Black Holes

Hello - Oct 19 10:43PM

Dr. Syphers,

I am Daniel and I am an Honors Physics student at […]. Though my favorite subjects in school are more in the areas of the arts and humanities, I like to think that I have a healthy appreciation for science and math. I was fascinated by your work with particle accelerators, especially because of how prominent they have been in the news in recently due to your project and the LHC project. I was wondering, did you consider any other fields or careers before pursuing your Ph. D. in particle accelerator physics? Thank you so much for participating in this program, and I am excited to have this opportunity to learn from you.

Thank you,

Daniel

Re: Hello - Oct 19 11:17PM

Hi Daniel,

Well, in all honesty, I think in my heart that I wanted to be a scientist ever since I was a very young kid (maybe 7 or 8 years old). But, at that time, I was very interested in astronomy. In fact, the Gemini and Apollo programs were going on, and men going to the moon, so that motivated me a lot. But, as I went through Jr and Sr High School, I did think about other fields -- most notably, architecture, mechanical drawing and graphic arts, and journalism. (I was editor of our high school newspaper, which was a very good paper at a big school in Indianapolis.) But, I finally decided against a career in journalism and follow my dream to learn more astronomy and ultimately physics.

It's nice to hear from all of you at [...]. How large is your physics class?

Cheers,
-Mike

Re: Re: Hello - Oct 25 11:29PM

I'm interested to hear more about your experience with astronomy. For me, I've always enjoyed marveling at the stars—and I do this quite often—but beyond this and the occasional use of a friend's telescope, I've never gone much deeper. Nevertheless, I would say that astronomy is probably my favorite topic in science. What fascinates me about it is the sheer beauty and vastness and magnificence of space. For example, to me, the photos from the Hubble telescope are just breathtaking, and I find it incredible to think of this massive expanse so filled with wonders and possibilities. What was it that drew you to astronomy, and in turn to physics?

Our school is pretty small—only about 100 students per grade—so my physics class only has 12 people in it.

Thanks!

Daniel

Re: Re: Re: Hello - Oct 25 11:49PM

Hi Daniel,

I think I liked astronomy for the very reasons that you do. When I was very young, the Gemini and Apollo space programs were in full swing. I would go outside and look at the stars and moon and think, "what would it look like from space"? And then I'd wonder about just what I was seeing when I looked at the stars. Finally, my parents got me a (very small) telescope, and I started trying to find star clusters and planets and such. This became a hobby from the time I was about 8 years old until well into adulthood. Anyway, when I got to high school and after studying the usual math courses and biology and chemistry, it was finally time for me to take a course called Physics. I had no idea what that was, but when I saw a chapter in the book entitled something like "Gravity and Planetary Motion", I suddenly knew that THIS was what I wanted to learn about -- REALLY learn about. And I've been hooked on physics ever since.

Now, even though I don't do astronomy much any more, I am helping to build an accelerator that is going to smash heavy elements together (like krypton and uranium atoms) to reproduce conditions that can only occur naturally in stars, and hence we will learn more about stellar formation and how nuclear fusion works inside of stars. Interesting how life "comes around" full circle, eh? …

I hope you enjoy your physics class. It can be an extremely powerful subject.

Cheers,
-Mike

Re: Re: Re: Re: Hello - Oct 28 5:52PM

Dr. Syphers,

That sounds incredibly fascinating! I don't know very much about accelerators, but the knowledge we could gain from them sounds extremely useful. I remember how, on the day the LHC project began, several of my friends were saying things like "they're making a black hole that's going to suck the earth into it!" and things like that…

I guess it would be good (and possibly reassuring!) to hear from someone on the forefront of the technology: how do these accelerators work? And is there any real risk that a black hole large enough to envelop the earth could be created?

Thanks,

Daniel

Re: Re: Re: Re: Re: Hello - Nov 01 12:18AM

Hi Daniel,

You'll likely talk about electricity and magnetism next semester in your physics class. The accelerators work by creating intense electric fields that "attract" charged particles and thus give them energy; then magnets are often used to steer them around corners or in circles so that they can be accelerated again by the electric fields until they reach very high speeds (near the speed of light). The most powerful accelerator in the world was, for the past 25 years or so, the accelerator at Fermilab where I used to work. Now, the LHC has taken that title over, though there is still work to be done there before it is at its full power.

As for black hole formation, I did study that a bit a year or so ago when everyone was talking about it. The concept of a black hole is very intriguing, and very likely does occur in stellar systems. And, in "theory", there can be very tiny black holes -- but, they wouldn't stick around very long. Black holes actually radiate away; and the time it would take for a black hole (again, in "theory" -- no one has ever definitively detected a black hole, of any size) created at the LHC to radiate away to nothing would be something like 10^-86 seconds (10 to the minus 86th power -- VERY short time!!!). That's one argument against anything happening with the LHC; before a black hole in the LHC could move over and start gobbling up other particles, it would be gone! The other argument is that particles come from the sun and galaxy with energies much much larger than the LHC can even produce. So, if black holes capable of eating up the earth could be formed through particle collisions, it would have happened by now and we wouldn't be here. So, I'm not afraid of anything like that occurring from the LHC or any other particle accelerator.

But, it's a good thing to discuss. Because black holes are all "theoretical", we cannot say for certainty that things absolutely cannot happen. We can only say that it's very, very unlikely, and try to make statistical arguments to convince people of this. But, some wise-guy who wants his name in the papers can always say "Then that means it COULD happen" and try to get everyone scared. That's what went on last year or so when it was all the buzz…

I was actually asked about this when I was on Modern Marvels (episode: "Collisions"), but they only gave me about 15 seconds on TV… But it was really cool being interviewed by them!

Cheers,
-Mike

Re: Re: Re: Re: Re: Re: Hello - Nov 01 11:28PM

Dr. Syphers,

Thanks for the reply, that explanation was more than adequate! I now feel much more informed about particle accelerators! How much time do you think it will take for the LHC to reach its full power? Also what are the implications for our understanding of the universe if the LHC reached this point? In other words, do you have any predictions about the exactly how much we could learn from a fully powered accelerator?

I'm not familiar with the Modern Marvels show, but I'll definitely want to look into it! Do you get many opportunities to be interviewed for TV shows any other types of media?

Thanks,

Daniel

Re: Re: Re: Re: Re: Re: Re: Hello - Nov 02 12:28AM

Hi Daniel,

The LHC has had a few technical difficulties, and they are operating at only one half of their top energy. So, they will shut the LHC off for about a year or so and make the repairs they need to make to get it to go to top energy. Since they're running right now, that means, it will be about 1.5 years from now before they get to top energy. Meanwhile, they still have a way to go until they reach the total number of particles in their particle beams that they want to have. So, to get to their ultimate numbers, it's probably about 2-3 years away. Meanwhile, the Tevatron collider at Fermilab near Chicago is operating right now at its peak performance. Even though it's only 1/7 the energy of the LHC's eventual top energy, it has lots more particle collisions per second and lots of data already taken and stored on computer disks for analysis. So, it will take the LHC about 3 years or more so to catch up to the Tevatron, and eventually pass it and go way beyond.

Some of the questions that the LHC will try to study when it gets all up to speed will be, "Why do particles (like electrons, protons, quarks, etc.) have the masses that they have?" "Are there other forces in the universe, and/or other dimensions to the universe that we can learn about at these new energies?" "Can we explain why there is more matter in the universe than there is antimatter? (Which is why we exist at all, and weren't just annihilated after the Big Bang)" And other things like that…

Modern Marvels is a show on the History Channel, if you have cable tv or satellite dish. I've been in a couple of newspaper articles, and a magazine article or two. I had the back of my head in a picture in TIME magazine once -- made it big time, eh?

Cheers,
-Mike

Re: Re: Re: Re: Re: Re: Re: Re: Hello - Nov 04 11:07PM

Dr. Syphers,

Wow, it sounds like this research will teach us plenty about our universe, and probably revel more questions that we haven't even considered yet!

I'm interested to know—how did you get involved all of this particle accelerator work, especially the Tevatron project? Also, what would you consider to be your dream scientific project? Or, if you could be researching anything in the universe at this moment, what would it be?

And congratulations on having the back of your head featured in TIME magazine—I'd consider that to be quite the accomplishment!

Thanks,

Daniel


Re: Re: Re: Re: Re: Re: Re: Re: Re: Hello - Nov 07 4:30PM

Hi Daniel,

When I got out of college I taught as a high school physics teacher for one year, and then found a job at Fermilab as an "accelerator operator." The job taught me how to control and operate the big accelerators at Fermilab, and after working at that for a couple of years I decided to go back to school to learn more physics so that I could better understand how these machines really worked, and how to help develop new ones. This was about the time that the Tevatron was being constructed, and so I got to help work on its final construction and commissioning. It was a very exciting time, much like the LHC project today.

Researching "anything"? I guess I still like the idea of studying the evolution of the universe, astrophysics, black holes, and so forth. To me, those topics incorporate some of the "ultimate" questions of the physical world.

-Mike

Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Hello - Nov 07 10:55PM

Dr. Syphers,

I was reading an article today, and it mentioned that Albert Einstein didn't believe in the existence of black holes. Have you heard anything about this or do know why he might have believed this? Are there many physicists today who still don't believe in black holes?

Also, what would you say the "ultimate" questions of the physical world are? And do you think we'll ever find the answers to them?

Thanks,

Daniel

Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Hello - Nov 08 12:18AM

Hi Daniel,

I don't know about that fact regarding Einstein, but I do think that the idea of a Black Hole must have sounded pretty crazy to folks 100 years ago, even though solutions to his own equations suggested their existence. Sometimes scientists come up with crazy-sounding solutions to problems. Sometimes we make mistakes (often?), but we keep testing and checking our answers until we convince ourselves and others that we have good answers; then, we do experiments to verify our results, etc. Einstein probably thought it was going to be very hard to verify that Black Holes exist, and that would have been a correct assessment!

These days, I think most scientists who are up on the subject believe that black holes exist. There is very strong evidence that they exist at the center of galaxies, including our own Milky Way galaxy! But, they have not been "directly" seen; we can only detect the motion of stars that are circulating about the center of the galaxy whose motions are "consistent" with a Black Hole being there. Pretty cool! Check out:

http://science.nasa.gov/science-news/science-at-nasa/2002/21feb_mwbh/

As for the second part of your question, check out this web site:

http://www.interactions.org/quantumuniverse/qu/

This report lists many of today's "ultimate" questions that you are speaking about.

Cheers,
-Mike

Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Hello - Nov 09 12:13PM

Dr. Syphers,

Thank you so much for being my adopted physicist for these few weeks! I have learned so much from you and I definitely have a greater appreciation for the field of physics than when we began. It is truly inspirational to encounter a person who truly loves their work and followed their dreams! Hopefully later in life, I can say that I did the same.

It has been a pleasure learning from you!

Thanks,

Daniel

Black Holes

Dr. Syphers,

I have heard a lot of concern about black holes resulting from an atom smasher. I understand that these black holes would be of little consequence due to size and stability, but you mentioned to another student that they would quickly "evaporate." How can a black hole evaporate... actually, what exactly IS ia black hole?

Thanks,
Lindsay

P.S. Thanks so much for your time, which this project must have taken a lot of. Your answers were very complete and I feel like I have a greater knowledge about supercolliders and such. I really enjoyed getting to ask you questions, so thank you!

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Thank you Lindsay,

About 100 years ago, Albert Einstein developed a new theory called the General Theory of Relativity. The theory describes how particles and light behave in reference frames that are accelerating. In particular, the theory shows that gravity can actually be thought of as space and time being "curved" by the presence of mass and energy. Thus a large star curves space around it and planets and spacehips traveling nearby will follow trajectories in space and time due to this curvature. For most "ordinary" cases, it gives the same results as Newton's old theory of gravity -- elliptical orbits, and so forth. However, Einstien's new theory was even more successful, as it explained why the planet Mercury's orbit seemed to "precess" in a way that Newton's theory of gravity couldn't explain. The theory also predicted that light rays will actually be "bent" in a strong gravitational field. This was soon observed to be true through measurements made during a total solar eclipse, and Einstein became world famous overnight!

Anyway, this same theory predicts that if there is enough mass and energy in one place in space, the gravity can be so strong -- space-time can be so curved -- that nothing can get away from the object, not even light. Since light cannot escape this region, it is called a "Black Hole." It requires a great deal of mass in a very small region of space. To date, there has not been any definitive evidence of a Black Hole, though there are some fairly good candidate regions of space that seem to imply a Black Hole might be there (like at the very center of the galaxy).

It wasn't until the 1970's that another famous scientist, Stephen Hawking, developed a theory that showed that a Black Hole (should one exist) should actually evaporate. His theory brings "quantum mechanics" into the Black Hole picture, and involves what are called "virtual particles" being created and instantly annihilated near the "edge" of the Black Hole. Anyway, he shows that this quantum mechanical process can lead to the evaporation of the Black Hole; the larger the Black Hole the longer it would take to evaporate. So, IF little Black Holes "could" be produced in our accelerators, they'd be very very tiny and would last only a very very short time.

I've only given the flavor of the issue; maybe we can talk more details in a future posting. Maybe you'll get to study it in more detail in college(!). It's very fascinating stuff!!

Thanks, and have a great school year,

-Mike Syphers

Atom Smasher LHC

Do you have any advice for the skeptics out there that think the LHC collider may create a black hole?

-AG

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There are equations and theories that can be written down, which show that any black hole formed in our accelerators would be VERY VERY small, and live for only VERY VERY short lengths of time. So short and so small, that they probably cannot be detected, certainly not very easily. They evaporate very quickly. But, to fear that they can be formed and destroy the earth (or even destroy the accelerator!) are totally unfounded.

One simple argument people point out is that we here on earth are constantly bombarded by particles from outer space. The sun and stars and distant galaxies spew out particles all the time (we call them Cosmic Rays) and pass through the earth. (They're passing through you right now!) We constantly detect these particles with our detectors here at Fermilab all the time. In fact, if you're interested, your teacher can see about getting a Cosmic Ray Detector through the QuarkNet program -- visit the web site:

http://quarknet.fnal.gov/

The point is, the particles from space often have MUCH more energy than we can produce with our accelerators. And these particles have been reaching the earth for billions of years -- and the earth is STILL HERE! So, if black holes can be formed this way, they've already been formed (and evaporated) and haven't harmed the earth. So, there should be no worry about the energies that we reach with our accelerators.

-Mike Syphers

Doomsday??

Hey, I'm Will. Thank you for participating in this program, it is very kind of you. I'm interested in doing some type of engineering and I'm interested in physics because of that. Do you think the machine your making could produce black holes and potentially destroy the world...a doomsday machine?

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Hi Will,

No, I do not believe we have anything to worry about. This is an interesting question that has come up in the (sensationalized?) news media lately regarding the LHC accelerator coming on line in Europe. The earth is bombarded every second by particles that are emitted from the sun and other sources, particles with much higher energies than what we can make in our accelerators. These particles have been bombarding the earth for billions of years -- and the earth is still here.

But, perhaps in a later post, I can go into more detail about the black hole question. It is interesting to think about and discuss...

Cheers,
-Mike

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Thanks for clearing that up. I did not know about all those other particles hitting the earth. It was just something I had seen on the news and thought you would be the perfect person to ask. If it ever did produce black holes, what would they do and how big would they be?

Thanks again, Will

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Hi Will,

First of all, let me point out that while Einstein's theory of General Relativity predicts that Black Holes can exist, and while there are several very good pieces of evidence that specific Black Holes do exist (like at the center of our galaxy), there has never been an absolute observation that says "this IS a Black Hole." (However, I personally think that the evidence for a Black Hole at the center of our galaxy is very convincing!)

Having said that, let me point out also that the way space and time behave in the vicinity of extremely massive objects, like stars and galaxies, does not necessarily mean that space and time behave exactly that way at very very small scales (like near "point particles" such as electrons and quarks). We call electrons "point particles" because, to our knowledge, they don't appear to have any real size. But to be honest, maybe we just haven't learned how to look at that small a scale yet.

The reason I bring this up is because the Black Holes that would be predicted to be created at, say, the LHC would be extremely small. Extremely small. There is a formula (which, again, we don't know if it is truly applicable at very small scales) for the size of a Black Hole. The formula is



where in the formula, R is the radius of the Black Hole, M is the mass inside, G is Newton's gravitational constant, and c is the speed of light.

So, I'll ask you to do the calculation -- if the LHC collides two protons, each with 7 TeV of energy, and all of that energy is turned into mass, and that mass just sits there as a Black Hole, what would its radius be?

Here's a hint: Mc^2 for our particle will have a value of 14 TeV; 1 TeV of energy = 1 x 10^12 eV; and, 1 eV = 1.6 x 10^-19 Joules.

Note that the "radius" of a proton is about 10^-15 m, and the mass of this particle that would be created in the LHC is about 14,000 times heavier than a single proton.

Let me know what answer you get!
-Mike Syphers


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R= 3.69 x 10^-48

WOW, that is small, since 10^50 is statistically impossible.....yeah there is nothing to worry about. Thanks for showing me that, i love numbers they really help show the magnitude, or lack there of, of the "black holes". Thanks again, Will.