Large Hardon Collider

[BerenTebogo]

Good job wooooozie!

[Tyche]

Can anyone tell me the difference between viewing perseids tomorrow vs today? I checked nasas fluxtimator page, and it seems pretty equal in terms of viewing. I'd mch rather shoot tomorrow over tonight so I can sleep in Saturday.

[Max™]

http://www.chiff.com/science/perseids.htm
They peak today, should hit 60 per hour at times.

[Tyche]

Looks like im going to tough it out and go tonight. Looking at a peak of 74 per hour tonight vs 45 tomorrow.

Work tomorrow will undoubtedly suck.

[BerenTebogo]

http://blogs.discovermagazine.com/ba...hip-hop-holst/

Pretty cool. Maybe Dre will be the driving force to turn out more Woozie and Mizangos!

[Kaylia]

Probably old, but w/e

http://www.phdcomics.com/comics/archive/phd081310s.gif

[Eliseos]

It's so true too.

[Woozie]

LOL

[Eliseos]

Woooozie, the Griffiths texts for QM and E&M are supposed to be pretty good for students, right?

[Woozie]

Yeah, I used him for E&M. Those two books are supposedly two of the best undergraduate texts there is. Also, you'll need them for your classes because almost every school uses them.

The E&M book can be rough though. For some of our homework assignments, the teacher would outright give us the answer and we still would get the problems wrong. On one of our exams he gave us the answers to three of the five questions (and we only had to answer four) and we still didn't do too well on it. Luckily we only needed an 85% for an A (not an A-, but an actual A).

There's a fair share of easy problems there too, so it's really only has hard as your professor makes it. If you're reading it on your own for self study, you'll want to download the solution manual from demonoid or something.

As for QM, the book seems easy to me, but that's because I read it after I already finished the graduate texts by shankar and the one by sakurai. I don't know how hard it would be if I read it without having done the higher level version already. But it's definitely a really good book (and, again, the solution manual can be downloaded if you're doing this for self study).

[Eliseos]

Awesome, thanks. I'm taking QM 1 & E&M 1 this Fall and those were the books listed for the class. Just flipping through them, the only thing I don't really like is that they don't have any answers to problems in the back of the book. Going to be a little harder to check my work.

[BerenTebogo]

Day after Kaylia posted that comic I went into my Calc 1 study group before class and the only other guy there pursuing grad school (in psych though, bleh) had the comic up on his iPhone and we were dying laughing (read it after spending 20 minutes looking through a loooong integration problem for one fucking sign change error.)

Nobody else got it

[Woozie]

I hate negative signs.

On the second or third week of my REU, I was solving the schrodinger equation for a system that required a lot of work. Basically the hamiltonion had a bunch of terms in it, and I had to take the fourier transform of each term, solve it, find the propogator, and then take the fourier transform of the initial wave function and apply the propogator to that. It sounds like a typical QM problem, but the amount of terms involved and the nature of the potential (and the integrals that came about when trying to do the fourier transform) made it a really long and mess problem if done by hand.

So I figured I wouldn't do it by hand. I put the stuff in mathematica, but it wouldn't give me an answer. I litterally spent about two hours trying to get mathematica to solve this.

I eventually gave up and did it by hand. It literally took a week of working 8 hour days (well 7 because of lunch) before I finished it and finished checking my work, etc.

After all that work, I looked up at mathematica and was like "Hey, there should be a negative sign there", *presses negative* *presses enter*, and the answer literally pops up instantaneously. The same answer that had took me a week to find...all because of a stupid negative sign.

[Kaylia]

For real...that goddamn negative sign owe me many hours of life.

[Eliseos]

I hate negative signs.

On the second or third week of my REU, I was solving the schrodinger equation for a system that required a lot of work. Basically the hamiltonion had a bunch of terms in it, and I had to take the fourier transform of each term, solve it, find the propogator, and then take the fourier transform of the initial wave function and apply the propogator to that. It sounds like a typical QM problem, but the amount of terms involved and the nature of the potential (and the integrals that came about when trying to do the fourier transform) made it a really long and mess problem if done by hand.

So I figured I wouldn't do it by hand. I put the stuff in mathematica, but it wouldn't give me an answer. I litterally spent about two hours trying to get mathematica to solve this.

I eventually gave up and did it by hand. It literally took a week of working 8 hour days (well 7 because of lunch) before I finished it and finished checking my work, etc.

After all that work, I looked up at mathematica and was like "Hey, there should be a negative sign there", *presses negative* *presses enter*, and the answer literally pops up instantaneously. The same answer that had took me a week to find...all because of a stupid negative sign.

I thought Hubble gotchu?

[Kryssan]

I thought Hubble gotchu?

Naaah, just Hubble's photographic negatives, man. It was shorter to just write Hubble. Close enough for government work.

[Mizango]

They are showing "Through the Wormhole w/ Morgan Freeman' on Discovery channel if any of you guys are interested. It normally airs on the Science channel, but they put it on a non-premium channel so that everyone can see what its about.

This episode is about blackholes and smbh's if anyone is interested.

[Max™]

http://www.bbc.co.uk/news/science-environment-11070991

http://news.bbcimg.co.uk/media/image...3_eso1035a.jpg

Astronomers have discovered a planetary system containing at least five planets that orbit a star called HD 10180, which is much like our own Sun.
The star is 127 light years away, in the southern constellation of Hydrus.
The researchers used the European Southern Observatory (Eso) to monitor light emitted from the system and identify and characterise the planets.
They say this is the "richest" system of exoplanets - planets outside our own Solar System - ever found.

Christophe Lovis from Geneva University's observatory in Switzerland was lead researcher on the study. He said that his team had probably found "the system with the most planets yet discovered".
The researchers said the system around HD 10180 as unique in several respects.
It has at least five "Neptune-like planets" lying within a distance equivalent to the orbit of Mars, making it more populated than our own Solar System in its inner region. And all the planets seem to have almost circular orbits.

So far, the astronomers have picked up clear signals from five planets, along with two slightly "fuzzier" signals. One of these possible sixth and seventh planets was estimated to be just 1.4 times the mass of the Earth; if its presence in the system was confirmed, it would be the lowest mass exoplanet yet discovered.

[foopy]

http://io9.com/5619954/the-sun-is-ch...s-of-chemistry

The Sun is changing the supposedly constant rates of decay of radioactive elements, and we have absolutely no idea why. But an entirely unknown particle could be behind it. Plus, this discovery could help us predict deadly solar flares.

It's one of the most basic concepts in all of chemistry: Radioactive elements decay at a constant rate. If that weren't the case, carbon-14 dating wouldn't tell us anything reliable about the age of archaeological materials, and every chemotherapy treatment would be a gamble. It's such a fundamental assumption that scientists don't even bother testing it anymore. That's why researchers had to stumble upon this discovery in the most unlikely of ways.

A team at Purdue University needed to generate a string of random numbers, a surprisingly tricky task that is complicated by the fact that whatever method you use to generate the numbers will have some influence on them. Physics professor Ephraim Fischbach decided to use the decay of radioactive isotopes as a source of randomness. Although the overall decay is a known constant, the individual atoms would decay in unpredictable ways, providing a random pattern.

That's when they discovered something strange. The data produced gave random numbers for the individual atoms, yes, but the overall decay wasn't constant, flying in the face of the accepted rules of chemistry. Intrigued, they checked out long range observations of silicon-32 and radium-226 decay, both of which showed a slight but definite variation over time. Intriguingly, the decay seemed to vary with the seasons, with the rate a little faster in the winter and a little slower in the summer.

At first, the researchers tried to rationalize the seasonal fluctuations as the result of instrument error, perhaps caused by changing heat and humidity. But that idea fell apart when nuclear engineer Jere Jenkins noticed the decay rate of the short-lived isotope manganese-54 dropped slightly during a solar flare. In fact, the decrease began a good 36 hours before the flare occurred.

That suggests two things: one that's theoretically puzzling, and another that's hugely exciting from a practical perspective. If decay rates really are affected by solar flares before the flares even occur, that could provide the first truly reliable early warning system for flares. Considering severe solar flares can wreak havoc on electrical grids and even kill astronauts who aren't properly protected, that would be a huge benefit for humanity.

But practical pluses aside, why is this happening? The seasonal fluctuations suggested the Sun could be involved somehow, and the solar flare connection confirmed it. The scientists speculated that solar neutrinos, the nearly massless particles created as byproducts of the sun's fusing of hydrogen atoms into helium, might be causing these variations. The fact that these neutrinos pass straight through the Earth with ease fit well with the fact that the decay rates were changing even at night, when the entire planet was between the radioactive isotopes and the Sun.

Once the researchers conclusively ruled out environmental influences, that left the Sun as the only possible cause of the decay variations. They also found that the amount of change varied in time with the Earth's orbit - the effect was greater when the orbit brought the Earth closer to the Sun and thus into contact with more neutrinos.

That's where renowned Stanford physics professor Peter Sturrock entered the picture. Confronted with this mystery, he advised the researchers to test how the decay fluctuations correlated with the Sun's own rotation. They found the decay rates recurred every 33 days, which didn't quite fit with the Sun's known surface rotation length of 28 days. But the neutrinos wouldn't be coming from the surface - they would be coming from deep inside the core. Unlikely as it might seem, the sun's core must be rotating a little slower than its surface, apparently once every 33 days.

All of this relies on some unlikely assumptions and the occasional bold intuitive leap, but the model they propose seems to hang together. And yet one mystery remains - how are the neutrinos managing to interact with the radioactive particles in this way? It doesn't fit with the known behavior of neutrinos, and it opens up the very real possibility that some previously unknown subatomic particle is actually behind this bizarre effect.

As Peter Sturrock explains:

"It's an effect that no one yet understands. Theorists are starting to say, 'What's going on?' But that's what the evidence points to. It's a challenge for the physicists and a challenge for the solar people too. [If it's not neutrinos,] it would have to be something we don't know about, an unknown particle that is also emitted by the sun and has this effect, and that would be even more remarkable."
If these new discoveries hold up, then we've discovered that the sun changes rates radioactive decay, that we can predict solar flares before they happen, that the sun's core rotates slower than its surface, and maybe even that an entirely unknown particle exists and is affecting our world in a tangible way. Not a bad set of results for what was supposed to be a simple search for some random numbers.

tl;dr: carbon dating isn't accurate. creationists win.
(jk, i can't do a tl;dr on something i don't understand. posting this article in the hopes one of you genius people can draw some possible conclusions. thanks.)

[Psion]

Well, for one thing, parapsychologists everywhere are probably freaking out and checking their data, as many used random number generators based on radioactive decay. If such an influence would alter the data enough to give a overall above chance result, there goes all the RNG experiments online... (though not the ganzfeld, macro-psychokinesis, ESP, and micropsychokinesis experiments based on other RNGs besides radioactive decay, such as ones that use atmospheric fluctuations instead that were recently developed.)

Other than that, the fact that RNGs based on radioactive decay rates might be possibly biased in a way and not truly random could be holy hell for any of the sciences that use RNGs for data, along with carbon dating and the like. I doubt it would be a big influence, but well, experiments have gone kaboom over less.

I'm intrigued by the fact that physics is getting possibly yet another wrench in the gears to screw their models up. I always love it when it happens, since you always find even more cool things you can do from those things. Quantum mechanics only came about from a small issue with older models after all, and look at how much we've learned and created from that one small issue. But... can a core of a star really rotate that much slower than the exterior? I suppose it could be possible, considering the sheer size of our star, or any star for that matter, but still.

Oh well, I look forward to hearing more about this mysterious influence over decay rates in the future. :D