| JMSNews Community Site |
|
|
|
#1
|
|||
|
|||
|
Quote:
Changing the physical & Gravitational environment Certainly does. A Bulldozer spends a large amount of power overcoming the problems inherent in moving heavy loads around in a Gravitational field. In an often Muddy Field. It uses a low RPM, High Torque engine. An old Engineering joke: With the right transmission, you can move a freight train with a sewing machine motor. Which is true, BTW. Although you might have to wait a couple days to see how Far the train moved... A Tugboat is using a very large screw to gain power in a Fluid environment. Most of the Useful work is achieved because of the Inertia possessed by the water. A Lot of power is wasted because fluids don't provide much in the way of "Friction". And that tugboat actually Loses power if the screw turns too Fast because it can create an "air pocket" around the blades. The PT boat has it easier. Once it is Moving, the engine just needs to Keep it moving. So, it uses a much smaller screw with a totally different blade pitch. A Tugboat sized screw would actually slow it down. The PT boat's screw is designed to minimize the cavitation (the "Air Pocket" problem) effect at high RPMs. Al these differences are because the Tugboat & PT Boat propulsion systems are solving Different sets of Physics problems. Aside from the fact that they are both in Water, they are very different. A Spacecraft is operating in a Microgravity environment where Inertia is the major controlling factor. A Very different environment, Physics wise, than Water. Or Air. Oh, and as far as maintenance of high performance engines, I've done a bit of it. What you are doing is Replacing the parts that Wore Out in a Very short period of time because of the high Stress placed on them. You should see what just a few minutes of a high speed run does to a Torpedo engine. You replace a Lot of parts. Most of them without even bothering to examine them because you Know they are trashed. And because the Maitenance manual counts it as a Major Safety violation to even Attempt to re-use most of them. In some ways it would almost be cheaper to just plug in a new engine. But, that doesn't look so good when you write Specifications for them, so the specs require "Frequent Maintenance" instead. So, I'll stick to my remarks about desinging an engine to tear itself apart for a short term advantage. |
|
#2
|
|||
|
|||
|
BTW, I've seen a Tugboat going Backwards in spite of the Engines being All Ahead Forward.
The ship we were on caught the wind Broadside and the Tug didn't have nearly as much power as a 15 know breeze pushing us in the other direction. We almost lost the tug. Pinched it between Us and the pier it was trying to guide us Around. It certainly needed a few repairs. I saw (and heard) the tug's main deck "pop". It bent Up several inches in the middle under the strain. Also lost the deck rail on the pier side. The tug's entire deck crew jumped off and went running down the pier, leaving the guy in the pilot house and the engineer alone on board. Another tug that had been standing by finally managed to get in where it could help push us away from the pier. Next time we went through there, they used more tugs to Start with.
Last edited by bakana; 07-29-2004 at 06:04 PM. |
|
#3
|
|||
|
|||
|
Meanwhile, back to Easter Eggs.
Marcus is from Arisia Colony. Two parter: 1. Name the Source of the name Arisia. 2. Name two other places where tribute was paid to the same source... ![]() |
|
#4
|
||||
|
||||
|
Arisia... its a convention somewhere....... and i think it came from a comic book... but without cheating with a google search i couldn't tell ya.
Maybe thats a good hint to help someone get it... or im off and i just sent everyone off on a wild goose chase.
|
|
#5
|
|||
|
|||
|
Quote:
If you define Physics as the science, the scientific principles of physics, the laws and principles are the same. The difference would be the lack of friction in the vaccum of space vs. friction from air or water. Same physics (Newton's laws of motion, with relativistic corrections if the speed is high enough), different physical environment. The friction actually causes loss of energy... useful work is achieved after overcoming this friction. Inertia is what keeps a ship moving when you stop applying a force. In the vaccum of space there's no friction to stop it, in water the friction from the water will eventually stop the boat. The inertia of the ship (heavy solid) moving matters moe than the inertia of the water (fluid being pushed away). The ship actualy has to overcome the inertia of the water to move. If the water is still inertia would keep it still, if the water is moving in a direction at an angle to the direction of the ship inertia would keep it moving in that direction, and that has to be overcome to displace the water around the ship. Only if the water has a component of motion in the direction of the ship's motion does the water's inertia contribute. The boat would waste power if there are air bubbles in the propeller because it doesn't push the water as effectively.
__________________
Such... is the respect paid to science that the most absurd opinions may become current, provided they are expressed in language, the sound of which recalls some well-known scientific phrase James Clerk Maxwell (1831-79) |
|
#6
|
|||
|
|||
|
Quote:
![]() How about the Source? Part 1 ?? (The Comic book was a Tribute) Anyone remember Reading the series ??
Last edited by bakana; 07-30-2004 at 02:35 PM. |
|
#7
|
|||
|
|||
|
Quote:
Change Which of the Laws of Physics are most Important/Applicable in solving that Particular Problem, in that Particular Medium, using those Particular Tools, Etc. |
|
#8
|
||||
|
||||
|
Quote:
|
|
#9
|
||||
|
||||
|
Quote:
Other than that, Bakana's description of the difference between the tugboat and the PT boat nade my point for me rather nicely. They are, indeed, of different engine and propulsion designs which was my entire point. And I looked a bit through the series and discovered that the "space tugs" used by B5 are, in fact, quite different from the Starfuries (my other point). The tugs have only two booms and two engines. |
|
#10
|
|||
|
|||
|
Quote:
The Convention Arisia and The Green Lantern were two "Tributes". There is also the Anime, but that was mostly a disappointment for Lensman fans even though it's not bad in it's own right. It just went off on a tangent. Arisia Web Site Quote:
Quote:
Last edited by bakana; 08-01-2004 at 06:04 PM. |
|
#11
|
|||
|
|||
|
The War Prayer
The episode's Title is itself an Easter Egg.
|
|
#12
|
||||
|
||||
|
<<Writer Guest of Honor - Barbara Hambly - Fantasy and Historical Fiction Author.>>
The woman who Star Wars fans have no doubt hired Boba Fett to deal with.
__________________
'This peevish attention to cleanliness, Jack, this busy preoccupation with dirt has something of the Brahminical superstition about it. It is not very far removed from nastiness, Jack — from cacothymia.' 'I am concerned to hear it. Pray, is it catching?' |
|
#13
|
||||
|
||||
|
I need to reread the Lensman series.
EE Doc Smith, thank you. And for those of you looking for some good SF to read, find anything you can by H. Beam Piper (Fuzzy series, Paratime series, Lord Kalvan of Otherwhen). Last edited by NotKosh; 08-01-2004 at 07:08 PM. |
|
#14
|
||||
|
||||
|
Quote:
Quote:
|
|
#15
|
|||
|
|||
|
Quote:
And it was well enough written that it's still being imitated 60 years later... It's Still better than "Enterprise", for instance... ![]() Oh, an interesting tidbit from the web site: EE Smith article Quote:
Last edited by bakana; 08-02-2004 at 02:09 PM. |
![]() |
| Thread Tools | |
| Display Modes | Rate This Thread |
|
|