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Coriolis Effect--Science or Superstition?


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Then how come rockets launched from the equator get a larger boost than rockets launched closer to the poles?

That is a wonderful question. That is one of the perspectives I have used to try and test or analyze Coriolis.

First, to give you a straight answer to your question: They Don't. Like all the other Earthly physical evidence of the 'Coriolis Effect', this one won't stand up to even mild logical scrutiny. I have searched everywhere I could think of on the web. I have been to every public and college library in this area. I have written to NASA, Goddard, JPL, everywhere I could think of. I have found NO scientific evidence of such a boost.

Of course there WOULD be such a boost if Coriolis' basic hypothesis were true--that 'space speeds' of Earth latitudes are REAL (physical facts). Which is simply bogus.

If you BELIEVE in Coriolis, then you would naturally BELIEVE that latitude and azimuth physically affect the ballistics of Earth- escape rocketry. But it is a belief, not a fact. SUPERSTITION AND LEGEND, not science.

Thanks for your question. Regards, CNG

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Then how come rockets launched from the equator get a larger boost than rockets launched closer to the poles?

Tormod: That is a wonderful question. Rocket-related science didn't exist when Coriolis presented his hypothesis about 150 years ago. But that relatively new science does provide a means of demonstrating the Coriolis effect caused by Earth's rotation (or the lack of same).

(A major problem in trying to analyze Coriolis is staying on track. Discussions tend to jump from latitudinal rocket boosts to Foucault's pendulum to weather phenomena, and so forth. Which destroys , rather than helps, the analytical thread. So I would suggest to everyone following this thread that they try and stick with us for now on this one artifact--latitudinal rocket boost--before moving on.0

I have spent many hours looking for evidence on this. Internet, several libraries, calls and letters to NASA, Goddard, JPL, institutes and universities. I have found NO actual data to support the widely held belief in latitudinal rocket boost. This is one of those scientific 'facts' which "everyone knows", but in reality seems to be legend rather than science. If ANYONE has seen actual data verifying the latitudinal rocket boost phenomenon as scientific fact, please come forward. EVERYTHING else I have studied leads me to the conclusion that this rocket boost idea is bad science--that the whole gamut of Coriolis 'science' is really Coriolis 'lore'.

The fundamental question is whether the 'space speed' of a particular Earthly latitude has physical relevance in Earth. The 'space speed' of a launch pad in Florida would be approximately 3% of the horizontal velocity required to achieve orbit. Even with all of the meteorological and engine performance variables, I'll bet you that every time a rocket puts something into orbit a knowable record is made which would conclusively prove or disprove the latitudinal boost idea--which goes to the essence of Coriolis.

I have been amazed to find an apparent absence of any Coriolis test as an offshoot of modern rocket science. I have asked dozens of exalted physicists this related question, "At what precise moment in the chronology of a shuttle mission does the shuttle cease to rotate precisely in synch with Earth?" Guess what--none of them had ever thought about that--and none of them could even come up with a cogent answer. In other words, the amount of academic energy spent on the basic facts of Earthly motion is shockingly tiny.

It comes down to whether 'space speed' computes to physical momentum. All of my analysis leads me to the conclusion that it does NOT.

So my short answer to your great question--how come rockets get a boost?--is this: they don't, actually.

Regards, and many thanks for your question. CNG

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I have spent many hours looking for evidence on this. Internet, several libraries, calls and letters to NASA, Goddard, JPL, institutes and universities. I have found NO actual data to support the widely held belief in latitudinal rocket boost. This is one of those scientific 'facts' which "everyone knows", but in reality seems to be legend rather than science.

The French Ariane rockets can increase their payload by more than 20% when launching from French Guiana - almost slap bang on the Equator - as compared to a similar booster launched from Cape Canaveral.

 

The US also launches from Canaveral and not, say, Alaska, simply because Canaveral is much closer to the equator. They do this because at the equator the rocket is already travelling at close to 1,700km/h relative to the Earth's centre of mass. If they launched from the pole, the rocket would have been travelling at 0km/h relative to the center of mass.

 

I don't think you have contacted NASA, Goddard or JPL - they would've told you the same thing. A quick search on Wikipedia might even illuminate the issue for you - http://en.wikipedia.org/wiki/Rocket_launch_sites

 

But this has nothing to do with Coriolis. This is simply relative motion. However, when you launch a rocket straight up, and you see the sucker curving over to one side (barring intentional changes made to the flightpath to achieve orbit) as its rising, that would be attributable to Coriolis.

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That is a wonderful question. That is one of the perspectives I have used to try and test or analyze Coriolis.

First, to give you a straight answer to your question: They Don't

...(snip)...

If you BELIEVE in Coriolis, then you would naturally BELIEVE that latitude and azimuth physically affect the ballistics of Earth- escape rocketry. But it is a belief, not a fact. SUPERSTITION AND LEGEND, not science.

Thanks for your question. Regards, CNG

 

What utter hogwash.

 

I work for a space agency and the very reason geostationary satellites and interplanetary probes are launched as close to the equator as possible is exactly the speed boost the get. this is mathematically very simple to prove. If you have not gotten any response from the agencies you have contacted I suspect your approach has been thrown in the loony bin.

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But this has nothing to do with Coriolis.

 

Or DOES it? Remember how this thread started out a few days ago? The reason I started out with the question about the source of the force which causes Earth to rotate is my belief that this gets right straight to the essence of the UNWRITTEN assumption upon which everything related to Coriolis actually relies. This is the universally accepted belief, as conveniently found just now in Wikipedia, on a page called "Rotational Energy": "Rotating objects contain kinetic energy.....Earth has a large amount of rotational energy..."

But a planet rotating in space and the globe you may spin there in your office operate according to entirely different laws of motion. Earth's motions in space do not (can not) have to be accounted for in terms of expression of energy. Therefore any hypothesiis which is essentially an extrapolation of the premise of Earth as a dynamic exhibit of kinetic rotational energy is bunk (as in its literal definition: pretentious nonsense).

If you challenged Jerry Falwell to debate his religious beliefs, he would end up waving his leather-bound Bible in the air and saying. in essence, "Nyah, nyah, na na nyah nah!".

Surely lovers of the scientific method wouldn't resort to that class of argument.

I find it slightly ironic that I have so much more faith in your intellect than YOU do yourself. I believe that you are every bit as smart as Coriolis. As Foucault. As all the well-meaning but misguided souls who have written all those thousands of pages of bogus Coriolis- related material (including everything you so confidently cited in your last post) into the body of 'scientific literature'. I believe that you have the ability to give ANY sacred cow of science an independent, careful, analytical, scientific examination.

I looked around on Wickipedia as you suggested, and found neither any data nor any cogent reasoning validating or correlating Coriolis with alleged Earthly kinetic rotational energy, relative motion, fluid dynamics, or any other component of the Coriolis world view.

If there is any actual evidence out there which would shed light on Coriolis, by all means let's look at it! That's why I think modern rocketry gives us such a great opportunity to test the old boy's work.

But waving a book in the air is a far different animal than actually analizing a part of that book. I have a little saying posted on my wall, and I like to re-read it from time to time. (It is an elegant way of saying, "Question Authority"): Believe nothing, no matter where you read it or who has said it, unless it agrees with your own reason and your own common sense--buddha.

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What utter hogwash.

 

Tormud: There, there. Calm down. Don't get upset. I'm saying you have been taught some bad science--not that you're a bad guy (or loony). If what you say is scientific fact, then I'll happily eat my hat. It either is or it isn't. If you refuse to discuss it, that's up to you.

 

Thanks for your interest, anyway.

 

CNG

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the reality behind Coriolis

 

No doubt most of the original resistance to Galileo's findings as to Earth's motions relative to the Sun arose from the appearance to an observer that Earth is a stationary platform. Absent wind and earthuakes: ponds and glasses of water remain perfectly still, grass and trees grow straight up, everything has an assigned place, equilibrium is the rule. No one had ever observed anything in Earth which cast doubt on the perception that the Sun was orbiting Earth.

Which is why Galileo's scientific search had to be OUTSIDE Earth--using astronomy. But once the true behavior of the Solar system became indisputable, a related belief arose, and persists to this day: that since we KNOW that Earth in fact rotates, there simply MUST be Earthly evidence of that fact--it is simply a challenge, a test of intellect.

Enter Coriolis and his space-speed based concept of Earth as a mosaic of bands of differing momentums parallelling the rotational equator. So Earth isn't a big ball of boring equilibrium, after all. Travel between momentum bands will be deflected. Which sounded like reality to everybody who thought they understood it, and has been part of accepted science ever since.

Obviously, the tools available to science have advanced amazingly since Coriolis' day. But as best I can tell, no modern scientific tools have ever been used in direct conjunction with Coriolis. I have been studying this area for ten years. As in reading, thinking, visualizing, testing, analyzing, and thinking some more. When I suggest, challenge or beg physicists to join me in examining Coriolis, the standard response is like Tormud's: the very idea of QUESTIONING Coriolis is ridiculous--loony.

So I have been trying to find a way to sneak up on them and trick them into thinking. One of the better tactics I came up with was to ask them, "At precisely what point in the chronology of a space shuttle mission does the shuttle cease to rotate precisely in synch with Earth?"

With all the modern tools-- astronomical telemetry, computers, lasers etc--there is no need to speculate. With the application of the right tools, we can absolutely prove or disprove whether travel between different 'space speed zones' results in E/W deflection. Is N/S travel an exception to the apparent principle that every particle (moving or not) in Earth's gravitational field naturally circles a common axis at a common angular velocity (360 degrees per day)?

Tormud no doubt knows how the 'ground tracks' of orbiting shuttles are produced. I am assuming that the 'ground track' visuals we see on TV are based on actual astronomical positioning technology (as opposed to theory-based computer models). So I believe it is most significant that the precise point in a shuttle mission when the shuttle ceases to exhibit a base eastward rotation of precisely 360 degrees-- absolutely unaffected by any underlying surface 'space speeds'--appears to be the precise moment when escape / orbit linear velocity is attained. It sure looks that way to me. And, if so, then thousands of scientific encyclopedias are wrong. And latitude in fact has no effect on escape velocity / payload of Ariane or any other rockets. And it is pure fluid dynamics, and not 'space speeds' which control weather systems. And something besides 'space speeds' is making all those pendulums wander around in circles.

But of course I don't have access to that arsenal of technology. But I'll bet that Tormud does. One of us IS loony--either Coriolis or me.

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Tormud

 

Hey pal, learn to read.

 

There, there. Calm down. Don't get upset. I'm saying you have been taught some bad science--not that you're a bad guy (or loony). If what you say is scientific fact, then I'll happily eat my hat. It either is or it isn't. If you refuse to discuss it, that's up to you.

 

You should be careful with what you promise. The rotation of the Earth means that the speed of the surface is much larger at the equator than at the poles.

 

Here's a PDF document explaining this en very simple terms:

http://pumas.jpl.nasa.gov/PDF_Examples/09_07_98_1.pdf

 

This not an "either or" fact. It is a measurable, useful scientific fact. And it is why they launch rockets from Korou in French Guyana.

 

Europe's Spaceport is near Kourou in French Guiana, on the northern coast of South America. This provides an ideal location suitable for safe launches over the Atlantic Ocean. It benefits from the Earth’s rotation near the Equator, which gives a free boost of 463 metres per second to eastward-launched rockets.

 

This translates into more work: Rockets launched near the equator gets a kick from the rotational motion and thus can lift much heavier loads.

 

When I suggest, challenge or beg physicists to join me in examining Coriolis, the standard response is like Tormud's: the very idea of QUESTIONING Coriolis is ridiculous--loony.

 

More hogwash from you. I have not questioned the coriolis effect, that is merely wishful thinking from you. I questioned your statement

 

Earth's rotation accelerates NOTHING within Earth's gravitational field (moving or stationary).

 

Which I have presented evidence against and which you have yet to present evidence in support of.

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I have been amazed to find an apparent absence of any Coriolis test as an offshoot of modern rocket science. I have asked dozens of exalted physicists this related question, "At what precise moment in the chronology of a shuttle mission does the shuttle cease to rotate precisely in synch with Earth?" Guess what--none of them had ever thought about that--and none of them could even come up with a cogent answer.

 

Have it occured to you that maybe there is no answer? Where do you have evidence that a space shuttle "rotates in perfect sync with the Earth"? It does no such thing.

 

At launch, a trajectory is followed. This trajectory is based on launch speed, launch location, and surface speed (among other things). On a normal launch where there is no engine problems etc, that trajectory will match the rocket's travel perfectly. They can measure to the second when the space shuttle reaches it's targeted orbit, and where. And it will be there. This has absolutely nothing to do with "lore" with with the facts of physics.

 

You may contest those facts as much as you want. Hundreds of booster rocket launches prove you wrong.

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Hundreds of booster rocket launches prove you wrong.

Tormod:

Thank you for your reply, and your continued patience with me. I keep thinking of that classic line of Strother Martin's (the Warden) in Cool Hand Luke, ('What we have here is a failure to communicate.")

Rest assured that I have read and studied many versions of that article on geography-based effects on rocketry. But I have never seen any evidence. Those positions adopt as their basis a shared assumption with Coriolis: that Earth's rotation represents the expression of energy-- that different Earth latitudes equate to different eastward momentums--that space speeds are part of the physical reality of life in Earth.

It is that basic assumption which I find bogus. I have studied this for ten years. I am striving to get someone to spend one hour--or just ten minutes--in the same kind of examination. To identify the BASIS of Coriolis--and to examine it.

 

I am very pleased to see you cite specific physical proofs of this widely held belief-- latitude as momentum. Now we're getting somewhere. And I am pleased to see that you feel passionately about the reality of this phenomenon. Now, can I persuade you to search out the BASIS for including latitudinal momentum in the plotting of the trajectory of an ascending rocket?

All of my study on this, from a hundred different angles, makes me predict that if you trace that 'absolutely scientific and proven and universally accepted fact' back to its origin--you'll find that it began with an assumption--the same one used by Coriolis--the physicality of Earthly Space Speeds.

I maintain that every rocket launch DISPROVES that universally held belief-- in the physicality of Earthly space speeds. That millions of physics students and thousands of encyclopedias assume otherwise never ceases to amaze me--but I trust my own mind.

All particles* (moving or stationary) in Earth's gravitational field naturally rotate at 360 degrees per day. * I know of only one exception--a gyroscopic high- velocity wheel. The only way to escape this rule is to escape the gravitational field (attain orbit velocity).

Question Coriolis--Please.

Thanks for your interest. CNG

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but I trust my own mind.

 

Hm.. then let's try this. Take a basketball and measure around the center of it. It's around 30 inches. Now measure the top of the basket ball (I don't have one, but I assure you it's less than thirty inches, for arugments sake let's say it 10 inches) Now make two black dots, directly above one another, one at the center, and one at the top where you measured. Now spin the basketball so it takes one second to complete a revolution.

 

Your "equatorial" dot has travelled 30 inches in 1 second. Your "polar" dot has travelled 10 inches in 1 second. It is undeniable that the equatorial dot is going faster than the polar dot.

 

Your equatorial dot has a greater velocity than the polar dot.

 

Let's say you can move the dot. Lift the dot for half a second and put it back down, the basketball continues to spin. If you move the dot left or right it lands directly on the "equator" half way around the basketball.

 

Now move the dot straight up, rotating the ball underneath it. Your dot will not land directly above it's original location (as it would if the ball were flat, or not spinning) but off to one side.

 

That's a simplified version of the Coriolos Effect. (Sans math.) It's pretty well an incontrovertible fact. Ask the British about it, it gave them some trouble during the Falklands War.

 

I know this won't satisfy though. In fact I'm not even sure what you mean by "the physicality of Earthly Space Speeds."

 

Best of luck with that,

TFS

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...I have spent many hours looking for evidence on this. Internet, several libraries, calls and letters to NASA, Goddard, JPL, institutes and universities. I have found NO actual data to support the widely held belief in latitudinal rocket boost. This is one of those scientific 'facts' which "everyone knows", but in reality seems to be legend rather than science. ...

The latitudinal rocket boost phenomenon is a physical fact. I am a scientist and aerospace engineer for a NASA contractor at the Johnson Space Center in Houston, TX. My most recent contract was upgrading the computer systems in the Flight Mechanics Lab, where they calculate and optimize orbits around planets and trajectories between planets.

 

A rocket sitting at the equator (say, French Guiana) has an inherent 1,000 mph rotation speed--just sitting there. To launch EAST into orbit requires a delta-V of 16,500 mph to reach orbital velocity of 17,500 mph.

 

A launch WEST would require a delta-V of 18,500 mph to reach orbital velocity of 17,500 mph. Delta-V ("change of velocity") is also a measure of how much fuel it will take to reach final orbit.

 

This is why the vast majority of satellites rotate from west to east. The required delta-V is less and therefore requires less fuel. Rockets are only launched westward in rare cases to achieve orbits with specific (usually military) properties.

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In fact I'm not even sure what you mean by "the physicality of Earthly Space Speeds."

 

 

TFS

Stone: Thanks for the reply. The term 'physicality of Earthly Space Speeds' is another way of boiling down the assumption upon which all the Coriolis lore rests.

After Galileo, all sane and educated people accepted the astronomical truths of our heliocentric neighborhood, and of our rotating Earth. So Sir Isaac was not confused about that when he set forth his Laws of Motion. Newton's Laws were his best and most careful conclusions as to the way things move here IN EARTH (yes, the Earth which constantly orbits the Sun at about 80,000 MPH while rotating about its own axis). That's where the word inertia comes from: IN EARTH. So Newton's prime example of an inertial frame of reference was EARTH.

Then along came Coriolis, who decided he was smarter than Newton. He

saw that IF the different space speeds of Earthly latitudes represented different PHYSICAL forces (momentums), then travel between latitudes would tend to be deflected accordingly (voila: the Coriolis Effect).

Your basketball illustration is accurate--and much more scientific than the pitiful 'rotating disk' which usually accompanies Coriolis. But the question is, "Is the rotating basketball physically comparable to a rotating gravitational field (Earth)????

If the British had something anomalitic happen down near the Falklands, and if it fit in with Coriolis, then what we have is either a new proof of Coriolis OR more bad science based on the original Coriolis assumption (Earth as spinning basketball). If you know of any actual data, I would be most happy to study it (with an open mind). But I warn you I would go in skeptical, because I have been looking for ten years for ANY actual scientific evidence--and found NONE so far.

I really think people should have required some honest scientific proof before deciding, 150 years ago--that Coriolis was smarter than Newton. Thanks again. CNG

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The latitudinal rocket boost phenomenon is a physical fact.

 

A launch WEST would require a delta-V of 18,500 mph to reach orbital velocity of 17,500 mph. Delta-V ("change of velocity") is also a measure of how much fuel it will take to reach final orbit.

 

QUOTE]

 

Pyrotex: Thank you for your reply. I am well aware that latitudinal rocket boost is accepted as scientific fact. I question whether it is good science.

The contrast between Delta V required for two different equatorial launches--one East, one West-- would be 2,000 MPH, or 6% of the combined orbit velocities. The effect would be proportional at other latitudes.

Who decided to include that data in rocket launch balistics? When? On what scientific basis?

Is there any actual data comparing the balistics of East vs West launches, factoring out meteorological variables?

Until I see data like that, I will remain firmly on Sir Isaac's side. I believe Earth is an inertial frame of reference. That a glass of water left alone will be still. That an arrow shot straight up (from any latitude) will fall straight down. That the effect of Earth's rotation here in Earth is exactly proportional to the degree to which said rotation changes Earth's form from a sphere. That a sphere is how nature describes an inertial field of reference. That a spherical pendulum does not vibrate in a plane. That if you built a big pendulum directly over the North pole it would behave EXACTLY as the same pendulum would at any other latitude. And that an ascending rocket rotates precisely in synch (angular rotational velocity) with Earth right up to the precise moment that orbital V is reached (that straying from a natural tendency to rotate precisely in synch with Earth is a byproduct of escaping Earth's gravitational field through sufficient horizontal V).

And I believe that Coriolis simply found it convenient to ASSUME otherwise (assumed physical relevance of Space speeds). And that-- over the years--no one has bothered to challenge that assumtion. As technology leaped wildly forward, no one stopped to use that new technology to test the assumption upon which Coriolis made his fortune.

You in the space travel business, above all others, ought to have done that a long time ago. But from everything I have been able to read, latitudinal space speeds received a free pass into the science of rocketry.

I know your computer programs are full of the idea of latitudinal V. And that millions of physics students for 150 years have been taught Coriolis as hallowed fact. Is it?

The only scenarios where latitudinal V would be an actual physical factor would involve travel AWAY from Earth, out into space. To try and maintain focus, let's agree to bear down on the simple logistics of attaining orbit V.

Thanks again. CNG

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