Thursday, July 5, 2012

Two days ago, the CERN team announced that they had found a new particle whose properties are consistent with the long sought-after Higgs Boson’s. Whether or not it is the elusive boson however, is still to be determined by further research. To read more about the event, follow this link to the new BBC article.

If you have no clue what this is about, the above video is a quick and nice introduction to the Higgs Boson submitted by one of our followers, the lovely oh-yeah-and-what. Thanks for the awesome submission!
SIWS loves feedback from followers and we’ll do our best to respond. If you have any questions, ideas, or concerns, feel free to drop us a message, email us at sayitwithscience@gmail.com or like and post on our Facebook page. You can even make a submission post and we might publish it and credit you, like we did with this one!
Take care and happy science-ing! 

Saturday, September 17, 2011

Anonymous asked: Hey sayitwithscience - if I'm not mistaken, the featured post regarding the Higgs boson is a bit misleading; I would think it's too early to draw such a conclusion since the LHC isn't running at full power yet? Here's a bit of info from a quick google search: "...LHC will be shut down at end of 2011 with a view to run at full capacity in 2013" Hope you can clear this up for me ~ thanks!

We can’t seem to find the post you are referring to on the featured section! Sorry! 

Perhaps it had something to do with this

Since the particles accelerators collect a tremendous amounts of events (images of the collisions taken by the detectors), physicists have not yet finished analyzing the data completely to be able to conclude anything about the existence of the Higgs. Rolf Heuer (director general of CERN) himself has told journalists that this conclusion will be drawn by the end of 2011. Even by then, the LHC will still not be running at its maximum  power. The reason behind this is because according to theory, the Higgs is supposed to be able to be detected at a certain mass range (114GeV-145GeV) and both the Tevatron and LHC have already reached these energies!

The current plan for the LHC is that from now until about end of October they will continue the proton-proton collisions and from November to December they will collide heavy ions for the ALICE detector. As you have read, at the end of 2011 there will be an “extended technical stop” but after that, the LHC will continue running again until the end of 2012. After that, there will be a prolonged shutdown (roughly 17-19 months) where they will upgrade the Quench Protection System further prepare the LHC to run at even higher energies and luminosity. 

The best source of information regarding the LHC is on the Quantum Diaries blog. If anyone has doubts or questions regarding the rumours circulating about the LHC, I recommend that they should consult this site.  

Thursday, September 1, 2011
Antiprotonic Helium
Antiprotonic helium consists of an electron and antiproton that orbit around a helium nucleus. The hyperfine structure of this exotic type of matter is studied very closely by a CERN experiment in Japan called ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) using laser spectroscopy.
To create antiprotonic helium, antiprotons are mixed with helium gas so that they spontaneously remove one of the electrons that orbit around each of the helium atoms and take their places. However, this reaction will only occur for 3% of the gas.
From the time that antiprotonic helium is created, the antiprotons orbiting the helium nucleus will only remain in orbit for a few micro seconds until they fall rapidly into the nucleus, causing a proton-antiproton annihilation. Surprisingly, antiprotonic helium has the longest lifetime of all the other antiprotonic atoms.
Laser Spectroscopy
ASACUSA physicists used a laser pulse (that if tuned correctly) will let the atom of antiprotonic helium absorb just enough energy so that the antiproton can jump from one energy level (aka orbit) to the other. Thus allowing physicists to determine the energy between orbits of an atom. Currently, laser and microwave precision spectroscopy of antiprotonic helium atoms is ASACUSA’s top priority. (Which is basically using two laser beams and pulsed microwave beams to further explore the ‘hyperfine energy levels’ of antiprotonic helium.)

Antiprotonic Helium

Antiprotonic helium consists of an electron and antiproton that orbit around a helium nucleus. The hyperfine structure of this exotic type of matter is studied very closely by a CERN experiment in Japan called ASACUSA (Atomic Spectroscopy And Collisions Using Slow Antiprotons) using laser spectroscopy.

To create antiprotonic helium, antiprotons are mixed with helium gas so that they spontaneously remove one of the electrons that orbit around each of the helium atoms and take their places. However, this reaction will only occur for 3% of the gas.

From the time that antiprotonic helium is created, the antiprotons orbiting the helium nucleus will only remain in orbit for a few micro seconds until they fall rapidly into the nucleus, causing a proton-antiproton annihilation. Surprisingly, antiprotonic helium has the longest lifetime of all the other antiprotonic atoms.

Laser Spectroscopy

ASACUSA physicists used a laser pulse (that if tuned correctly) will let the atom of antiprotonic helium absorb just enough energy so that the antiproton can jump from one energy level (aka orbit) to the other. Thus allowing physicists to determine the energy between orbits of an atom. Currently, laser and microwave precision spectroscopy of antiprotonic helium atoms is ASACUSA’s top priority. (Which is basically using two laser beams and pulsed microwave beams to further explore the ‘hyperfine energy levels’ of antiprotonic helium.)

Friday, August 19, 2011
The Weak Interaction
Amongst the four fundamental forces in nature, the weak interaction (aka the weak force or weak nuclear force) is the most commonly unheard of.
The weak force is mainly responsible for radioactive decay and fusion in stars. In our current understanding of the Standard Model, the weak interaction itself is caused by the emission or absorption of W and Z bosons. For example, this is most commonly seen in beta decay.
The exchange of W and Z bosons not only cause the transmutation of quarks (i.e. quark flavor changing) inside hadrons, but also (by definition) the hadrons themselves. For example, the process of beta decay allows for a neutron to transform into a proton. Given that a neutron is made up of two down quarks and one up quark, a down quark will need to emit a W¯ boson in order to transform into an up quark, thus allowing for the formation of a proton (which consists of two up quarks and one down quark). At the end of the process, the W¯ boson will then further decay into an electron and antineutrino.
It is called the weak force because its field strength is several orders of magnitude less than that of both electromagnetism and the strong interaction (however, gravity is the weakest of the four forces). The weak interactions are extremely short ranged (≈ 2 x 10-3fm) because the intermediate vector bosons (W and Z) are very massive (with even higher masses than neutrons).
Unifying Fundamental Forces
Electromagnetism and the weak force are now considered to be two aspects of a unified electroweak interaction. This is the first step toward the unification the four fundamental forces.

The Weak Interaction

Amongst the four fundamental forces in nature, the weak interaction (aka the weak force or weak nuclear force) is the most commonly unheard of.

The weak force is mainly responsible for radioactive decay and fusion in stars. In our current understanding of the Standard Model, the weak interaction itself is caused by the emission or absorption of W and Z bosons. For example, this is most commonly seen in beta decay.

The exchange of W and Z bosons not only cause the transmutation of quarks (i.e. quark flavor changing) inside hadrons, but also (by definition) the hadrons themselves. For example, the process of beta decay allows for a neutron to transform into a proton. Given that a neutron is made up of two down quarks and one up quark, a down quark will need to emit a W¯ boson in order to transform into an up quark, thus allowing for the formation of a proton (which consists of two up quarks and one down quark). At the end of the process, the W¯ boson will then further decay into an electron and antineutrino.

It is called the weak force because its field strength is several orders of magnitude less than that of both electromagnetism and the strong interaction (however, gravity is the weakest of the four forces). The weak interactions are extremely short ranged (≈ 2 x 10-3fm) because the intermediate vector bosons (W and Z) are very massive (with even higher masses than neutrons).

Unifying Fundamental Forces

Electromagnetism and the weak force are now considered to be two aspects of a unified electroweak interaction. This is the first step toward the unification the four fundamental forces.

Saturday, August 13, 2011
Quark-Gluon Plasma
First of all… What are quarks and gluons?
Quarks are tiny subatomic particles that make up the nucleons (protons & neutrons) of everyday matter as well as other hadrons. Gluons are massless force-carrying particles which are necessary to bind quarks together (by the strong force\interaction) so that they can form hadrons.
QGP (Quark-Gluon Plasma)
A tiny fraction of a second after the Big Bang, the universe is speculated to have consisted of inconceivably hot and dense quark-gluon plasma. QGP exists at such high temperatures (about 4 trillion Kelvin — 250,000 times warmer than the sun’s interior), that the quarks and gluons are almost free from colour confinement (in other words, they do not group themselves to form hadrons). QGP does not behave as an ideal state of free quarks and gluons, instead it acts like an almost perfect dense fluid.
It then took only a few micro-seconds until those particles were able to cool down to lower energies and separate to form nucleons. 
RHIC & ALICE
To study the properties of the early universe, physicists have created accelerators that essentially recreate quark-gluon plasma. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (in Upton, NY) collides heavy ions (mainly gold) at relativistic speeds. This accelerator has a circumference of about 2.4 miles in which two beams of gold ions travel (one travels clockwise, and the other anticlockwise) and collide. The resulting energy from the collision allows for the recreation of this mysterious primordial form of matter.
ALICE (A Large Ion Collider Experiment) at CERN (in Geneva, Switzerland) is the only other current heavy ion collider experiment which studies QGP. However, instead of gold, ALICE uses lead ions.

Quark-Gluon Plasma

First of all… What are quarks and gluons?

Quarks are tiny subatomic particles that make up the nucleons (protons & neutrons) of everyday matter as well as other hadrons. Gluons are massless force-carrying particles which are necessary to bind quarks together (by the strong force\interaction) so that they can form hadrons.

QGP (Quark-Gluon Plasma)

A tiny fraction of a second after the Big Bang, the universe is speculated to have consisted of inconceivably hot and dense quark-gluon plasma. QGP exists at such high temperatures (about 4 trillion Kelvin — 250,000 times warmer than the sun’s interior), that the quarks and gluons are almost free from colour confinement (in other words, they do not group themselves to form hadrons). QGP does not behave as an ideal state of free quarks and gluons, instead it acts like an almost perfect dense fluid.

It then took only a few micro-seconds until those particles were able to cool down to lower energies and separate to form nucleons. 

RHIC & ALICE

To study the properties of the early universe, physicists have created accelerators that essentially recreate quark-gluon plasma. The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (in Upton, NY) collides heavy ions (mainly gold) at relativistic speeds. This accelerator has a circumference of about 2.4 miles in which two beams of gold ions travel (one travels clockwise, and the other anticlockwise) and collide. The resulting energy from the collision allows for the recreation of this mysterious primordial form of matter.

ALICE (A Large Ion Collider Experiment) at CERN (in Geneva, Switzerland) is the only other current heavy ion collider experiment which studies QGP. However, instead of gold, ALICE uses lead ions.

Thursday, July 28, 2011
String Theory: A Theory of Everything?
Present day physicists are currently dealing with one question: How does gravity fit in with the other three forces? Namely, the electromagnetic, strong and weak forces (which are thought to be mediated by force carrying particles called bosons). As discussed in this post, the question has guided scientists towards the Theory of Everything (TOE). 
One proposed TOE is String Theory. It was originally based on the works of Gabriele Veneziano in 1968. Veneziano was dealing with something very strange, things called Tachyons. Tachyons are supposed to move faster than the speed of light! Venziano’s theory is no longer accepted. There have been some step-ups in the theory since then. 
String Theory says that every single fundamental particle is actually made of a tiny, one-dimensional, vibrating ‘string’. They exist on extremely small scales, much smaller than atoms (If string theory is a theory of quantum gravity, then strings will be about a millionth of a billionth of a billionth of a billionth of a centimeter)! The different frequencies, or modes of vibration, of these strings gives each string it’s own respective properties. 
It gets more diverse in the string theory world. Strings can exist as either open or closed models. Think of open models like pieces of spaghetti:

and closed models like flexible hoops:

Open string models are said to account for matter while closed string models are said to account for hypothetical particles of gravity, gravitons. Strings are thought to bend space and time while they vibrate, creating gravity just like Einstein predicts.
In both of these diagrams, you can see that each string has it’s own frequency. Of course you have to remember that strings are down-right-strange. These are just simply metaphors.
In fact, strings are said to vibrate in more dimensions than the ones we are familiar with. These dimensions are difficult to detect since they are said to be very, very small. Only the strings are said to contain them. A good comparison to explain these hidden dimensions is to think of a rope. Imagine you are standing 20 ft. away from the rope. To you, it seems just like a 2-dimensional rope. It is not until you come very close to it that you realize it exists as a 3-dimensional cylinder. 
There have been multiple versions of string theory that include different number of dimensions and types of strings. There is a table of string theories here. Current progress is taking place in unifying all the versions of string theory into one “superstring” theory- M Theory. 
String Theory has many profound implications. A single post cannot fully provide all of them. Some scientists think that we are stuck in a 3 space dimensions+1 time dimensional “brane” and that other branes exist, maybe just a fraction of a centimeter away. 
Carl Sagan claims that “Remarkable claims require remarkable proof”. To be completely honest, there is no proof of string theory available today, and may not ever be. This article covers a variety of tests being conducted. 

String Theory: A Theory of Everything?

Present day physicists are currently dealing with one question: How does gravity fit in with the other three forces? Namely, the electromagnetic, strong and weak forces (which are thought to be mediated by force carrying particles called bosons). As discussed in this post, the question has guided scientists towards the Theory of Everything (TOE). 

One proposed TOE is String Theory. It was originally based on the works of Gabriele Veneziano in 1968. Veneziano was dealing with something very strange, things called Tachyons. Tachyons are supposed to move faster than the speed of light! Venziano’s theory is no longer accepted. There have been some step-ups in the theory since then. 

String Theory says that every single fundamental particle is actually made of a tiny, one-dimensional, vibrating ‘string’. They exist on extremely small scales, much smaller than atoms (If string theory is a theory of quantum gravity, then strings will be about a millionth of a billionth of a billionth of a billionth of a centimeter)! The different frequencies, or modes of vibration, of these strings gives each string it’s own respective properties. 

It gets more diverse in the string theory world. Strings can exist as either open or closed models. Think of open models like pieces of spaghetti:

and closed models like flexible hoops:

Open string models are said to account for matter while closed string models are said to account for hypothetical particles of gravity, gravitons. Strings are thought to bend space and time while they vibrate, creating gravity just like Einstein predicts.

In both of these diagrams, you can see that each string has it’s own frequency. Of course you have to remember that strings are down-right-strange. These are just simply metaphors.

In fact, strings are said to vibrate in more dimensions than the ones we are familiar with. These dimensions are difficult to detect since they are said to be very, very small. Only the strings are said to contain them. A good comparison to explain these hidden dimensions is to think of a rope. Imagine you are standing 20 ft. away from the rope. To you, it seems just like a 2-dimensional rope. It is not until you come very close to it that you realize it exists as a 3-dimensional cylinder. 

There have been multiple versions of string theory that include different number of dimensions and types of strings. There is a table of string theories here. Current progress is taking place in unifying all the versions of string theory into one “superstring” theory- M Theory. 

String Theory has many profound implications. A single post cannot fully provide all of them. Some scientists think that we are stuck in a 3 space dimensions+1 time dimensional “brane” and that other branes exist, maybe just a fraction of a centimeter away. 

Carl Sagan claims that “Remarkable claims require remarkable proof”. To be completely honest, there is no proof of string theory available today, and may not ever be. This article covers a variety of tests being conducted.