Unofficial Tex Murphy

Intricacies is just a fancy word for details. And thermodynamics has to do with the science of energy conversion involving heat and other forms of energy. Having said that what do you all have to say about this fascinating subject?

It's needed to make cheeseburger goulash?

-Fred

It might be a hot topic but I'm rather cool towards it. I don't have the energy to think about it.

That's my job. What do you want to know about it?

The biggest pain about thermodynamics (as with everything else) is that it isn't perfect. We always lose energy in the conversion.

Flawed thinking. Just because it doesn't do what you want it to do, doesn't mean it's not perfect.

I believe in free equality for principles of nature! They are all perfect just the way they are!

Just like me!

-Fred

Totally jumping topic, Sam, when's the launch scheduled for? Is this your last one?

Well funny enough we just had a launch attempt this past Friday but encountered mechanical problems (STS-133). It's been rescheduled for the week of November 30-December 5. I'll probably be traveling to KSC for the next launch attempt. Hopefully it will go off then.

I'm currently scheduled to travel to FL for the next launch (STS-134) in February. That should be my last launch. If STS-133 doesn't go off this year it will get shoved into the February time slot and then STS-134 will get shoved down to a later time slot.

Plus we've got another launch that may or may not go next year. We've asked for one extra mission (STS-135). We are still waiting for money for that mission from Congress. We've gotten approval but no money has exchanged hands yet.

So all I know is that sometime next year I'll be out of a job. Anybody here looking for a used Aerospace Engineer?

Know that I greatly admire your work, Sam. I salute all the people who courageously strive for the human race to go upward and forward, and into the stars.

Start applying with ESA, I suppose? There's probably a whole list of space organisations. Take your pick.

-Fred

Move to Europe? That's a long way to go for a job. I am definitely not fluent in French. At least the thermodynamic equations would be the same. Haha.

At this point I'm considering a career change out of the space business for a while. Not forever. Since NASA won't be doing anything spectacular for a while I figured I should do something else until they need us again.

If not french, then certainly german.

-Fred

sam10100 wrote:That's my job. What do you want to know about it?

The biggest pain about thermodynamics (as with everything else) is that it isn't perfect. We always lose energy in the conversion.

Ah well first off Sam how long have you been posting here? Where I'm going with this is I'm trying to find out if James description "The place to discuss whatever comes to mind, from the intricacies of thermodynamics to Grandma's de-e-licious Cheeseburger Goulash recipe!" was inspired by your career path or was just a coincidence.

Also tell me a little about your job. Is thermodynamics related to rocket science? I've always thought of a correlation between the two.

I didn't even notice that James made that change. I honestly always go to the General Section and never stop off at the main page. I think it used to say something else before, but can't recall the exact wording. Maybe somebody else can refresh my memory.

Anyway, back to your other questions. I've been a poster on and off over for several years. I took a long hiatus a while back but have gotten back into a regular routine again.

Thermodynamics is related to everything in life not just rocket science. It's a fairly broad category. I'll give you an example.

Imagine you just bought a case of beer and you put in the fridge to cool. The amount of time it takes for your beer to cool is a function of the amount of beer, the thermal conductivity of the glass of the bottle or metal of the can, heat capacitance of the beer, heat capacitance and thermal conductivity of the air surrounding the beer, the starting temperature of the beer, and the current temperature of the air inside your refrigerator.

For rocket science, it's all about thermodynamics. For the shuttle we start out with liquid oxygen and hydrogen. It takes a lot of energy to keep these gases in liquid state. Then when we ignite the rocket motors you are converting solid chemical propellants into gaseous propellants. The liquid hydrogen and oxygen are also converted into gaseous propellants at ignition to produce a hell of a lot of thrust to get that big shuttle into space.

There are three major concepts that determine how all those wacky equations work.

1st Law of Thermodynamics - You can only transform energy from one form to another. You cannot create or destroy energy. Typically when you transform energy you some that has been converted to heat or friction which you can't capture. The energy is not destroyed but ceases to be energy that you can use.

2nd Law of Thermodynamics - This discusses Entropy which is a measure of the amount of disorder in a system. Very fuzzy topic, but basically says that you can't ever get 100% conversion of energy into work. There will always be losses.

3rd Law of Thermodynamics - Defines absolute zero as the temperature at which entropy equals zero which of course is an idealized case which we can ever hope to achieve.

I hope that wasn't too long-winded. It's a huge topic to summarize.

You've done this thread proud, Sam.

-Fred

Huge ain't the word for it... I did a report back in high school... I don't think the teacher even bothered to read it...

All in all, that wasn't a bad summary at all Sam, was pretty good in fact...

"The energy is not destroyed but ceases to be energy that you can use."

I agree with most of these laws but how is ceasing to be energy not the same thing as destroying energy?