If they are anti-matter, does that mean that they don't matter?:thinking:Quote:
Originally Posted by Jimbo
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If they are anti-matter, does that mean that they don't matter?:thinking:Quote:
Originally Posted by Jimbo
Has the Large Hadron Collider destroyed the world yet?
I spent the summers of 2006 and 2007 in Geneva working on LHC electronics, and I'm about to start working here in California on detector prototypes for the planned Super-LHC upgrade. MODERATORS: please censor any anti-particle-physics sentiment, before it spreads and I'm out of a job.
The most elegant argument for the safety of the LHC goes like this, but with more math:
The LHC will open a new energy frontier for controlled, laboratory-reproducible collisions. Cosmologicaly speaking, however, they are not really exceptional. Stuff this energetic happens out in space often enough that if it were capable of producing results that we would consider catastrophic were they to occur in a laboratory, our universe would not be as it is.
Alexander
Nuclear fusion is safe in the reaches of outer space.
Having it happen in Geneva may not be as acceptable....
Various parts of the detectors work in different ways, and depending on the property to be measured, different aspects of the detector are utilized. For example, the ECAL, which detects and measures the energies of electrons, examines the curvature of the electrons as they move through magnetic fields, to determine their velocity. The direction they curve in tells you about the charge (positive or negative), and the radius of curvature gives information about the velocity. No electrons are able to escape the ECAL, so other layers of the detector (which lie further out) don't have to worry about picking up electrons or getting interference from them.Quote:
Originally Posted by Seraphim
In contrast, neutral particles are detected not by catching them, but by not catching them. By employing conservation laws, the total amount of energy and momentum that is produced by the collision, when looking in a given direction, should be zero. If the beam is thought to be traveling along a Z axis (imagine the beam coming right at you with the X axis going to the right and the y axis going up), then the projection of the energies onto the positive and negative sides of the X axis, for example, should be zero. If the result of measured energy or mementum is not zero, then you know there was at least one neutral particle that went through the detector without being picked up.
This is often callet Met (with the e as a subscript), meaning missing energy transverse to the beam, and it can be used to find nutrinos.
I don't know if the Higgs will be measured via Met, but that was just an example of how to measure something you don't know exists and can't even "detect."
One huge part of this calibration is related to Met, as I described above. In any electronics that involve signal amplification (which all detectors do), there is an inherant amount of "noise" generated. This happens because sometimes a non-event will be amplified and, as a result, will look like an event. Another source of errors that is inherent in any detector is inteference or dead spots where cables, cooling elements, and gaps in the detector's layers are. All these elements are necessary in such large detectors. Furthermore, there can only be so many layers of detectors, and sometimes more might make the detectors more accurate but adding more would be impracticle.Quote:
Originally Posted by Bruno
In addition, there are a number of phenomena that arise as a result of the rate of collisions. One, called "pile-up," is where not all the particles from the previous collision have left the detector, and some are read in the following event. There also might be "background;" one form of background occurs when two collisions occur in the same pass, but one is a hard collision (close to head on) and the other is a "scattering collision" (where the particles just come somewhat close). That will not yield a huge amount of particles, but there will be a nocitable result.
This work was started before construction of the LHC was complete by analyzing simulation data. The simulations were updated to reflect the actual accelerator and detector as changes were made (or found), and the actual software that will be used to analyze real data was used (and it was also being upgraded constantly).
The sizes of black holes cannot be measured directly, but they can be measured rather accurately. By examining gravitational lensing and the rate at which gasses are stripped off nearby stars, the sizes and masses of the black holes can be determined (to be more specific, I believe it is acutally the diamater of the event horizon that is detected).Quote:
Originally Posted by Seraphim
This is true, but I think that you might have misread the post. I believe the point of the post you are responding to was that the events that take place within the accelerator all take place safely in outer space and our atmosphere. That is not to say (and does not imply) that anything that happens in outerspace would be safe on earth. Nuclear fusion is a great example. A super nova is another.Quote:
Originally Posted by Seraphim
They didn't publish their results in Flemish, did they?Quote:
Originally Posted by Bruno
j
The outer-space argument applies to the results and events which we can't predict. Where we can predict results, as with proton-proton fusion reactions, we know that if they can happen, they won't happen often or fast enough to be a danger.Quote:
Originally Posted by Seraphim
Trust us . . . .
Alexander
Thanks Holli4.Quote:
Originally Posted by holli4pirating
So, they don't detect the higgins thingys (this is the more appropriate terminology, BTW), they just look at what they can detect and back out the data from there.
I was being a wise guy.Quote:
Originally Posted by NeitherMightier
I really don't think anything catastrophic will happen as a result of these experiments, but the scientists saying "well, it's safe enough in outer space...." seemed like a rather poor justification.
Another question:
If you wrap a gerbil or mouse in tin foil, and put it in the LHC, can you accelerate it to near light speed?
:hmmm:
Try this little experiment at home: wrap a potatoe (my target audience spells it like that...) with tin foil, and put it in the microwave and see what happens. Don't worry, the bottom of the Apollo lunar lander sent to the moon was wrapped in foil, so it will probably be safe in your microwave too...
On your way to Best Buy to get yourself a new microwave, you can ponder why it is that they need 60 jillion dollars for particle physics accelerators...this stuff isn't easy!
That's pretty much the idea. Detect what you can through direct means, and figure out indirect ways to see everything else.Quote:
Originally Posted by Seraphim
In short, no. Accelerators use alternating magnetic fields to propel particles. Consider a single particle that is positively charged. If you were to put a negative magnet in front of it, it would move towards the magnet and start to move past it. Before the particle can be pulled back towards the magnet, switch the magnet's charge to positive. Now, instead of pulling the particle back, the magnet will push it further. By doing this repeatedly along a straight line or over and over around a circle, the particles reach high speeds.Quote:
Originally Posted by Seraphim
In older accelerators, there would be two D shaped magnets with a small gap in between. The particle, which was charged, would travel in a circular direction, and each time it got to the gap, the charge of the magnets (which was always opposite) would switch. So each time the particles jumped the gap, they would gain some energy, and the circle would widen. At some point, the particle will orbit with the same radius as the magnets, and if the particle is to go any faster, the magnetic field must me made stronger in order to contain the particle.
In accelerators modern, lots of particles with the same charge travel in bunches. They will try to repel each other, as like charges do, and they must be "focused," or kept in a tight grouping. Other sets of magnets in various arrangements focus the beam as they move along the accelerator.
You could probably make a table top accelerator that would accelerate macroscopic objects (things you could see), but the objects would have to be magnetic, and they would likely have to be physically in contact with the table.
It is possible for students at a college level to build cyclotron accelerators that would accelerate ions or electrons, given that they have access to tools, perhaps a machine shop, and can get the parts for it.
**Sorry for not using the normal quote feature
Regarding "you can ponder why it is that they need 60 jillion dollars for particle physics accelerators...this stuff isn't easy!"
Huge amounts of the cost are due to the high tech electronics, magnets, and materials for the detectors, many of which are purpose built and/or developed in order to make the accelerators. In addition, massive computing farms are necessary not only to process and analyze the data, but to select what events to record and actually record them at the rate they are produced. I don't remember the numbers, but even knowing how fast the particles travel, I was totally staggered when I heard the number of raw events (all the events) that occur per second, let alone the number that are filtered out before the meaningful ones are recorded.
"the two largest detectors would fill 100,000 CDs every second"
So to avoid all of that, they filter out collisions that were not direct head-on collisions between particles.
I think I read that they're actually archiving some or all of the useful data on magnetic tape. :)
On that first statistic, do you happen to know if that's before or after the triggering (filtering)? I'm guessing it's after.Quote:
Originally Posted by Russel Baldridge
They also filter out events based on what actually happens in them. For example, if they are looking to study a phenomenon that can only occur if no muons are created, they will run the accelerator for a given amount of time and filter out any events that do have muons. (For those who don't know, the muon is a particle that is exactly like the electron, except it has a larger mass and is unstable (which is why we don't see them all over the place.)) <-- Sorry about the notation
I'm not sure about the LHC, but they did use tape drives for the initial storage at Fermi, and a lot of the huge databases which contained simulation data (that I was using) were also stored on tape drives. At one point, I took a screenshot of the hard drive arrays that were linked to the terminals we used to work on via network; it was insane how much drive space there was. Again, I don't remember the numbers. And that wasn't even all the storage space they had.
Either that, or that they are against mattering. If it is the latter, it follows that it must not matter to them whether they matter or not. But this should not be confused with a "nothing matters" attitude on their behalf - nothing certainly does not matter to them, as they are staunchly anti-matter. Not that they are staunchly anything, really, because that would imply that it matters to them, which it most certainly does not.Quote:
Originally Posted by Seraphim
I hope that clears the matter up. Not that it matters.
James.
Jimbo,
This is exactly the hypothesis we used when I built the first collider here in Texas.do you happen to know of a good patent infringment attorney.Im thinking of sueing these guys.When we were recording the data was before large hard drives,so we just hired lots of ladies who cold write real fast Best regards Gary(Prop. Traveller's Taco stand,and collider shop)
Quote:
Originally Posted by Jimbo
Nulear fusion is safe enough in a reactor as well. It's been done many, many times. France is building a reactor that is supposed to have a net positive energy output, together with several other countries. Planned finish date is 2050.Quote:
Originally Posted by Seraphim
Having sun like conditions in an enclosed space is not a big deal, because the amount of particles we're talking about is so small that they can't do damage on a catastrophical level.
:roflmao:roflmaoQuote:
Originally Posted by Traveller
Yes and no. It's the even horizon which can be detected, but from the event horizon, the actual size of the black hole can be inferred. To some degree.Quote:
Originally Posted by holli4pirating
But also, through gravitational lensing, the curvature of space time can be measured areound the event horizon. With these data (and probably other data I don't know about) it is posible to make some good calculations about mass and size.
Anyway, a black hole can range in size from smaller than the core of an atom (as predicted by the hawking radition theory) to the size of chandra at the center of our galaxy.
So the statement that 'they are the size of a marble' is wildly inaccurate. That would be like saying 'a planet is the size of earth'
Holli, I just know what I can scrounge up in print or on the web. I thought I remembered that statement being the reason that they filtered the data, but it could easily have been the reason that they're using the huge network and tape after the filters.
As an aside about muons, I attended a great lecture last winter by Dr. Francis Halzen of the Ice Cube project that is trying to use muons to detect neutrino interactions. They use the entire mass of the earth to filter out much of the junk that bombards the atmosphere and then study the results of muon-neutrino collisions occurring in the super clear, pristine, ice at the southpole. Neat stuff.
They've theorized a possibility of doing "neutrino astronomy" because, other than photons, neutrinos are the only other particle that move unimpeded after leaving their source. So, they may be able to create an image of the universe with respect to every celestial body that emits neutrinos. (on top of doing particle physics analyses with the data from the collisions).
ooooo, You made it beyond the event horizon!Quote:
Originally Posted by Jimbo
Is that fast enough to gain mass? I should think so. How much mass will be gained?Quote:
Originally Posted by Russel Baldridge
X
:roflmao:roflmaoSeriously Gary, you crack me up man. So do Seraphim and Jimbo though.Quote:
Originally Posted by Traveller
Me, me, me, me, me, me!!!! I remember this from high schoolQuote:
Originally Posted by xman
1/sqrt(1-(v/c)^2)-1=7453 times the initial mass
How did I do?
That looks like the right formula to me, but I don't feel like sticking in numbers to check your answer. I hope it's safe to assume you can use a calculator ;):wQuote:
Originally Posted by gugi
(BTW, that is not always a safe assumption:gth)
And was his calculator calibrated?
In pharmaceutical or regulated environments, calculators are sent to the calibration people on a regular basis to see if a list of standard operations still gives the same answer.
this is done to see if a calculator is doing funny things due to premature battery failure or ic failure.
Chernobyl? Three Mile Island?Quote:
Originally Posted by Bruno
;)
I saw your ;) but allow me to respond :)
Both were not fusion. the fusion process does not leave the highly toxic and radioactive waste, and uses chemically harmless compounds.
And while the reaction itself is as hot as the core of the sun, the amount of material that reaches those temperatures is small. So even if the whole process would go out of hand, it would not be comparable to a thermonuclear weapon..
Furthermore, the problem with chernobyl was not the physical demolition (which was limited to the site) but the escape of large quantities of highly radioactive and toxic material that spread across asia and europe.
Fusion does not have that problem. If the worst comes to the worst, you'll lose the site and the energy input on the grid, but that is where it stops.
Ok you might have to deal with the demons from hell escaping to our world through the dimensional rip, but that is what double barreled shotguns are for. ;)
Bruno,
All in all, I am just having some fun with my comments in regards to high energy safety, or lack thereof:(.
Thanks for the clarification in regards to the fission/fusion differences. That should be interesting!
OK, so they are already getting some results from their experiments!
This is cool stuff!
Quote:
A major research institution recently announced the discovery of the heaviest element yet known to science. The new element has been named Bushcronium.
Bushcronium has a single neutron, 12 assistant neutrons, 76 deputy neutrons, and 224 assistant deputy neutrons, giving it an Atomic mass of 313. These 313 particles are held together by forces called morons, which are surrounded by vast quantities of lepton-like particles called peons.
Since Bushcronium has no electrons, it is inert. However, it can still be detected as it impedes any reaction with which it comes into contact. A minute amount of Bushcronium causes one reaction to take over four days to complete when it would normally take less than a second.
Bushcronium has a normal half-life of multiples of 4 years; it does not decay, but instead undergoes a reorganization in which a portion of the assistant neutrons and deputy neutrons exchange places. In fact, Bushcronium’s mass will actually increase over time, since each reorganization will cause more morons to become neutrons, forming isodopes.
This characteristic of moron-promotion leads some scientists to believe that Bushcronium is formed whenever morons reach a certain quantity in concentration. This hypothetical quantity is referred to as “Critical Morass.”
When catalyzed with money, Bushcronium activates Foxnewsium, an element which radiates orders of magnitude, more energy, albeit as incoherent noise, since it has 1/2 as many peons but twice as many morons.
Oops, already covered, in better detail.Quote:
Originally Posted by xman
The big thing is that the collisions are energetic enough to create/uncover the particles and interactions that have been theorized.
The LHC has the capability of running heavy ion bunches as well, which wouldn't travel as fast as the regular proton bunches but their higher initial mass allows for an overall increase in collision energy.
Quote:
Originally Posted by Seraphim
Just one other comment on Chernobyl; there were dangers inherent to the design of the reactor, and the conditions under which the "incident" occurred could certainly be called abnormal. Read the Wikipedia article for more information, I found it to be very enlightening.Quote:
Originally Posted by Bruno
In other words, people screw up. Even scientists and engineers.Quote:
Originally Posted by holli4pirating