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Physicists Find More Precise Gravity Number
DM writes "Physicists establish the most precise measurement ever achieved of Isaac Newton's gravitational constant and use this information to recalculate the mass of the earth. Check out the article at ScienceDaily." Now if they could only recalibrate to make me really buff, that would be nice.
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CAIMLAS
~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
I am very close to finalizing my anti-gravitation device and the only thing I needed to include in my source code was the exact definition of gravity. I should now be able to release (Open Source, of course) the code and agdk (anti-gravitation developer kit) in the next month or so. Here's some early demos
-- Stalkers Should be Shot in the Head
...42 by any chance? ;-)
Okay, so they found a much more precise constant. But I don't see the new constant in that story/press release - its just filled with blurbs about how important it is that they know it. Can anyone find it?
Sorry, Emmett. They're scientists, not miracle workers.
Disclaimer: The opinions expressed are not necessarily my own, as I've not yet had my medication today.
Seems they tried this before, with a big failure:
;)
:)
""That is a huge embarrassment for modern physics, where we think we know everything so well and other constants are defined to many, many digits," Gundlach said. "
Hmm.. well it's great that they have recalculated Newton's Gravity Number, but.. in what will we gain with knowing the mass of Earth?
"Gundlach acknowledged that the more precise calculation probably won't mean much to the average person."
Ahh here we go.. not much to us, hrmm..
What will many different Earth Scientists/Chemists learn from this then? The article doesn't seem to mention anything.. Wow, we know the Earth's mass, lets move on to the next operation to waste money..
How really important is the value of 'G'?
If this is going to make teleportation devices and enhance lightspeed development, I'm all for it! I can't wait to teleport to China and back within seconds, wouldn't anyone love that?
""Gravity is the most important large-scale interaction in the universe, there's no doubt about it," Gundlach said. "It is largely responsible for the fate of the universe. Yet it is relatively little understood.""
What? I'm sure every student in every High School does *many* things concerning gravity, and different sorts of energy and how gravity affects them.. at least *I* did..
Gravity the most important part of this world? I thought it was evading black holes.. Oh wait, that does deal with gravity!
Ah well, anything new about our Earth to help to explain it is worth it to me. Good work Gundlach!
"There are no shortcuts to any place worth going."
"Be regular and orderly in your life, so that you may be violent and original in your work." -Flaubert
Around here the term "Buff" is reserved for the unique bulging curvature of "the mound of venus". That female body part for which we have found so many colorful names ( including "Red" ).
In this case the various stages of Bufness are on a scale similar to the various levels of Bufness the way emmett probably meant it. Therefore by being "really buff" would make you attractive to Heterosexual men. The same kind who get mad when the realize they are dating a man in disguise.
So emmett. Next time be more careful what you wish for. A larger more muscular body is more accurate.
--= Isn't it surprising how badly I spell ?
In other news, Physicists admit to generally rounding their constants to 3, 2, or even 1 significant digit.
"I always used Pi Squared for g, the math seemed to come out right", said local physicist Fred Flintstone.
However, his assistant Barney Rubble disagreed, saying "Gee, Fred, I thought Pi was somewhere between 2 and 5. That doesn't sound very precise to me!"
Apparently the tried-and-true method of waiting for an apple to fall from a tree and counting "One Mississippi, Two Mississippi..." doesn't offer significant resolution to reliably yield a better approximation for g, either. Scientists are now experimenting with coconuts, and early results look optimistic.
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pb Reply or e-mail; don't vaguely moderate.
pb Reply or e-mail; don't vaguely moderate.
I have an energy well test in two days. These results will almost certainly affect my calculations by the 0.0015% error that the previous G value had. Looks like I'll lose 0.0015% on each question of the test now.
Cheers to Ep = -GMm/d
amnesty
I would laugh if the unified theory wasn't completed because they weren't using the right G.
"Sorry, but you know all that research you guys threw out. Well bring it back out we have a new G for you guys."
"A fool finds no pleasure in understanding but delights in airing his own opinions." Proverbs 18 : 2
Q: What do you think about American Culture?
A: I think it's a good idea.
Q: What do you think about American Culture?
A: I think it's a good idea.
(adapted from Gandhi)
Ever try to fly ... I did ... it didn't work ... no matter how many times I flapped my arms up and down I just couldn't get off the ground ... I blame science and for good reason ...
Ignore the "p2p is theft" trolls, they're just uninformed
I wonder how many other calculations and theories could be proved wrong that are belived to be true. Interesting though.
...must be some heavy packets, eh?
I use Macs for work, Linux for education, and Windows for cardplaying.
Currently, G is defined as
6.67259 x 10 ^ -11 m^3/km/s^2
and the standard uncertaintity is
0.00085 x 10 ^ -11 m^3/kg/s^2
which is quite high when comparing to other fundamental consants
-- Note: These Comments are Generated by ME! Not You! ME!
9.8 m/s^2 = acceleration in earth's gravitational field (near earth). Certainly, this is rough, as it changes depending on your distance from earth (unless I'm totally screwed up).
What they are referring to here is the gravitational constant, used to calculate the force of attraction between two masses.
"Either way, that's about 1 trillion metric tons for each person on Earth. Put another way, 1 trillion metric tons is thought to be the total
weight of all plant and animal life on the Earth's surface."
I call all the plant & animal life!!!!! (I know, I know, I'm gonna have to pay somebody rent, sigh).
It all really depends on where on earth you are. The closer you get to the center of the earth, the more gravity there is going to be. Therefore making the number higher. If you were to stand on a tall mountian, however, that number would be less.
And I was just about to use this 16,000,000 mile lever to move the world and NOW its 20 feet to short... damn scientists!
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Now if I get any problems wrong on this Friday's Final Exam in Physics I can claim I was using the new 'exact' gravitational constant =)
Nothing in our Universe is an absolute constant, ie nothing stays the same for all eternity. The fact is that not only the size of the Universe is changing and all the protons in the universe are decaying so that in 10^31 years not a proton will be left in this Universe so all atoms will decay with all protons. The actual mass of an electron is changing over time (we used to think in terms of constants and they are in comparison to a humans life time or even to a life time of the human race.) The gravitational "constant" is also changing over time however we will not see the significant change for the next ten billion years.
You can't handle the truth.
I'm a 4th Year Honours Physics Major who did something similar and did a lot of research into this so I know something about this.
As the article said, G is very vague in its defination. Some new calculations have acutally put G at 6.64x10^-11 to 6.69x10^-11 which is quite a huge range. Whereas the two other constants, h [planck's contant] and c [speed of light in vaccum] is more well defined and had gotten more accurate.
The biggest problem with measuring big G [what we are discussion here, instead of little g which is 9.81m/s^2] is the influence of other objects. We did the experiement for our class in a basement labratory and I was able to predict based on minute changes in the data I was getting that people were moving their desks around. I was 4 floors down from the top floor and when I went upstairs, the professor [I was able to predict where in the building from the measurements and the fact that he was the only one up there in that section] admitted he was moving around to re-orient his new desk.
Also, another time, a huge pickup truck came to the parking lot in front of the physics building. I noticed right away my measurements go askew cause of it.
As I said, G is very sensitve to tiny changes in the enviorment, much more then h [planck's constant] and c [speed of light]. Often, to measure the constant G, people has to work when there is no activity going [either at night] or somewhere remote. In fact, one of the recent measurements was taken in the middle of the Nevada Desert.
-- Note: These Comments are Generated by ME! Not You! ME!
That's why we told you not to use weight. We knew something like this would happen. Just wait until the mass of the earth doubles or gets cut in half. All of your stupid weight data will be off by a factor of two. Long live mass!! muwhahaha!!
Here is another article from Discovery. A little more info, but not much.
I thought the earth gains weight every year...
If the earth is about .008 sextillion metric tons lighter than we thought it was, the sun won't be able to hold us, and we'll go spinning off into the coldness of space.
WHY, oh WHY, couldn't they have left well enough alone?
"The map calling the territory black."
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First off your exponents of the mass of Earth keep changing, 10^21, 10^27, but really the mass of Earth is a 10^24 value.
Using more accurate values and your logic, GM=G'M', thus G' = (6.67259x10^-11)(5.9736x10^24)/(5.792x10^24)
Which gives G' = 6.8818x10^-11. That gives a -3.04 % error.
However I'm not sure if we can arbitrarily equate the two.
no, but the cosmological constant was measured to be 42 a couple of years back, in whatever units it's usually reporte in (like nanometers of red-shift per megaparsec of space, or something like that). i thought that was pretty cool
cheers,
sh_
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It was suggested that life in the Universe may take on many different forms and shapes. There are theories (hypotheses) of having life on neutron stars (the left overs of the star cores that collapsed on itself to produce a remnant size of earth and mass of 2-3 Suns that due to its huge mass and small size spins at almost the speed of light.) Life on such an object would not be supported by chemical reactions since no molecules not even atoms can withstand enormous temperatures produced on the neutrino stars. Still, we should not lose all hope, for life based on strong forces remains conceivable there.
:)
Strong forces hold together the nuclei of all atoms more complex than hydrogen. Suppose a proton some 10^-13cm in size travelling at speed of 1000kilometers per second (average speed for a proton) at temperature of 1million K. It would cover a distance of 2 meters in 10^-21 of a second. Human would cover this distance in about a second. So for a proton 10^-21 second means the same as 1 second for a human.
Collisions of many elementary particles on a neutron star could produce massive nuclei, each made of thousands and tens of thousands, of elementary particles. They would last for 10^-15 of a second and then decay. In other words, a massive nucleus might have a million different collisions or other interactions before it decayed.
So if these particles could produce some equivalent of a structure capable of storing information and of replication by selective copying (like the DNA or RNA) star might produce forms of life. Individuals that interact with their environment and with other individuals in an organized way.
If this really happened, the development of life would happen much faster than what we observe in our solar system.. 10^-21 second is one billion-billionth of the thousandth of a second then the origin of life would require not about 1 billion years (our planet: ~600million years) but about 1/billionth of a year, of 1/13 of a second! It may seem short to us but it might exist on the surface of a neutron star. (too bad we could not interact with them)
On the other extreme end of this is the type of life we could call a "Gravitational Life" based on Gravitational forces. A typical subunit of life would be so large that gravity would be the dominant force for it, not electromagnetic force, a star would work in this case as a base unit. Individual stars would play the role of atoms (or molecules) on Earth. An organism so large that its basic building units are stars and galaxies (maybe even multiple universes) could in principle be possible. Would you like to think about yourself as of basicly microorganisms living in a huge super organism? Of-course star and galaxy interactions are upon scale of millionth of years, so if life originated from repeated effects of such interactions (like molecule interactions) then there is a long way to go before a living organism based on this interactions could develop.
And you think the mass of earth is important
You can't handle the truth.
There is something called the Free Air Anomaly (FAA). This is the change is relative gravity if one moves in the vertical direction while neglecting the affect of "local" gravitational masses. You may want to review Gauss's Law. The FAA is about 0.31 milligals per meter (most students could measure to at least 1 mgal precision). We used to do a lab experiment that required one to measure the height of the tallest building on campus by measuring relative gravity. Neglect (which is to the 1st order isokay) the mass of the building. The measurements turned out to be relatively very good. One such measurement was performed on a structure that recently housed a relatively large Tetris game.
Old relative gravity measurements were made using submarines and pendulums. Remember 1st year physic classes/labs. This cyclic motion (period) of a pendulum is not based on the mass, but is a function of the length of the pendulum and gravity (sqrt(length/g). The subs provided a stable platform.
With an inaccurate value of G, doesn't this mean that all the planet masses and densities have to be recalculated? From what I understand we mass a planet is to throw something in orbit, and from knowing the period and speed of orbit, equate centripetal force and GMm/r^2. So if G changes, so do all the masses and densities.
And on a lighter note, my calculator's now obsolete. The press of a button gives me G and mass of the Earth, which have since both changed.
The closer you are to the SURFACE of eath, the more it weighs on you, if you get farther away, the effect is weaker. When you get closer to the center, gravity pulls you more directions, at the true center, it would seem like you were weightless
Anyway, that affects little g (the gravitational attraction between anything and earth), not big G (the gravitational attraction between any two objects, depending on mass and distance). Big G stays the same everywhere.
ReadThe ReflectionEngine, a cyberpunk style n
What you need is a device that will dynamically adjust gravity. It will increase gravity on you, so that you get a continual and constant workout during the day. But, then when you need to lift things or jump (and land too) it will reduce gravity.
This would use the increased gravity to build and tone muscle. Then the reduced gravity to lift the car, jump over buildings. And of course, increase gravity between your fist and the bully's face so, when you punch him/her you get a gravity assist.
Now if it can be done for less than $6,000,000 it's a deal. :)
Fight Spammers!
JESUS CHRIST!!! WHAT IS WRONG WITH YOU?
Gravity, or big G is constant everywhere, its used in a formula (that I cannot remember) to calculate the gravitational force between any two objects (along with there mass and distance (increases with mass, decreases with distance).
You aren't being pulled toward the center of earth, you are being pulled toward every particle in it. The average vector points to the earth's center of gravity. When you get closer to that point, more and more of the vectors would be pointing away from that. When you got to the center, the average vector would be (0,0,0), so it would seem that you were weightless. When you get farther away from earth, the distance to those particles would be less, so the effect of gravity would seem to be less. That's why don't fall into the sun (since it has more mass then earth)
Its one thing to be misinformed, like the author of the root comment. It's quite another thing to be wrong and insult people who are correct. The second thing makes you an idiot.
ReadThe ReflectionEngine, a cyberpunk style n
what were you going to use as a fulcrum?
ReadThe ReflectionEngine, a cyberpunk style n
This of course has had it's ramifications in the modern view of the Universe. See this Slashdot Story, and the recent developments which suggest that is it "flat".
What I say is, this is a good start, but we have a long way to go.
AND, does this also include the all ellusive, but ever present Dark Matter in the calculation?
It's 95% of the universe, you know....
*Carlos: Exit Stage Right*
"Geeks, Where would you be without them?"
*Carlos: Exit Stage Right*
"Geeks, Where would you be without them?"
"Got Linux?"
If you're a nerd being buff is really not that important.
This was a great discussion related to a /. poll before the "need" for moderation. I have said it once and and must say it again. Ask the freaking question again: toliet paper, under or over? This was a great question as eventually the cat ppl came out in force.
No. They're talking about the universal constant G, not the average gravitational acceleration on earth (g). G, if it's anything like the other universal constants, is the same everywhere in the universe.
Now, wouldn't it throw the physicists for a loop if G turned out to be the first "universal constant" to have local variations?
Hmmm... only way I can think of to test that is to watch the orbit of some planet or double-star system for a few gazillion years.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
...or a solution waiting for a problem. Has anybody come up with any good applications yet? How expensive is this device? Could you use it to find, oh... trapped miners, people burried under earthquake debris, or gold veins? I mean, if you can tell that your professor is moving around upstairs, then you can presumeably tell that there is a tiger behind door number 2, but could it be made more precise and/or accurate than other techniques (e.g., ultrasound, cat scans, etc.).
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
and apparently I forgot it all the second I left the room... sorry 'bout that (thinking different mass rather than different constant... if only that preview button had a clue stick)
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They're still in, aren't they?
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I'm not ashamed. It's the computer age, nerds are in.
They're still in, aren't they?
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I don't know about you, but I am currently
orbiting the sun (which, to paraphrase some of the
posts above, is basically "falling but missing")
This just means there is less of Natalie Portman's cute teen buttocks to love.
Less weight, same mass, less droopy...
Gravity only affects weight, not mass. So there is exactly the same amount of cute buttocks there, it just weighs less.
--- Can i borrow your Clue-Stick(tm)? I need to go beat a few people with it...
And here I was just wrapping up my 10 year reclusive doctorates thesis on calculating how to harness the force, these new data have set me back 20 years! I think I'll resort to plan B and take over the world with my armed robotic army set to replace/install every machine on the planet with CP/M (!)
Fuck Ajit Pai
Check out this cool little java applet that lets you draw using gravity and stars.
http://www.snibbe.com/sc ott/dynamic/gravilux/gravilux.html
Kinda offtopic, but gravity-related and FUN! Try collecting a bunch of the stars into a small cluster, and then clicking right in the middle of it. BOOM!
- Isaac =)
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Actually the earth is loosing more weight than it is gaining. Due to the constant solar wind being blasted out from the sun and small but significant portion of our atmosphere is being carried into deep space. Of course its nothing to be alarmed at since it would take over 10 billion years for us to noticably measure the difference. Anyhow its not worth losing any sleep over, which brings up the other question... why the heck am I even typing this reply when it is already 2:02AM in the morning. Good night /.ers I'm off to bed.
Nathaniel P. Wilkerson
NPS Internet Solutions, LLC
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Nathaniel P. Wilkerson
www.haidacarver.com
actually, for all your equations and explanations, you didn't hit a single situation for which you need G. for *every* case above, if you adjusted the earth's mass by 1/2 and G by 2, say, you'd end up with the exact same accelerations due to gravity everywhere.
:-)
that is to say, for sattelite trajectories, gravitational potential energy, you get everything you need to know just by measuring little g right here.
I could go on forever[...]
but you didn't even start
cheers,
sh_
Interested in learning Chinese or Japanese? check out Chinese/Japanese-English Dictiona
In principle I don't see a problem with this - my personal belief on the subject is that life *could* form wherever there is a system of sufficient complexity, no matter the exact details of that system. So if you had enough "macroatoms" or whatever, the gravitational force could cause this to happen.
But the real killer is the timescale. Bearing in mind how many times smaller than the electrmagnetic force gravity is, the timescale would be correspondingly larger - rather than a ~10^9 second lifespan like we have, an equivalent gravitational being's lifespan would be ~10^49 seconds long, but for it, that time would seem the same length as a human lifespan.
In that length of time, the structure of the Universe will change. Spacetime will expand, leading to increased delays for communication between different components of the entity, stars will die, galaxies will collide, black holes will form and entropy in general will increase. The lifespan of this entity would be so great that by the time it could have formed, either all protons in the Universe will have decayed, all matter will be in slowly evaporating black holes, or we'll have had the Big Crunch.
So I think it's possible in principal, but not in practice. Of course, I could be totally wrong here :)
The problem is that gravity is so puny! Compare it with the other fundamental forces:
Force : Strength : MediatiorStrong : 10 : Gluon
Electromagnetic : 10^-2 : Photon
Weak : 10^-13 : W and Z
Gravitational : 10^-42 : Graviton
5.972 sextillions? What the hell is that? Oh, you mean 5.972 x 10^18. Is this mag for scientists or what?
Also, did I miss it or did they not tell us the new value? Yesterday, GPS is opened up to civilians, but today G becomes proprietary information. One step forward...
Well this is Netwons gravitational constant, big G, which is the interaction between two objects with mass, not earths gravitational constant little g which most know to be approximately 9.8m/s^2.
;-) His experiment involved suspending two very very large masses by a thin wire, and measuring the attraction caused by another mass placed nearby (causing the wire to twist). Think of a gigantic barbell suspended by a cable in the middle, the tourque caused by gravitational attraction of another mass placed near one end would cause the cable to twist slightly. Using Newton's law of gravitation and some measurements, the constant could be calculated
:-)
I believe the first measurement of this quantity was by Henry Cavendish. He was a wealthy noble and could afford to do physics experiments and nothing else. Must be nice
Well thats all for today's physics lesson. Have a good one
Spyky
Newton successfully laid the groundwork for everything we understand about gravity, which made other things like Kepler's laws make sense. Einstein added more to it by in essence equivilating gravity and acceleration.
BUT we still don't fundamentally understand what gravity is.
Newton: 'Gravity makes things fall to earth.'
How?
Einstein: 'Gravity bends space'.
How?
We really still have no idea about how the force of gravity is transmitted from one object to another. (The other fundamental forces all seem to have a medium to transfer force.)
The one interesting thing about this experiment is that it uses more precise methods to measure forces in the same ol' torsional pendulum experiment! (A pretty old technique..)
Seeing as we get this story every few weeks!
"the universe is now bigger/smaller than previously thought"
Which is it?!
Wasn't he wrong about his theory of gravitation? What about the orbit of Mercury? What about general relativity?
How can this article call it an important fundemental constant when it really is just an approximation of gravity and not even an accurate prediction of its effects?
JESUS CHRIST!!! WHAT IS WRONG WITH YOU? Gravity, or big G is constant everywhere, its used in a formula (that I cannot remember) to calculate the gravitational force between any two objects (along with there mass and distance (increases with mass, decreases with distance).
I'm not Jesus Christ, but I'll play.
It should be noted that big G can refer to different things in a gravitational context.
On the one hand is the forumula |F| = G m1 m2 / r^2 that you refer to in your post. m1 and m2 are masses, r is the distance of separation between the masses, F is the force, and G is the constant of proportionality. The direction of the force is such to attract the two bodies towards one another. Each mass feels an equally strong force pulling it toward the other. If there's a whole bunch of mass points, like in the case of Earth where many particles are globbed together, then you sum up each individual mass point to get the total force on a body in Earth's gravitational field. This is Newtonian physics, and it is good enough for most applications.
A somewhat more interesting formula that also uses a big G is that of general relativity: "G = 8 Pi T." Here big G is a second rank tensor that describes the curvature of the spacetime manifold, and big T is a second rank tensor that has as its components the local density of energy and momentum and fluxes of energy and momentum at every point in spacetime. In the most general case, this is a set of coupled nonlinear differential equations, and it is not solvable exactly except for a few special cases. If you work through the math and make the approximation of a low density of matter (which is fine for Earth but bad for black holes) that does not bend spacetime very drastically around it, then you also get the attractive force of gravity occurring through curvature in the space-time manifold. At the center of a spherically symmetric distribution of non-infinite density matter the spacetime manifold is, to leading order, flat (which is trivially the case except at spacetime singularities), and it is also flat to first order corrections, implying that the gravitational force vanishes there. The case of a uniform distribution of matter inside of a radius R can be solved exactly. The case of a nonuniform, yet spherically symmetric, distribution of matter may be expressed in terms of quadratures.
In the article the first big G is the one they measured. (Incidentally, though I'm a physicist I haven't done any GR in ages, so I welcome any corrections in the above from the experts out there).
Then maybe the next experiment should be done on a satellite platform up in geosynchronous orbit. From the satellite's point of view, nothing will be moving - not the earth, nor any of the other satellites near it. As a bonus, you get hard vacuum and low temperatures for free (cheap, anyway - some venting and thermal blankets).
The problem then is designing an apparatus that will survive launch and still be accurate. Probably the thing to do is take the parts up to the space station, assemble and test it there, then move it slowly and carefully up to GEO - maybe with an ion drive.
To a Lisp hacker, XML is S-expressions in drag.
Um, what? Sure we do - it's presumably (since we haven't seen one) transmitted by an exchange of gravitons which move at the speed of light. The other forces do not have a "medium" but rather a particle which is exchanged to provide the force. For example:
electromagnetic force -> photon
weak force -> Z, W particles
In some sense you're correct - we do not have a quantum theory of gravity as quantum theory, at its most basic level is not relativisitically correct (take a look at the Schrodinger equation - it doesn't treat time and space equally).
We do have a fairly good understanding of how Einstein's equations tell us how gravity bends space and that bend in space tells gravity how to move.
There's already been a very good book written on this called the Dragon's Egg by Robert Forward. A manned mission is sent to a drifting neutron star that passes near the solar system. The natives evolve from 'plants' to an intelligent species in the time the mission takes to reach the star and they go from 'stone age' sun worshipers to space travelers more advanced then us in a matter of days. Communication is established with a gamma ray based mapping device that some of the natives can see.
Yes, i was going to put one of the reasons, but I figured that it would be obvious to anyone who knew. My only point was that we arn't orbiting the sun very fast, and that if you didn't figure distance in when figureing gravity, the attraction to the sun would be much greater.
ReadThe ReflectionEngine, a cyberpunk style n
Do you work at NASA?
Did you forget to convert centimeters to inches?
In post-9/11 America, the CIA interrogates YOU!
This guy is overestimating the speed of his "life" by a factor of over 100 billion -- a mistake comparable to (but graver than!) claiming that only one human lives on our planet.
Has anyone contacted the game maker about this?? :^)
Ender
Nothing to see here
you can calculate the gravitational field without knowing either G *or* the mass of the planet. and even now you can make much more precise calculations about energy needed to put a sattelite into geosynchronous orbit "4.215x10^7m" away based on g than G.
your example of star masses is the first one you got right. however, the significance is purely scientific at that point, and has little to do with engineering, as your first post claimed.
i maintain that G has little engineering significance (if it had engineering significance, it wouldn't be so hard to measure!)
cheers,
sh_
Interested in learning Chinese or Japanese? check out Chinese/Japanese-English Dictiona
Beowulf Cluster solving the problem ?????
no sig
My astrophysics book lists the earth at 5.974 E 24 kg. Considering that the influence of gravity from the sun is ~0.0006 that of the earth, I would expect an uncertainty of at least 0.003 E 24 kg. If you want more digits of accuracy, you will have factor in the tidal forces from the moon and sun. But how can you do this without knowing more accurate measurements of the mass of the moon and sun and the distances in between? Oh, are you still using Newton's Law of gravity? Well its wrong; you need to use Einstein's field equations. AGHHGGHGHG! TENSORS !#@^$#
In the end we have to merge a bunch of satellite data, whereby radio waves are bounced off of planets (this gives distances to within kilometers) with the G value gotten from super precise balances, as with this experiment. These measurements always have and always will be a tremendous pain in the ass. We know the mass of an electron with more certainty than the mass of our own planet! And you can't see an electron!
What was that old saying about gravity. It was the first fundamental force discovered, but it is excluded from the rest our modern fundamental forces because we don't understand it enough to fit it in with the rest of our theory.
Anyway, I hope them good luck with the torsion balance, and may equivalence be with you all.I guess as a relative i should post something-- all hail the apple that fell on his head, for if not for him all of us would have floated away or became math majors(calculus)!
"Most people are other people. Their thoughts are someone else's opinions, their lives a mimicry, their passions a quota
Leno just said "about six sextrillion tons." Stupid talk show hosts...
Okey Dokies all ya'll... Here are the problems I'd like to point out in all the arguments that I'v read: 1. Mass-Energy is constant. How far away you are from a planet has NO affect on your Mass-Energy. I call it mass energy because Mass and Energy are one and the same. 2. G is the universal gravitational constant. g is an approximated value you get if you solve the equation: m1*a=G*m1*m2*r^-2 for acceleration and assume r to be the AVERAGE radius of the earth. If you take account the difference between sea level and the tallest mountain it causes an error facter of ~10^-10. In other words, you're getting screwed by the incorect calibration of the scales more than the wrong g(LITTLE). 3. As this applies to Grand Unified Theory, it doesn't affect the work much at all. All the equations are being worked in variables... much easier to NOT drop a decimal point when you don't need any.
Humans are slow, innaccurate, and brilliant; computers are fast, acurrate, and dumb; together they are unbeatable