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Is Earth Weighed Down By Dark Matter?
Nerval's Lobster writes "There may be a giant ring of dark matter invisibly encircling the Earth, increasing its mass and pulling much harder on orbiting satellites than anything invisible should pull, according to preliminary research from a scientist specializing the physics of GPS signaling and satellite engineering. The dark-matter belt around the Earth could represent the beginning of a radically new understanding of how dark matter works and how it affects the human universe, or it could be something perfectly valid but less exciting despite having been written up by New Scientist and spreading to the rest of the geek universe on the basis of a single oral presentation of preliminary research at a meeting of the American Geophysical Union in December. The presentation came from telecom- and GPS satellite expert Ben Harris, an assistant professor of mechanical and aerospace engineering at the University of Texas- Arlington, who based his conclusion on nine months' worth of data that could indicate Earth's gravity was pulling harder on its ring of geostationary GPS satellites than the accepted mass of the Earth would normally allow. Since planets can't gain weight over the holidays like the rest of us, Harris' conclusion was that something else was adding to the mass and gravitational power of Earth – something that would have to be pretty massive but almost completely undetectable, which would sound crazy if predominant theories about the composition of the universe didn't assume 80 percent of it was made up of invisible dark matter. Harris calculated that the increase in gravity could have come from dark matter, but would have had to be an unexpectedly thick collection of it – one ringing the earth in a band 120 miles thick and 45,000 miles wide. Making elaborate claims in oral presentations, without nailing down all the variables that could keep a set of results from being twisted into something more interesting than the truth is a red flag for any scientific presentation, let alone one making audacious claims about the way dark matter behaves or weight of the Earth, according to an exasperated counterargument from Matthew R. Francis, who earned a Ph.D. in physics and astronomy from Rutgers in 2005, held visiting and assistant professorships at several Northeastern universities and whose science writing has appeared in Ars Technica, The New Yorker, Nautilus, BBC Future and others including his own science blog at Galileo's Pendulum."
"Any headline which ends in a question mark can be answered by the word no."
It's standard not to write all the technicalities down in a scientific presentation. They usually last 30 to 45 minutes. There is no way, even for a scientific mind, to follow all the technicalities in 45 minutes when it took several months for the speaker to grasp the subject. Nobody in the audience would understand anything aside from the coauthors. Imagine your 20 hours advanced graduate course on physics condensed in 45 minutes with no simplification at all.
Disclosure: I'm a mathematician, not a physicist.
Let's wait for the proceeding or the full paper even though it's true we should be skeptical at this point.
The excess mass is an invasion force of cloaked ships.
I thought we'd been using tiny variations in gravity to detect Oil for 20 or so years now, fly over an area and map the underground caverns based off gravity variation.
" one ringing the earth in a band 120 miles thick and 45,000 miles wide."
Presumably that would be outside the planet, and therefore would be counteracting the force of gravity towards the centre of the planet.
Or is there some other wierd geometry involved.
> geostationary GPS satellites
A what now?
this sounds like a new religion. watch out Scientology!
Gaia got married.
How was the accepted mass of earth measured? It should at least be consistent with large-scale behavior of our solar system. Now satellites see a harder pull from earth. The same pull should be seen from the sun. It would make sense to me if satellites saw a lower pull than sun, implying that some mass is at earth, but further out than the satellites. This way, not so much.
Is it drag induced by the outer parts (not perfectly vacuum) of the atmosphere?
There are two types of waves in water. Gravity Waves are the ones large enough to be held together by gravity, and capillary waves are held together by surface tension.
Yo mama!
A house divided against itself cannot stand.
Many animals on earth.
Yeah probably, I'm not a physicist. Just a specialist in another field who sometimes reads up on physics stuff as a hobby :)
Seven puppies were harmed during the making of this post.
Thanks for contributing nothing to the discussion.
You laugh at the power of Lord Cthulhu, the Great and Glorious One. You try to come up with "scientific" theories and fancy math but the truth will become apparent to you very soon.
Your screams of terror will be like the song of angels to me.
Dedicated Cthulhu Cultist since 4523 BC.
More information complexity creates more entropic potential energy.
http://en.wikipedia.org/wiki/Entropic_force
http://arxiv.org/abs/1207.4803
http://arxiv.org/abs/1001.0785
No, this research wasn't even published, it's a conference talk and a PR release. Go read the actual link, at the bottom of the long post, where Matthew Francis dishes it out. Here it is again in case you missed it:
http://galileospendulum.org/2014/01/02/no-dark-matter-is-not-messing-up-gps-measurements/
The later link from Dr Francis points out that the calculation has yet to be adjusted for the gravitational contributions of the Moon or Sun, and that it also doesn't make any relativistic corrections.
Those omissions puts the dark matter claim on par with "hey guys I haven't looked at it from far away but from right here it looks the Earth is pretty flat, yeah?"
The dark matter ring is merely a hypothesis. In my field (or science, engineering, or mathematics generally) we should follow the scientific method when reporting results at a meeting.
This guy was unfortunately presenting a hypothesis. He should have waited and tried to find more compelling evidence before presenting. New Scientist should be familiar enough with the scientific method to avoid publicizing a radical and unproven hypothesis.
A master of the art at work:
"Making elaborate claims in oral presentations, without nailing down all the variables that could keep a set of results from being twisted into something more interesting than the truth is a red flag for any scientific presentation, let alone one making audacious claims about the way dark matter behaves or weight of the Earth, according to an exasperated counterargument from Matthew R. Francis, who earned a Ph.D. in physics and astronomy from Rutgers in 2005, held visiting and assistant professorships at several Northeastern universities and whose science writing has appeared in Ars Technica, The New Yorker, Nautilus, BBC Future and others including his own science blog at Galileo's Pendulum."
Do NOT burn the goats - they're much better medium rare.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
The conclusions I read sounded like science fiction. I try very hard to get on-board and understand what is being explained, even for a layman like myself, I can usually wrap my head around a good portion of science on Slashdot. The claims being made come from a very small observation window, IMO. ...Sorry, that does not seem like enough time to develop anything resembling a reasonable scientific conclusion. For contrast, I got this from the tele watching Professor Andrea Ghez. Before she dared go on international media with her proof of objects orbiting a black hole, she collected 10+ years of data. She undoubtedly believed she was correct, well before the ten year mark, but, she waited, bided her time, and when she showed the orbit of these objects around the black hole, there was simply no argument against her proof. I wish more science was like that, but I understand the need for the theoretical side of it. This just reeks of sensational journalism, more than science. Also, keep in mind, we have the guy who "shot bigfoot" recently and is claiming proof... Oh, and that little war on evolution in our textbooks. *sigh*
Unless they have peer reviewed papers - however can you trust them?
The earth is getting lighter...
And Leon's getting laaaarger...
“He’s not deformed, he’s just drunk!”
I'm surprised no one has pointed out yet that this was exactly the behavior predicted by the Flying Spaghetti Monster pressing down on objects to keep them from floating into space.
I am officially gone from
This statement is inaccurate: "...predominant theories about the composition of the universe didn't assume 80 percent of it was made up of invisible dark matter" 80% of the universe is made up of with Dark Matter and Dark Energy. The theories suggests the universe is made up of about 27% dark matter (not 80%) which is the subject of the article. Dark energy is a sort of negative gravity and is the force pushing galaxies apart faster and not relevant to this article's topic. Dark energy makes up most of the energy mass of the universe at 68%. Taken together they make up 80%, but affect the universe in completely different ways. http://en.wikipedia.org/wiki/Dark_energy
Dark matter's really unambiguous in the experimental data. You need a lot of theoretical solipsism such as weird new forms of gravity to write it back out of the physics.
No kidding!!! What do you say at this point?
We would of had to know the precise mass and gravitational pull for any of the rockets or satellites we sent into space to work. Given that they have not all fallen back to earth, if their is any invisible matter out there, it is obviously in insignificant infinitesimally small amounts.
Well, the linked refutation points out the problems with the argument, but the guy is arguing that the amount of dark matter is fairly small. It wouldn't mess with the ability to launch a rocket. Sure, you might end up in a slightly different orbit than intended, but you'd end up in orbit. Almost all launches involve minor corrections anyway - it isn't like you can just calculate nothing but a burn time when the rocket to LEO spends its entire time inside the earth's atmosphere, and the target orbit is inside the atmosphere as well (just a VERY THIN part of the atmosphere). If you wanted to do everything ab initio then you'd need to know about every single piece of space junk in orbit, every passing rock, and so on...
Usually because they contain fuel and thrusters designed to last the lifetime of the satellite in order to make regular course correction because those, especially in LEO, are actually falling back into the atmosphere. Although part of that may be on purpose incase the sat fails it will eventually fall back into the atmosphere and burn up. But I've heard before the other reason was the tendency for them to want to fall back to earth despite calculations saying otherwise...
"The problem with socialism is eventually you run out of other people's money" - Thatcher.
Who had been around for millions of years to detect them?
Your question implies you also have a theory about trees silently falling in the woods, right? It is not all about you, sometimes it is about them .
This issue is a bit more complicated than you think.
Would've. It's a contraction of "would have".
And, no, we don't need to know the precise mass of Earth for satellites to work. Admittedly, we'd need to be pretty damn close for things to actually be in their design orbits.
However, this guy is making noise because he's seeing long-term effects on his satellites that he (supposedly) can't account for by more conventional means. Personally, I think it would have been noticed before now, if such effects exist, but you never can tell. And a belt of Dark Matter is certainly possible, though extremely unlikely.
"I do not agree with what you say, but I will defend to the death your right to say it"
Nobody can see that you shit your pants while typing that but anyone in the room can easily tell.
Violence is like duct tape. If it doesn't solve the problem, you didn't use enough.
planets can't gain weight over the holidays like the rest of us
Actually they do. It's estimated that the Earth gains at least 164,000 kg per day from meteoric accretion. (Barker, J.L. and Anders, E. "Accretion rate of cosmic matter from iridium and osmium contents of deep-sea sediments." Geochimica et Cosmochimica Acta 32, 627-645 (1968))
You never really know how close to the edge you can go until you fall off.
80% of the universe is made up of with Dark Matter and Dark Energy. The theories suggests the universe is made up of about 27% dark matter (not 80%) which is the subject of the article. Dark energy is a sort of negative gravity and is the force pushing galaxies apart faster and not relevant to this article's topic.
The whole notion of "dark matter/energy" seems a little desperate to me. We have evidence that our models of gravity cannot account for certain observations. That means one of two things. Either A) the model is correct and there is something out there that has mass that we cannot presently see OR B) the we can see all the matter out there meaning the model is wrong and needs revision. So far I've seen no compelling argument that A is more likely than B. I understand the hesitation to revise our model of gravity but invoking dark matter/energy is an awfully big fudge factor in the absence of any plausible explanation for what might constitute dark matter/energy.
Subject != headline.
There YOU go.
There are two types of people in the world: Those who crave closure
27 + 68 = 95. Our physical laws don't predict about 95% of the universe.
I read this several years ago.
And have you read anything about it since?
systemd is Roko's Basilisk.
I work with GPS a lot, and there are many MANY people around the world who spend their entire lives making sure that there are very precise measurements of where those satellites are and how good predictions of where they'll be going are. These orbit calculations take into account the pressure of light from the sun on the satellites along with several other very small effects, so if there was some large extra mass in a ring around the earth it would have been noticed many years ago. I think this guy needs to recheck his calculations.
I know you're joking but even if there was a mini blackhole at the center of the earth, it would just be absorbing matter from the earth.
Earth loses 100kg, the mini blackhole gains 100kg, but from the outside the combined mass of both the earth and the mini blackhole would be constant.
These comments are my personal opinions and do not necessarily reflect the opinions of the other voices in my head.
Probably because dark matter doesn't interact with itself. When normal matter hits other normal matter it will be slowed down and eventually the stuff gets bigger and bigger. But dark matter doesnt hit anything, so even though it's gravitationally attracted to other dark matter particles they will fly right through each other. Therefore, i think, it won't be concentrated enough to form black holes.
From New Scientist :
That, alone, would make this fail peer review, not to mention that the GPS satellites (which are big and messy and do stationkeeping and get replaced) are not the satellites to use to do this with (the Lageos satellites fit both requirements, being both well monitored and with very low non-gravitational perturbations). The Lageos orbit at a lower altitude than GPS, and so would be expected to exhibit a greater difference with the orbit of the Moon (the other very stable and well characterized Earth orbiter, thanks to Lunar Laser Ranging).
Back in 2008, Adler compared Lageos and LLR estimates of Earth gravity in http://arxiv.org/pdf/0808.0899.pdf and concluded that Earth bound dark matter (outside of the 12,000 km semi major axis of Lageos) is 4 x 10^-9 Earth masses, much below Harris's 5 x 10^-5 estimate (which is based on a comparison with an ancient IAU determination from the 1960's). Given the poor analysis and the discrepancy with the more accurate data used by Adler, I do not think that these results can be given any credence.
Dark matter is nothing but unexplained data. There is unambiguous experimental data that indicates there is something we don't understand about the universe, but not what that something is. "Dark matter" is the current popular hypothesis, but nothing more than that.
So I'm not really getting fat. I just have a ring of dark matter around my midsection that looks like fat. My weight gain is actually a physics experiment.
I don't trust this whole "theory of gravity." Obviously, this "theory" is just an unknowable guess and therefore doesn't have the full consensus of "science". I say we need to teach the controversy that the reason we stay on the earth is because some supreme being wants us there. Birds and planes only work because when their wings are outstretched they make a holy cross.
Teach the controversy. Don't believe "theories".
Slow Down Cowboy! It's been 1 hour, 47 minutes since you last successfully posted a comment
Obviously it'd be dumping the mass of the earth out the other end of the black hole.
If television has taught me anything, it's that black holes are portals to other places - mostly bad places, but other places nonetheless.
I wish I could have just written "Dark Matter" as the answer every time my math homework didn't add up to the correct number due to math errors. Obviously nobody knows precisely how much the Earth weighs...or the entire universe. In fact, how are they counting stars' mass from 10 million light years away by viewing 10 million year out of date light from it? And how are they counting mass that's already inside black holes from a not so viewer friendly distance away? Dark Matter is a myth.
Honey bunches of goats is good for breakfast.
rewriting history since 2109
is where I stopped reading.
No one has ever come up with a theory of Modified Gravity that can explain the data we have , but Dark Matter does.
Never mind the tiny, little, minor detail that we have NO idea if dark matter actually exists or what it might be composed of it it does exist. It's not an unreasonable theory to investigate but I'm pretty reluctant to invoke some new exotic form of matter as a go-to explanation. Remember it was 400 years between Newton and Einstein. If the math model needs adjusting (and dark matter turns out to not be the answer) it might be a while before we figure it out.
Like, I dunno, maybe dark matter?
Maybe but the point you ignored is maybe-not. With the evidence in hand, an incorrect model is a much cleaner explanation than some as yet undiscovered exotic form of matter than we aren't actually sure exists. I'm not saying dark matter doesn't exist, merely that I'm skeptical in light of the lack of evidence. It sounds like an effort to make the data fit the current model when there is a non-trivial chance the current model is wrong somehow.
I say we need to teach the controversy that the reason we stay on the earth is because some supreme being wants us there. Birds and planes only work because when their wings are outstretched they make a holy cross.
OK, then, explain balloons and the Flying Wing aircraft! Clearly your cross-based supreme being is a fraud, and the FSM is the One True Being (not to be confused with the molpy-laden One True Thread, but I digress even deeper into metasarcasm).
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
Isn't the whole point of DM that we can't detect it except by the gravity distortion? Its basically "unfound matter"...
And what means is what we really have is a distortion of gravity in a given area that we cannot count for... its therefore not dark matter but dark gravity.
Or am I wrong? have we actually found dark matter? The actual stuff. Proven to exist? Or is it just what we write down when our math doesn't add up?
I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
Some people are dense enough to cause an aberration in the gravitational field.
C'mon, don't reinvent the wheel here. The theory of Intelligent Falling is the go-to parody, and is well-known enough to have a Wikipedia page. You might also find last-Thursdayism amusing.
Socialism: a lie told by totalitarians and believed by fools.
Both your post and his are quite funny. And stupid.
It's not direct detection of gravitational radiation, but observations of PSR B1913+16 have been considered convincing enough proof of the existence of gravitational waves as predicted by general relativity. It's a binary pulsar: a neutron star and another object that might be another neutron star or possibly a black hole, orbiting each other. They're spiraling in together, which could only happen if their orbits were losing energy due to gravitational radiation, and calculations based on their observations conform exactly with the predictions of general relativity for gravity waves. This was convincing enough to have won the 1993 Nobel Prize in Physics for the scientists involved in the discovery and analysis of the pulsar, Russell Alan Hulse and Joseph Hooton Taylor Jr.
Qu'on me donne six lignes écrites de la main du plus honnête homme, j'y trouverai de quoi le faire pendre.
If the headline is a question the en answer is almost certainly "No", and the reporter unqualified for the topic.
kartune85 : Incapable of reason, observation or learning. A kind of dim, drab, flightless parrot.
Dark matter..remembers me of ether.
The Moon and Sun would act to counter earths gravity, making it appear lighter not heavier.
Remember when we smashed a Mars Lander because we converted wrong?
Maybe dark matter is just somebody making a similar conversion error.
-- Tigger warning: This post may contain tiggers! --
Wait, so there are only gravity waves and capillary waves in water?
How do you get water to ignore light waves? Is it dark underwater where you lives?
-- Tigger warning: This post may contain tiggers! --
Surely they mean mass. The earth is in freefall (orbit) around the sun, hence it has a weight of 0!
The earth getting heavier is my fault. I need to ease up on the McRibs.
Its entirely possible Dark matter is about the only thing capable of explaining what I hurked up last time I attempted to eat mcdonalds. Theres definately exotic matter in those "burgers".
Perhaps this is where my recently acquired extra weight is coming from
Excuse the Unicode crap in my posts. That's an apostrophe, and slashdot is busted.
It already explains that this matter exists, and is even used by humans: as packing peanuts.