Questions and Answers from Virtual Ask-a-Scientist of March 12, 2003

More information about the program

Moderator
Welcome to Virtual Ask-a-Scientist. My name is Elizabeth Clements, of the Office of Public Affairs at Fermilab. Our guest scientists tonight are Jen Raaf, of Fermilab’s MiniBooNE experiment and Ryan Patterson, also of Fermilab’s MiniBooNE experiment. And now we are ready for your questions.

Moderator
Learn all about the MiniBooNE experiment: http://www-boone.fnal.gov/

Drago
Hi. I was just wondering how you decided to become physicists?

Ryan Patterson
Hi Drago. I always new I'd do one kind of science or another. Physics had the extra attraction of being, in a sense, the most fundamental of them all. The real attraction, though, is that it's a life of continous problem solving.. something I love to do.

Jennifer Raaf
Hi Drago, I kind of just fell into physics... I wanted something that would be challenging, and that would let me play with cool toys and learn how stuff works, and physics seemed to be a good choice for that.

Moderator
The MiniBooNE experiment is testing for neutrino mass by searching for neutrino oscillations. Just what are neutrino oscillations? http://www-boone.fnal.gov/publicpages/nuosc.html

Will
I know there are two neutrino experiments at Fermilab. What's the difference?

Jennifer Raaf
Hi Will, Yes, there are two neutrino experiments -- NuMi/Minos and MiniBooNE. NuMI is a long-baseline experiment, which means they make the neutrinos here at Fermilab and shoot them through the earth to Minnesota to see what happens to them. MiniBooNE is a short-baseline experiment, where we make the neutrinos here and send them to a detector that is also located here.

Moderator
Take a virtual tour of the MiniBooNE experiment: http://www-boone.fnal.gov/public/introduction/Introduction.html

Moderator
Interesting facts about MiniBooNE: http://www-boone.fnal.gov/publicpages/interestingfacts.html

Moderator
FermiNews: New Neutrino Experiment at Fermilab Goes Live http://www.fnal.gov/pub/ferminews/ferminews02-09-20/p1.html

Drago
Thanks. So is it everything you expected so far?

Jennifer Raaf
It's pretty cool. We get to do lots of different things each day. For instance, one day I might be sitting in a lab playing with electronics, and the next day I'm sitting at a computer writing a simulation of something I expect to see in the experiment.

Moderator
On this webpage you can see Live Events from the detectors of CDF and DZero http://www.fnal.gov/pub/now/live_events/index.html

Moderator
On the Fermilab website you can find a High Energy Physics timeline, explaining who discovered what and when. This is the url: http://www.fnal.gov/pub/inquiring/timeline/index.html

kevinmartz
What kinds of experiments did the two of you work on before MiniBooNE?

Ryan Patterson
Before this, I worked on an experiment with the not-too-excited name of UCN-A. When it starts up, it will measure properties of neutron decay more precisely than ever before. The hope is that such a measurement will reveal new physics.

Jennifer Raaf
Hi kevinmartz, I worked on an accelerator experiment in Japan before MiniBooNE. You can check out the website at http://belle.kek.jp

Moderator
What is the Tevatron doing right now? Check the Tevatron status: http://www-bd.fnal.gov/servlets/d11?project=outside

Phil
Hello

Moderator
Hi Phil. Thanks for joining Virtual Ask-a-Scientist. We are ready for your questions.

Jennifer Raaf
Hi Will, I forgot to tell you the websites for the two neutrino experiments... MiniBooNE (my favorite!) is http://www-boone.fnal.gov and NuMI is http://www-numi.fnal.gov

Moderator
To get our protons on the way we use a "chain of accelerators". Here is more information: http://www.fnal.gov/pub/inquiring/physics/accelerators/chainaccel.html

Moderator
Physics questions from real people and physics answers from Fermilab scientists. http://www.fnal.gov/pub/inquiring/questions/index.html

zoe
Do physicists have any idea where neutrinos go when they disappear?

Ryan Patterson
Good question. It depends on what you mean by "disappear". Neutrinos only interact in two ways. In one case, they sort of "bounce" off another particle, staying just as much a neutrino as before. In the other case, they change identities altogether, becoming either an electron or one of the electron's companion particles, the muon and the tau.

Neutrinos do come in three varieties, or "flavors", and a given experiment may be able to detect only one flavor of neutrino. A detectable neutrino might change flavor en route to the detector and become undetectable, and the experimenters might say that some of the neutrinos have disappeared (since they will see fewer than expected.)

Moderator
Fermilab produced its first high-energy particle beam on March 1, 1972. Since then hundreds of experiments have used Fermilab's accelerators to study matter at ever smaller scales. Here an overview of the top ten achievements so far. http://www.fnal.gov/pub/inquiring/physics/discoveries/index.html

Moderator
Here's a page of Frequently Asked Questions about Fermilab: http://www.fnal.gov/pub/about/faqs/index.html

Moderator
Learn about the history of Fermilab: http://www.fnal.gov/pub/about/whatis/history.html

Moderator
Many wonderful brochures and bookmarks about high-energy physics are available to order online: http://www.fnal.gov/pub/about/public_affairs/brochures.html

kevinmartz
I know that neutrinos interact very rarely with matter. Can you give me an idea how often they "show up"?

Jennifer Raaf
There are about a million neutrinos in every gallon of space. And they can happily pass through hundreds of earths without interacting. We produce lots and lots of neutrinos every second so that just a few will end up interacting...

Moderator
Discoveries at Fermilab: http://www.fnal.gov/pub/inquiring/physics/discoveries/index.html

Moderator
New neutrino lecture series at Fermilab! Nu Horizons: Neutrinos Off the Axis http://www.fnal.gov/pub/events/nuhorizons.html

Moderator
HEPAP Publication: The Science Ahead, The Way to Discovery http://www.fnal.gov/pub/forphysicists/hepapbook/index.html

Moderator
Physics is our mission, but buffalo may be Fermilab's main attraction for visitors. What are buffalo doing at a physics laboratory? Here is the answer: http://www.fnal.gov/pub/about/campus/ecology/wildlife/bison.html

Moderator
A short while ago we put together an online photo collection that introduces Fermilab in all its facets. Here is the link: http://www.fnal.gov/pub/about/whatis/picturebook/index.html

MDC
What first led scientist to believe that there must be neutrinos?

Jennifer Raaf
Hi MDC, neutrinos were first proposed in 1933 to make up for a discrepancy seen when a neutron decays, producing an electron and a proton. T The energy must be conserved in this decay, but there was missing energy after... so Wolfgang Pauli proposed the neutrino (little neutral one) to make up for it.

zoe
Is there some subatomic equivalent of dark matter?

Jennifer Raaf
I'm not sure what you mean, Zoe, but we suspect there is something we call dark matter from observing the motions of stars in distant galaxies.

Moderator
We have VideoNews and streaming video of lectures and colloquia. Here is the url: http://www-visualmedia.fnal.gov/VMS_Site/s_videostreaming.html

Moderator
Director Michael Witherell's vision for the lab: http://www.fnal.gov/pub/about/directorsoffice/index.html

Moderator
Who was Enrico Fermi? http://www.fnal.gov/pub/about/whatis/enricofermi.html

Moderator
Fermilab’s Founding Director, Robert R. Wilson, greatly influenced the design of the entire laboratory. Learn more about all of the interesting architecture at Fermilab: http://www.fnal.gov/pub/about/campus/architecture.html

Moderator
Internships in Science Communication http://www.fnal.gov/pub/about/public_affairs/internship.html

Phil
How is it that particles traveling forward in time are equivalent to their anti-particle traveling backwards in time?

Ryan Patterson
Good question. The mathematics describing particle behaviour have some elegant symmetries. And, all the math describing anti-particles looks just like the math describing particles except that there's a negative sign present all the time.

kevinmartz
How do you produce neutrinos in Miniboone?

Jennifer Raaf
Hi kevinmartz, we start with protons from the Fermilab Booster, and focus them into a long piece of beryllium (our target). When the protons hit it, they interact to produce mesons such as pions and kaons, and these then decay to produce some neutrinos and other particles. These are then sent through the earth for about 500 meters to get to our detector. Only the neutrinos can make it through all that dirt without interacting, so we get a really pure beam of neutrinos.

Will
So, what do you see as the value of your work? What do we get from it in practical terms?

Jennifer Raaf
Will, I think that in the sense of "what good will this do for me?" physics may not seem all that useful, but really there are lots of things that come from pure research. In the process of answering interesting questions about how the universe works, we end up having to come up with new ways of doing things. For instance, the World Wide Web was created by physicists at CERN!

Moderator
Subscribe to the Interactions.org electric news wire! http://www.interactions.org/

Moderator
How many different languages are spoken at Fermilab? http://www.fnal.gov/pub/about/faqs/languages.html

Moderator
Everybody is asking excellent questions. Please be patient because our scientists are working on all of them right now!

Moderator
Learn all about the MiniBooNE experiment: http://www-boone.fnal.gov/

Bob
Can you explain why electrons have "intrinsic spin"?

Ryan Patterson
Well, "why" they have it is beyond me. But, several experiments in the early part of the 20th century could only be explained if electrons weren't simply billiard balls but in fact had an intrinsic feature that behaved a lot like angular momentum. (Hence the name "spin".)

zoe
I was thinking of the macrocosm equals microcosm.

Jennifer Raaf
Hi Zoe, I guess by macrocosm/microcosm you might be referrring to the idea that our inner world represents the outer world in miniature?

zoe
Yes, inner/outer. I've always thought of the Universe as looking something like a mobius strip, with one part folding back into another part, large/small.

Jennifer Raaf
That's really interesting, Zoe. I had never thought of it that way before. Moderator
Reasons to support physics: http://www.fnal.gov/pub/inquiring/matter/whysupport/index.html

Moderator
What is the Tevatron doing right now? Check the Tevatron status: http://www-bd.fnal.gov/servlets/d11?project=outside

Moderator
Just what do all of those scientists at Fermilab do? Learn more about Fermilab research: http://www.fnal.gov/pub/about/experiments/index.html

Larry
If we are capable of generating a small Black Hole, I believe that this idea might work. We must put a negative time into the radioactive decay process. To do this I am going to refer to the Higgs Bosson because of its dynamic density for its size if it exist, and I strongly believe it does. I feel that radioactive waste or radioactive material is locked in a very compressed time.

Jennifer Raaf
Hi Larry, I'm not quite sure what you're asking here. Let me think about it for a minute

Moderator
Curious about neutrinos? Learn more about them here: http://www.fnal.gov/pub/inquiring/physics/neutrino/index.html

Moderator
Subscribe to Fermilab’s free publication, FermiNews: http://www.fnal.gov/pub/ferminews/index.html

Moderator
Particle Physics for Regular People – Recommended Readings http://www.fnal.gov/pub/ferminews/reading.html

zoe
Well, in science fiction (smile) you could enter the smallest particle and find yourself in a huge galaxy.

Jennifer Raaf
Yes! I always thought that was really interesting. That and falling into worlds with extra dimensions. I don't really know much about how feasible it actually is, but it's certainly a cool idea!

Moderator
Current Status of Access to Fermilab: http://www.fnal.gov/pub/about/public_affairs/currentstatus.html

Bob
Does an electron always have the same spin, or will it change when it interacts with another particle or field? If I wanted to find out more information, which experiments/experimenters should I look up?

Ryan Patterson
An electron always has the same "amount" of spin -- it is a fundamental property of the particle -- but the direction of the spin can and does change all the time. As far as references, introductory quantum mechanics books (e.g., Griffiths) are good sources. You can also look for experiments on the Zeeman effect (which is how it first came about).

Moderator
Questions people ask about physics: http://www.fnal.gov/pub/inquiring/questions/index.html

Moderator
Virtual Tour: The next best thing to visiting Fermilab in person. http://www.fnal.gov/pub/about/tour/index.html

zoe
When you work with neutrinos, how does the concept that all time is happening at once affect your ideas?

Jennifer Raaf
Hi Zoe, we use very small increments of time (like nanoseconds, which are one billionths of a second) to watch our events happen. So in this respect, all time is not happening at once.

Moderator
Fermilab has a big audience that visits the lab for cultural events. On this page you can see what we offer: http://www.fnal.gov/pub/events/culture.html

Sinh
Do you think space is absolutely empty or it is an entity other than absolute vacuum?

Ryan Patterson
Hi Sinh. Space is alive with activity! Aside from the occasional hydrogen atom floating around, there is a sea of photons left over from the big bang. Even if those weren't there, "virtual" particles are popping in and out of existence all the time.

Moderator
QuarkNet is a research collaboration between high school students, teachers and particle physicists. This is the QuarkNet website: http://quarknet.fnal.gov/

zoe
So where do they go when they aren't "in existence"?

Jennifer Raaf
Sorry Zoe, it's a little confusing to keep track of a couple different conversations... Where do what go when they aren't in existence?

Moderator
Did you know that there is an exceptional variety of birds living, breeding on Fermilab grounds? Here is a link to our "bird pages": http://www.fnal.gov/pub/about/campus/ecology/wildlife/birds.html

Moderator
The Fermilab Education Office offers seven programs for under-graduate students: http://www-ed.fnal.gov/lasso/program_search/undergrad.lasso

Bob
Based on our current theories, is it theoretically impossible to measure electrons as waves and particles at the same time or have we just not figured out an experiment to do it yet?

Ryan Patterson
Not at all. You can often get away with only looking at the particle or wave properties of an electron, but many experiments have to deal with the fact that electrons -- and everything else -- are more complex beasts with both particle and wave properties.

larry s
If you create a negative time in the radioactive time decay and apply it to say a underground radioactive waste site it will act as a domino effect and reduce the half life of the waste to near zero.

Jennifer Raaf
Hmmm... I'm not sure what you mean by this, Larry.

Moderator
A total of 53 species of butterflies have been identified at Fermilab. Here is the complete list: http://tdpc02.fnal.gov/peterson/tom/Butterflies/FermilabButterflyTable.html

Moderator
Learn more about Fermilab’s Chain of Accelerators: http://www.fnal.gov/pub/inquiring/physics/accelerators/chainaccel.html

Moderator
This is how seventh graders described scientists after they visited Fermilab: http://www-ed.fnal.gov/projects/scientists/

Moderator
Questions people ask about physics: http://www.fnal.gov/pub/inquiring/questions/index.html

Moderator Discoveries at Fermilab: http://www.fnal.gov/pub/inquiring/physics/discoveries/index.html

zoe
I must leave. Thanks so much for your time and sharing your knowledge. Bye.

Jennifer Raaf
Hi Zoe, Thanks for your questions! Bye!

Ryan Patterson
One of the peculiarities of quantum mechanics is the "uncertainty principle" which, among other things, says that nature doesn't allow you to know a particle's energy perfectly if you know the amount of time it has that energy perfectly. In fact, it allows for particles to pop into existence as long as they go away before a corresponding time has elapsed.

larry s
I am not a scientist, just a deep free thinker. But I play with ideas far bigger than my mind's ability.

Jennifer Raaf
Don't sell yourself short Larry. A lot of good new theories come from free thinkers!

Moderator
Many wonderful brochures and bookmarks about high-energy physics are available to order online: http://www.fnal.gov/pub/about/public_affairs/brochures.html

Moderator
A total of 273 species of birds have been recorded at Fermilab. Here is a diary of recent bird sitings at Fermilab: http://www.fnal.gov/ecology/wildlife/diary.html

Moderator
On this webpage you can see Live Events from the detectors of CDF and DZero http://www.fnal.gov/pub/now/live_events/index.html

Drago
So with CDF and DZero at Fermilab, do you guys feel like you play second fiddle?

Jennifer Raaf
Hi Drago, MiniBooNE is a very small experiment (about 60 people) and CDF and D0 are on the order of 500 each, so it may seem like we would play second fiddle, but really the lab directorate makes sure that each experiment gets what it needs to run. :)

Moderator
Director Michael Witherell's vision for the lab: http://www.fnal.gov/pub/about/directorsoffice/index.html

Moderator
Learn more about the accelerators at Fermilab: http://www.fnal.gov/pub/inquiring/physics/accelerators/index.html

Moderator
What is the world made of? http://www.fnal.gov/pub/inquiring/matter/madeof/index.html

Attrition
What would happen if the effects of gluons were somehow suppressed?

Ryan Patterson
Interesting idea. Since gluons are the, well, glue that holds quarks together to make protons and neutrons and holds protons and neutrons together to make nuclei, those things would break apart. That'd be some mess!

Moderator
The Fermilab Education Office offers seven programs for under-graduate students: http://www-ed.fnal.gov/lasso/program_search/undergrad.lasso

Bob
Do undergraduate physics majors ever get to participate in experiments like miniboone?

Jennifer Raaf
Absolutely! Every summer we bring about 20 undergraduates to Fermilab to see what working on a physics experiment is like.

Moderator
At Fermilab we have an education center called "Lederman Science Center". This is their homepage: http://www-ed.fnal.gov/ed_home.html

Moderator
Fermilab Instructional Materials for Students and Teachers: http://www-ed.fnal.gov/trc/projects/index_all.html

Jennifer Raaf
I'm sure CDF and D0 also have undergraduates working for them during the summers.

Moderator
Internships in Science Communication http://www.fnal.gov/pub/about/public_affairs/internship.html

Moderator
Learn more about the Collider Experiment at Fermilab: http://www.fnal.gov/pub/inquiring/physics/collider/index.html

Moderator
Neutrino Physics at Fermilab: http://www.fnal.gov/pub/inquiring/physics/neutrino/index.html

Bob
Is it difficult to get one of those spots? About how many people are applying for an opening?

Jennifer Raaf
Hi Bob, I think it's not terribly difficult, but it probably depends on how big your physics department is. I know that my advisor, for instance, is always very excited when students come to him and ask about working for the summer. You should definitely go ask someone in your physics department!

Moderator
HEPAP Publication: The Science Ahead, The Way to Discovery http://www.fnal.gov/pub/forphysicists/hepapbook/index.html

Sinh
Hi Ryan. If you say that space is full of activity. Is there a mathematical model for the space? And does the space have mass?

Ryan Patterson
This is a very active area of research. Some stuff is understood (e.g., how virtual particles are allowed, what effects the photon background has), but much is not (like the source of dark matter, asked about above.)

Will
Do you think you will keep working in Neutrino physics?

Jennifer Raaf I'm not sure right now. It's certainly interesting, but maybe sometime in the future I might want to check out some other areas.

Will
Like what?

Jennifer Raaf
Good question. I used to work a bit on B-physics, which also involves particles, but they're much larger and easier to detect. I've also looked into condensed matter physics, like studying quantum dots or nanotubes. There are so many things, I guess it's hard to pick one right now while I'm still so interested in neutrino physics.

Ryan Patterson
Will, it's hard to say what I'll be working on a few years from now. High energy physics experiments are very large these days, and I like a small collaboration, so neutrino experiments are attractive. (They tend to be smaller.) There are lots of good questions we need to answer regarding neutrinos, too, so the field is definitely exciting right now.

Moderator
Did you know that Fermilab had the second (or third) website in the U.S.A.? Read more about this: http://www.fnal.gov/pub/help/history.html

Moderator
Learn about the history of Fermilab: http://www.fnal.gov/pub/about/whatis/history.html

Bob
Haha...I am only in high school, but I am interested in pursuing it in the future. What are the top universities for physics, in your opinion?

Jennifer Raaf
Last summer we had 2 high school students working for us on MiniBooNE also! You should look into some opportunities for that! Let me see what I can find.

Moderator
These are programs at Fermilab that the Lederman Science Center offers for students: http://eddata.fnal.gov/lasso/program_search/search_programs.html

Jennifer Raaf
Hi Bob, check out the link the moderator just put up.

Moderator
Astrophysics at Fermilab: http://www.fnal.gov/pub/inquiring/physics/astrophysics/index.html

Moderator
Fermilab’s Fields Guides for Teachers and Students: http://www-ed.fnal.gov/data/life_science.html

Bob
Ah, thank you.

Jennifer Raaf
Sure. If you're very interested, contact the Lederman Center here, and they can probably set up a tour or something for you.

Moderator
Here is a list of some great high-energy physics websites: http://www.fnal.gov/pub/inquiring/more/more.html

ave
Do you know of any websites that have lots of animations (not static displays) of quantum mechanics in action, i.e. photoelectric effect, tunneling effect, Feynman diagrams, etc.?

Jennifer Raaf
You might want to check out http://physnet.eprints.org/PhysNet/education.html I think they have some Java applets of various physics topics, including quantum mechanics.

Will
Is Fermilab security affected by all the homeland security stuff?

Moderator
Hi Will. Yes, right now Fermilab has limited access for visitors. This means that visitors cannot drive on site or enter any buildings except for the Lederman Education Center.

larry s
I am not sure anything is scientifically correct, but I have a database of such speculative ideas.

Jennifer Raaf
Well it's always good to be coming up with new ideas!

Moderator
Here is a new instructional unit for teachers about Neutrinos: http://www-ed.fnal.gov/samplers/hsphys/cts/cts.html

Moderator
Fermilab's art gallery has regular shows: http://www.fnal.gov/pub/Art_Gallery/

Moderator
There is also a very active lecture series.. http://www.fnal.gov/culture/lecture.shtml

Attrition
What, exactly, is hard radiation?

Jennifer Raaf
Hi Attrition, I think hard radiation is usually considered to be high energy x-rays, or photons in the upper end of the energy spectrum.

Moderator
On the Fermilab website you can find a High Energy Physics timeline, explaining who discovered what and when. This is the url: http://www.fnal.gov/pub/inquiring/timeline/index.html

Attrition
About how much antimatter would it require to generate a reaction of sufficient size to be observable without any specialized equipment?

Ryan Patterson
Good question. I'll take "no special equipment" to mean that you can just see the effect. If we took hydrogen and anti-hydrogen atoms and mixed them together, it would take 3 billion pairings to get 1 Joule of energy, plenty enough to, say, lift an apple a few feet. 3 billion hydrogen atoms only weighs 0.000000000000005 grams!

Moderator
Accelerator Updates are available online: http://www.fnal.gov/pub/news03/update.html

Will
I know it's not exactly you're area, but how are things going with Tevatron Run II?

Jennifer Raaf
I just talked to a grad student from DZero, and he said, "Things are going pretty well." They've acquired enough data to start putting out papers on RunII, so that's good!

Moderator
Here are some Run II luminosity charts: http://www.fnal.gov/pub/now/tevlum.html

Moderator
Have physics acronyms got you stumped? Maybe this will help: http://www.fnal.gov/pub/inquiring/more/acronyms.html

Kevin
Are you guys from the midwest? How do you like Fermilab winters...?

Jennifer Raaf
Hi Kevin, I'm not so fond of the Fermilab winters. I'm originally from Annapolis, Maryland. I grew up right on the Chesapeake Bay, so the midwest is a bit of a shock... with its lack of "big water." But it has its good points too...

Ryan Patterson
Kevin, I actually grew up in Mississippi, so the cold weather is brutal!

Kevin
What are the good points?

Jennifer Raaf
Ah, you caught me. I was trying to be nice. :) Let's see... Chicago is a lot of fun! There's not so much to do in the suburbs though. Or maybe I just haven't found it.

Moderator
Available materials from the Office of Public Affairs that you can order online: http://www.fnal.gov/pub/about/public_affairs/materials.html

Moderator
Explore the FermiLabyrinth: http://www-ed.fnal.gov/projects/labyrinth/games/

Moderator
Contributions that high school students made to MiniBooNE: http://www-boone.fnal.gov/public/introduction/Introduction.html

Sinh
Hi, Ryan.The space contains photons. The photons contains energy. Energy can be converted to mass. So the space may have mass, Does it?

Ryan Patterson
Photons are intrinsically massless, but you are correct that they can be turned into massive particles. I wouldn't say this means photons are massive, though. As for the other things out in space, some of it does have mass. (The "dark matter" mentioned above is a related mystery. When we look at the motions of objects in galaxies and even the motions of the galaxies themselves, we see them move in ways that require more sources of gravity than we actually see. We clump all of this unknown stuff into the "dark matter" category. There are several possible explanations for it, and many experiments are testing these.)

Attrition
Would I be correct in assuming that pointing a geiger counter, with sensitivity turned all the way up, at a computer terminal linked directly (IE, close proximity) to any large scale equipment and telling the user, "I think that you may want to move away from that thing..." is not considered a highly approved of practical joke?

Jennifer Raaf
You would be correct. Safety is a number-one priority here at Fermilab... two of my friends were joking around one time and put a radiation sticker on a water bottle and left it in one of the control rooms.... bad bad idea. They got a big lecture and caused some of their co-collaborators to have to take all sorts of extra safety training courses. :)

Bob
What role did the high school students play in the Miniboone experiment? That is, how did they help out?

Jennifer Raaf
They got to work on various things. One project, which they both worked on, was to create an official poster in collaboration with Visual Media Services here to explain about neutrinos and what MiniBooNE does. They also got to work on some hardware projects, like helping to test photomultiplier tubes (which we use in our detector) and testing various properties of oil.

Moderator
Check out the MiniBooNe posters: http://www-boone.fnal.gov/publicpages/posters.html

Moderator
Science in the Neighborhood: Fermilab and the Community http://www.fnal.gov/pub/about/community/index.html

ave
I looked at the site you reccommended and found that it is very limited in actual animations. I'm thinking of doing a service project where I would create full page animations of various quantum mechanics functions, such as: photoelectric effect, tunneling effect, Feynmen diagrams, Young's and Aspect's light experiments, etc. These would be geared for middle and high school students, so they can "see" the functions. Would this be of value to Fermi, the Lederman Science Center, or IMSA, and do you know of a physicist would be willing to serve as my guide?

Jennifer Raaf
Hi ave, that sounds like a great idea. I'm sure that if you created such a page, many people would be interested in accessing it. I suggest you contact someone at the Lederman Science Center, and they may be able to provide you with the name of a physicist who could help you.

Attrition
What is the approximate energy consumption of Fermilab... say... annually?

Jennifer Raaf
we buy our energy from ComEd for about $12-$18 million a year. I don't know what the energy consumption is in watts or some other unit of power though. It would be cheaper for us to generate our own energy, but when the site was procured here, a deal was made to purchase electric power from the power company because it's helpful to the economy around here.

Moderator
Fermilab produced its first high-energy particle beam on March 1, 1972. Since then hundreds of experiments have used Fermilab's accelerators to study matter at ever smaller scales. Here an overview of the top ten achievements so far. http://www.fnal.gov/pub/inquiring/physics/discoveries/index.html

Larry
This has been the most enjoyment I have had. I hope my questions or near questions did not upset anyone. bye

Jennifer Raaf
Bye Larry! Don't worry, your questions didn't upset anyone!

Kevin
I grew up near Fermilab and there were always "legends" about the lab, radiation, etc. From "don't go near Fermilab or your credit cards will be erased" to "the buffalo are there to detect radiation". How do you debunk such things?

Ryan Patterson
Explaining exactly what goes on here is the best way I've found. The beams can make a lot of radiation, but radiation safety is a primary concern in design and operation of the lab, and the radiation areas are well defined.

Bob
I have to go. Thank you for your time!

Ryan Patterson
Bye, Bob. Thanks for your excellent questions!

Moderator
The Future: Particle Physics in the 21st Century: http://www.fnal.gov/pub/inquiring/matter/future/index.html

Moderator
Worldwide discoveries that led to the standard model: http://www.fnal.gov/pub/inquiring/matter/ww_discoveries/index.html

Will
It strikes me that now may be a tough time to get funding for "pure science"--what with all the defense initiatives and all. Is that the case?

Jennifer Raaf
It is a bit tough to get funding, but to give you an idea, the Fermilab budget for 2001 was $277 million and the budget for the Dept. of Energy's Office of Science (which takes care of 17 DOE national labs) was $3.18 billion. The proposed defense funding levels for basic and applied research, etc. were $6.02 billion for the Army, $9.22 billion for the Navy, and $13.76 billion for the Air Force (totalling $29 billion in scientific research for defense). So the total funding for all 17 national labs was about 11% of the R&D budget for defense.

Moderator
Fermilab's photo archive has a lot of wonderful high-energy physics images and graphics: http://www.fnal.gov/pub/presspass/vismedia/index.html

Moderator
Fermilab's Budget, Statistics and Organization Chart: http://www.fnal.gov/pub/about/organization/budget_statistics.html

Attrition
What's the most common method of shielding against radiation at Fermilab?

Jennifer Raaf
Usually iron and huge slabs of concrete.

Attrition
Which bosons have been experimentally confirmed to exist?

Ryan Patterson
Boson refers to a large range of particles, so hundreds have been observed. Most of these are actually made up of quarks and antiquarks, and with 6 types of quarks and 6 types of antiquarks you can make lots of combinations. There are a few special bosons, though, associated with the forces that act on particles. These are seen all the time. (In fact, you are seeing some right now! Photons are bosons.)

Ryan Patterson
Attrition, another good "shielding" is just plain distance. Radiation levels fall off fast as you move away from the source, so keeping people (offices, etc.) away from the radiation areas helps, too.

Moderator
Just how do those scientists find those extremely small particles? http://www.fnal.gov/pub/inquiring/matter/smallest/index.html

Sinh
What happens if a photon hits a black hole. Will the black hole become lighter (both less heavy and brighter)? If myriads of photons hit a black hole, will the black hole disappear?

Jennifer Raaf
Hi Sinh, the definition of a black hole is that it's a region of space with such a dense concentration of mass that even light (or photons) are trapped in it. So photons hitting a black hole would presumably just be sucked into it.

Moderator
Theory at Fermilab: http://www.fnal.gov/pub/inquiring/physics/theory/index.html

Moderator
We are getting down to our last few minutes of the chat session. Please submit your final questions now.

Attrition
What about just the force transmitter bosons? Which of those are experimentally confirmed?

Ryan Patterson
There are three forces that particle physicists are usually concerned with. The electromagnetic force is the one most familiar to us. Photons are the force carriers (or "transmitters", as you put it) of this force. The "strong nuclear force" (a strange name) is transmitted by gluons. No one has seen a gluon directly, but there are several experiments trying. THe "weeak nuclear force" is transmitted by three particles with the innocuous names W+, W-, and Z0. These are produced and observed all the time in experiments like CDF and D0. I haven't mentioned gravity yet. No one has come up with a complete particle-based theory of gravity yet, but the force carrier is already named -- the graviton. It has not been seen.

Sinh
What happens if a photon just misses a black hole and being bent into round circle around the black hole. By this way, the black hole will give a very small amount of energy to the photon and the black hole will be less heavier an equivalent amount of mass. If myriads of photons are bent by the blackhole, will the black hole disappear?

Jennifer Raaf
Hi Sinh, there's an interesting web page written by Ted Bunn concerning black holes. http://cosmology.berkeley.edu/Education/BHfaq.html

Moderator
Jen and Ryan are working on the final questions right now. Don't forget to check back in a couple of weeks for the Virtual Ask-a-Scientist transcript! http://www.fnal.gov/pub/inquiring/virtual/index.html

Shadia
I have read that Fermilab has several accelerators, I mainly wish to know whether such a device may enable one to produce "anti-matter" capable of traveling through Time.

Ryan Patterson
Fermilab does make antimatter, but antimatter moves through time the same way regular matter does: forward. It's true that matter processes look like antimatter processes if you watched them in reverse, but that's different from actually being able to make them go in reverse. It's sort of like this: I'm right-handed, so when I look in a mirror I see a left-handed person staring back. If I could go into the mirror world, I would be that left-handed person. But, I can't go into the mirror world. I can talk about that world all day long, and I may even find it useful to do so, but in the end I am stuck in this world as a right-hander. So, even though we can visualize matter as antimatter going backwards through time, it can't actually do it. (I hope my analogy doesn't just confuse the issue!)

Jennifer Raaf
Good question. Actually, we do produce anti-matter here at Fermilab... the TeVatron accelerates protons in one direction around the ring, and anti-protons in the other direction. We smash the protons and anti-protons together at specified points around the ring where the CDF and D0 detectors are located and watch to see what happens. One way of talking about anti-matter is to explain it as matter going backward in time, because mathematically these are identical.

Henry Wright
Could the refractive index of a material - a pure glass? - be used to determine if that material's density changes as gravity changes? That is, would there be a measurable change in the refractive index between measurements take at sea level and measurements taken in orbit? If so, what might the results indicate?

Jennifer Raaf
Hi Henry, this is an interesting question. The physical density of a material (which is often referred to as its specific gravity) is its mass/volume ratio. If you change the forces acting on a material (like gravity, or acceleration, or air pressure, etc.) the volume of the material can change a bit but its mass will remain the same (assuming we're not talking about accelerating the material to relativistic speeds), and therefore its specific gravity will change. Specific gravity and index of refraction are related, so the index of refraction should also change. But I'm not sure if this would actually be a measurable change... it might be such a tiny change in refractive index that it would barely register on your measurement device. If you could measure the difference though, I guess you could use that to go back and figure out the change in density. I'm not really sure you would learn anything from doing this.

Ryan Patterson
You're right that a material's index of refraction changes as its density changes, and this effect isn't too hard to measure in the lab. As for gravity causing density changes... Glass doesn't compress very much when you squeeze it, and the only extra squeezing it gets sitting on earth is from its own weight and (depending on your setup) the weight of the atmosphere. This amount of squeezing isn't going to change the density a whole lot, so the index of refraction isn't going to change a whole lot either. (I just ran some quick numbers -- and someone should check my math -- but a 10 cm cube of glass would have its index of refraction go up by something like 0.000005% . That'd be pretty hard to notice!)

Sinh
Thank you all for your time.

Jennifer Raaf
Thanks for your questions!

Moderator (Mar 12, 2003 10:07:53 PM) Thank you for participating in tonight's chat session! What an interactive group! Everybody asked terrific questions!

Attrition
What methods are used to contain more... significant quantities of antimatter?

Ryan Patterson
Antimatter storage is a difficult game, as you can imagine, since the antimatter can't touch anything! There are several techniques out there, but they always involve magnetic and electric fields trying to keep the antiparticles off the walls.

Jennifer Raaf
Goodnight, guys! It's been fun!

Ryan Patterson
Unfortunately, we're out of time. Thanks for all the great questions!

Moderator
Goodnight, everybody! Thanks for participating!