PLato said,"Look to the perfection of the heavens for truth," while Aristotle said "look around you at what is, if you would know the truth" To Remember: Eskesthai
If the histograms and data are exactly right, the paper quotes a one-in-ten-thousand (0.0001) chance that this bump is a fluke. That's pretty small; although bear in mind that lots of distributions like this get plotted. If you plot 100 different distributions, the chances become about one in a hundred (0.01) that you'll see something odd in one of them. The Tevatron goes bump
Thinking outside the box See: A physicist inthe cancer lab
Ackerman became interested in physics in middle school, reading popular science books about quantum mechanics and string theory. As an undergraduate at the Massachusetts Institute of Technology, she traveled to CERN, the European particle physics laboratory near Geneva, to work on one of the detectors at the Large Hadron Collider, the most powerful particle collider in the world. Then she spent a summer at SLAC working on BaBar, an experiment investigating the universe’s puzzling shortage of antimatter, before starting her graduate studies there in 2007.
27. Moshe Says:
October 23rd, 2011 at 5:00 am
Igor, I am not sure I understand. We have an initial value problem, so today’s observations are determined once you specify an initial state at some time in the distant past. If you specify the time to be the beginning of the big bang evolution, with the correct but very contrived initial state (nearly homogeneous with just the right kind of fluctuations) then you get no conflict with observation. By contruction, same applies to inflation, because it reproduces that initial state and all subsequent evolution. The only point of inflation is to make that initial state the outcome of prior evolution. By construction all current observations will then be identical, but the initial state will be more natural and less contrived. As I understand Sean’s statement, quantifying this intuitive notion of naturalness is tricky, and it is not always clear inflation indeed comes ahead. I hope I am not mangling things…
And, for the record, in my mind the notion of “naturalness” is one instance of “algorithmic compression”, which is the whole point of seeking a scientific explanation. Without invoking such criteria, by definition (for example) the particle data group review book would be always the best “theory” of particle physics, and you’d never need to learn about gauge theories and spontaneous symmetry breaking and all that stuff.
Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass
And so that's what we did. We turned off the lights, and then we put it in a vacuum and sucked out all the air, and then we cooled it down to just a fraction of a degree above absolute zero. Now, all alone in the elevator, the little chunk of metal is free to act however it wanted. And so we measured its motion. We found it was moving in really weird ways. Instead of just sitting perfectly still, it was vibrating. And the way it was vibrating was breathing something like this -- like expanding and contracting bellows. And by giving it a gentle nudge, we were able to make it both vibrate and not vibrate at the same time -- something that's only allowed with quantum mechanics.
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| A European Network For Astroparticle Physics in Europe |
The Chicagoland Observatory for Underground Particle Physics (COUPP) collaboration looks for bubbles in chambers filled with a compound containing carbon, fluorine and iodine. The fluid is superheated beyond the boiling point but has no rough surface to form bubbles. When a specific type of particle interacts in the chamber, it can deposit enough energy to boil the fluid and make a bubble. Electrons do not produce bubbles, while a dark matter particle interacting with a nucleus can – making this the key for dark matter detection. See:Bubble chamber gets more precise in dark matter search
The accelerating universe is the observation that the universe appears to be expanding at an increasing rate, which in formal terms means that the cosmic scale factor a(t) has a positive second derivative,[1] implying that the velocity at which a given galaxy is receding from us should be continually increasing over time[2] (here the recession velocity is the same one that appears in Hubble's law; defining 'velocity' in cosmology is somewhat subtle, see Comoving distance#Uses of the proper distance for a discussion). In 1998, observations of type Ia supernovae suggested that the expansion of the universe has been accelerating[3][4] since around redshift of z~0.5.[5] The 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics were both awarded to Saul Perlmutter, Brian P. Schmidt, and Adam G. Riess for the 1998 discovery of the accelerating expansion of the Universe through observations of distant supernovae.[6][7]
In cosmology, baryon acoustic oscillations (BAO) refers to an overdensity or clustering of baryonic matter at certain length scales due to acoustic waves which propagated in the early universe.[1] In the same way that supernova experiments provide a "standard candle" for astronomical observations,[2] BAO matter clustering provides a "standard ruler" for length scale in cosmology.[1] The length of this standard ruler (~150 Mpc in today's universe[3]) can be measured by looking at the large scale structure of matter using astronomical surveys.[3] BAO measurements help cosmologists understand more about the nature of dark energy (the acceleration of the universe) by constraining cosmological parameters.[1]
SDSS III: 2008-2014
In mid-2008, SDSS-III was started. It comprises four separate surveys, each conducted on the same 2.5m telescope: [9][10]
- Apache Point Observatory Galactic Evolution Experiment (APOGEE)
- Baryon Oscillation Spectroscopic Survey (BOSS)
- Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS)[11]
- Sloan Extension for Galactic Understanding and Exploration 2 (SEGUE-2)
Baryon Oscillation Spectroscopic Survey (BOSS)
The SDSS-III's Baryon Oscillation Spectroscopic Survey (BOSS) will map the spatial distribution of luminous red galaxies (LRGs) and quasars to detect the characteristic scale imprinted by baryon acoustic oscillations in the early universe. Sound waves that propagate in the early universe, like spreading ripples in a pond, imprint a characteristic scale on the positions of galaxies relative to each other [12] .
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Source: University of Chicago Library |
Enrico Fermi's notebook of December 1948 contains four pages that represent the genesis of his theory of cosmic rays, particles that can hit the Earth's atmosphere at high speeds. In these pages, he worked out the acceleration of cosmic rays due to a series of collisions with magnetic clouds moving through the universe, a process later named Fermi acceleration.SEE:Archive: Logbook
