Age-related deterioration of high-frequency hearing may be a common experience, but as the previous posters prove, there's no hard-and-fast rule for when people lose certain frequencies.
As another bit anecdotal evidence -- I am 35 and can easily hear the 21 kHz sine marketed as audible by those "18 and younger" on the ringtone sites. I can also hear one particular kind of "ultrasonic" motion sensors, which is really annoying.
If the 19 kHz pitch suggested doesn't get filtered out, I would definitely find it unlistenable.
Your subject seems to imply that the mass limit of a stellar black hole is the Chandrasekhar limit. I believe you are confusing this with the Tolman-Oppenheimer-Volkoff limit.
The difference is that the Chandrasekhar limit involves electron degeneracy pressure. Above this limit, the star can still collapse into a neutron star but still support itself with neutron degeneracy pressure. The mass limit that can be supported at this stage (before the star collapses to a black hole, or perhaps a quark star) is not as well known because QCD is hard.
No, the Chandrasekhar limit is based on electron degeneracy pressure versus self-gravitation and is the maximum mass for a white dwarf. From the wikipedia article you reference:
As white dwarf stars are supported by electron degeneracy pressure, this is an upper limit for the mass of a white dwarf. Main-sequence stars with a mass exceeding approximately 8 solar masses therefore cannot lose enough mass to form a stable white dwarf at the end of their lives, and instead form either a neutron star or black hole. [emphasis mine]
I remember hearing the same kind of dooms day predictions about RHIC at Brookhaven national labs. Also it was said that some scientists predicted the first atomic bomb would ignite the atmosphere destroying the planet. At any rate none of those doomsday predictions occurred and RHIC has been operating since 2000. Yes, exactly. A nice summary of the RHIC report from Skeptical Inquirer is here.
The most convincing argument in my mind why this is nonsense: the Earth is bombarded every day by cosmic rays which are ~100 billion times more energetic than the particles colliding in the LHC, and we haven't been destroyed yet.
It's a Well Known Fact that there are far more research grants for proving already-known scientific laws than there are for efforts to find out things we don't know. [...] The key to fame and fortune in research science clearly lies in defending the status quo. As an astrophysicist I see exactly the opposite: funding is going to answering unknown questions like "What is dark matter?" and "What is dark energy?", not to mention the multibillion-dollar colliders like LHC, one the main goals of which is to figure out how and at what energy the Standard Model of particle physics breaks down. This is exactly the opposite of "defending the status quo."
OK, but sarcasm aside, there is a tendency among those who teach science to put the Known Laws on an unassailable pedestal... largely in reaction to the rebellious students who refuse to believe anything they say. This is problem with how science is taught -- this is not how science is practiced. I do agree, however, that science educators (at least in the U.S.) do a horrible job of actually teaching how and why science actually works. If teachers would spend more time on explaining critical thinking and the scientific method, we'd have a much better educated populace, and one that was better equipped to examine the pseudoscientific claims that show up all the time (like this story).
Most others have covered the important points, but let me add a few refinements:
- I'd keep the astrophotography on the back burner for now as you ramp up.
- I second (third/fourth/...) the idea of getting binoculars to learn the sky. IMO, image stabilization is well worth the money you pay for it in large binoculars. If you get a computer-controlled telescope you could avoid the learning curve, but part of the fun in astronomy is learning where things are in the sky.
- As one post already said, the best telescope to buy is the one you'll use. I use my little Meade Maksutov-Cassegrain *way* more than I ever used my big Dobsonian.
- After you learn the sky, get a decent finder on your telescope. For a small scope, I like red-dot finders but am also eager to try green laser-pointer finders.
IAAA [I am an astrophysicist], and I'd like to point out what I feel is an important caveat to this nevertheless very interesting work. From the paper itself:
"We cannot exclude the possibility that the delay we find [...] may be due to some energy-dependent effect at the source."
What they are saying is that there are still details we don't understand about AGN [active galactic nuclei] like Markarian 501. So, while this effect could be a first sign of quantum gravity (*not* string theory in particular, as others have pointed out), it could also simply be something going on in the intrinsic spectrum of the flares themselves. I'd personally consider the second explanation more likely at this stage.
As they also point out, one approach to sort out the ambiguity would be to observe other flary AGN at different redshifts (distances). One could then, for example, see if the delay gets shorter or longer as the distance changes, as one would expect with a quantum gravity effect due to propagation to Earth.
The Sun will never go supernova (or nova, for that matter). It will eventually blow off its outer layers to form a planetary nebula, but the Earth will be long dead by then anyway as the Sun swells to become a red giant.
SGI might have had the resources to keep MIPS competitive, but they lacked the will.
I worked for SGI when they decided to spin off their MIPS microprocessor division and go with Intel. Even before that, the division was horribly mismanaged, with entire projects being cancelled after years of investment even as they were nearing completion. Even after they spun us off, they kept one design team around (at *great* expense), still unwilling to commit fully to one architecture or another.
As a separate company now, MIPS is completely aiming at the embedded market with an IP business model that is working reasonably well. I agree with several others here -- forget about MIPS workstations.
A 3.5 sigma result (if the statistics are correct) is much better than 95% -- it excludes chance fluctuations to 99.95%. However, it's not accepted as strong enough for proof of discovery (people start really paying attention at 5 sigma). And for something as extraordinary as this result, they will likely need confirmation with a totally different experimental technique.
Agreed -- your prior degree may make a lot of difference. Most academic science jobs are going to require a Ph.D in the relevant field, so you may have a lot of school ahead of you.
However, I wouldn't let that discourage you. I am hoping to make a similar transition (from microprocessor design to physics), for similar reasons. Be aware that it's a long road, though. Even with an undergrad degree in physics I have already spent the last 9 months or so preparing for GREs, lining up recommendations, etc. to apply to grad school.
The desire to make some contribution to science, however small, is what keeps me going.
Slashdot Mirror
Age-related deterioration of high-frequency hearing may be a common experience, but as the previous posters prove, there's no hard-and-fast rule for when people lose certain frequencies.
As another bit anecdotal evidence -- I am 35 and can easily hear the 21 kHz sine marketed as audible by those "18 and younger" on the ringtone sites. I can also hear one particular kind of "ultrasonic" motion sensors, which is really annoying.
If the 19 kHz pitch suggested doesn't get filtered out, I would definitely find it unlistenable.
Your subject seems to imply that the mass limit of a stellar black hole is the Chandrasekhar limit. I believe you are confusing this with the Tolman-Oppenheimer-Volkoff limit.
The difference is that the Chandrasekhar limit involves electron degeneracy pressure. Above this limit, the star can still collapse into a neutron star but still support itself with neutron degeneracy pressure. The mass limit that can be supported at this stage (before the star collapses to a black hole, or perhaps a quark star) is not as well known because QCD is hard.
Here is a technical analysis of the risks (PDF).
The most convincing argument in my mind why this is nonsense: the Earth is bombarded every day by cosmic rays which are ~100 billion times more energetic than the particles colliding in the LHC, and we haven't been destroyed yet.
Most others have covered the important points, but let me add a few refinements:
- I'd keep the astrophotography on the back burner for now as you ramp up.
- I second (third/fourth/...) the idea of getting binoculars to learn the sky. IMO, image stabilization is well worth the money you pay for it in large binoculars. If you get a computer-controlled telescope you could avoid the learning curve, but part of the fun in astronomy is learning where things are in the sky.
- As one post already said, the best telescope to buy is the one you'll use. I use my little Meade Maksutov-Cassegrain *way* more than I ever used my big Dobsonian.
- After you learn the sky, get a decent finder on your telescope. For a small scope, I like red-dot finders but am also eager to try green laser-pointer finders.
Have fun!
IAAA [I am an astrophysicist], and I'd like to point out what I feel is an important caveat to this nevertheless very interesting work. From the paper itself:
"We cannot exclude the possibility that the delay we find [...] may be due to some energy-dependent effect at the source."
What they are saying is that there are still details we don't understand about AGN [active galactic nuclei] like Markarian 501. So, while this effect could be a first sign of quantum gravity (*not* string theory in particular, as others have pointed out), it could also simply be something going on in the intrinsic spectrum of the flares themselves. I'd personally consider the second explanation more likely at this stage.
As they also point out, one approach to sort out the ambiguity would be to observe other flary AGN at different redshifts (distances). One could then, for example, see if the delay gets shorter or longer as the distance changes, as one would expect with a quantum gravity effect due to propagation to Earth.
How about fraudulent WoW upgrades to Blizzard, like just hit my card? I had to cancel.
m l?t=450004
This is a crappy site:
http://forums.moneysavingexpert.com/showthread.ht
but apparently others have had the same problem.
See http://www-astronomy.mps.ohio-state.edu/~pogge/Lec tures/vistas97.html for more info.
The human race is doomed anyway as the universe keeps expanding, but by colonizing other planets we delay our demise substantially.
I picked a *great* day to wear my SGI "Kudzu" shirt (internal codename for an IRIX release)...
It's also going to make that "Silicon Graphics: Best Computer Company on the Planet" t-shirt seem a little, shall we say, tongue-in-cheek!
SGI might have had the resources to keep MIPS competitive, but they lacked the will.
I worked for SGI when they decided to spin off their MIPS microprocessor division and go with Intel. Even before that, the division was horribly mismanaged, with entire projects being cancelled after years of investment even as they were nearing completion. Even after they spun us off, they kept one design team around (at *great* expense), still unwilling to commit fully to one architecture or another.
As a separate company now, MIPS is completely aiming at the embedded market with an IP business model that is working reasonably well. I agree with several others here -- forget about MIPS workstations.
A 3.5 sigma result (if the statistics are correct) is much better than 95% -- it excludes chance fluctuations to 99.95%. However, it's not accepted as strong enough for proof of discovery (people start really paying attention at 5 sigma). And for something as extraordinary as this result, they will likely need confirmation with a totally different experimental technique.
For those interested in the actual paper (Phys. Rev. Lett. 96), the PDF is available on the researcher's publications page:
http://www.nat.vu.nl/~wimu/PUBS.html
Agreed -- your prior degree may make a lot of difference. Most academic science jobs are going to require a Ph.D in the relevant field, so you may have a lot of school ahead of you.
However, I wouldn't let that discourage you. I am hoping to make a similar transition (from microprocessor design to physics), for similar reasons. Be aware that it's a long road, though. Even with an undergrad degree in physics I have already spent the last 9 months or so preparing for GREs, lining up recommendations, etc. to apply to grad school.
The desire to make some contribution to science, however small, is what keeps me going.