperature became -273 C, 0K or absolute zero.

Since space has no matter to collide with, anything in space will cool, as the atomic particles at the surfaces of the substance will have nothing to bounce them back into the substance and the kinetic energy that is temperature will be lost over time.

Atomic particles absorb light waves and so increase their energy. Light waves of the Infra Red spectra are know to increase the heat of a substance and so must cause and increase in atomic particle velocity in some way. And microwaves are know to heat water molecules.

So the sun would heat you direcly from radiation and particles it emits, but the sun doesnot heat the space that you fly through.



posted on Jul, 15 2012 @ 02:37 PM
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In space light equals heat. A satellite in space, the side facing the sun will heat to about 150*C (about 300*F) while at the same time just inches away on the back side in the shade the surface will be as low as -273*C (-459*F) or just a bit above absolute zero. Space is a very ruff place. You can get 700* F temperure swings in just a few seconds.
Space is the idea environment for thermoelectric generators. Too bad they weight s bit too much.



posted on Jul, 15 2012 @ 03:12 PM
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"""Space is the idea environment for thermoelectric generators. Too bad they weight s bit too much."""


That's why they are using Tethered satellites instead. The incoming energy hits the natural and man made Radiation belts....they are using tethered satellites to receive the incoming highly charged particles as they hit the Radiation Belts.

Believe it was early 2011 when the Air Force issued the contracts to build them. They did earlier tests with the Shuttle and satellites tethered to it. At first they got much more energy than they were expecting.

Many countries protested the Tethered Satellites, one major complainer was New Zealand. They KNEW what we could do with that energy...discharge it to the atmosphere to make life not so good for some people. Make an Army...er an entire country unable to get up and do anything. Well.....we got it. Cross your fingers.



posted on Jul, 15 2012 @ 05:47 PM
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Originally posted by epsilon69

Originally posted by bigfatfurrytexan
As it loses the energy, its heat dissipates and it cools. Heat is not tangible. It is a by product of energy. A disturbance.


Heat may not be a very useable or useful form of energy but it is still a form of energy. Heating water up to create steam; to drive a turbine as primitive as it sounds is still the main way we power our society. Heat can still be transformed into higher forms of energy, but it must be done so extremely inefficiently.


Heat tends to be a display of entropy. Heat is created as a by product of energy transfer. Thus, some energy is lost as heat.

At least, in the manner we are talking. Thermal energy is not always a by product. But in the context of this conversation, it is.



posted on Jul, 15 2012 @ 05:57 PM
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Originally posted by jiggerj

Wait a minute, wait a minute! lol We just made clear that there aren't enough atoms in outer space to radiate heat. So, if the atoms of the shuttle heat up, that heat energy has to go SOMEWHERE. If not in the space surrounding the shuttle then where does it go before it literally boils the shuttle?


You're sort of conflating a few things. Quick review:

Common ways for transferring heat are:

1) convection - this works only in a working fluid, like on Earth, where the working fluid is air. The air in a boundary layer around the object to be cooled is heated by conduction and radiation, then loses density, and rises away from the object, being replaced by cooler air. Doesn't work in space.

2) conduction - an object can shed heat by dumping it into a heat sink, which can be anything cooler with some thermal capacity. On Earth, this happens a lot by transferring heat to the surrounding air. Conduction still works in space, if you've got a heat dump, but for something isolated like a shuttle, doesn't count.

3) radiation - any object with a temperature higher than absolute zero is always emitting EM radiation. Any object that is also not perfectly reflective (none are) will always be receiving EM radiation from the environment. This ends up as heat. Whether an object is getting cooler or hotter depends on the balance of what comes in and what goes out. This is mostly what you get in space. The "goes out" part works real well, because in general emitting to empty space might as well be to absolute zero. Since the amount of energy you radiate out is related to the fourth power of the temperature difference, and the background of space is within a few degrees of zero, you dump heat into it pretty aggressively.

4) sublimation/evaporation - any object that can shed its faster moving molecules can dump heat really effectively. This is used a lot by NASA in a cooling technique called sublimation. Basically you spray a fine mist of water on a heat sink, dump the heat into the water, and the water will pick up the heat and depart into space with the energy

To answer your statement directly, radiation doesn't depend on atoms in space. That would be convection or conduction. You can pretty much scratch those. Radiation always works. Whether it's working in your favor or not depends on the gozintas and comzoutas.

edit to add: The shuttle does a trick with the bay doors. Sorry, forget you guys might not catch this stuff. Ever wonder why you always saw the bay doors open all the time during orbital phase? The inside of the doors is a radiator for the shuttle's cooling systems. You pipe your cooling fluid (I think they used glycol) through the radiators on the inside of the doors, and let it passively radiate the heat away. It's a nice big surface, really dark, really emissive. And you turn the doors to the shade. Voila, thermal balance.

Older craft (Apollo etc) used "passive thermal control", otherwise known as a barbecue roll. You just put some spin on the craft such that the sunward side rotates through darkness. Doesn't have to be fast. It doesn't change your overall heat balance but it evens out the load. They also used a sublimator.
edit on 15-7-2012 by Bedlam because: (no reason given)



posted on Jul, 15 2012 @ 06:17 PM
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Originally posted by Pervius

That's why they are using Tethered satellites instead. The incoming energy hits the natural and man made Radiation belts....they are using tethered satellites to receive the incoming highly charged particles as they hit the Radiation Belts.


Um, no. It's complicated, but that's not what's happening.

There's another very active poster (hey zorgon!) that gets this confused too, but he's got an entire CT cosmology based on it and I hate to pop his bubble.

There are several reasons to tether. I've only got about five minutes before I have to head out so I can't explain all of it. All tethering is not for the same reason. However, most CTers tend to conflate all of it together without making any distinction as to what SORT of tether and why it's there, and end up with some conclusions that are no longer reality-based.

So, first, all tethers are not the same, and are not for the same reason. There are both qualitative and quantitative differences. Sort of smoogeing them all together in one lump is like saying "a cable is any twisted assemblage of fibers. Cables are used to anchor warships at sea. Threads are exactly like cables because they're twisted fibers. Therefore sewing clothes is like anchoring warships at sea, and the reason clothes are sewn is to hold you in place during marine warfare"

One reason you see tethered satellites is, they're establishing a large aperture. You see this in both optical and radar ground observation satellites. The maximum resolution of ground detail is limited by aperture size (and a couple of other things). The larger your aperture, the better your resolution. You can only get so much aperture from one satellite - a lens can only be so big, an antenna structure can only be so big. So, to work around it, you make fake apertures. One way is to do something like SAR which I don't have nearly enough time to explain, but you can do it with one satellite and fake the aperture with math, sort of.

Another is to have an assemblage of satellites that are tethered with a VERY inelastic tether (the problems with making this work are many), and spin the group so that the tether is in tension. Then you can combine the optical (tough!) or radar (easier) data from the satellites and fake an aperture as large as the entire group again using math. That's what you see tethered Navy radar sats doing, or tethered NRO optical sats doing (cough cough).

That's 99.9% why you see that done.

The other tether is a loop, albeit long and flat in many cases, that's used to intercept geomagnetic field lines. By throwing a load on it, you can apply drag to the satellite and move to a lower orbit. I suppose you could theoretically apply power to it and move to a higher orbit, but it would be remarkably unstable and you couldn't maneuver with it, just adjust speed. Although you'd be torquing all over the place too.



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