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Re: Vacuum Bubbles
Posted: Wed May 04, 2011 1:53 pm
by chelle
Stephen wrote:Have I missed any safety arguments concerning Pb + Pb collisions?
Hi Stephen, it's cool to see you passing by again.
What I would like to see on the list are the arguments of the
environment where collisions happen, along with the
frequency. There isn't one place in our solar system where there is such a concentration of collisions, with so much luminosity at one spot, as at the lhc.
btw there is this previous post by this 'alpha - omega' guy with a biblical quote, it made me think of relevant story from that book:
"On the seventh day they were to march around the city seven times and the priests were to blow their ram's horns. This Joshua did, and he commanded his people not to give a war-cry until he told them to do so. On the seventh day, after marching around the city the seventh time, the priests sounded their ram's horns, and Joshua ordered the people to shout. The walls of the city collapsed, and the Israelites were able to charge straight into the city." Battle of Jericho
Just to point out that the louder and more intense you go, the bigger the chance becomes that you start to shake solid structures apart.
grtz,
chelle
Re: Vacuum Bubbles
Posted: Wed May 04, 2011 8:09 pm
by Kasuha
Chelle wrote:What I would like to see on the list are the arguments of the environment where collisions happen, along with the frequency. There isn't one place in our solar system where there is such a concentration of collisions, with so much luminosity at one spot, as at the lhc.
This is 'one spot' is in fact, compared to lead nucleus size, pretty much as big as Earth is for humans. Maybe bigger. So it's like if you said that all car accidents on Earth within a day happened in one spot and at the same time (and before you start talking about chain accidents ... I am talking about *all* of them, not a few. Even the biggest chain collision does not stretch from US to India).
On the other hand, centers of bigger neutron stars are in state of permanent collision of something way bigger than two lead nuclei. And I have yet to see vacuum bubbles emanating from them. Matter (including iron) falling into black holes is producing even far more energetic collisions (still way above the event horizon) and it still appears to produce just X-rays and cosmic rays rather than vacuum bubbles.
And there is also no proof that such thing like a vacuum bubble can ever be created by anything in our universe. It's nothing more than an unprovable mathematical construction which somebody likes to use to scare uneducated people. I find it really funny how these people happily spend time "proving" that it cannot happen at any exotic place in our universe any still fail to prove that it cannot happen at such a dull place like LHC.
Re: Vacuum Bubbles
Posted: Wed May 04, 2011 9:18 pm
by chelle
Kasuha wrote:Chelle wrote:What I would like to see on the list are the arguments of the environment where collisions happen, along with the frequency. There isn't one place in our solar system where there is such a concentration of collisions, with so much luminosity at one spot, as at the lhc.
This is 'one spot' is in fact, compared to lead nucleus size, pretty much as big as Earth is for humans. Maybe bigger. So it's like if you said that all car accidents on Earth within a day happened in one spot and at the same time (and before you start talking about chain accidents ... I am talking about *all* of them, not a few. Even the biggest chain collision does not stretch from US to India).
Hi Kashua, your comparisons are a bit rough.
At ATLAS, CMS the beams collide at 16 μm (10^-5) (
source)
The size of a proton is 0.1 nm (10^-10)
The difference is 10^5, if we say that a human is 1 meter than the scale would be 100.000 m that is 100 km
Next to that the LHC detectors might produce 10^34 collisions per second and per cm^2. (
source)
And for: Pb82+ ions ... each bunch will contain 1.6x10^8 ions (
source)
Note that these ions are larger than individual protons, and the fact that 2 bunches collide.
btw, the frequency difference between Cosmic Ray's and the LHC:
The plot below shows a graph of flux, measured in number of particles per square meter per second per steradian per GeV (10^9 eV), on the vertical axis, versus particle energy, in electron volts, on the horizontal axis. You will see that the largest flux is at low energy (about 10^9 eV), where the flux is about 1000 particles/m^2-s-sr-GeV . So in one
square meter, looking over the whole upper half of the sky (2 pi = 6.2 sr), in a bandwidth of 1 GeV, one sees 1000 particles every second. That is very small compared to the luminosity of the LHC, which is somewhere around 1.000.000.000 collisions per
square centimeter per second, the difference is a million times (10^6)
*10^2.
One can say that omg particles have an energy of 1.0×10^20 eV but these single events happen only a few times a year and we actually haven't got a clue what they are.
![Image](http://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Cosmic_ray_flux_versus_particle_energy.svg/360px-Cosmic_ray_flux_versus_particle_energy.svg.png)
(image:
http://en.wikipedia.org/wiki/Cosmic_ray)
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 3:01 am
by JNW
Chelle wrote:The size of a proton is 0.1 nm (10^-10)
That's atomic size. The size of a proton is around 10^-15 m.
Next to that the LHC detectors might produce 10^34 collisions per second and per cm^2. (
source)
That's not the number of collisions. That's what you multiply by the extremely small cross section to get the number of collisions. When two bunches of protons collide, there may be around 10 collisions. For lead ions, there is usually no more than one collision. (with ions, having more than one collision in a bunch crossing makes it hard to analyze the debris.)
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 8:08 am
by Kasuha
JNW wrote:Chelle wrote:The size of a proton is 0.1 nm (10^-10)
That's atomic size. The size of a proton is around 10^-15 m.
... and lead nucleus is not a whole lot bigger.
Plus, the space where collisions occur may have small diameter but is several millimeters long so it's rather BIG space compared to the nuclei size.
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 10:44 am
by chelle
JNW wrote:Chelle wrote:The size of a proton is 0.1 nm (10^-10)
That's atomic size. The size of a proton is around 10^-15 m.
You are correct.
JNW wrote:Next to that the LHC detectors might produce 10^34 collisions per second and per cm^2. (
source)
That's not the number of collisions. That's what you multiply by the extremely small cross section to get the number of collisions. When two bunches of protons collide, there may be around 10 collisions. For lead ions, there is usually no more than one collision. (with ions, having more than one collision in a bunch crossing makes it hard to analyze the debris.)
This puzzles me a bit. I've asked the person of the spanish website that I referred to about how many collisions there are, and he gave me this explanation:
I think that your mistake is when you say: 10^30 "collisions" per square centimeter per second.
The correct expression would be: 10^30 particles (usually protons at LHC) crossing per square centimeter per second.
Actually, the correct value is 10^34 (in ATLAS and CMS) when energy reaches 14 TeV.
So, it is not "collisions" but "particles crossing".
To calculate the number of collisions it is necessary to consider a very important parameter: "cross section" which is, in this case, a measurement of the probability that an inelastic collision occurs.
If you do (Luminosity x Cross Section) you get the number of that collisions.
For inelastic collisions at 7 TeV protons the value of cross section is 6·10^-26 . So the number of collisions at 7 TeV is : (10^34)x(6·10^-26) = 600 millions per second, or about
10^9 collisions per second (no 10^30, as you said).
You can follow better the explanation in my website:
http://www.lhc-closer.es/php/index.php?i=1&s=4&p=10&e=0
Ok you say 10 per crossing but I say 10^9 per second (for how many seconds?) and that's what I also mentioned it in the 2nd part of that post:
That is very small compared to the luminosity of the LHC, which is somewhere around 1.000.000.000 collisions per square centimeter per second, the difference is a million times (10^6)*10^2.
Also take in account that the difference should also be seen in relation with cosmic rays, if you want to use those as a safety argument.
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 11:12 am
by Kasuha
An average car consumption is about 1,000,000,000,000 or 10^12 liters per parsec. Aren't you afraid? And that's just one car! Who's going to pay for that???
![Screaming :angry-screaming:](./images/smilies/angry/screaming.gif)
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 11:14 am
by chelle
Kasuha wrote:Plus, the space where collisions occur may have small diameter but is several millimeters long so it's rather BIG space compared to the nuclei size.
Ok, let's try to put size in perspective. If you you do a double-slit experiment how far can the distance be between the 2 slits in such a way that the wave-function of a photon or an electron 'feels' the second opening. Wouldn't this be the same as saying that someone in NY can sense something in Calcutta? It just goes to show how agile the Vacuum/Aether is.
And on a secondary note I would like to bring up an airplane disaster where a flock of birds made a Hercules airplane crash:
The accident was initiated, most probably as a reaction to observing birds, by the go-around which was made at a low altitude during which a flock of birds could no longer be evaded. The accident became inevitable when:
- bird ingestion in the two left engines occurred due to which the power of these two engines was lost;
- as a result of power loss, the aircraft became uncontrollable at a very low altitude and crashed.
Source
Anyone remembers this post:
Particles That Flock
I'd like to bring it up cause if we increase energy for finding the Higgs, luminosity will aso increases, and we'll start to generate unknown bunches of more energetic particles that could cause interference with the mechanism of the surrounding matters nuclei, making them crash and loose their composition/energy, and like the flock of birds that made the big plane go down, a few of them birds wouldn't have cause any harm, it is the increasing quantity that did.
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 11:18 am
by chelle
Kasuha wrote:Aren't you afraid?
It's not about fear, I'm just curious.
![Mr. Green :mrgreen:](./images/smilies/icon/mrgreen.gif)
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 2:07 pm
by adam_jeff
I haven't had the time to check your figures, but I think there's a false assumption in the way you're using the cosmic ray data anyway.
If you assume that cosmic rays are evenly distributed, then it's true that the flux and thereforer the rate of collisions in a given volume) is much smaller than in the LHC.
But the collisions from cosmic rays aren't evenly distributed. Those very energetic 10^20eV particles (in fact they don't need to be that energetic) cause showers of particles which also have very high energies. These cause clusters of collisions.
The density of the LHC beams is very low, even when they're squeezed for collision (half a miligram per m^3, by my back-of-the envelope calculation) so in fact, the chance of secondary collisions is much higher in the case of, say, a high-energy cosmic ray hitting a block of metal, than in the LHC.
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 2:20 pm
by Kasuha
adam_jeff wrote:Those very energetic 10^20eV particles (in fact they don't need to be that energetic)...
10^20 eV particle hitting a stationary target makes as energetic collision as two 10^10 eV particles colliding head-on - so in fact to be accurate it is necessary to look for such high energy particles to be able to see effects of what's going to happen in LHC happening naturally in our neighborhood.
There sure are not too many of them but there are enough to be reasonably certain that even head-on collisions of two such particles happen occasionally somewhere in the space.
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 3:17 pm
by chelle
adam_jeff wrote:I haven't had the time to check your figures, but I think there's a false assumption in the way you're using the cosmic ray data anyway.
If you assume that cosmic rays are evenly distributed, then it's true that the flux and thereforer the rate of collisions in a given volume) is much smaller than in the LHC.
But the collisions from cosmic rays aren't evenly distributed. Those very energetic 10^20eV particles (in fact they don't need to be that energetic) cause showers of particles which also have very high energies. These cause clusters of collisions.
The density of the LHC beams is very low, even when they're squeezed for collision (half a miligram per m^3, by my back-of-the envelope calculation) so in fact, the chance of secondary collisions is much higher in the case of, say, a high-energy cosmic ray hitting a block of metal, than in the LHC.
Hi adam_jeff, I don't want to be rude, but could you perhaps just take a few minutes, to have a look at the data and questions, before posting your comment. Otherwise we're going into circles, I know that LHC-fans like that kind of s**t but here it's slightly counterproductive.
Simple reason, I posted the figures indicating that per square centimeter there is a difference of 10^8 (cosmic vs lhc) and in your post you go saying that the density of the beam is very low, just like JNW mentioned that there are only 10 collisions each time.
I'd like to add two pictures, the first one is from a collision between a high-energy cosmic ray particle and an atom
link, the second one is from the RHIC of the collision of 2 gold ions (100 GeV per ion)
link.
What I understood from your remark is that the density (right) behind the cosmic ray collision is similar to those at the LHC, which is correct. But the point I'm trying to make, is that collisions on top of our atmosphere or on the moon happen relatively spread, in contrast to the lhc where there is for a few seconds a constant bombardment at one specific spot (a collision rate of 40 MHz). If one imagines that each collision generates vibrations within the Vacuum (Aether), than during that time everything that surrounds the collision area gets to be shaken for a far longer time, and at a much intenser rate than in nature. btw the difference is 10^8
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 5:08 pm
by Kasuha
First of all, there is no point in taking number of collisions per square centimeter as an argument. There is no such square centimeter in LHC, all collisions happen in space (so we might eventually talk in cubic centimeters ... but talking in cubic micrometers could bring us closer to real orders of magnitude) and time. And in all of these four dimensions, they are safely spaced.
Re: Vacuum Bubbles
Posted: Thu May 05, 2011 8:22 pm
by chelle
Kasuha wrote:First of all, there is no point in taking number of collisions per square centimeter as an argument. There is no such square centimeter in LHC, all collisions happen in space (so we might eventually talk in cubic centimeters ...
Squared or cubic the argument stays the same. It's about density and frequency at on one target place during a certain time.
Kasuha wrote:... but talking in cubic micrometers could bring us closer to real orders of magnitude) and time. And in all of these four dimensions, they are safely spaced.
How can you say that they are safely spaced, when you have no references at these unique densities & frequencies, and also with the new world record intensities? All the papers focus on single events at one time, never on the whole collision process and the environmental setting.
Frequencies and Densities
Posted: Thu May 05, 2011 9:06 pm
by chelle
Edit: This was a request to split the density discussion out of the '
Vacuum Bubble' topic.