UBC physicists may have solved one of nature's great puzzles: what causes the accelerating expansion of our universe?
PhD student Qingdi Wang has tackled this question in a new study that tries to resolve a major incompatibility issue between two of the most successful theories that explain how our universe works: quantum mechanics and Einstein's theory of general relativity.
The study suggests that if we zoomed in-way in-on the universe, we would realize it's made up of constantly fluctuating space and time.
"Space-time is not as static as it appears, it's constantly moving," said Wang.
"This is a new idea in a field where there hasn't been a lot of new ideas that try to address this issue," said Bill Unruh, a physics and astronomy professor who supervised Wang's work.
In 1998, astronomers found that our universe is expanding at an ever-increasing rate, implying that space is not empty and is instead filled with dark energy that pushes matter away.
The most natural candidate for dark energy is vacuum energy. When physicists apply the theory of quantum mechanics to vacuum energy, it predicts that there would be an incredibly large density of vacuum energy, far more than the total energy of all the particles in the universe. If this is true, Einstein's theory of general relativity suggests that the energy would have a strong gravitational effect and most physicists think this would cause the universe to explode.
Fortunately, this doesn't happen and the universe expands very slowly. But it is a problem that must be resolved for fundamental physics to progress.
Unlike other scientists who have tried to modify the theories of quantum mechanics or general relativity to resolve the issue, Wang and his colleagues Unruh and Zhen Zhu, also a UBC PhD student, suggest a different approach. They take the large density of vacuum energy predicted by quantum mechanics seriously and find that there is important information about vacuum energy that was missing in previous calculations.
Their calculations provide a completely different physical picture of the universe. In this new picture, the space we live in is fluctuating wildly. At each point, it oscillates between expansion and contraction. As it swings back and forth, the two almost cancel each other but a very small net effect drives the universe to expand slowly at an accelerating rate.
But if space and time are fluctuating, why can't we feel it?
"This happens at very tiny scales, billions and billions times smaller even than an electron," said Wang.
"It's similar to the waves we see on the ocean," said Unruh. "They are not affected by the intense dance of the individual atoms that make up the water on which those waves ride."
Their paper was published last week in Physical Review D: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.95.103504.
Explore further:
Quest to settle riddle over Einstein's theory may soon be over
More information:
Qingdi Wang et al, How the huge energy of quantum vacuum gravitates to drive the slow accelerating expansion of the Universe, Physical Review D (2017). DOI: 10.1103/PhysRevD.95.103504

HannesAlfven
2.4 / 5 (10) May 15, 2017There is a sense about this that they are GUESSING.
Zzzzzzzz
4.1 / 5 (9) May 15, 2017Whydening Gyre
2.3 / 5 (3) May 15, 2017Sounds like Zeph may have been onto something...:-)
Gigel
5 / 5 (5) May 15, 2017Sorry, RNP :)
Steelwolf
1 / 5 (2) May 15, 2017rogerdallas
4.2 / 5 (5) May 15, 2017Dingbone
2 / 5 (8) May 15, 2017These fluctuations aren't so minute and everyone can detect it with his TV set as a CMB noise. CMB noise is vacuum analogy of Brownian noise at the water surface. If we would have microwave eyes, we would see how the vacuum is undulating like the hot air above camp fire. And these fluctuations also result in red shift of distant light sources. Because the light scatters the more, the shorter wavelength it has, this red shift is nonlinear with distance.
Dingbone
2 / 5 (8) May 15, 2017Dingbone
2 / 5 (8) May 15, 2017Dingbone
1.8 / 5 (10) May 15, 2017baudrunner
1 / 5 (3) May 15, 2017Just an idea (ideas aren't pseudoscience - we're allowed to have 'em), but what if everything, and everything that everything is made of, is shrinking all the time - atomic diameters getting smaller and smaller with time. How long can that go on before this process encounters some quantum threshold?
dnatwork
not rated yet May 15, 2017That idea has been around since at least the 1930's, but I think it's framed wrong. What if you and I and everything else are not shrinking, but our reference frames are? They theorize in terms of inertial reference frames, but then they worry about contraction and expansion, and go off and invent vacuum energy.
If space has energy and structure, then it should push back on everything in a gravity well, stopping it from getting deeper when the mass reaches equilibrium with the stiffness of space itself (rubber sheet analogy). If space is nothing, then gravity wells should keep getting deeper forever. In that case, two wells that are close should form a common well over time (dark matter), and distant wells should gradually get farther apart (dark energy).
No quantum limit because nobody shrank, just appeared to from afar.
dnatwork
not rated yet May 15, 2017That idea has been around since at least the 1930's, but I think it's framed wrong. What if you and I and everything else are not shrinking, but our reference frames are? They theorize in terms of inertial reference frames, but then they worry about contraction and expansion, and go off and invent vacuum energy.
If space has energy and structure, then it should push back on everything in a gravity well, stopping it from getting deeper when the mass reaches equilibrium with the stiffness of space itself (rubber sheet analogy). If space is nothing, then gravity wells should keep getting deeper forever. In that case, two wells that are close should form a common well over time (dark matter), and distant wells should gradually get farther apart (dark energy).
No quantum limit because nobody shrank, just appeared to from afar.
Dingbone
3.4 / 5 (5) May 15, 2017Whole the quantum uncertainty is all about it.
billpress11
1 / 5 (4) May 15, 2017Quote from link below:
"The accelerated expansion was discovered in 1998, when two independent projects, the Supernova Cosmology Project and the High-Z Supernova Search Team simultaneously obtained results suggesting an acceleration in the expansion of the universe by using distant type Ia supernovae as standard candles."[5][6][7
https://en.wikipe...universe
rrwillsj
1 / 5 (1) May 15, 2017I would opinion, that based on all the hypothetical commentaries that follow these articles of imminent total universal scientific comprehension.
Promising, with just a little more funding? All questions will finally be answered beyond all possible disagreement.
And we can all smugly bask in the glory of our awesome genius.
However, 'Science' is an eternally continuous and infinite process rife with incomplete information of splendiferous contradictions and questionable speculations.
Hey! That's what makes Science fun!
brodix
1 / 5 (1) May 15, 2017Basically a cosmic convection cycle, of radiation expanding and mass/gravity collapsing.
(Keeping in mind the measures of space contracting are based on mass/gravity and the observations of space expanding are of light/radiation.)
jsdarkdestruction
not rated yet May 15, 2017I am having difficulty understanding how this works. How would this cause the universe to explode?
Da Schneib
not rated yet May 15, 2017Interesting idea, but not the solution to quantum gravity. At least not the way it's stated here. Now to go read the paper... thanks @Gigel.
Seeker2
1 / 5 (1) May 15, 2017Seeker2
3.3 / 5 (3) May 15, 2017Seeker2
1 / 5 (1) May 15, 2017Sure seems that way. However you would get no strong gravitational effect. That comes only with a gradient in the energy of this explosion. Nature does that with quantized energy. That is quantized matter consists of a fixed amount of spacetime which misses out on all the expansion. It has no way to resist the expanding spacetime so it gets the squeeze. Called gravity.
Seeker2
3.7 / 5 (3) May 15, 2017someone11235813
not rated yet May 16, 2017Seeker2
1 / 5 (1) May 16, 2017Seeker2
3 / 5 (2) May 16, 2017Ojorf
3.7 / 5 (3) May 16, 2017It basically means (it true) that the quantum fluctuations at incredibly minute scales (always predicted by QD), also include expansions and contractions of spacetime, with their math suggesting a bias toward expansion via SR.
The idea seems so simple and logical I hope the math all pans out.
This is great, why wouldn't the "quantum foam" include shrinkings and stretchings?
Could be one of those things that in retrospect seem totally logical, why didn't someone think to explore this earlier?
Well done.
Da Schneib
4.2 / 5 (5) May 16, 2017It's a very good idea, and marvelously well developed. Checking the math will be a huge project, and likely take a long time to happen. But this looks like a viable explanation for the huge difference between the predictions of cosmological constant by QM and GR/observation.
I will have to absorb this for a while more and then reflect upon it before I start to see other implications. But I estimate this should give the pot a pretty big stir in gravity physics.
Da Schneib
4.3 / 5 (6) May 16, 2017Dingbone
1.8 / 5 (5) May 16, 2017Dingbone
1.8 / 5 (5) May 16, 2017But there is no reason for not to presume, that the vacuum fluctuations are doing it all: both Hubble red shift, both dark energy effect. Actually we have multiple observational evidence for both already. And here I explained, how the same principle can even also explain the inflation. The physicists guessed lotta effects correctly - they just missed their natural physical origin, because they fitted them to observations. They see evolution and changes of Universe where it doesn't actually exist: it's just an optical effect of light wave scattering.
Old_C_Code
4 / 5 (4) May 16, 2017Mimath224
5 / 5 (2) May 16, 2017Kron
not rated yet May 16, 2017Is the *PDF* download not working for you?
Dingbone
5 / 5 (2) May 16, 2017Seeker2
not rated yet May 16, 2017swordsman
1 / 5 (2) May 16, 2017snoosebaum
5 / 5 (1) May 16, 2017Da Schneib
5 / 5 (2) May 16, 2017Ojorf
5 / 5 (2) May 17, 2017Yes they do, see: https://en.wikipe...ctuation
Mimath224
5 / 5 (2) May 17, 2017I'll be comparing 'notes' with the CEM tensor and the various Friedmann Walker etc. models but as a layman it will need some determined effort.
@Dingbone
'@Kron: Preprint - but in my experience the people who cannot find source info themselves aren't intelligent enough for to understand it anyway.'
Your experience must be very limited then!
Whydening Gyre
5 / 5 (2) May 17, 2017Ones that spin..:-)
Mimath224
5 / 5 (2) May 18, 2017xinhangshen
1 / 5 (3) May 18, 2017The most obvious and indisputable experimental evidence, which everybody with basic knowledge of special relativity should immediately understand: is the existence of the absolute time shown by the universally synchronized clocks on the GPS satellites which move at high velocities relative to each other while special relativity claims that time is relative (i.e. the time on each reference frame is different) and can never be synchronized on clocks moving with relative velocities.
Da Schneib
5 / 5 (2) May 18, 2017Mimath224
5 / 5 (2) May 18, 2017xinhangshen
1 / 5 (2) May 18, 2017My original post was much longer, but the website cuts off the other part. Yes, the article is closely related to SR. I have disproved SR and confirmed that time is absolute and there is no such a thing called 4D spacetime continuum in nature. Therefore, GR is also disproved, and so are the existences of dark matter and dark energy which are introduced as patches of general relativity.
I will also be glad to debate with you and all other interested people about clocks on GPS.
xinhangshen
1 / 5 (2) May 18, 2017xinhangshen
1 / 5 (2) May 18, 2017xinhangshen
1 / 5 (2) May 18, 2017Whydening Gyre
5 / 5 (2) May 18, 2017Since it is Space that is spinning - exactly the right amount...:-)
But...
At that size, does centripetal/centrifugal even apply?
(Not to mention that it is space (nothing) doing the spinning...)
And I'm thinkin'....
A 'string' is a serial collection of points. What keeps them aligned into a string...?
Could it possibly be direction of motion in a particular vector?
(If that is the case, then they should be called Directions, not Dimensions...)
Seeker2
5 / 5 (1) May 18, 2017antialias_physorg
5 / 5 (7) May 18, 2017And yet we have already done experiments with actual clocks that show it's not as you say.
Reality trumps thousands and thousands of pages of theory any day.
Whydening Gyre
5 / 5 (2) May 18, 2017Isn't that what recalibration is? A re-sync of the collection of clocks? Regardless of "frame"?
Whydening Gyre
5 / 5 (4) May 19, 2017Only if their velocity is "synchronized" as well (not to mention - their position relative to any other massive body{s})
idjyit
5 / 5 (5) May 19, 2017This might help you understand why the clocks on earth don't stay synchronised ...
https://en.wikipe...of_Earth
Mimath224
5 / 5 (3) May 20, 2017Dingbone
3 / 5 (2) May 20, 2017Dingbone
3 / 5 (2) May 20, 2017Dingbone
3 / 5 (2) May 20, 2017xinhangshen
1 / 5 (1) May 20, 2017It's true that reality is the king. But we must understand reality correctly. As I pointed out, the interpretation of the corrections of the clocks as relativistic effects is wrong. I never deny that clocks need corrections just like your watch that need corrections too because there are many factors can influence the accuracy of the atomic clocks. But none of these corrections is observer dependent correction as claimed by special relativity because the corrections are absolute.
idjyit
5 / 5 (4) May 20, 2017I have no idea what your on about...
"Einstein's general relativity theory says that gravity curves space and time, resulting in a tendency for the orbiting clocks to tick slightly faster, by about 45 microseconds per day. The net result is that time on a GPS satellite clock advances faster than a clock on the ground by about 38 microseconds per day."
http://physicscen...will.cfm
For this reason the satellites clocks are designed to run "slow", because of empirical observation.
Ground control stations also monitor and update a satellites time as well as other navigational data, at least once a day.
Because a GPS receiver ("Observer") has no idea when the satellite sent it's signal it relies intrinsically on its internal clock for distance calculations, if the clocks on the ground aren't synchronised with the clock in the satellites you would have ever increasing errors in the calculations.
ZergSurfer
4.2 / 5 (5) May 20, 2017Name them. Deny Doppler. I dare you.
(He realised things were different for observers moving relative to each other)
(GPS satellites are not in geosynchronous orbit, but a fast orbiting net)
:)
Da Schneib
5 / 5 (4) May 20, 2017Here we have someone arguing about the definition of a second. Good luck with that.
Seeker2
not rated yet May 20, 2017Da Schneib
not rated yet May 21, 2017@Seeker, nothing different.
That's the point, see.
Seeker2
not rated yet May 21, 2017Seeker2
not rated yet May 21, 2017Da Schneib
not rated yet May 21, 2017Seeker2
not rated yet May 21, 2017Da Schneib
not rated yet May 21, 2017You can only see things with light, and if gravitation alters the propagation of light compared with its propagation in flat space, then you can expect what you see to be altered by gravitation. And BTW, that's also true for simple velocity; relativity of simultaneity shows that.
Seeker2
not rated yet May 21, 2017Da Schneib
not rated yet May 21, 2017Mimath224
5 / 5 (2) May 21, 2017Since I am not a member SPIE I cannot access the main paper from volume 9570. according to the abstract SR is wrong and any consequences of SR are also (this is not an actual quote but an interpretation of what is written there).
Seeker2
not rated yet May 21, 2017Da Schneib
5 / 5 (5) May 21, 2017On another thread it has been pointed out that this individual's claims directly contradict the Hafele-Keating experiment performed in 1971. It's the one where they took cesium clocks on airplanes; I'm sure you've heard of that.
Having checked, it appears that this individual has neglected to note that time is not invariant under the Lorentz coordinate transformation. And that only one transformation can be applied at one time. These are basic errors.
It's unfortunate that the SPIE doesn't peer-review all its publications. If this individual had actually proven SRT is incorrect in 2015, it would be in all the newspapers.
Da Schneib
not rated yet May 21, 2017idjyit
5 / 5 (3) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017First I was absolutely not kidding in any way about kids doing Science Fair projects proving relativity: Michelson-Morley is a common test.
Second, Hafele-Keating has been repeated many times by satellites, most recently in Gravity Probes A and B.
And I was unfortunately not kidding at all about the non-peer-reviewed status of the Proceedings of the SPIE. Hopefully they do better in their technical journals of record.
Seeker2
not rated yet May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017I don't understand why you think relativity isn't part of the Laws of Physics. I assure you it is accepted to that level by the general physics community.
Not if you're local to the clock. If you're not, then lots of need.
Da Schneib
not rated yet May 21, 2017Seeker2
not rated yet May 21, 2017No need to account for gravity with orbiting clocks. Well I'm not so let's use it.
Da Schneib
not rated yet May 21, 2017Which means you'll have to account both for velocity and gravity.
Weren't you just saying you didn't have to account for gravity? Looks like that was wrong.
Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017I been tryin' to tell you that for about five posts now.
Dingbone
3 / 5 (2) May 21, 2017Dingbone
3 / 5 (2) May 21, 2017Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017As an example: "low-dimensional models." Quantum mechanics uses dimensions to describe scores of quantum parameters you have never even heard of. This is perhaps the silliest thing I've heard anyone say in the last week, and I have dealt with a #climatecrank who pretended heat could be dissipated in an open vacuum by convection, and someone who thinks that they can make a laboratory a couple hundred miles high stretching around the Earth.
I strongly recommend you do not demonstrate your ignorance further but instead remain quiet and see if you can learn some real physics.
Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017Either that or coffeeposting.
Look dude nobody cares about your manifesto. Either you have specific statements you can prove or not; posting word salad doesn't help, it just makes you look like a nutjob.
Dingbone
3 / 5 (2) May 21, 2017Da Schneib
not rated yet May 21, 2017When you are compared with those who can it's apparent you have no idea what you're talking about; you're making meaningless comparisons between things that don't have anything to do with one another.
Dingbone
3 / 5 (2) May 21, 2017In addition, you're underestimating my knowledge of general relativity and quantum mechanics a lot. Both theories are actually about the same thing, just from dual observational perspective - which thing it is? What these theories have in common?
Da Schneib
5 / 5 (1) May 21, 2017Dingbone
3 / 5 (2) May 21, 2017Seeker2
not rated yet May 21, 2017So why do they define it for flat space? Why correct clocks for gravity anyway? Who needs general relativity?
Da Schneib
5 / 5 (2) May 21, 2017Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017Because details matter. And if you ignore GRT your GPS gives a position that's way off.
Da Schneib
5 / 5 (1) May 21, 2017I can explain the inverse square law quite simply: the surface area of a sphere increases as the square of its diameter. The total flux of a force must be evenly divided over the surface at any diameter. Any remaining questions about the inverse square law, or are you admitting you're too stupid to understand basic math?
Would you like to discuss magnets now, so I can make a further fool of you?
Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017Pro Tip™: Don't try to change the subject when you make up a lie claiming someone can't explain something and they explain it. It makes you look like a complete idiot. Or a @Dingbat.
Dingbone
3 / 5 (2) May 21, 2017I'm not even required to ask you for it: I know already quite well, what the mainstream physics is able to explain and what it doesn't. So I'm not required to ask its proponents, what they're actually able to do. The fact you're confusing inverse square law with gravitation speaks for itself. Some people cannot find the answer for questions, because they're not even able to understand, that there are such a questions unanswered. They're safely separated from any further progress in this way.
Mimath224
5 / 5 (2) May 21, 2017Apart from knowing absolutely nothing about SPIE journals (think this is my first encounter on the net) I am with you on this. I was trying to get to the full paper so that I could see the equations and thought if I couldn't someone here might. As you might remember I have ideas about Time, but they certainly don't conflict with SR or GR. I do agree we should not waste more time with xinhangshen.
But you might help me with Dingbone comment '...They apply to seemingly "large" but apparently "empty" areas of observable Universe...'?????? Other comments are equally...or do I bin my GR books?
Da Schneib
5 / 5 (1) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017If you want an explanation why gravity follows it, it's because it works in 3D space, which is what spheres exist in. That's why I used a sphere in my proof, duhhh ummm. If this is too difficult for you to follow you are not smart enough to understand physics.
Now stop lying.
Da Schneib
5 / 5 (1) May 21, 2017There is a certain amount of gravity for a given object.
Gravity works across space.
The farther from the object, the bigger the surface area of the sphere it must work over.
The surface area increases as the square of the radius of the sphere.
Therefore, the strength of the gravity decreases as the square of the radius.
Duuuuuuuuuhhhhhhhhhhhhhhhh ummmmmmmmmmmmmmmmmmmm.
Dingbone
3 / 5 (2) May 21, 2017Why the nuclear forces or let say force between magnets doesn't decrease in the same way? They also work across space, blah, blah?
Da Schneib
5 / 5 (1) May 21, 2017I'm sorry you can't follow mathematics. But it makes you an idiot for trying to discuss physics.
Get over it.
What's going to happen here is I'm going to keep explaining what you claimed I can't explain in ever simpler terms until the most idiotic cretin can't help admitting it. If you want to be exposed as an idiotic cretin, it's no concern of mine. Your alternative is to lie, when the most idiotic cretin can see you're lying.
Do we really need to go there?
Da Schneib
5 / 5 (1) May 21, 2017This is like arguing about molecular biology with someone who doesn't understand sexual reproduction.
Or like arguing about math with someone who doesn't understand 1.
Dingbone
3 / 5 (2) May 21, 2017Get over it. Your alternative is to lie, when the most idiotic cretin can see you're lying. Actually you're not even realize your lie. You simply don't understand its difference from fact.
Da Schneib
5 / 5 (1) May 21, 2017Give this up, @Dingbat, you're looking stupider and stupider, or like more and more of a liar, the farther you go. There isn't anywhere to hide, there's no lie you can tell that will make it right, and it's time to admit it and move on.
Like I said, like arguing math with someone who doesn't understand 1. Or worse yet, with someone who lies about what 1 means.
Dingbone
3 / 5 (2) May 21, 2017Give this up, @Schneibo: you're looking stupider and stupider, or like more and more of a liar, the farther you go. Of course your personal example isn't important here at all: it just illustrates well the dumbness of attitude, with which whole the community of mainstream physicists is thinking: a collective Dunning-Krueger effect.
Da Schneib
5 / 5 (1) May 21, 2017It really is that simple. You'd be surprised how much physics depends on it. But maybe not since you don't appear to know any physics.
Dingbone
3 / 5 (2) May 21, 2017It's really is that simple. You'd be surprised how much physics depends on it. But maybe not since you don't appear to UNDERSTAND any physics. The knowledge of facts doesn't imply their understanding.
Da Schneib
5 / 5 (1) May 21, 2017In other words, the fact I can perform an experiment in New York and the same experiment in Tokyo and get the same results implies not only that momentum is conserved but that the universe has only 3 space dimensions. This is basic physics, Physics 101. It's not a theory; it's a theorem, subject to mathematical proof.
Welcome to reality.
Da Schneib
5 / 5 (1) May 21, 2017All that's necessary is to make a long magnet and measure the force from a nearby pole; one finds that the longer the magnet, the closer to the inverse square formula its force comes. Given the non-existence of monopoles implied by ∇⋅B = 0 this is the expected result.
You can try echoing my claims all you like, but all it does is make it obvious you're a #physicscrank.
Dingbone
3 / 5 (2) May 21, 2017Welcome to our hyperdimensional reality.
But we observed the monopoles. Not only you don't understand the facts - you even don't know them.
Da Schneib
5 / 5 (1) May 21, 2017Why are you lying? You appear to be a #physicscrank.
@Dingbat, what monopoles? Please link experimental evidence.
Why bother lying? Do you think someone won't notice? Do you only want to talk to other #physicscranks?
I'm getting tired of this; it's a waste of time talking to a #physicscrank who is either ignorant or lying. Boring.
Dingbone
2.3 / 5 (3) May 21, 2017Da Schneib
5 / 5 (2) May 21, 20171. @Dingbat #physicscrank claims I can't explain the inverse square law.
2. @Dingbat #physicscrank claims I can't show why gravity should obey the ISL.
3. @Dingbat #physicscrank claims I can't show magnetism obeys the ISL.
4. @Dingbat #physicscrank claims color and weak forces not obeying the ISL disproves the ISL.
So far every claim has been dismissed. Now, is this person lying, or a complete #physicscrank? Or both?
This is getting more and more boring. It must be Sunday morning because otherwise I wouldn't be bothering with this #physicscrank.
Bullsxxt. Direct lie. Link it again and prove me wrong. Or tacitly admit you lied.
Right here right now, #physicscrank.
Dingbone
2.3 / 5 (3) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017You ain't linked jack sxxt. You lie, and you are proven to lie.
Now produce the link or admit you lied and go post somewhere else where they are OK with liars.
Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017We just want to know what your character is here so we can ignore you if you're another #physicscrank liar. There's no point in discussing science with a liar; they'll say anything. And they never have a link.
Dingbone
3 / 5 (2) May 21, 2017Da Schneib
5 / 5 (1) May 21, 2017You claim it you prove it @Dingbat #physicscrank liar. Bring the link. No link, you lie. Simple as that.
No linkie, you are a liar, @Dingbat #physicscrank liar.
You claim it you prove it @Dingbat #physicscrank liar. Bring the link. No link, you lie. Simple as that.
ProTip: don't claim you linked it when you didn't. Don't lie. You'll get caught, and it's obvious when you try to change the subject.
Da Schneib
5 / 5 (3) May 21, 2017You can just about tag them by this behavior. Personally I find it insulting that anyone would think I was paying this little attention, so I wouldn't notice, and I despise anyone who tries this trick. You should too; they're insulting your intelligence.
Da Schneib
5 / 5 (3) May 21, 2017It's the assumption that everyone else is stupid that is the signature. You can usually spot this early on when they start denying experimental evidence.
Dingbone
3.7 / 5 (3) May 21, 2017You should check it harder... :-) And I linked it here just because you started to deny the experimental evidence of monopoles.
Now you're still denying it and you're even denying the existence of link. That's simply amazing.
Da Schneib
4 / 5 (4) May 21, 2017You can ask @Lenni or @RealitySchmeck about that. Enjoy.
Da Schneib
4 / 5 (4) May 21, 2017There is no reason anyone should accept anything you say as having anything to do with reality and you should be ashamed of yourself.
Shame shame shame.
Dingbone
2.3 / 5 (3) May 21, 2017Mimath224
4.2 / 5 (5) May 21, 2017Well, I wasn't actually asking ...purely rhetorical hence my multiple '?'. I was just trying to be 'nice' about it. The reason was, that I was following you and Dingbone and I wondered why YOU were entering into such a lengthy 'conversation' this 'observer of monopoles'. I think you have wasted more time on Dingbone than I have, and I suggest that is precisely what Db wants. Have a nice day etc. (genuinely)
Da Schneib
4.2 / 5 (5) May 21, 2017tomwaders
4.3 / 5 (3) May 21, 2017Dingbone
2.3 / 5 (3) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017So why do they define it for flat space? Why correct clocks for gravity anyway? Who needs general relativity? They sure do. I haven't detected any problem in measuring gravity locally.
Seeker2
1 / 5 (2) May 21, 2017Da Schneib
5 / 5 (5) May 21, 2017If you're asking why we need relativity, it's to allow us to make those corrections so we can account for the clock in orbit, among many other such situations, running differently.
As for GPS, it's pretty much all based on clocks, so these little details can result in your GPS receiver telling you the wrong thing if we don't make these corrections.
I have no idea what you're talking about with Earth's gravity. Gravity on Jupiter (which is undeniably in space) is stronger than Earth's, so what you said doesn't seem to make much sense.
Da Schneib
5 / 5 (4) May 21, 2017You beat me to the punch on the monopole link thing; I think @Dingbat got a little confused which thread it was posting on. Of course, there were no such posted links on the monopole thread either, AFAIK, so perhaps it was a confusion with the conversations it has with the voices in its head.
RealityCheck
1 / 5 (3) May 21, 2017Check (and click on) @Dingbone's in-line links; as distinct from separate stand-alone links as used by most posters here. :)
Seeker2
1 / 5 (1) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017tomwaders
5 / 5 (2) May 21, 2017Whydening Gyre
5 / 5 (3) May 21, 2017Technically, they did not.
They observed "quantum" monopoles decaying into magnetic monopole "analogues"...
From that article;
"Scientists at Amherst College (USA) and Aalto University (Finland) have made the first experimental observations of the {dynamics} of isolated monopoles in quantum matter."
Whydening Gyre
5 / 5 (1) May 21, 2017I use Google and it show only a slight color difference. it also underlines, but only when you hover over it.
Whydening Gyre
5 / 5 (2) May 21, 2017Never did get the "flat space/time" thing...
It's always curving somewhere...
As to your question - 1g is a measurement parameter of (local) space/time. (which also happens to correspond with curvature of space/time - go figure)
The cesium transition frequency should always read the same in whatever locality it is a part of - TO the local observer. The difference appears when it it has spent any time in - a different locality.
TheGhostofOtto1923
2.3 / 5 (3) May 21, 2017Just report him until he's banned again. Hey alizee how many times has it been? Thirty maybe?
This is wg's fault.
Da Schneib
5 / 5 (2) May 21, 2017The gravity field is omnipresent throughout space. At various points in space it is influenced to various values by matter that is present near those points; but the gravity field itself isn't "exerted" by anything. It's not possible to distinguish "Earth's gravity field" from "the Sun's gravity field" somehow.
[contd]
Da Schneib
5 / 5 (2) May 21, 2017It's a calculational convenience to say that the gravity field on Earth's surface is such-and-such, due to its mass, but in fact, Jupiter, the Sun, and the Moon all influence the value of the curvature of space time on the Earth's surface all the time too, though with much less influence than the Earth's at that point.
In fact, this is true of all fields. There isn't some sort of way to determine where the value of the field "came from." We often use the calculational convenience to say "this much of the field came from this, and that much from over there" but the fact is, the field is what it is.
Does that help clear things up for you?
Da Schneib
5 / 5 (2) May 21, 2017Perspective and history are important here.
Da Schneib
5 / 5 (2) May 21, 2017Da Schneib
3.7 / 5 (3) May 21, 2017As I posted in that article, the so-called "monopoles" are not actual magnetic monopoles. They are phenomena which, when viewed from a certain angle, have what appears to be the same field configuration as a monopole; but viewed from other angles, do not.
@Dingbat remains a #physicscrank; I can't state whether it's a liar or not, because I can't tell whether it is merely foolish enough not to understand the article, or deliberately falsifying it.
Da Schneib
5 / 5 (2) May 21, 2017Or is in such a locality now. You have it precisely, @Whyde.
Da Schneib
5 / 5 (3) May 21, 2017And I still think this is a peek at the math that will be required for any quantum theory of gravity.
Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017No, that's not what I said. I said "are they the same lab as you define it." And you just answered, "No." So that's fine, the DC lab is local to DC and the Denver lab is local to Denver.
Eventually, yes, they must. They are not local to one another.
An important question here is what you choose to define as local.
Seeker2
1 / 5 (1) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017The theory is a description of how it happens. We have telescopes and can look and see what it does; the theory is the description of what we see in the telescopes.
Why it happens is currently in the realm of conjecture or even speculation.
I can't imagine how you think it's done if it's not from local atomic clocks. How about you explain that to me.
I have to tell you I am an amateur astronomer and I keep time in my house that is good to 10^-6 seconds. It's important enough to be worth the effort. And I don't need an atomic clock.
Seeker2
1 / 5 (1) May 21, 2017that's not how it's done I did once but I guess you weren't paying attention. You have to know enough about GR to apply the right correction for altitude to your local time.
Da Schneib
5 / 5 (2) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (2) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Seeker2
1 / 5 (1) May 21, 2017Da Schneib
5 / 5 (1) May 22, 2017As for timekeeping, no, I need accuracy. Astronomy requires good timekeeping so you can see things like Jupiter's moons disappearing behind it and reappearing on the other side, and so you can point the telescope.
Seeker2
1 / 5 (1) May 22, 2017antialias_physorg
5 / 5 (2) May 22, 2017Along a geodesic. Which can be towards a massive body like Earth - but if your lateral motion is great enough it can be around the Earth as well (notice how rockets always curve when they go up? It's because they need to get *lateral* speed rather than height to get their stuff in orbit - and stay there)
Instead of typing it out this guy gives a pretty good answer
https://physics.s...e-no-for
Seeker2
1 / 5 (1) May 22, 2017antialias_physorg
5 / 5 (3) May 22, 2017Wherever the geodesic ends. Or if your geodesic just curves onto itself you'll just keep going "round and round". Note that the word 'curve' is to be taken with a grain of salt. It only seems to curve if you want to impose a euclidean view on space. From a spacetime point of view stuff (like Earth, or the sun or the ISS) moves in straight lines.
Humans (unfortunately) do tend to think in terms of euclidian space. It's a useful approximation to the circumstances that were relevant during our evolution. But space isn't euclidian. There's a reason why it's called spacetime and not "space and time"
Seeker2
1 / 5 (1) May 22, 2017antialias_physorg
5 / 5 (2) May 22, 2017If spacetime were universally flat then what you would call a straight line in euclidian space and what is a geodesic in spacetime would be identical.
Seeker2
1 / 5 (1) May 22, 2017Seeker2
1 / 5 (1) May 22, 2017In curved spacetime, however, you don't need a nudge. That's why they call it free fall. Curved spacetime, however, is only approximately true, because you could fall straight down. No curve required.
rossim22
1 / 5 (1) May 22, 2017Da Schneib
5 / 5 (2) May 22, 2017Da Schneib
5 / 5 (2) May 22, 2017To us, as we fall toward the event horizon, the tetrahedron remains a tetrahedron, as long as the satellites are close enough, and "close enough" gets closer and closer the further in we go.
To someone far away watching, the tetrahedron gets more and more distorted, and the laser beams look more and more curved.
It's just as important where you're watching from as where what you're watching is. This is a key concept.
Seeker2
not rated yet May 23, 2017Da Schneib
5 / 5 (2) May 23, 2017Seeker2
not rated yet May 23, 2017Seeker2
not rated yet May 23, 2017Well I guess you could say stretching is curving. But I just don't see it that way.
Seeker2
not rated yet May 23, 2017For example gravity pulls down on a rope suspended between its two ends. The rope is curved but spacetime is stretched.
Seeker2
not rated yet May 23, 2017Seeker2
not rated yet May 23, 2017sort of like confusion between cause and effect.
Da Schneib
5 / 5 (1) May 23, 2017Just sayin'.
xinhangshen
1 / 5 (1) May 23, 2017Seeker2
not rated yet May 23, 2017Whydening Gyre
not rated yet May 24, 2017Orbits, are a combo of gravity and kinetics. Constantly recalculated (re-added), every single moment of Planck time(or even less). They are travelling a combined 2 straight vectors (possibly 3 or even more) WITHIN space/time. Curvature of space/time is irrelevant (other than that it trickle-down determines subordinate curvatures....) If it ISN'T curved, why would anything inside of it curve?
Seeker2
not rated yet May 24, 2017Seeker2
not rated yet May 24, 2017Whydening Gyre
not rated yet May 25, 2017So.... You're saying gravity determines space/time characteristics?
Seeker2
not rated yet May 25, 2017xinhangshen
1 / 5 (1) May 25, 2017It seems that you don't have any idea about kinematic time dilation which is observer dependent, very different from the gravitational time dilation, and can't be corrected in the same way. It is this time dilation that does exist in the corrections of the atomic clocks on the GPS satellites. Please review special relativity again.
Whydening Gyre
not rated yet May 26, 2017Seems like that is what your saying.
Only other option is that Space/Time creates curvature. Which it can only do by being - curved.
Seeker2
not rated yet May 26, 2017Whydening Gyre
not rated yet May 26, 2017You are saying a vector direction, then...
Seeker2
not rated yet May 26, 2017Whydening Gyre
not rated yet May 26, 2017I see...
And gravity is generating that force, right? A property of mass...
Question... is everything within our visible U in motion? Straight or curved? (or cork-screwing...)
To me, the cork-screwing appears to be a result of gravity affecting massive bodies from a number of different vectors...
Seeker2
not rated yet May 27, 2017Whydening Gyre
not rated yet May 27, 2017Kinetic, then?
In a roundbout way - there are..:-)
I disagree. We know where we ARE. And what our motion(s) are.
The U does like to take the path of least resistance...:-)
Seeker2
not rated yet May 27, 2017Seeker2
not rated yet May 27, 2017Da Schneib
5 / 5 (2) Jun 01, 2017Seeker2
not rated yet Jun 02, 2017Seeker2
not rated yet Jun 02, 2017Seeker2
not rated yet Jun 02, 2017Seeker2
not rated yet Jun 02, 2017Mimath224
5 / 5 (1) Jun 02, 2017'They are using classical gravity coupled to the expectation values of the quantum field theory, a mixture known as 'semi-classical gravity' in which gravity is not quantized.'
As a layman I'm uncertain about knowledge of these deep papers (well, deep to me anyway) but I do recall reading somewhere that 'quadratic coupling' is also expected in/with the S-E tensor. I then wondered if this was in the paper...it doesn't seem to be. Of course, that might simply mean that it is but not as I would recognize it or accounted for elsewhere and I haven't the knowledge to see it. Da Schneib, you really are well informed and knowledgeable
Great stuff...I like it.