A Revolution in Thought: Part Two

[davidm]

Hey, peacegirl: In order to send spacecraft to Mars, we need to know precisely where Mars is, when we launch our rocket! Not "kinda, sorta" where it is, but precisely where it is. This is because we have to carry out complex mathematical calculations to determine where to point the rocket, so that, taking into account all sorts of factors like gravitation pull, orbital speed etc., the rocket eventually makes a rendezvous with Mars. Capice?

The point here, as I'm sure you understand but which I will now spell out so that there can be no evasion, is that Lessans and science DISAGREE on where Mars is located in the sky, when we launch our rocket!

Lessans says that Mars is located EXACTLY WHERE WE SEE IT IN THE SKY, because we are seeing it in real time! That is to say, the apparent location of Mars, and its actual location, are the same.

Science says that the apparent location of Mars, and its actual location, are different. Science says that when we look at the sky and see an image of Mars, we are seeing Mars as it was in the past; its actual location is somehwere further ahead in its orbit. We can calculate its actual location, science says, by taking into account the speed of light.

So, when we send our rockets to Mars -- bearing in mind we need to know precisely where Mars is actually located when we fire the rockets -- which caluclation do you think NASA uses?

The ACTUAL calculation that NASA uses, when aiming the rocket, is based on the SCIENTIFIC idea that the apparent location of Mars, and its ACTUAL location, are DIFFERENT. This is in direct variance to what Lessans said.

If Lessans was right, EVERY ONE OF OUR ROCKETS WOULD MISS MARS.

Instead, EVERY ONE OF OUR ROCKETS HITS MARS.

How do you explain that, peacegirl? It is a direct refutation of Lessans!

Shall we take this to the astronomy forum for you?

[peacegirl]

Originally Posted by LadyShea

NASA Toolkit from NASA.gov

These are all inferences based on what is believed to be happening. If it turns out that Lessans is correct based on actual observances on Earth, then scientists will have to rethink what they believe is occurring and why. These examples are not conclusive proof LadyShea.

[davidm]

Originally Posted by peacegirl

You're the one in extreme denial David.

Am I, now? Shall we take this to the astronomy forum, hmm?

You can't even, for a second, entertain the idea that we see the present ONLY, not the past, which means that science could have made an honest mistake.

Pray tell David, tell me how it cannot be denied that the way we calculate sending spacecraft to distant worlds must factor in the differential between the actual position we're aiming for, and the delayed light, when reaching for a distant target?

See my latest post! It's all spelled out so that even you can understand it!

[davidm]

OK, who wants to take this to the astronomy forum for peacegirl? Maybe she can explain to the big community of professional astronomers and astrophyscists over there how science has made "an honest mistake" in calculating how to send rockets to Mars -- an "honest mistake" in which, MIRACULOUSLY, all our ships rendezvous with Mars, despite the fact that, according to peacegirl and Lessans, all our calculations would have to be WRONG, since science makes its calculations on the assumption that we do not see in real time!

[Dragar]

Originally Posted by peacegirl

These are all inferences based on what is believed to be happening. If it turns out that Lessans is correct based on actual observances on Earth, then scientists will have to rethink what they believe is occurring and why. These examples are not conclusive proof LadyShea.

Indeed, peacegirl, all inferences that are based on what is believed to be happening. Believed by NASA. To launch rockets. That reach their destination.

If those scientists believed Lessans, they'd have got it wrong.

And I explained earlier what barycentering is, and how the time delay factors in, and why NASA use it when launching rockets. You ignored that post, too. As you always do when it starts clearly showing Lessans was wrong.

[peacegirl]

Originally Posted by davidm

Hey, peacegirl: In order to send spacecraft to Mars, we need to know precisely where Mars is, when we launch our rocket! Not "kinda, sorta" where it is, but precisely where it is. This is because we have to carry out complex mathematical calculations to determine where to point the rocket, so that, taking into account all sorts of factors like gravitation pull, orbital speed etc., the rocket eventually makes a rendezvous with Mars. Capice?

The point here, as I'm sure you understand but which I will now spell out so that there can be no evasion, is that Lessans and science DISAGREE on where Mars is located in the sky, when we launch our rocket!

Lessans says that Mars is located EXACTLY WHERE WE SEE IT IN THE SKY, because we are seeing it in real time! That is to say, the apparent location of Mars, and its actual location, are the same.

Not necessarily. We have to account for the movements of these actual celestial bodies. But, yes, if what we see is in real time, then the light that you say scientists are factoring in to give us the exact location, would throw them off.

Originally Posted by davidm

Science says that the apparent location of Mars, and its actual location, are different. Science says that when we look at the sky and see an image of Mars, we are seeing Mars as it was in the past; its actual location is somehwere further ahead in its orbit. We can calculate its actual location, science says, by taking into account the speed of light.

Don't you see the confusion? I am not arguing with the way they determine the location of Mars using the speed of light. I am arguing the case that they do not use the actual mathematical position of Mars based on delayed light when they factor into their equation the actual position of their target. The speed of light and this differential between apparent locations and actual locations [based on light] are two different things.

Originally Posted by davidm

So, when we send our rockets to Mars -- bearing in mind we need to know precisely where Mars is actually located when we fire the rockets -- which caluclation do you think NASA uses?

The ACTUAL calculation that NASA uses, when aiming the rocket, is based on the SCIENTIFIC idea that the apparent location of Mars, and its ACTUAL location, are DIFFERENT. This is in direct variance to what Lessans said.

If Lessans was right, EVERY ONE OF OUR ROCKETS WOULD MISS MARS.

Instead, EVERY ONE OF OUR ROCKETS HITS MARS.

How do you explain that, peacegirl? It is a direct refutation of Lessans!

Shall we take this to the astronomy forum for you?

Let's discuss the moon because man has landed there and scientists have the exact calculations. I wouldn't mind you taking this to an astronomy forum. I'd like to know where they have factored into their equation the actual versus the apparent location of the moon based on this differential of light. To reiterate, I need to see how they calculated the actual position of the moon (not Mars because there's too many unknowns that could cause a false reading); and did they use this differential of light in their equation to calculate the moon's position.

[LadyShea]

Originally Posted by peacegirl

These are all inferences based on what is believed to be happening. If it turns out that Lessans is correct based on actual observances on Earth, then scientists will have to rethink what they believe is occurring and why. These examples are not conclusive proof LadyShea.

Um, those are the terms and definitions that NASA actually uses in its programs. They apparently work since we have landed on Mars and have orbited other planets with probes.

They seem to be correct inferences.

If it turns out Lessans was right, then somehow NASA got extremely lucky multiple times since they were using completely wrong calculations.

[peacegirl]

Originally Posted by Dragar

Indeed, peacegirl, all inferences that are based on what is believed to be happening. Believed by NASA. To launch rockets. That reach their destination.

If those scientists believed Lessans, they'd have got it wrong.

And I explained earlier what barycentering is, and how the time delay factors in, and why NASA use it when launching rockets. You ignored that post, too. As you always do when it starts clearly showing Lessans was wrong.

That time delay is real because the phenomena of barycentering is real, but this has nothing to do with the time delay based on light, which is not real, if we don't see the image of the past in light alone.

[davidm]

Originally Posted by peacegirl

These are all inferences based on what is believed to be happening. If it turns out that Lessans is correct based on actual observances on Earth, then scientists will have to rethink what they believe is occurring and why. These examples are not conclusive proof LadyShea.

Yeah, peacegirl, they are inferences based on what is believed to be happening, but unfortunately for you and Lessans, they are inferences that can be TESTED. They are TESTED every time we launch a rocket to Mars. And -- Voila! The rockets arrive based on the inferences! Therefore they are no longer mere inferences, they are FACTS, and the FACT is, Lessans was WRONG, as proved by the FACT that we successfully send rockets to Mars based on the calculations of delayed-time seeing!

[davidm]

Originally Posted by peacegirl

That time delay is real because the phenomena of barycentering is real, but this has nothing to do with the time delay based on light, which is not real, if we don't see the image of the past in light alone.

What the hell does the above sentence even mean, peacegirl? You don't know yourself, do you? It's just some word spew!

The fact is, if Lessans were right, all our probes to Mars would miss it by a wide margin. Instead, they all succeed. Very dramatic and incontrovertible proof that Lessans was wrong!

Shall we now escort you to the astronomy board?

[Dragar]

Originally Posted by peacegirl

That time delay is real because the phenomena of barycentering is real, but this has nothing to do with the time delay based on light, which is not real, if we don't see the image of the past in light alone.

Barycentering isn't a phenomena. It's a mathematical technique to place all observations (made on a moving planet, Earth) at a stationary location (the Sun). This requires a correction due to the time delay of light. Please go read the NASA article.

This is how NASA records all their observations of apparent location of the planets. And they'd be getting it wrong if they believed Lessans.

Here, I'll quote it again. Are you going to ignore it again?

Originally Posted by NASA

For high precision timing work, one often has to account for the fact that the spacecraft and earth are moving through the solar system. Since the speed of light is finite, the arrival time of a photon from a target will be delayed or advanced, depending on the position of the observatory within the solar system. The amount of delay or advance varies approximately sinusoidally with time, with a period of one year and an amplitude of about 8 minutes. Any astrophysical observed variations from the target will be advanced or delayed by the same amount.

Astrophysical observed variations from the target. Like it moving, for instance.

Time to face facts, peacegirl. You asked for evidence NASA corrects for their observations being out of date due to the travel time of light. Here you have an example of them correcting for it when they use barycentering to place all observations as if they were made at the Sun. That's what you asked for. So why are you still dodging?

If Lessans is right, why does the whole wide world seem to contradict him, peacegirl?

[LadyShea]

What part of "Dragar is an astrophysicist" are you not understanding here peacegirl?

[davidm]

Originally Posted by peacegirl

...and does this [imagined] delay factor into the equation which determines the actual location of the planet?

Peacegirl has accepted the question, along with so touchingly putting the word "imagined" into brackets! So, can someone post the question there? If it posted like this, the very first thing that everyone is going to attend to is the bracketed word "imagined" -- guaranteed!

[LadyShea]

Originally Posted by davidm

Peacegirl has accepted the question, along with so touchingly putting the word "imagined" into brackets! So, can someone post the question there? If it posted like this, the very first thing that everyone is going to attend to is the bracketed word "imagined" -- guaranteed!

Her addendum is redundant. The original question already states the image of a planet produced by a telescope shows a delayed true location

I don't mind asking questions, but I don't want to sound like a child of subnormal intelligence doing so.

Can we use Dragar's question as is, or rewrite it so peacegirl understands?

[davidm]

Originally Posted by LadyShea

Her addendum is redundant. The original question already states the image of a planet produced by a telescope shows a delayed true location

I don't mind asking questions, but I don't want to sound like a child of subnormal intelligence doing so.

Can we use Dragar's question as is, or rewrite it so peacegirl understands?

Yes, actually, the adendum is completely redundant. It's just Dragar's question reworded!

I would say post Dragar's question, without peacegirl's redundancy. Maybe you can say that a child asked the question, and while you know the answer, you would like professionals to explain it.

[LadyShea]

I registered last night, but have not received my email to complete the process and I cannot post on the forums.

Looking for a NASA address to email.

[thedoc]

'For the believer, no proof is necessary.
For the non-believer (skeptic) no proof is enough'.

I am trying to come up with a comparable statement for a scientist.

'For a scientist, consistant evidence is adequate, - for now'.
In science there are no more 'Lord Kelvins' to be the 'authority' everyone is questioned.

Each individual will be a believer on some things, and a scientist about others.

A few other thoughts, according to a friend of mine,
- 'Common sense - isn't',
- 'To most people the obvious - isn't'.

I have heard it said about raising children, 'choose your battles', or make sure that what you are enforcing is really that important. This principle can also be applied to life and learning, I don't need to see and understand all the calculations or examine all the technology for a space flight to believe that the scientists know what they are doing. On the other hand I need to do the cooking my self to know how to fry an egg just the way I like it. I used to frequent dinners and would order 'home fries', I would always ask for 'well done' and I ment they should be brown and crispy. I finally started telling the watress that the only way they could be 'over done' is if they were 'black'. That helped a little but i still don't get home fries the way I like them. Some things you need to do yourself, others you need to trust that the 'experts' know what they are doing.

[LadyShea]

Sent to NASA from this page http://www.nasa.gov/about/contact/ask_nasa_form.html

Hello,

In the course of discussing light physics and vision, the question has been asked how the actual location of a planet, say Mars, is determined and if the calculation uses the apparent location as a variable. and if the calculation corrects for the light time delay. If we can get an actual formula and brief explanation, that would be most helpful.

Here is the actual question

"When sending rockets to other planets, do scientists take into account that the image of a planet produced by a telescope shows a delayed true location, due to the finite speed of light?"

Although redundant, I have been asked to include this addendum

"does this delay factor into the equation which determines the actual location of the planet"

Any response is most appreciated

[thedoc]

Originally Posted by thedoc

http://www.stargazing.net/kepler/ellipse.html

From the link,

A larger effect with the outlying planets will be caused by the finite speed of light. Indeed, one of the first estimates of the speed of light was obtained by careful timings of the eclipses of the Galilean moons of Jupiter. Light takes about 50 minutes to reach us from Jupiter, and so we see Jupiter in a position it was about 50 minutes before we looked!

Did anyone look at this, plenty of math.

[LadyShea]

It's just like Jupiter's Moons experiement, thedoc, merely an observation that could have many different explanations in peacegirl's mind.

The NASA calculations, OTOH, result in landing objects on other planets. That can't be as easily waved away by magical, possible, but unknown explanations.

[thedoc]

Using the JPL Solar System Ephemeris

from the article by JPL,

Time Delay and Apparent Direction
Specifying a planet's position in the sky can be quite confusing because it can be done in any one of a number of spherical coordinate conventions (B1950, J2000, current epoch, etc.), and there are two physical corrections for the finite speed of light. We will say more about the coordinate conventions in a separate document. For the moment let's look at the light travel time corrections
Things are always as they appear, but it depends on whom you ask. When we look at a planet we are actually seeing the planet where it was when its light left the planet. This could be minutes or even hours before the current time. The procedure for compensating for this time delay is to compute the distance to the planet at the time of observation. From this compute the light travel time, recompute the planet's position for current time minus light travel time, and use this earlier planet's position with the current observatory, moon, and earth-moon barycenter positions in the Planet(a,b,c) equation above.

The planet's position obtained from this procedure is its "astrometric" position in the reference frame of the solar system ephemeris. That is, it is the position of the planet as it would appear on the background of stars as plotted in this frame, J2000 for example.

The second correction to the apparent direction of a planet, due to the finite speed of light, comes from the motion of the observer. The same correction needs to made to star positions, where it is called "aberration of star light." The time-worn analogy is of a person running in the rain. If the person is standing still, the rain appears to be coming straight down, but, if the person is moving, the rain appears to be coming from the direction of motion. The aberration correction to the apparent direction of a star or planet, in radians, is the ratio of the velocity component of the observer's motion perpendicular to the line of sight to the speed of light. The earth's orbital velocity is about 30 km/s so the annual aberration can be much as 30 / 300,000 = .0001 radians or about 20 arcseconds.

One might ask "velocity with respect to what?" when computing aberration. In the case of stars we dodge the question by computing only differential aberration for different times of day and year, hence, the terms "diurnal aberration" and "annual aberration." For a planet we can use the observer's lateral velocity with respect to the planet, but this correction will include the time-of-flight correction for the speed of light outlined above. Since the time-of-flight correction used the planet's velocity with respect to the solar system barycenter, we can add the aberration correction using the earth's velocity with respect to the barycenter. Another, slightly more rigorous approach is to compute the sum of both corrections together by computing the direction of the planet using the positions of both the planet and observer at the current time minus the light travel time.

The Astronomical Almanac is not entirely consistent on how it lists planetary positions. Pluto's position is tabulated as astrometric. In other words, it is corrected for the light's time-of-flight but not for aberration, and the coordinate frame is J2000 as given by the DE200 ephemeris. All other planetary positions are listed as "apparent", the position with respect to the current equator and equinox including the correction for aberration. In other words, these positions are corrected for precession, nutation, aberration, and time-of-flight.

[thedoc]

Light-time correction - Wikipedia, the free encyclopedia

[LadyShea]

Good find. JPL stands for Jet Propulsion Laboratory, peacegirl

Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena [1] on the border of La Cañada Flintridge and Pasadena. JPL is managed by the nearby California Institute of Technology (Caltech) for the National Aeronautics and Space Administration. The Laboratory's primary function is the construction and operation of robotic planetary spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA's Deep Space Network. Jet Propulsion Laboratory - Wikipedia, the free encyclopedia

[LadyShea]

Originally Posted by thedoc

Light-time correction - Wikipedia, the free encyclopedia

I had posted that yesterday. She ignored it.

[thedoc]

This looked like an interesting forum to lurk around,

Apparent position and light travel time

Didn't get to look at the rest of the forum yet.