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Measuring The Distance From Earth To Moon
lewiz writes: "Tom Murphy at UW is attempting to measure the distance between the Earth and The Moon to the nearest millimetre according to this BBC News article. 'His tape measure will be a giant telescope at Apache Point in New Mexico. Retroreflectors left on the surface of the Moon by various space missions, including the Apollo 11 lunar landing, will also come in handy.'"
... according to my Solar Systems Dynamics textbook, we already know the rate at which the Moon is receding from the Earth: 1 nanometer/second. Which is, of course, a better precision than this group seeks to take on. But that measurement probably used the Doppler shift. It just goes to show that it's much easier to measure radial velocities than distances!
The moon revolves around the earth in an eliptical orbit, not a circular one. Unless he's talking about getting the average distance.
Jesus used to be my co-pilot, but we crashed in the mountains and I had to eat him.
...Check the Odometer on the Apollo 11 capsule.
They that would sacrifice their
Force = Weight.
the formula for Force is: F=ma, replace a with the acceleration caused by gravity and you got weight.
Only dead fish swim with the stream...
My old encylopedia says it's precisely 300,000 km and it also says that "someday we hope to go there."
All that and the Kaiser Wilhelm still doesn't know what to do with his country.
Wheeeee
Weight is the measure of attraction between two masses, such as the gravitational force between the Earth and you. But force certainly does not equal weight.
Force is also a vector, which weight is not.
What?
...his wife [sobbing]: "Dammit Tom! You could measure how far it was to the moon! But you couldn't see the distance between... between US!
Why can't he do something more useful? Like measure the cheese composition of the moon...?
Current estimates predict that all known gorgonzola deposits on Earth will be depleted by 2016. We need to think about cheese-mines on the moon now, before it's too late...
- The moon's orbit about the Earth is a 100-page equation, not a constant.
- The Earth's rotation is not circular (it "sloshes").
- The Earth's shape is not constant.
- The Earth's mass is not constant, so the general relativistic field in which the moon orbits is not constant.
- Okay, so we know where that telescope is relative to the moon. Now where is it relative to my house? To Washington? To Wendy's?
- Isn't this just an attempt by the Bush White House to wag the dog to distract attention from the fistfight the President and Vice President had during the game Sunday?
--Blair
Yes, but the moon moving closer to the Earth could seriously affect how squished I get when it lands on me.
Weight _is_ a vector. Weight _is_ a type of
force. Remember, mass is a number, weight is
a vector.
I think when they say weight of gravity they
mean that gravitons or grabity waves have
non-linear dynamics, i.e. they interact with
themselves and Einstein equations are needed to
deal with this self-consistently. But the simplest
way to correct Newtonian gravity is to analyze
corrections from gravity interacting with itself,
which could be worded as measuring weight of
gravity.
... according to Bart Sibrel :D
To sum up: "we never went to the moon, hence there are no reflectors on the moon."
Moderators: Put down the crack pipe and the mouse. Step away from the keyboard. Take a DEEP BREATH and READ. This is not a troll. I repeat. This is not a troll.
No, I don't believe the "moon hoax" loonies. Anyone with an above-kindergarten education can easily refute the "moon hoax" loonies claims.
For your amusement, this is the gallery of the 'barking mad'...
Some anonymous kook
Bill Kaysing
Ken Overstreet
"mpeeters"
Therefore, by measuring the distance to an accuracy of a millemeter, we might be able to gain some insight about: earth's gravity, the sun's gravity, and Jupiter's gravity. The point of this experiment is not to know how far it is to the moon. The point is to better understand the moon's orbit, and the various influences which affect it.
Unfortunately, he's not really measuring the distance between the centers of the two planetoids... he's measuring the distance between the top of some piece of equipment on the Moon and the lens of his telescope.
This reminds me of the human genome project. At some point, the scientists announced, "we've finished mapping the human genome! It's finished!" And as it turned out, it wasn't anywhere near completion. I believe it's still unfinished.
Is modern science really so desperate to inspire interest in people? Lies are not impressive.
I have a theory that FOX doesn't really exist and it's only a conpiracy to make us think we are dumber than we really are.
sic transit gloria mundi
The moon distance measurement is obviously good. It seeks to do something no one else has ever achived. Even if the results aren't interesting, the new techniques used are. Anyone that doesn't see its intrinsic value is shortsighted.
Too big to fail? Does that make me to small to succeed?
Weight _is_ a vector
Well, yes and no. I know the equation suggests it is (W = m.g, where bold represents vectors. But weight is not used as a vector, and it leads to silly conclusions if it is.
For example, I weigh myself here to be 100kg (or 980N) - what is the direction of this weight vector: towards the centre of the earth. Thought experiment time. Two 100kg men weight themselves, on at the north pole, one at the south pole. What is the sum of their weights?
Well, if weight is a vector then the sum is zero. If, however, you take weight as a scalar then it is 200kg. What people mean when adding weights only works if weight is a scalar. Basically, defining weight as a vector fails the common sense, similar to defining glass as a liquid as opposed to a solid.
All that is happening is that specialists are taking a word that is in common usage (weight in this case) and defining a new (and different) techincal meaning for the word, which is similar to but distinct from the everyday meaning. Then they complain when people use it in the everyday sense.
That's pretty stupid, considering the distance will obviously change more than a millimeter all the time. Hell even the astronaut's footprints will be several millimeters thick, assuming they are undisturbed still. So...within a millimeter of *what*, exactly?