[ironlung]

Anyone been watching the comedy central Dennis Leary program tonight? He was making fun of kids, basically calling them stupid. He gets a kid to put his hand into an oven that was at 270 Kelvin according to him. It got me thinking.. how many people know about kelvin as a temperature unit? People in the sciences use it all the time.. I thought it was pretty uncommon in daily lives.. but he said it as if it was an everyday 'thing'. What do you guys think?

[Maciej]

Dennis Leary really has some issues, the man acts like he's a loose cannon, and maybe he is? Either way he's got something wrong...

I don't really think many people know what Kelvin is, no one really uses it, and would only have any idea what it is if they took some chemistry classes. At least I don't think many people remember their high school chem classes, not in the US.

[EmC]

I'd stick my hand into an oven at 270 Kelvin. When I was 5 I doubt I would have because I knew not to play around the stove. But seeing how an oven at 270 Kelvin is colder than the refrigerator I don't think I would have any problems. He was probably using Kelvin because people vaguely remember it from high school chem, but other than that they are clueless. It helped him get is rant across to the audience.

[Moogs]

Pretty much... all people remember about Kelvin is that there are extreme temperatures associated with it. They don't recall how the scale works at all though. Why I remember playing golf on a sunny, 300 Kelvin day last spring.

[bassplayinMacFiend]

Well, absolute zero is zero on the Kelvin scale. If you remember that, then you'll probably be able to figure out 270 Kelvin isn't all that hot.

[Brad]

Originally Posted by bassplayinMacFiend Well, absolute zero is zero on the Kelvin scale. If you remember that, then you'll probably be able to figure out 270 Kelvin isn't all that hot.

Well, that still doesn't matter if you don't know what a degree in the Kelvin scale represents.

It's much more important to just know that 0C = 273.15K and that a degree change in Celcius is the same as a degree change in Kelvin. So, 270K is actually below freezing, roughly -3C.

[EmC]

BAWOOOOOP! BAWOOOOOP! NERD ALERT. NERD ALERT. BAWOOOOOP!


I love threads like this.

[scratt]

Yup. What Brad said.

I always rememeber it from a physics teachers lecture. We had this freaky guy who used to be one of Britain's early 'rocket scientists', retired.

He would always talk about 0K being the temperature in space and that that was about -270 degrees C, give or take.

I was reminded of it the other day in a space simulator which was showing the outside temp as -270.

[billybobsky]

Originally Posted by scratt Yup. What Brad said. I always rememeber it from a physics teachers lecture. We had this freaky guy who used to be one of Britain's early 'rocket scientists', retired. He would always talk about 0K being the temperature in space and that that was about -270 degrees C, give or take. I was reminded of it the other day in a space simulator which was showing the outside temp as -270.

Bah! Space is 2 K...

[scratt]

Originally Posted by billybobsky Bah! Space is 2 K...

And your point is?

If you mean 2K then that is about -271 degrees Celcius - what I said.

If you mean 2000 then what system are you using?

Perhaps be a little clearer...

[Brad]

Originally Posted by billybobsky Bah! Space is 2 K...

Yeah, it's impossible (as far as we know) to entirely escape all of the background radiation (and thus any heat) that presumably came from the Big Bang.

[Brad]

Originally Posted by scratt And your point is?

Note that your teacher said it was 0K in space...

[scratt]

Actually I was pretty sure that he explained that it depended on the 'quality' of the space.

By that he was talking about deep space where it really is a vacuum, and not local space which is *relatively* quite high in gasses like hydrogen.

Therefore in our Solar System, for example, the temperature is slightly higher than in deep space, where it is truly 0K.

It all depends on what part of space you are looking at.

And then we could get into issues of radiation etc..

At the end of the day to all intents and purposes, taken as a whole across the Universe the temperature of space is 0K.

There is a lot of stuff that still doesn't add up based on what we understand.. For example, the third law of thermodynamics says nothing can ever get to zero temperature, so by that definition there wouldn't be any vacuums. There are differing schools of thought on that too. Just like there are differing schools of thought on Quantum physics....

The 'background' temperature from 'radiation from the Big Bang' that billybobsky is talking about and you find talked about all over the internet, giving us a 2.7K 'background' temperatue in space assumes that this background radiation get's everywhere... It plainly does not.

As Brad says, 'as far as we know', and that is the crux.. We have barely got outside of our own pin prick of a Solar System with probes which is pitiful (in terms of cosmic scale)!

[billybobsky]

Actually, the background radiation is by definition everywhere.

Where there is universe there is background radiation. Where there is no background radiation there is no universe.

We can observe the background radiation of so called deep space and it measures 2.7 K.

There is nothing really maintaining the temperature at that point except for photons. There is no such thing as an absolute vacuum as there is always a density of photons -- to 2.7 K...

[scratt]

Originally Posted by billybobsky Actually, the background radiation is by definition everywhere. Where there is universe there is background radiation. Where there is no background radiation there is no universe. We can observe the background radiation of so called deep space and it measures 2.7 K. There is nothing really maintaining the temperature at that point except for photons. There is no such thing as an absolute vacuum as there is always a density of photons -- to 2.7 K...

Well there is background everything, everywhere.. If you want to argue semantics. That does not quantify the level of that background 'whatever' though..

But when, pray tell, were you last out in deep space with your Kelvin Thermometer?

We can be picky about this all day.. I effectively said that space was -270 degrees C which is about 3K.
I mentioned that my Physics professor said it was effectively 0K.
You then said it was 2K.
And now you seem to have picked up on my 2.7K info for the 'background radiation'.

I mean you did not even mention Neutrinos in your stuff yet.. Come on.. What about the billions and billions of those bombarding everything everywhere every second of the day and night.... Hmmmmmm.

Basically Space is Very Cold, and (back on topic) 270 Kelvin is not that cold at all.....

[billybobsky]

Its not semantics as much as science.

And yes, your 2.7 K is more correct than my 2 K... But you can't actually expect me to memorize the digit after the decimal...

Regardless. I wouldn't want to be naked in space nor would you.

[scratt]

Funnily enough I was discussing this in another forum I participate in....

And no I would not want to be naked in space with you!

You could also (based on your .7 degree of error - no pun intended) argue that the difference between 0 and 2, or even 0 and 2.7 is less than 1% of error.. Also not really worth getting het up about!

Although there are more extremes such as the cold, in a psyiological sense what would happen to the body is a very exagerated version of 'the bends', something divers experience if they have been at depth for a long time and come to the surface without allowing the increased pressure of gas in their body to release gradually at each depth as they ascend. The degree of injury and permanent damage is dependant on how deep you were, and how quickly you ascended. As you (stupidly) exit the space craft you could liken it to a diver surfacing from great depth to the surface in an instant! Obviously you will die very quickly. But soft tissue damage in the brain and other areas makes it very unlikely that you would be 'the same' after even a short exposure to *real* space. Scenes from all movies to date are very very innacurate. With the suprising exception of the scene at the end of 'Total Recall' which is, how should I put it, *interesting*! The freezing as air rushes out of your lungs would also, as others have said cool and eventually (in a very short period) freeze you from the inside out in your airways. This would be very hard to reverse even if you 'shot straight back into another air lock'! Also, if you were stupid enough to hold your breath you would rupture, and potentially (I guess) explode in a very small organic sort of way. More like a silent pop in space. By that time you would be pretty much flash frozen anyway.. So you might sort of crack and pop at the same time. The holding your breath thing can happen in diving as well, actually very easilly in the top couple of meters (as that is where the biggest change in pressure is) if you hold your breath while ascending. So, what to do? Hold your breath - Rupture. Don't hold your breath - Freeze your airways. Either way - You will freeze and suffocate. How about.. Stay in the spaceship!

[Banana]

Oh, shit.

I almost listened to the Guide....

I'm calling in for a refund...

[Brad]

Originally Posted by scratt But when, pray tell, were you last out in deep space with your Kelvin Thermometer?

The problem here is that we'll never actually be able to find anything at absolute zero with a thermometer because as soon as our instrumentation enters it, it warms it up. We might be able to make educated guesses, but we can't actually know.

There's a succinct name for this principle that escapes me at the moment. It's that we can never properly observe the natural state without interacting and tainting the results. Grrr... I know it's in one of these books I have here, but I don't feel like flipping through all of 'em.

[Banana]

Heinberg's (speeling) Uncertainty Principle.

[Luca]

Brad: It's the Heisenberg Uncertainty Principle.

Scratt, I'm pretty sure you are mistaken and you don't seem to understand the very fundamentals of billybobsky's argument. He's not arguing his opinion or anything, there is research (please don't ask me to cite it; I've heard it mentioned by numerous reliable sources but I don't feel like hunting them down right now) that says that there is background radiation. In deep space (a relative term; the space between stars is deeper than the space between planets, and the space between galaxies is deeper than the space between stars), the cosmic background radiation leads to a temperature of 2.7K.

Let me explain what that means. First of all, there are particles everywhere. Their density just gets lower and lower as you get deeper into space. But there are particles there anyway, there just aren't many of them. Those particles are moving with a certain amount of energy, and in the deepest space possible, they should have 2.7K of energy. That 2.7K comes from the Big Bang, and it's the reason scientists came up with that theory in the first place. It's possible to measure the amount of background radiation coming from deep space and that's the conclusion that many scientists have arrived at.

If you've heard the phrase "nature abhors a vacuum," that applies in this situation. There is no such thing as a perfect vacuum—the density of particles simply gets lower and lower but it's never zero. Like Brad said, if you put a thermometer in deep space, it introduces energy of its own which heats up the surrounding particles. Absolute zero is only a theoretical concept. It doesn't actually exist anywhere in the universe. You can say that deep space is "basically" absolute zero, because 2.7K is indeed very very cold and very close to absolute zero, but it's not correct to say that "basically absolute zero" is the same as "exactly absolute zero."

[Brad]

Thanks, Banana and Luca.

[Banana]

Originally Posted by Luca Brad: It's the Heisenberg Uncertainty Principle. Scratt, I'm pretty sure you are mistaken and you don't seem to understand the very fundamentals of billybobsky's argument. He's not arguing his opinion or anything, there is research (please don't ask me to cite it; I've heard it mentioned by numerous reliable sources but I don't feel like hunting them down right now) that says that there is background radiation. In deep space (a relative term; the space between stars is deeper than the space between planets, and the space between galaxies is deeper than the space between stars), the cosmic background radiation leads to a temperature of 2.7K. Let me explain what that means. First of all, there are particles everywhere. Their density just gets lower and lower as you get deeper into space. But there are particles there anyway, there just aren't many of them. Those particles are moving with a certain amount of energy, and in the deepest space possible, they should have 2.7K of energy. That 2.7K comes from the Big Bang, and it's the reason scientists came up with that theory in the first place. It's possible to measure the amount of background radiation coming from deep space and that's the conclusion that many scientists have arrived at. If you've heard the phrase "nature abhors a vacuum," that applies in this situation. There is no such thing as a perfect vacuum—the density of particles simply gets lower and lower but it's never zero. Like Brad said, if you put a thermometer in deep space, it introduces energy of its own which heats up the surrounding particles. Absolute zero is only a theoretical concept. It doesn't actually exist anywhere in the universe. You can say that deep space is "basically" absolute zero, because 2.7K is indeed very very cold and very close to absolute zero, but it's not correct to say that "basically absolute zero" is the same as "exactly absolute zero."

In theory, I could take a box made out of Tungsten and using a super vacuum, sucking out everything out of the box. Assuming that the vacuum I use is a perfect one (in reality that would be impossible because we have to have gaskets, rubbers, and whatnots which would bounce off back some materials), the tungsten would vaporize into the middle of box until the pressure equals its vapor pressure.

I've heard some says that if you reach absolute zero, the atoms would collapse and disappear... bullock, I say.

[scratt]

Originally Posted by Luca Brad: It's the Heisenberg Uncertainty Principle. Scratt, I'm pretty sure you are mistaken and you don't seem to understand the very fundamentals of billybobsky's argument. He's not arguing his opinion or anything, there is research (please don't ask me to cite it; I've heard it mentioned by numerous reliable sources but I don't feel like hunting them down right now) that says that there is background radiation. In deep space (a relative term; the space between stars is deeper than the space between planets, and the space between galaxies is deeper than the space between stars), the cosmic background radiation leads to a temperature of 2.7K. Let me explain what that means. First of all, there are particles everywhere. Their density just gets lower and lower as you get deeper into space. But there are particles there anyway, there just aren't many of them. Those particles are moving with a certain amount of energy, and in the deepest space possible, they should have 2.7K of energy. That 2.7K comes from the Big Bang, and it's the reason scientists came up with that theory in the first place. It's possible to measure the amount of background radiation coming from deep space and that's the conclusion that many scientists have arrived at. If you've heard the phrase "nature abhors a vacuum," that applies in this situation. There is no such thing as a perfect vacuum—the density of particles simply gets lower and lower but it's never zero. Like Brad said, if you put a thermometer in deep space, it introduces energy of its own which heats up the surrounding particles. Absolute zero is only a theoretical concept. It doesn't actually exist anywhere in the universe. You can say that deep space is "basically" absolute zero, because 2.7K is indeed very very cold and very close to absolute zero, but it's not correct to say that "basically absolute zero" is the same as "exactly absolute zero."

Luca.. I understand perfectly what Billybobsky is talking about. And I thought we had brought this to a happy ending anyway... We agreed to differ on a light hearted note. Although I think we basically have the same scientific knoowledge sources...

Whilst the wealth of information on the internet seems to suggest that space is 2.7K it is all based on theories, and long range observartions, and just because it says so on the internet does not mean it is correct, nor does it say that that is the only explanation. Simply it is the explanation that has greatest exposure to date.. Heck the internet has pictures of Kylie Minogue doing it doggy style on the top of Mount Everest.. That does not mean it's true.. Nor does half a million scientific journals that all agree mean that something is true until it has been proven in fact. Which most of our current "knowledge" about space has not!

But seeing as you wish to resurrect it.. Everything that we *think* we know about what goes on in deep space is based on theories and long range observations. The very Big Bang theory you refer to is also still conjecture. Although it is pretty good conjecture based on the evidence we have.

Brad is absolutely right about bringing the measuring implement into space would affect the surrounding environment. But then we are talking about theories and absolutes here. So even sending a probe into outer space is affecting all things, including the ambient gravity of the entire theoretical Universe.

It's like the drop of water in the sea argument. Yes it does raise sea level across the entire ocean. But by how much. A pretty pointless argument! So although I like Brad's point. It makes me chuckle, it's not really relevant to what the real temperature is in space *before* we pop out Kelvin'o'mometer out of the space ship door!

I was actually bringing billybobsky up on his 'bah It's 2K' comment, as I found it as trivial as him picking me up on my 0K comment.... I am well aware of the reasons behind space not being an absolute vacuum (in theory) and temperature never being able to reach absolute zero. That does not mean that there is no such thing as an absolute vacuum, nor that there are not places as cold as absolute zero. We just assume there are not, based on our current scientific knowledge.

But then we used to believe that travelling over 30 miles an hour would sufffocate you, and that there are weapons of mass distruction in Iraq (based on long range satellite observations)... Go figure....

At the end of the day. No one knows for sure. Scientific theories change every day, and much of what we think we know now changes over time... The intraweb is not the only course of info... Reading a few scientific journals and taking on a few new ideas from people with diverse scientific backkgrounds an theories is a very helathy thing. If we all sing the same tune and never question the established theories we'd never get anywhere..

Back to the travelling thing.. Is it still right that we believe that as you approach the speed of light your mass and dimensions will tend to wards infnity, and time will stand still? Because that is just one theory that's been around for a while.. Never made sense to me.. I mean, I understood the physics... But then something in me kind of thinks something is missing from that one....

[Luca]

Absolutely. Science is meant to be flexible and open to change, but I'm not just citing sources from the internet as if they are the gospel truth. I was reading about cosmic background radiation long before my family even had internet access, in astronomy books when I was growing up. Yeah, it was really basic but the concept was the same. And that concept has been the same for decades. Cosmic background radiation is an almost universally accepted, well-founded theory, one which probably won't be going away for a while. There may be changes in how accurately we can measure the level of radiation or new theories as to where the radiation comes from, but it's pretty widely accepted that the radiation is a result of the Big Bang. I think the point is it's going to take a LOT of new research, helped along by a lot of new technology, in order to change the way the theory is accepted. But I won't dispute that it will likely change in the future, because I'm almost certain it will (eventually).

I didn't think I was resurrecting anything though... right now, where I am, it's 2 AM, and your conversation took place around 9-11 PM, and it didn't look like you really finished the conversation. I was just picking up where you had left off.

[scratt]

Originally Posted by Luca I didn't think I was resurrecting anything though... right now, where I am, it's 2 AM, and your conversation took place around 9-11 PM, and it didn't look like you really finished the conversation. I was just picking up where you had left off.

No worries, man! It was just sort of becoming a pointless circular debate.. But your input is cool. Always.

It's a subject matter very close to my heart, so perhaps I came accross spikey. Didn't mean to.

I am working on a Mac based simulation that relies on an awful lot of cosmic physics and contemporary theories at the moment so actually find this whole field fascinating.

By the way.. have you ever read 'SuperNature'. I read this when I was still in school.. Amazing stuff. Not sure how much of that book is still relevant or is now considered old news... But most of what I rememeber from it is still in place today, as you say. Hawkins also has some amazing stuff to say.

I tend to think that a lot of our explanations of things, particularly Black Holes, are just too simple in a lot of ways, and we are kind of fitting things into our cosmic view, which is pretty blinkered.

A lot of our theories are so dependant on a few basic assumptions that we see as being correct, when it would only take one small new discovery for us to realise that everything is wrong.

Take for example even the question of how big the Universe is?

Is it infinite? Can anyone imagine that? Has it been here for ever? What was around before the Big Bang, if that indeed happened?

Is the Universe some kind of circular *thing* which appears infinite but si not in fact. In which case what is outside it?

Light is a waveform and not an particle? Right! It has no mass, but it is a particle?
Hmmm.... But if an object travels at the speed of light it has inifinite mass, length and time stands still, relatively.
So how can light be a particle? Oh no it's not, it's a particle and a waveform..
Aww come on.. You can't tell me we have all the answers, by any means!

I know I am oversimplifying.. Anyway..

Shrodingers Cat...... and on and on and on.....

So you see if any one of those theories fall down at any point, how many other dominoes do they take with them?

We can only imagine, or experience that which we are able to conceive...

If I put a big blue dragon in front of you and your mind told you that that is impossible, what would you see?

But now I am crossing into philosophy.. But I hope you get my point..