Talk:Aeolipile

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I've taken a picture and stuck it on here for now, hoping it will make it easier for readers to visualize the device; it's not a good picture, though. The model is fairly unlike Hero's original, and the photograph is poorly composed. If anyone has a better one, I hope we can replace this quickly! -FZ 23:58, 3 Aug 2004 (UTC)

The acticle I linked to has a good image, which fits what I understand it to look like; Of course, I'm no expert, and I guess we'd need permission to use it. Barring that, I've been making a 3D animation of the aeolipile, a still of which could be used, but a photograph would definately be preferable. --GalanM 05:23, Aug 4, 2004 (UTC)

Okay, I've added the image. Turns out that the image was from a government site, and therefore public domain.--GalanM 21:05, Aug 8, 2004 (UTC)

Lovely work. -FZ 12:39, 9 Aug 2004 (UTC)

1 Useful work? ? ? ? ?
2 pile: ball or gate?
3 An aeolipile is not a rocket
4 hero engine

[edit] Useful work? ? ? ? ?

Can this thing do a useful amount of work?

Is escaping steam an efficient way of using the energy?

A steam engine builds up pressure inside its boilder to severals atmospheres, and the higher the pressure the more work it can do.

The boiler of the Aeolipile works at 1 atmosphere, so its poer potential is surely very small.

Tabletop 08:50, 29 May 2005 (UTC)

There's no reason that the boiler would have to be at 1 atmosphere. To a fair degree it depends on how much heat you put under it. Beyond a certain point the jets will do what's known as 'choke' and then the pressure can go above 1 atmosphere.WolfKeeper 17:17, 13 September 2006 (UTC)

The question remains of had he connected some sort of machine to it and made it do work, would he have developed the idea into something that could do useful work. Seeing that it couldn't produce enough energy to do much work, he might have attempted improved/alternate designs that had more power. All of the basics exist in the aeolipile, it just needed some thought into how it could be used. -GamblinMonkey 04:09, 25 April 2006 (UTC)

It was used in a small way to open doors in temples and such like.WolfKeeper 17:17, 13 September 2006 (UTC)

[edit] pile: ball or gate?

I 've read a reference on Heron that called aeolipile Αιόλου πύλη or αιολοπύλη. Aeolus was the god who ruled the winds and πύλη is the greek word for gate, porte.

Although Pneumatika has survived in greek I could only find an online version translated in english (searching Heron's external links).

So Heron used this invention to open temple door with help of wind and perhaps this is how the term aeolipile occured. But we can only verify that 100% by checking a copy of Pneumatika in greek and see how he spelled aeolipile etc. MATIA 11:31, 19 August 2005 (UTC)

[edit] An aeolipile is not a rocket

An aeolipile is a rocket-like device, but it was not the first rocket.

The first reaction engine, the aeolipile (a ball that rotated as a reaction to escaping steam),
was constructed by the inventor Heron (or Hero) of Alexandria. Developments through the centuries
have resulted in two general types of reaction machines, the true rocket and the airstream engine,
commonly known as the jet engine. Unlike a jet engine, a rocket engine carries with it chemicals
that enable it to burn its fuel without drawing air from an outside source.
- The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2003, Columbia University Press

--Sean Brunnock 13:15, 13 September 2006 (UTC)

Rocket engines *are* jet engines (as in an engine propelled by a jet). And lots and lots of sources say that the aeolipile *is* a jet engine. Given that they haven't defined what 'true rocket' means, it doesn't seem to settle the question. And I googled for 'airstream engine' and dug into the hits and essentially found only copies of this article on the web. They are defining aeolipile using non standard terms. Also, rockets don't have to involve combustion, there's steam rocket cars and water rockets and thermal rockets. This definition is flawed on multiple levels. WolfKeeper 15:34, 13 September 2006 (UTC)

Rocket engines and jet engines are different. The Columbia Encyclopedia states that true rockets burn fuel and carry all of the chemicals needed for propulsion. The Columbia Encyclopedia is a reliable source. Your expert opinion is not. --Sean Brunnock 15:45, 13 September 2006 (UTC)

Careful here:

American Heritage Dictionary - Cite This Source new!
jet engine
n.
  1. An engine that develops thrust by ejecting a jet, especially a jet of gaseous combustion products.
  2. An engine that obtains the oxygen needed from the atmosphere, used especially to propel aircraft and 
distinguished from rocket engines having self-contained fuel-oxidizer systems.

Note that both definitions are used; many people use it almost exclusively in the second sense basically as in short for 'turbojet', but the aeolipile (and a rocket) is a jet engine according to the first definition.WolfKeeper 16:22, 13 September 2006 (UTC)

You gave us a definition for a jet engine. It states that they are distinguished from rocket engines. You seem to be shooting yourself in the foot. --Sean Brunnock 16:26, 13 September 2006 (UTC)

Careful again. You apparently misunderstand dictionary definitions. When dictionaries number their definitions the definitions are distinct definitions. There are *two* definitions listed above, not one. Nobody is saying that a rocket is an air breathing jet engine, but it clearly is an engine that develops thrust by ejecting a jet; so it meets that definition of jet engine.WolfKeeper 16:35, 13 September 2006 (UTC)

It's common to call non-combustion powered steam rockets, like the NERVA nuclear rocket, rockets. 83.70.70.229 23:55, 30 November 2006 (UTC)