...And here we thought that the worse we had to fear from mankind was global nuclear warfare and destroying the Earth. Who woulda thunk we'd be taking the whole cosmos down in flames with us. Now correct me if I'm wrong, but is the particle in question here the higgs boson? I remember reading how the zero point field pervades the vacuum of space, so in that case aren't they referring to the higgs?

They probably mean twin-particles. Something that´s been postulated but never proven.

Twin particles actually refers to the phenomenon of "Quantum Entanglement". This is not only a postulated phenomenon, but demonstrated several times to exist. However, Quantum Entanglement is not what this super laser is spesifically for, but as they talk about it in the article it could help reveal the so called "virtual particles" that exists in the vacuum of space, among many other things. If anyone wishes some more information about these virtual particles and reasons for their existence, just shout out and I'll try to explain a bit =)

/me shouts out.


Kind regards,

The Traveler

Allright, here goes

These virtual particles pop in and out of existence through something called Quantum Fluctuations. It is indeed very strange and incredible. I mean, how can "something" pop out of "nothing"? What makes this remarkable phenomenon possible? It is something that lies in the very heart of Quantum Mechanics, namely Heisenbergs Uncertainty Principle. It asserts that you simply can't measure both position and momentum (momentum being the product of mass and velocity) for a given particle precisely. In words the equation can be written as:

Uncertainty in position x uncertainty in momentum is bigger than or equal to a fundamental constant.

This means that the more you know about for example the position of say, an electron, the less you will know about its momentum and vice versa. One might wonder why this is the case, and I'll try to give an idea: To make it simple, one cannot detect anything with better precision than the wavelength of the radiation used to detect it. To localize something that is incredibly small means we need to use incredibly small wavelengths as well, and the smaller the wavelength the greater the frequency of radiation, and the greater the frequency the greater the energy of the individual photons the radiation is composed of will be. When the photon hits the object of interest, say again an electron, we can find its position pretty accurately because the wavelength is so small, but the energetic photon will upon hitting the electron disturb its momentum. If its the other way around, using longer wavelengths, the radation will have smaller frequency and thus the individual photons less energy, and we do not disturb the electron so much. However, with longer wavelengths we must sacrifice precision in position (because the wavelength is longer).

Heisenbergs Uncertainty Principle also asserts a similar situation when it comes to the precision in measuring the energy of a particle and how long the particle has this definite energy. It is a little bit more of a delicate matter, but the general idea is that you can't say that a particle has a definite energy in a definitive time. The bigger the precision in an energy measurement, the greater the time the particle has this energy must be. Equivalently a particle can't have a definite energy in a very short timespan, so it can fluctuate wildly between different extremes as long as the interval of time is short enough. Here lies the key to Quantum Fluctuations. Just the way that you can borrow big money form your bank as long as you pay it back quick enough, Quantum Mechanics lets a particle "borrow" large chunks of energy as long as it is "paid back" fast enough. In this way the law of energy conservation is satisfied at macroscopic scales.

As we can see, the microcosmos is extremely chaotic and nuts. So nuts that even in an empty box these uncertainties in energy and momentum exists, and they will fluctuate more wildly the more we shrink the box and the lesser the time is. If the energies of these fluctuations gets big enough, we can have matter production from E = mc^2. For example we can out of nothing suddenly have that an electron and its anti-particle, the positron, pops into existence even though we had total empty space to begin with. This is what we call virtual particles, and they will annihilate eachother almost instantly to "pay back" the energy that was borrowed. This happens all the time, but since these fluctuations in average cancel eachother out, empty space seems rather calm and boring.

This all sounds very incredible, but this is not something crazy physicists just make up for fun. These fluctuations have effects that we can observe, whereas a famous example is known as the Casimir Effect. Here we have two neutral metal plates placed parallel to eachother with a very very small distance between them, in complete vacuum. What we actually can observe here is an attractive force between the plates that is caused by the virtual particles popping into existence between them. If each plate for example has the area 1m^2 and the distance between them is 10^-6 m, the attractive force between them will be 0.0013 N.

And don't be bothered if you don't understand this crazy shit, because no one understands quantum mechanics =)

So, what´s behind this? are these particles, particles that normally exist in such a state or dimension that they cannot be detected, like say, the supposed 'dark matter'? Is it like there´s a lightswitch that 'turns them on', so they can suddenly seem to pop-up out of nowhere?

Or are these particles realy virtual particles in the sense that their 'existence' is only a mathematical model to explain fluctuations in spacetime, where we have no clue what´s realy happening?

well thats a relief, i thought i was gonna have to stay after class....

I must understand quantum mechanics. I must understand quantum mechanics. I must understand quantum mechanics. I must understand quantum mechanics. I must understand quantum mechanics. I must understand quantum mechanics. I must understand quantum mechanics. I must understand quantum mechanics......

My two cents on quantum mechanics (from someone who used to do QM for a living):

1. The mathematics behind (non-relativistic) quantum mechanics is not that difficult and thousands of people understand QM on this level perfectly.
2. The so-called "mystery" of quantum mechanics originates in trying to think of subatomic particles in similar ways we think about normal objects, like cars and trees. Don't DO this. Particles are just VERY different from cars.
3. IMHO quantum mechanics tells us nothing about spiritual issues, in contrast to the flood of books over the years like "The Tao of Physics." Your spiritual insights are validated or refuted by YOUR spiritual experiments, not by a particle collider somewhere.

eH

I guess that this depends a little upon whom you ask. I would say that yes, they are real particles. Why? Because they have observable effects that can't be explained without them, and they predict results that can't be predicted without them. I gave an example of this with the Casimir Effect, but there are numerous other results that can be explained and calculated with because of them (for example the fundamental forces of nature can be explained as being interactions between virtual particles). Their properties and consequences are well "understood" within the framework of quantum mechanics, the most successful framework we have ever devised.

Wow; I had been staying away for awhile because of security concerns, and I just came in tonight for the first time in a couple weeks.

I was shocked and dismayed to see that The Traveller himself came in to tell me I was being an ass. Pretty embarrassing. I suppose I had gotten a little too comfortable; and I figured that since I am careful to be respectful to everyone here and never to directly attack another's point of view, it was okay to say that I think something is poppycock -- yes, even an aspect of particle physics. I certainly meant no insult to any specific physicists, or other scientists.

In the wiki article on "virtual particle," are these two paragraphs:

An important example of the "presence" of virtual particles in a vacuum is the Casimir effect.[9] Here, the explanation of the effect requires that the total energy of all of the virtual particles in a vacuum can be added together. Thus, although the virtual particles themselves are not directly observable in the laboratory, they do leave an observable effect: their zero-point energy results in forces acting on suitably arranged metal plates or dielectrics.

In order to conserve the total fermion number of the universe, a fermion cannot be created without also creating its antiparticle; thus many physical processes lead to pair creation. The need for the normal ordering of particle fields in the vacuum can be interpreted by the idea that a pair of virtual particles may briefly "pop into existence", and then annihilate each other a short while later.


I'm sorry, but to say that "the explanation requires" that something be so is not, to me, reason enough to assert that it is indeed indisputably so. And this is my problem with several aspects of particle physics.

The wiki article has a link to an article from Scientific American entitled, "Are virtual particles really constantly popping in and out of existence? Or are they merely a mathematical bookkeeping device for quantum mechanics?" I might point out that the fact that a respected science publication sees fit to publish such an article would seem to suggest that it is not only the hopelessly ignorant and science-retarded who have questioned these theories -- else why bother to respond at all?

The article goes on to enumerate the reasons why the author believes that these virtual particles are real. Well and good. However, if you scroll to the bottom, there are a number of comments from seemingly educated people, expressing opinions that, to a greater or lesser degree, are similar to my own.

Are these people all 'ignorant" and "non-smart" too?

Really, I think it was rather heavy-handed to call my intellect and education into question simply because I disagree with the standard model; although I acknowledge that I may have expressed my disagreement in a somewhat flip manner.

(the "surf bum" that I was referring to, incidentally, is A. Garrett Lisi, author of "An Exceptionally Simple Theory of Everything." I don't think you could call him "non-smart" either.)

I don't mean to get in between an argument that doesn't concern me, but I would like to add something. Science is a process, not an end all which I am sure all of you know. Some of our current ideas, hypotheses and perhaps even established theories might not be good enough - we might miss something, we might be slightly wrong, we might be looking at the wrong place etc. Doubting scientific consensus is good, this is what leads to progress, because it fosters new thinking. It is also something that characterizes every intellectual giant in science throughout history.

However, and here comes the most important point; these people with these really new and great ideas, they didn't doubt consensus just on principle, or to be an ass or to be special or different or whatever... they doubted consensus because they had sound and viable alternatives. They had different explanations, or they were working their asses off while searching for them. So when one really doubts scientific consensus, while it is a healthy attitude for doing research, I think an important part of that doubting must be that you are able to argument for your opinion through reason, theoretical foundation and sound logic. Coming with claims to the contrary of scientific consensus while ridiculing current ideas and scientists does not come off as very intelligent and thoughtful, unless one can actually provide some foundation for those meanings.

This is just my two cents about this matter, and it is not meant for anyone in particular.

And to the whole virtual particle mess, there are very good reasons for their existence (unless someone can come up with better reasons for their non-existence), as I have tried to argue already in a few posts above. And I'm sorry, but the general public doesn't in general really know shit about high-energy particle physics, TimePantry. Actually, smashing things up is kinda the best way to study particles experimentally, and is one of the reasons we know so much about the structure of atoms, the history of the universe and even have certain technological (important) advances. If you want to know about the structure of cells, would you not use a microscope to better your knowledge? If you were to find out what is under a rock, wouldn't you need to lift it in order to see what is really there? If you were to find out what is inside the rock, would you not need to smash it up? Some mysteries of Nature requires lifting up her skirt every once in a while in order to be understood^^

i'm not sure what that kid has to do with anything

have you seen this? http://www.liveleak.com/view?i=91e_1301861454

I would have to agree with those who said something in them said it would be a very bad idea.
We know far too little, in fact close to nothing, about the particles suspended in the vacuum of space.
So how would we have any idea how they would react when they are fed THAT much energy in such a
concentrated beam. I say let's first find other, less destructive & potentially cathastrophic ways
of investigating these particles, before we blast laser beams into space that equal the energy that
the earth receives from the Sun.

The Particle Colliders are a wonderfull new tool, born in the 20th century(right?) to study such illusive particles.
We need more tools like that to study such illusive particles. As optic technology advanced rapidly, soon enough
there will be new and more powerfull microscopes & telescopes. Who knows; The right optic technology may just make
Atoms and particles far smaller than atoms still, visible to our human eyes.

Let's keep the Deathray plans in the basement for now. And if we were ever to use it, we might try it on earth first before
we zap into a random direction in space with who knows what kind of consequences.

I don´t agree with this.

The laser is one of the most beautiful things man has ever invented.
It´s a very elegant type of equipment.

Oh it's a marvelous device no doubt, but that's besides the point.
I love lasers everybit as much as you do. And I deeply igmire
the many scientists & engineers that make such research possible.
What I was wondering was; Is it all that safe a thing to do?

Where will the focal point be? Don´t you have the slighest notion
that whatever, high energy reaction will take place at the focal
point just might affect the Earth in ways we cannot conceive?

And why a 200 petawatts laser. Has anyone ever even built &
tested a laser that uses even a quarter of that wattage?
Because a Laser being fed 200 petawatts; Is there anything it won't burn right through?
Do they plan on shining the beam into space from earth? How would that unnaturally intense
light interact with the Ozon layer as it passes through it?

I guess we will see. Or we won't because we'd get whiped out with the speed of light
I'd still vote No, IF I had any say in it.

Wow it seems like they are making lasers for everything, this laser could probably come in handy if we had like a large meteorite tumbling towards earth.

My cat just recently was neutered by a laser.

I think it is important that you understand how this machine operates and how the experiments will be conducted.

One Google search away I found the website for this project: ELI project

On this page you will read:


So this laser will not be a star wars battleship class laser. This will be a highly focused laser that has an extreme short burst of extremely high energy. So the total energy used for the burst is not that much but since it will be focused on such a short area they hope to create some special effects there.

You can also Google a bit further and then you will find that they will use several blocks for the lasers each with about 10 PETAWATT power for a very short burst that will have an output of 200-300 J in 15-20 fs (RED: Femtosecond, One quadrillionth of one second) pulses. Considering that the total machine will have a combined power of about 200 PETAWATT then you can take 20 of these for a total of 4000-6000 J.

6000 J (joules) is equal to 6 kJ (kilojoules), 0.001667 kW h (kilowatt hours), 1.667 W h (watt hours), or about 1.4 times the energy released by the explosion of 1 gram of TNT (dynamite). So if you fire this laser into the ozone layer you will see that not much will happen I'm afraid...


Kind regards,

The Traveler

I have been invited to CERN a few times, they do some great work there for example.

Thanks for explaining that in layman's terms, Traveller.
When you translated the energy that the laser generated at the
focal point into 1.4 times of the energy generated by detonating
1 gram of TNT, I realised you're right; It wouldn't generate all
THAT much energy after all.

So is it reasonable to assume the energy generated at the focal
point will be significantly less than that generated by the explosion
of one of those 20 cm long TNT sticks used in mines, rock-quaries
& tunnel-building projects back in the old days?

That is far more graspable for me that the concept of PetaWatts. Thnx.
And indeed, that difuses my concerns immediately.


I've never been the type to be over concerned and apprehensive about going
face first into the unknown, especially when it comes to fascinating new
technology and scientific experiments that might reveal treasures of in-
formation to us and advance our species.
It's just that 200 Petawatts sounded to me like it might make Hydrogen bombs
pale & weak puffs of dust in comparisons.

But if that energy is indeed less than setting off one 20 cm TNT stick,
then I don't see too much that can go wrong either.

As allways, Time wil tell.