top The Meteors You've Waited All Year For
When the Moon is full, it rises at sunset and sets at sunrise. Each day, the Moon rises (and sets) about one hour later. So, 2 or 3 days after the full Moon, the Moon will rise 2 or 3 hours after sunset, and set 2 or 3 hours after sunrise.
Which means that, after midnight, the Moon will be high in the sky, ruining the view of the Perseids. It will not "set several hours before dawn."
In short, the response above is wrong.
top The Andromeda Galaxy Just Had a Bright Gamma Ray Event
And here's a very nice, easy-to-understand explanation of what happened, written by one of the SWIFT astronomers:
top The Andromeda Galaxy Just Had a Bright Gamma Ray Event
The team which announced the event has now figured out that it wasn't interesting after all:
TITLE: GCN CIRCULAR
NUMBER: 16336 SUBJECT: Swift trigger 600114 is not an outbursting X-ray source DATE: 14/05/28 07:57:12 GMT FROM: Kim Page at U.of Leicester
K.L. Page, P.A. Evans (U. Leicester), D.N. Burrows (PSU), V. D'Elia (ASDC) and A. Maselli (INAF-IASFPA) report on behalf of the Swift-XRT team:
We have re-analysed the prompt XRT data on Swift trigger 600114 (GCN Circ. 16332), taking advantage of the event data.
The initial count rate given in GCN Circ. 16332 was based on raw data from the full field of view, without X-ray event detection, and therefore may have been affected by other sources in M31, as well as background hot pixels. Analysis of the event data (not fully available at the time of the initial circular) shows the count rate of the X-ray source identified in GCN Circ. 16332 to have been 0.065 +/- 0.012 count s^-1, consistent with the previous observations of this source [see the 1SXPS catalogue (Evans et al. 2014):
We therefore do not believe this source to be in outburst. Instead, it was a serendipitous constant source in the field of view of a BAT subthreshold trigger.
This circular is an official product of the Swift-XRT team.
Better luck next time.
top NASA Offers Bounty For Improved Asteroid Detection Algorithms
If you're interested in the current state of the art, read this article from the Publications of the Astronomical Society of the Pacific (April 2013). It describes the hardware and software used by the Pan-STARRS team to detect asteroids automatically in data taken with their 1.8-meter telescope on Hawaii and its 1.4-gigapixel CCD camera.
top Fermi and Swift Observe Record-setting Gamma Ray Burst
I wrote up a short summary of the observational details for one of my classes -- you can find it at
You can also follow a nice summary of the latest results by following Don Alexander's thread on the Cosmoquest forum:
http://cosmoquest.org/forum/showthread.php?143754-GRB-130427A-burst-of-the-(quarter)-century about a year and a half ago
top Possible Supernova In Nearby Spiral Galaxy
Oh, rats. I've been working on measurements of SN 2011fe for too long and I had "type Ia" on the brain. You're right, this is a type II. My bad.
It's still too far away to produce detectable gravitational waves or neutrinos, though.
top Possible Supernova In Nearby Spiral Galaxy
First, this is a type Ia supernova, which produces fewer neutrinos and a much smaller gravitational wave signal than a core-collapse supernova.
Second, any supernova in a galaxy beyond the Local Group (the Milky Way, the Andromeda Galaxy, and some smaller companions) is too far to produce enough neutrinos or gravitational waves to be detected by our current instruments.
top When Getting Rid of College Lectures Makes Sense
The "expensive AV stuff" is 2 projectors per room (we need to project onto opposite walls because students sitting at tables aren't all facing in the same direction), times 7 workshop rooms. 14 projectors cost a lot to maintain.
Yes, we've completely eliminated traditional labs from the introductory physics sequence.
There is a small amount of data on how students did on the FCI before and after the switch, but not enough to be significant. I don't think that the FCI is a very good way to measure the knowledge of a student in physics, by the way.
When I said "move away from the median student", I mean "teach at a level which is far from that appropriate for the median student." In a lecture, one can choose to go faster or deeper, knowing that one may leave most of the class behind; the lack of feedback makes it easy. In a workshop, because one is so close to the students, one sees the effect and it's hard to ignore it. The question of "should one teach to the level of the median student" is a big one, of course, and I can't address it here.
top When Getting Rid of College Lectures Makes Sense
... and it's okay.
At RIT, we switched from the traditional lecture + lab approach to the "workshop" approach about six years ago. The students meet in a room with small tables and maximum class size of 42, three times a week for two hours each. The room has equipment at all the tables, so that students can quickly set up small experiments which may not take the entire 2-hour meeting.
I taught in the traditional manner for about seven years, and in this manner for an equal duration. Does the workshop have advantages? Sure: students are less likely to fall asleep because they are often working examples, and because they are in a small, well-lit room. I can walk around and talk to individual students for a minute or two at a time, so I can find those who are having problems and try to help them. It's easy to introduce a concept, give one simple example, then ask the students to do another example, within a span of 20 or 40 minutes. In some cases, this cycle of introduction - observation - action may help students to understand or remember the material.
But there are disadvantages, too: in a workshop, it's difficult to move away from the median student. I can't go too much faster or deeper, because it's clear that many students are not getting it; so some students are held back. I can't slow down for the slowest learners, either, because it becomes obvious that the majority of the class is bored. This approach is MUCH MORE EXPENSIVE than the traditional one, because we need to offer 10 or 15 sections of the class each quarter; that means a lot more faculty time. The rooms can't be used for any other classes, and the AV requirements are pretty steep -- we need to spend around $10K just on projectors each year. We need more equipment than we would have in traditional labs, and that stuff isn't cheap.
It's not clear that this approach causes students to learn any better; some are helped, some are hurt. It's difficult to compare student achievement in workshops vs. lectures, because at the same time that workshops were introduced, we changed the content of our classes as well.
My summary, after years of experience: not a silver bullet, a lot more fun to teach, more expensive overall.
top Should College Go Online?
I teach at a large university. My university is pushing for faculty to sign up for on-line courses. My guess is that they see two economic incentives: they can appeal to a larger customer base -- students who can't attend in person -- and they can cut costs by increasing the number of students enrolled relative to the number of professors.
What's in it for me? What do I gain by agreeing to teach on-line? I lose the give-and-take relationship with my students; how can I see if my explanation of a new concept is working if I can't see the expressions of the students as I try to explain it? I contribute to putting myself and my colleagues out of a job. I implicitly support the idea that the best way to teach is to give students videos to watch.
Actually, all of my course materials ARE on-line already. See
http://spiff.rit.edu/classes. Anyone who wants to use these materials to teach himself -- go for it! So I'm not lazy, and I'm not trying to keep knowledge secret. I just think that teaching college students in person is better than doing so via web pages and videos.
top 'Instant Cosmic Classic' Supernova Discovered
Alas, we shouldn't expect any neutrinos to be detected from this event. I am an astronomer who studies supernovae, and the Type Ia events --- those due to a runaway thermonuclear reaction inside a white dwarf --- do _not_ produce the same sort of giant burst of neutrinos as core-collapse events.
In addition, this supernova is much, much farther away than SN 1987A. This event, in M101, is about 6400 kpc away, while SN 1987A was only about 50 kpc away. So, in very rough terms, the new SN is about 100 times farther away
... which means than the flux of particles from it will be about 100*100 = 10,000 times weaker than that from an object at the distance of SN 1987A. We only detected about 30-40 neutrinos in total from SN 1987A, so, even if this new supernova was a core-collapse event (which it isn't), we might only expect 40/10,000 = 0.004 neutrinos to be detected.
Yes, yes, today's neutrino detectors are larger than the ones operating in 1987. However, I don't think they could make up this sort of difference. And remember, a Type Ia supernova doesn't produce as many neutrinos to start with.
But this should be a good object for people to see through telescopes or (possibly) binoculars!
top Editing Wikipedia Helps Professor Attain Tenure
We're in a job search right now for two tenure-track professors in a Physics Department. None of the five candidates interviewed so far has mentioned Wikipedia. I'm pretty sure that if one did, he wouldn't gain any credit by doing so.
Our department made recommendations for a tenure decision earlier this year. No mention of Wikipedia in the supporting materials for that candidate, nor have I ever seen such a mention. I am pretty sure that neither my colleagues nor the administrators involved in granting tenure would give any credit for editing Wikpedia.
top Robonaut To Escort On Space Shuttle Mission
The Voyagers were launched in 1977 (I remember the hoopla), so that makes their current age around 33 years. They are wonderful devices, but they can't warp time
top What Objects To Focus On For School Astronomy?
I teach astronomy courses to university students.
The best object by far to look at is the Moon, as
others have said.
it's big and bright, so you can't miss it students can compare the view through the
telescope to the view with their naked eyes students can compare the view through the
telescope to the view through binoculars
I've written a number of outdoor lab exercises
for introductory astro students which would
be perfectly appropriate for your students.
You can read
one on the Moon, in particular. Or you can
look at the lists of exercises in
this other class for more ideas.
I'd recommend the "Limiting Magnitude" exercise
as one which you can do when the Moon isn't up.
It will help if you have several pairs of binoculars
in addition to the telescope.
top Spectrum of Light Captured From Distant World
Astronomers have measured transmission spectra of a planet circling the star HD 209458 and a planet circling the star HD 189733 (and probably others). The first successful measurements, which found sodium in the spectrum of HD 209458b, were published by Charbonneau et al. in 2002. See
ApJ 568, 377 (2002).
top White House Plans Open Access For Research
Here's the way things work right now in my field, astrophysics: a scientist has an idea. He writes a grant proposal to the NSF and receives money. He uses the money to (hire a grad student, travel to telescope, build an instrument, etc.). He writes a paper on the results. In order to have the paper published in one of the big journals -- which is necessary to gain credit for tenure, promotion, reputation among peers -- he PAYS THE JOURNAL ~$110 PER PAGE. The journal makes the information available only to subscribers, who pay around $50-$100 for individuals or $1500-$3000 for institutions.
If you don't publish in the big peer-reviewed journals, you don't get recognition.
So, suppose that the government changes things: now the journals must make government-funded research available to the public without charge. The journals will lose money from their subscriber base; after all, who would bother to pay for the articles when they are free? Where do the journals make up the money? My guess: they increase the page charges. Now it might cost $200 or $250 per page to publish an article in a journal. Whence comes that extra money? From the government grant.
Result: the scientific papers are now available freely to the public, but scientists must ask for more money from the NSF in order to pay the higher page charges.
top MIT Moves Away From Massive Lecture Halls
Disclaimer: I teach physics at an American university.
When you switch from a big lecture class to small, "workshop"
rooms which use computer-based sensors, you raise the cost of
the class by factors of many.
it now takes six professors to teach the class instead
of one the computers and sensors are now used almost every day,
instead of once a week or so, which means that if
they break, they halt a class dead in the water.
That means you need more spares, and you need to
upgrade computers more frequently.
Smaller classes are good -- of course. I am much more
effective in smaller classes than in a big lecture.
But do students want to pay 4-7 times more for the
privilege of having small classes?
I'm teaching a "workshop" class in which I can't depend
on the computers at all. It doesn't bother me --
I have exercises which use metersticks and stopwatches.
But it does cause problems for professors who have
become used to using the nice computer-based sensors.
Our department/university just can't afford to replace
the computers right now.
I'm just trying to point out that changing the
way some courses are taught may lead to increased
costs. That's all.
top The End of Individual Genius?
... but "the age at which researchers have built
up large research teams to carry out projects for
which they (for the most part) acquire funding."
In other words, eighty years ago, a 30-year old
physicist and a technician or two could build
a device to study the absorption of X-rays by
various elements. The resulting publications
might win a Nobel Prize.
These days, a 30-year old physicist is working
as a post-doc in someone else's lab. He won't
by the leading author on the grant proposal to
design a new detector for CERN -- some 50-year
old with an established track record will be.
That 50-year old guy will probably still be
alive when the detector is finally built and
goes into action. He MIGHT still be alive when
the Nobel Prize committee gets around to
considering the results of the research.
If you think this is lamentable, ask yourself
about bridges. How many people design and
build large highway bridges BY THEMSELVES
these days? None. Do you long for the days,
millenia ago, when a single man, or perhaps
a man and his brothers, might construct a
bridge to span the local creek?
Practical architecture has become too big
for one man to do all by himself. The
items of interest just cannot be built by
a single person in a human lifetime.
The same is true in SOME spheres of the
sciences, but not all.
top Carbon Dioxide and Water Found On Exoplanet
So the announcement about the discovery of a planet not capable of supporting life... is proof that Hubble's replacement will be able to find planets that will support life?
Kepler will be a small telescope (about 1 meter) in orbit, with the sole
mission of looking at a few fixed areas on the sky and
searching for planets by the transit method: take thousands
of pictures and look for stars which become dimmer for
a few hours due to a planet crossing their disks. This small
mission will launch in spring 2009 and is NOT a replacement
The James Webb Space Telescope (JWST) is Hubble's replacement.
It will be much larger (with a mirror around 6.5 meters in diameter)
and carry out many, many different types of observations.
This mission will launch, uh, some time around 2013, if all
top Inside the World's Most Advanced Planetarium
The National Astronomical Observatory of Japan, in Mitaka, has a system called "4D2U" set up in a small building. It features dome about 20 meters wide with (if I recall correctly from my visit in the spring) 11 or 13 projectors. Most of the projectors face in one particular direction, the same direction which the seats face, so that the resolution and color balance are highest where people are looking. The team at Mitaka has written their own software to do real-time motion through space and time; it looks a lot like Celestia, and may be based in part on it.
You can see details and download code for your own use by going to