A long tradition of cosmology research in Cornell's College of Arts and Sciences has given birth to a vigorous effort by a new generation of cosmologists to understand the Cosmic Microwave Background (CMB), the thermal radiation left over from the Big Bang.
"A large portion of all knowledge about the history of the universe as a whole is revealed when you fully understand the CMB," says Michael Niemack, assistant professor of physics, whose work centers on CMB measurements.
Cosmology, the study of the nature and evolution of the universe, has progressed enormously during the past 30 years, says Jeevak Parpia, professor and chair of physics. "We are in an era of 'precision' cosmology."
"This is a time of very rapid advances in the field," agrees Liam McAllister, associate professor of physics and a specialist in string theory. "You don't know on any given day what new discovery you're going to see posted that night on arXiv."
Henry Tye, the Horace White Professor of Physics Emeritus, was one of the pioneers in understanding inflation in string theory, and he left a legacy of unusual cooperation at Cornell among cosmologists of all sorts. McAllister says it's quite rare to find a university like Cornell where there are meaningful collaborations linking string theorists, experimentalists and astronomers, such as his and Niemack's research with associate professor of astronomy Rachel Bean.
"Cosmology at Cornell is a wonderful example of the culture of collaboration within arts and sciences disciplines, between highly skilled instrumentalists and researchers pondering the theoretical implications of physical laws," says Gretchen Ritter, the Harold Tanner Dean of the College of Arts and Sciences.
"CMB research is a rich, ever-evolving field with a science mix that excites both the astronomy and physics communities," adds Terry Herter, chair of astronomy. "Striving to understand the origin and evolution of the universe and fundamental physics at the same time – it doesn't get much better than that."
McAllister, recipient of a National Science Foundation Early Career Award for his work on theoretical models of the early universe, seeks to understand how the theories of the inflation that occurred in the universe's earliest moments can be founded on a secure theoretical footing and emerge from a mathematically consistent structure.
"We'd like to understand the physics behind inflation," he says. "One of our responsibilities as theorists is to try to predict the results of future experiments and interpret the results of existing experiments."
According to McAllister, what's needed is a theory in which the laws of gravity are fundamentally quantum mechanical, but that behave according to classical physics in systems that are big enough and slow moving. So far, he says, string theory is the only approach that offers a consistent theory of quantum gravity.
On the experimental side, the higher resolution CMB measurements that Niemack is pursuing relate directly to the tests of general relativity that Bean is interested in.
The completion of the Cornell Caltech Atacama Telescope (CCAT) project, which will be the largest submillimeter telescope in the world, will be a boon for cosmologists, says Niemack. He and Bean plan to use CCAT to probe galaxy cluster velocities with much higher precision than is now possible.
Experiments probing the CMB have the potential to reveal laws of nature at a much more fundamental level than has been proven in any other way. "For example, results from CMB polarization observations could have a transformative effect on the kinds of problems related to the early universe that we theorists pursue," says McAllister.
"That's what makes it so compelling," adds Niemack. "Any one of these observations or experiments could fundamentally change how we see the universe."
Experimental cosmology
Cornell's experimental cosmology research group – which includes assistant professor of physics Michael Niemack, postdoctoral researchers Francesco De Bernardis and Shawn Henderson, and graduate students Brian Koopman and Patricio Gallardo – recently announced the first results from a Cosmic Microwave Background study using a polarization-sensitive camera (ACTPol) that Niemack led the design of for the 6-meter Atacama Cosmology Telescope.
"ACTPol has a unique niche in science that we can pursue better than anyone else because of the capabilities that we've built into our instrument," says Niemack. "We're looking for tiny, tiny signals, roughly a part in 107 above the background over a range of scales that have not been probed before."
An upgrade to be completed this year will add three times as many detectors and an additional frequency channel to ACTPol, enabling the group to probe physics at grand unification energy scales, a trillion times higher energy than is probed at the Large Hadron Collider.
Explore further:
Revealing dark energy's hold on the Universe: What a new collaboration hopes to uncover
fourinfinities
They have been saying that for decades, without justification.
Gravity is a phenomenon of acceleration, not force. Forces have to be quantized; acceleration does not. Equations describing gravitational acceleration are simple; they include no properties of the object being accelerated. Equations describing electromagnetic force include properties of the particle the force is acting on, e.g. its mass and charge. These extra variables in EM, with respect to gravity, require extra "constants:" the quantum of electric charge and the quantum of action. There are no extra variables in gravity; there is no room for extra constants.
What's needed is the recognition that gravity is an acceleration, not a force, and as such, it cannot be quantized.
Uncle Ira
Well Skippy, this is your lucky day. You just won the right to wear a silly looking pointy cap when you come to the physorg. Actually it's not a right, in your case he is a requirement.
Jixo
Sep 05, 2014Jixo
Sep 05, 2014Jixo
Sep 05, 2014Jixo
Sep 05, 2014Torbjorn_Larsson_OM
@fourinfinities: "Forces have to be quantized". Not at all. Van der Waal forces are residual classical forces, for example. What needs to quantized are fields. And as opposed to what the troll spews forth later, here is where relativity and quantum mechanics meet, quantized field theories are relativistic. They live in a semiclassical world, where gravity isn't too strong. (E.g. no black holes.)
Gravity itself has been quantized in the low energy regime long ago. That is how we know gravitons should exist. Whether or not string theory is the quantization that holds over the whole of gravity (which is spacetime curvature, not "acceleration") is unknown.
Torbjorn_Larsson_OM
Now you are just trolling. Contemptible.
saposjoint
Aligo
Sep 05, 2014Aligo
Sep 05, 2014Aligo
Sep 05, 2014Shootist
RobertKarlStonjek
So if you put together two theories, neither of which have a thread of evidence for their existence, you get 'precision cosmology'???
If we collected all the empirical evidence for string theory, and all the empirical evidence for inflation, you could fit all the text on a single string, even if you used a really big font.
But seriously, if a hypothesis is unable to garner any empirical evidence at all for decade then it should be considered philosophy rather than science. String theory and Inflation are *philosophical* and not scientific. There is more empirical evidence for the flat Earth theory than there is for any of the numerous versions of string theory and inflation theory...I don't hold to flat Earth either, though flat Earthers are just as convinced that they are right.
RobertKarlStonjek
Someone doesn't like the facts...string theorist, inflation theorist or religionist? (all function equally well in an empirical science free environment)
Captain Stumpy
it is zephir
his other puppets are: osnova Zwentoo Pejico Spadia Antuka Teper Incosa ahsan67 Jantoo Sikla otero Doiea Technico DoieaS Pexeso Arties Toiea Watebba Aligo Jixo
the following are used to downvote mostly: rhsthjnty, tirahobis, pehawev, yefeb, bikuxem, retejap, xanuxul, debokolin, gipagajege, yejen, godivecu, befa, rovodeh, vudamezire, cuyajuyino, yolepugor, begalifowi, megayugo, juhodo, bibigak, fetem, sosamuca
@zephir
interesting would be something that included a study as well as science that is not debunked
you continually provide your awt while forgetting that it is already debunked before you post
as proven here: http://arxiv.org/...1284.pdf
and many more studies (meaning containing empirical evidence that debunks your awt)
RealityCheck
Like in the BICEP2 instance, you may ignore my caution to you at your own peril to your own credibility, CapS. Bye. :)
PS: By the way, I was just surfing through sciforums and saw you and Bell accusing each other of being me (RC). How absurd and hilarious can that place and its mods-trolls get! Next thing, all you mod-troll idiots will be 'seeing me', like those idiots who 'see Elvis', everywhere! So much for people who claim to be 'speaking for mainstream science, logic and reason', hey? What a hoot. Couldn't stop laughing out loud for minutes! LOL. Perfect. :)
Captain Stumpy
2- the experiment is also supported here: http://exphy.uni-...2009.pdf
and many other places
IOW - empirical data from a reputable peer reviewed source. I just tire of putting all the links out there every time zeph posts bs about awt
3- your comment is a troll comment trying to bait for yet another round of your righteous indignation where you can post your bs
I ain't gonna play.
I justified my comments with empirical evidence
p.s. how is your undefined account at sciforums? how come you don't PM me there or on Sapo's page?
always seems to be someone for you to blame
never any personal responsibility on your part
interesting
AmritSorli
http://cosmology....Time.pdf
RealityCheck
Again, just because 'reputable mainstream source', it doesn't 'guarantee' that it is reality. If circuitous 'speed of light' flawed assumptions 'in-built, then 'outputs' may be 'self-deceiving' to those who follow flawed maths-analysis/interpretations 'blindly' trusting it isn't flawed 'exercise' as I have cautioned.
Like the current professionl theory, some of his stuff is good analogy, some of it a little off. BUT then again, many of your 'mainstream sources' references involve 'results/exercises' which have in-built fallacies/assumptions/interpretations which make them 'circuitous' and self-consistent only within thier own limited/abstraction analytical/setup constraints/constructs...and the 'results/claims', as in BICEP2, do not represent the actual reality. So imagine how 'tired' Zephir is trying to 'get through' to you? :)
So when a victim blames a perpetrator, and proves his case by experiments as I have done over the years on the forums in question, you still 'opt' for 'blaming the victim' as a 'preferred' approach to the facts/situation? How 'sane and just' is that?
And how silly (and failed in checking the facts) do you have to STILL NOT realize that I am permabanned there (by the usual crooked mod-troll tactics gang abuses), and so CANNOT PM you or anybody else there? :)
PS: I am going to Sydney for Fathers' Day and won't be back for few days. Take care. :)
Captain Stumpy
http://exphy.uni-...2009.pdf
it was not just a reputable mainstream source,
it was a study that was peer reviewed and not disputed nor proven wrong in any way,
nor was it debunked, retracted or dismissed
it was empirical and offered proof
not just mainstream acceptance
Therefore it is empirical proof supporting a valid scientific theory while zeph has offered only evidence which has been debunked or retracted (or known pseudoscience) supporting awt
the rest of your comment is trolling/baiting and there was no empirical data supporting your assertions
RealityCheck
Get Real. :)
Captain Stumpy
ok, you made a claim: there are flaws in the system making everything we know crap
this is called conspiracy and is a typical troll tactic
unless you can prove it with the same level of evidence which was given TO you (using the scientific method and publishing it in a reputable peer reviewed source with an impact in the subject) then you are essentially saying that your conjecture is more accurate than the combined intelligence of the scientific community
and again, I will ask:
WHERE IS YOUR EVIDENCE PROVING MY EVIDENCE IS FLAWED ETC
you say "get real"... and I DID get real
now it is your turn to reciprocate
NO EVIDENCE means you are trolling/baiting
Captain Stumpy
you have continually made this claim here and elsewhere without any proof at all whatsoever
you are on a science site
you made a claim
you did not provide evidence supporting your claim
therefore:
1- it can be dismissed as conjecture because there is no proof at all
2- it only reinforces the trolling/baiting assertions due to my evidence and your complete lack of it
http://sci-ence.o...-flags2/ , http://phys.org/n...firstCmt
don't change the subject
don't try to offer some diatribe on your delusional conspiracy against you
don't continue to repeat the same tired lines with no proof
I gave proof
I demand the same level of proof in return OR STOP TROLLING
RealityCheck
Captain Stumpy
I will reiterate:
don't change the subject
don't try to offer some diatribe on your delusional conspiracy against you
don't continue to repeat the same tired lines with no proof
I gave proof
I demand the same level of proof in return OR STOP TROLLING
http://sci-ence.o...-flags2/
http://phys.org/n...firstCmt
do I need to start another running tally of your troll posts on this comment thread showing where you offer no proof and continually tell everyone you are withdrawing from detailed science discussion?
How many times have you posted in the last 48 hours on PO alone?
and how is THAT removing yourself from detailed scientific discussion?
last time I ask
after that, you will simply be reported as a troll, bud
RealityCheck
saposjoint
Aligo
Sep 07, 2014fourinfinities
Today's physicists search mightily for quantum gravity, because all the other forces are quantized.
They just know it.
barakn
You forgot Callippo.
rockwolf1000
And Jizby!
Captain Stumpy
@barakn
@rockwolf1000
THANKS for that update... I don't know what happened to those... or when they dropped off the list. Likely when my laptop swapped from Linux to Win8 (not by choice)
@nofate
EU is a known PSEUDOSCIENCE, so there is NO empirical data supporting it
are there SOME bits of actual science in it?
yep
that is what makes it such a draw to the uneducated (especially those not well versed in physics) - it is the HOOK that con men use to set the scam deep into the sucker so that the sucker then becomes an acolyte used to spread the word to others which adds validity to the faith (this is also used by religion, although a more common method is flawed logic and fear)
That is why EU is a FAITH, while mainstream science is FACT
Uncle Ira
And Natello-Skippy, and Yash17-Skippy, and Franklins-Skippy,and Socratic-Skippy, and Calisto-Skippy, and Remi-Skippy, and Teach-Skippy, and Sabine-Something-Skippy and the some more Skippys that I forget right now.
RobertKarlStonjek
Spaghettification does not occur in free fall. In free fall all the forces are balanced and you would just glide gently across the event horizon.
But if you stopped, say you landed on a stationary platform (not moving relative to the event horizon) then you would be crushed flat. If you somehow could avoid that and stepped off the platform then spaghettification *would* occur because your inertia would prevent you from reaching free fall speed immediately and so force of gravity (spacetime curvature) would be much greater on your feet than your head.
It is easy enough to demonstrate mathematically. If you were sitting on a rod that is accelerating then light coming from the front of the rod toward the observer at the centre will be blue shifted and light coming from the rear will be red shifted.
RobertKarlStonjek
If there are any acceleration or gravitational forces on the rod then red or blue shift must come from the ends as measured by an observer in the middle of the rod.
Have you ever seen pictures or film of people inside the space station?? That is EXACTLY what it is like during free fall. In other words, any measurement you try to make of the gravity will show that there is no gravity eg if you stand on the bathroom scales in the space station or in any other free fall condition the scale will show zero weight ie NO gravitational effect whatsoever ~ As long as you accelerate toward the massive body.
Einstein noted this over 100 years ago...
Black Holes are just like any other massive body with regard to free fall.
field_gareth
RobertKarlStonjek
Tidal forces are there of course. But the force of acceleration is also present and it is in the opposite direction and so they cancel each other out nicely. That is why when you are stationary above a massive body you feel the force. If you are free falling it disappears. If you accelerate at a constant altitude you feel the force of acceleration but if you turn and accelerate toward the massive object much of that acceleration force disappears.
Why does anyone even question this??? Haven't these people ever sky dived? Haven't they ever travelled in a plane? Haven't they read Einstein?