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Messages - spork

1
Science / Re: Tesla's heat engine (split from DDWFTTW)
We need an update on your heat engine.
2
Science / Re: Direct Down Wind Faster Than The Wind
@Spork; Do you recall the name of the guy from Christchurch NZ you sparred with back in '09 at JREF?
I remember the guy, and the experiment, but not the name.
3
Science / Re: Direct Down Wind Faster Than The Wind
OK, Heinz has just corrected me on something...
HOLY CHRIST - you're kidding me!?
4
Science / Re: Direct Down Wind Faster Than The Wind

Sorry, I'm probably confusing things unnecessarily. I thought I remembered those gears as being 1:1, but I'm sure whatever I said in the video is right.  I do still have the cart, but it's 3000 miles away at the moment (I'm back east for the holidays).

Helicopter World and Century Heli is the same place.  I think Century Heli became the brand and Helicopter World is the shop.  But it's the same building.  Also, if I said 3" wheels in the video that will be right.

5
Science / Re: Direct Down Wind Faster Than The Wind
Hmmm... it looks like your gear-set is not 1:1.  That will have an impact on the prop-pitch and/or wheel size you want.  Let us know what the ratio is between the two gears, and which one is on the axle vs which is on the prop-shaft.

I'm surprised you're having to order anything overseas.  I'm pretty sure I could walk into Aeromicro and get all the parts needed.
6
Science / Re: Tesla's heat engine (split from DDWFTTW)

On this diagram where does the heat go in?

Also, it's not clear to me whether the ice-water is cooling the pipe or vice versa.


http://calypso53.com/stirling/Self_Cooling_Stirling_5.jpg
7
Science / Re: Tesla's heat engine (split from DDWFTTW)
I think you're proposing a heat engine that operates using the heat of the atmosphere, but no heat "flows through" the heat engine - is that correct?  If so, is it cooling the atmosphere in exchange for the work done?  If so, where does this cooling occur?  Thanks.
8
Science / Re: Tesla's heat engine (split from DDWFTTW)
Tom,  I'm probably not following closely enough, but let me ask anyway...

I think you're proposing a heat engine that operates using the heat of the atmosphere, but no heat "flows through" the heat engine - is that correct?  If so, is it cooling the atmosphere in exchange for the work done?  If so, where does this cooling occur?  Thanks.

9
Science / Re: Tesla's heat engine (split from DDWFTTW)
Sorry Spork but I have not been paying attention. 

No worries.  Thanks for checking in.

Quote
I have not read all the thread since I was here last but you still seem confused...

Fair enough.  But the rest of what you wrote seems to agree completely with my current understanding.  Can you tell me what I've posted that I got wrong?  Thanks.
10
Science / Re: Tesla's heat engine (split from DDWFTTW)

So I was on a plane all day today and you guys put out a lot of words.  I get back late Weds night and will try to start catching up then.
11
Science / Re: Tesla's heat engine (split from DDWFTTW)
Entropy as some kind of measure of "disorder" seems just a tad subjective to me. My sense of order and arangement could be different from yours and yours could be different from my friends and whatever we can think of may be different from nature.

Yes, but entropy is not defined as "some kind of measure of disorder".  That is just a very rough description of what it tells us.  As Cold One says, it's rigorously defined.

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Living things grow and increase in complexity. Are we all to believe there is no such thing as creativity. No building up of anything. Only a gradual and inevitable breaking down towards that final heat death of the universe?

Nope - that's not what the 2nd law says.  If you add energy to a system it can definitely move toward lower entropy.

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As far as mathematics goes. I suppose I could develop a mathematics based on the number of hairs on angels heads determined by their nearness to God. That doesn't necessarily make it a real thing or a real quantity.

What?
12
Science / Re: Tesla's heat engine (split from DDWFTTW)
I'm not really inclined to go into agonizing detail regarding how Stirling engines work. Information on the subject is abundant on the internet, I see no real point in my repeating it here.

And I'm not asking you to describe how a Stirling engine works - unless that happens to be exactly the mechanism you're proposing.  And even then I'm not asking you to describe it unless you want me to weigh in on the topic.

If you're getting exactly what you came here for I guess you're good to go.  Of course it doesn't seem to me that you are getting what you came here for (but I could be wrong).  As a result of your being here I've studied up on the gas laws.  I learned I was wrong about some stuff I was pretty sure I knew.  I studied up a bit on the Stirling engine.  Others have weighed in as well.

From what I understand, you don't have the funds to do the desired experiment yourself and you can't get others to do it for you.  I was under the impression that you were hoping to convince people that your proposal was workable.  But I don't see you trying to do that, so I'm no longer sure what your objective is.

My objective here is to have fun.  It's a diversion.  I enjoy discussing physics, particularly physics that seems counter-intuitive.  If that's your objective as well, then we're all having fun.

13
Science / Re: Tesla's heat engine (split from DDWFTTW)
It is true Tesla spoke about heat engines in very broad abstractions.

But this is the key to my problem.  You keep referring to Tesla and Stirling engines.  I'm talking to *you* and wanting a description of the process you proposed.  I gave an example earlier.  I'd like to see a description like...

- Heat the air in an enclosed space.
- Let that air act on a piston.
- When the piston moves it opens a valve that allows the hot air to escape...

I'm no expert on Stirling engines.  I have studied up on them as a result of this discussion so I'm pretty sure I understand the basics.  But what I'm inclined to look at is whether the proposed cycle is theoretically possible - not whether it has been achieved or could be relatively easily.

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Basically you have a can of air. Completely sealed. Heat the can from the outside and the air inside gets hot and tries to expand. Attach a cylinder with a piston and the expanding air can do some work.

Great!  That's exactly the sort of description I'm looking for.  And I have good news... that will definitely work.

14
Science / Re: Tesla's heat engine (split from DDWFTTW)
What I would propose to start with is to just take an off-the-shelf LTD Stirling engine. Get a small block of ice and put it in a dewar flask with an open top. Set the engine on top of the flask and get it running. We might just be surprised to find that the engine runs indefinately and that the ice never melts.

As far as I'm aware, no such experiment has ever been tried.
That doesn't really tell me the mechanism your proposing - but it's closer.  I could presumably study the Stirling engine and figure out for myself what mechanism you're proposing.

But what seems more to the point is that that sounds like a trivial experiment to run.  Why haven't you tried it?
15
Science / Re: Tesla's heat engine (split from DDWFTTW)
The question is simply; can we run a heat engine on ambient heat by utilizing an artificially manufactured "cold hole" or refrigerated space, without that cold space filling up with heat as the heat passes THROUGH the heat engine.
Yes - I understand that.  But that question is abstract.  I have not seen a mechanism described to attempt to do that.    I'm tempted to ask you again to describe what you propose, but I'm pretty sure we're just going in circles at this point.
16
Science / Re: Tesla's heat engine (split from DDWFTTW)
The analogy is in keeping with that which was common at the time...

But it is of no use to us now.  It seems to me that you're asking the question "is it possible?".  But I have yet to understand what "it" is.
17
Science / Re: Tesla's heat engine (split from DDWFTTW)
Of course, though clearly that was only intended as an illustration or analogy.

That particular illustration or analogy has an obvious flaw.  I'm still wanting to hear a basic plan for something that could work.
18
Science / Re: Tesla's heat engine (split from DDWFTTW)
...all the water flowing into the tank would be decomposed into oxygen and hydrogen before reaching the bottom, and the result would be that water would continually flow in, and yet the tank would remain entirely empty, the gases formed escaping
It seems to me that he's ignoring the enormous amount of energy required to separate the water into oxygen and hydrogen.
19
Science / Re: Direct Down Wind Faster Than The Wind

I'll be happy to shoot the video of that with the HFC while munching on a tasty piece of pepperoni and mushroom!

Windgrins :grin:

Do you ever make it out this way?  It'd be great to see you - even if you do put pepperoni on your pizza.
20
Science / Re: Direct Down Wind Faster Than The Wind
And I claim that the cart on the treadmill will behave completely differently if there are > 3 boxes of pizza in the same room.  So hey tiny sporky ("Chief Scientist"), have you ever indulged your keen desire for scientific correctness and integrity, and taken a look at whether your cart will continue to advance on the treadmill if there are lots of pizza boxes in the room?  No?  I thought not!  And I do not wonder why; I know why . . . . you are scared shitless of what you will see . . . . wheels magically transforming from circular to square . . . and your fantasy world will implode along with Heinz's empty head.
Hmmm... if there's pizza involved maybe I will do this experiment :)
21
Science / Re: Direct Down Wind Faster Than The Wind
Have I got this right? In HeinzFizik, any reference frame is inertial if it 'looks' stationary for a 'moment' with respect to the ground. 
Yup!  And you're an idiot if you disagree!  :)
22
Science / Re: Direct Down Wind Faster Than The Wind
There is no reference frame in which the belt as a whole is at rest, even momentarily.  Perhaps you mean the frame in which the upper surface of the belt is at rest.  (And it's more than just "momentary".)


Yeah - but you've gotta love the fact that heinz thinks moving objects are stationary if you look at them briefly enough.
23
Science / Re: Tesla's heat engine (split from DDWFTTW)
Getting back to the part I was finding counter-intuitive...  I've been trying to reason my way through the relation between energy and entropy.  Something (remotely) interesting occurred to me as a way of looking at this syringe problem...

When we compress the air with the plunger we're really doing two different things.  We're making the volume smaller *AND* we're working on the gas.  But we can look at them separately.

Let's first imagine making the volume smaller without doing any work on the gas.  To do this I'm inclined to simply push the plunger to 1/2 the initial volume with the tip of the syringe not sealed.  So we lose half the gas.  It's not a closed system at this point, but that's OK.  This is just a way to think of the problem. 

So I now have half as much gas in half the volume.  Nothing special going on here.  But what if now employ Maxwell's demon to operate the door at the opening of the syringe.  Whenever he sees an air molecule heading for the entrance he opens the door and lets it in.  When he sees air trying to exit he closes the door.  Doing this for a while will give us the original amount of gas in half the volume.  We will have compressed gas without doing any work (even if this can't actually work).  The gas molecules will be hitting the wall twice as often, but they won't be moving faster because we didn't do any work on them to get them into the smaller volume.

So now, we haven't put any work into the gas, and we haven't lost any energy to heat.  But we still have a volume that contains gas at lower entropy, and that gas can clearly do work (pushing the plunger back out).  If we allow it to push the plunger back out against some resistance, it will be doing work on the plunger.  So in addition to reducing the pressure as the volume increases, we'll also slow down the gas molecules as they work on the plunger.  In other words the gas will get colder.  We will be extracting energy that was in the gas to begin with - and cooling it down in the process.  We obviously won't be extracting the energy that we put into compressing the gas because we never compressed it.

Not sure this is accurate, but if it is, it helps make the whole thing more intuitive to me.
24
Science / Re: Tesla's heat engine (split from DDWFTTW)
Th first thing that should be done IMO would be to test some off the shelf model Stirling engines to see just exactly what is ALREADY happening.
Hmmm... Are you suggesting we should test off the shelf Stirling engines to learn more about their performance and efficiency, or are you saying we should do it to figure out how they work?  I'm not sure what you mean by "see what's happening".
I'm struggling a bit with your prior description because I have nowhere near the background you do with Stirling engines.  I have to admit I was hoping to understand your proposal based on first principles, not based on modifications that could be made to existing designs.  By that I means something more like...   
- Use a heat source to raise the temperature of the air in a closed chamber.
- Allow that hotter air to push a piston.
- Capture some of that work with a generator.
- Use that generator to run a heat pump to maintain that heat source.
...
I'm by no means proposing that scheme.  Just explaining the type of description I had in mind.  I think I stand a better chance of saying something intelligent about a process that's described in that manner.
What I would not worry about at this point would be any real world efficiency limitations.  I would of course be concerned with theoretical efficiency limitations though.  In my mind the first question to be answered is "could this thing theoretically work".   If so, then we worry about whether we could achieve real world efficiencies to demonstrate it.
25
Science / Re: Tesla's heat engine (split from DDWFTTW)
If it is true that a heat engine can use up ALL the heat that flows into it while continuing to do work utilizing the innate, internal or intrinsic energy of an expanding gas, then I believe Tesla's idea of a "perpetual' heat engine operating between ambient heat and it's own self-maintained "cold hole" is a real possibility.

Now that I've been staring at these gas laws and trying to get my head around this part I found very counterintuitive, I feel like I have a slightly greater chance of deciding whether your proposal is possible.  If I could trouble you to describe the proposed mechanism again I'll certainly noodle on it.