Friday, December 14, 2012
Geminid Meteor Shower
If it's clear where you live, take a look at the Geminid meteor shower tonight, starting around 10 pm but especially after midnight. The peak was last night (Dec. 13/14), but tonight (Dec. 14/15) should be quite good as well. You can look anywhere in the sky. For more information, check out the EarthSky site.
Monday, November 12, 2012
Supersymmetry dealt a blow
The popular physics theory of supersymmetry was dealt a blow by the publishing of a crucial paper by CERN. Physicists who work at the Large Hadron Collider (LHC) look at specific particles, which are unstable. This just means that they split into smaller particles as they decay. Of course, there are many different kinds
of smaller particles into which the larger particle can split. Some of the
decays rarely happens.
According to the standard model, the decay in the question only happens in three out of 109 B-decays (A B-decay is a decay where a B-meson decays. A B-meson is a particle consisting of a anti-bottom quark and an up, down, strange, or charm quark). The fraction of all decays that lead to a particular final result is also called the branching ratio. So of all the possible decays that the B-meson can do, only 3 x 10-9 of the decays lead to the decay in the paper. Actually, they treat two different B-decays, but the branching ratio of both of them is in the order of magnitude ~10-9 - 10-10. According to Supersymmetry, the branching ratio of these decays is much higher.
What this all comes down to is if we have a billion of the large particles, only one of them splits into a certain combination of smaller particles. Thus, we say that the chance for that certain decay is one in one billion. The article is about one particular kind of decay.
Now, different theories have different chances for that particular decay of happenings. In the standard model, that is one in one billion. In super symmetry, it's maybe one in one million. That means it happens a thousand times more often.
Sometimes, scientists don't know whether a decay actually happens at all. But down at LHC, they've found the decay, so they know it happens. But they've only found it once out of maybe a billion other decays.
While this decay happens rarely, it happens many times in LHC. What's new with this publication is that they are now fairly certain that the amounts of decays they detect aren't some kind of freak accident or a problem with the test. The probability that background processes can produce the observed number of decay candidates is 5x10-4 and corresponds to a statistical significance of 3.5 sigma. That is that if they did the same experiment 5x104 times, one of them would be wrong.
This all comes down to that the standard model predicts that one in one billion decays is that particular decay, but super symmetry predicts maybe a thousand in one billion decays is that particular decay. So, according to SUSY, this decay should have happened many more times than this single one they've found. This means that right now, the standard model seems correct and super symmetry has something wrong.
According to the standard model, the decay in the question only happens in three out of 109 B-decays (A B-decay is a decay where a B-meson decays. A B-meson is a particle consisting of a anti-bottom quark and an up, down, strange, or charm quark). The fraction of all decays that lead to a particular final result is also called the branching ratio. So of all the possible decays that the B-meson can do, only 3 x 10-9 of the decays lead to the decay in the paper. Actually, they treat two different B-decays, but the branching ratio of both of them is in the order of magnitude ~10-9 - 10-10. According to Supersymmetry, the branching ratio of these decays is much higher.
What this all comes down to is if we have a billion of the large particles, only one of them splits into a certain combination of smaller particles. Thus, we say that the chance for that certain decay is one in one billion. The article is about one particular kind of decay.
Now, different theories have different chances for that particular decay of happenings. In the standard model, that is one in one billion. In super symmetry, it's maybe one in one million. That means it happens a thousand times more often.
Sometimes, scientists don't know whether a decay actually happens at all. But down at LHC, they've found the decay, so they know it happens. But they've only found it once out of maybe a billion other decays.
While this decay happens rarely, it happens many times in LHC. What's new with this publication is that they are now fairly certain that the amounts of decays they detect aren't some kind of freak accident or a problem with the test. The probability that background processes can produce the observed number of decay candidates is 5x10-4 and corresponds to a statistical significance of 3.5 sigma. That is that if they did the same experiment 5x104 times, one of them would be wrong.
This all comes down to that the standard model predicts that one in one billion decays is that particular decay, but super symmetry predicts maybe a thousand in one billion decays is that particular decay. So, according to SUSY, this decay should have happened many more times than this single one they've found. This means that right now, the standard model seems correct and super symmetry has something wrong.
Monday, November 5, 2012
Hunting for the Higgs Boson
If you're in the East Bay tonight, you should check out the 2012 Segre Lecture at UC Berkeley. Peter Jenni, a CERN Scientist and former ATLAS Spokesperson, will present "Hunting for the Higgs Boson and more at the LHC."
This annual lecture was conceived as a way for the Physics Department to honor and bring the work of an experimental physicist to the general public. Many renowned experimental physicists have been hosted. The observation of the Higgs Boson at the LHC was easily the biggest science story of the year, so this should be an excellent lecture. It will begin at 5PM in the Pauley Ballroom and is an lecture that any budding astronomer or science enthusiast won't want to miss! Click here to say you're going.
The lecture abstract is as follows:
For the past three years, experiments at the Large Hadron Collider (LHC) have begun exploring physics at the high energy frontier. A rich harvest of initial physics results has been obtained that allows us to test the Standard Model (SM) of elementary particles and to make searches Beyond the SM (BSM), at the highest energy level ever reached in a laboratory. Most exciting is the recent discovery of a new particle that may well be the long-awaited Higgs Boson. This discovery would also establish the postulated electro-weak symmetry breaking mechanism in the SM. Other far-reaching results can be reported for BSM physics searches like Supersymmetry (SUSY) and its implication for Dark Matter in the Universe, Extra Dimensions, and the production of new heavy particles. Besides these physics results, the history and technical challenges of the LHC project, its status, future physics prospects, as well as Cal and LBNL’s prominent role in them will also be covered briefly in this talk.
This annual lecture was conceived as a way for the Physics Department to honor and bring the work of an experimental physicist to the general public. Many renowned experimental physicists have been hosted. The observation of the Higgs Boson at the LHC was easily the biggest science story of the year, so this should be an excellent lecture. It will begin at 5PM in the Pauley Ballroom and is an lecture that any budding astronomer or science enthusiast won't want to miss! Click here to say you're going.
The lecture abstract is as follows:
For the past three years, experiments at the Large Hadron Collider (LHC) have begun exploring physics at the high energy frontier. A rich harvest of initial physics results has been obtained that allows us to test the Standard Model (SM) of elementary particles and to make searches Beyond the SM (BSM), at the highest energy level ever reached in a laboratory. Most exciting is the recent discovery of a new particle that may well be the long-awaited Higgs Boson. This discovery would also establish the postulated electro-weak symmetry breaking mechanism in the SM. Other far-reaching results can be reported for BSM physics searches like Supersymmetry (SUSY) and its implication for Dark Matter in the Universe, Extra Dimensions, and the production of new heavy particles. Besides these physics results, the history and technical challenges of the LHC project, its status, future physics prospects, as well as Cal and LBNL’s prominent role in them will also be covered briefly in this talk.
Wednesday, October 31, 2012
Adventures with America's Cup
AC45 boats race during qualifying rounds this year
(AP Photo/Eric Risberg; The Big Story)
In honor of all the America's Cup excitement here in the Bay Area, it's important to understand how these massive boats work.
One of the fundamentals of sailing is tacking into the wind. This translates into forward motion for a sailboat, when you might otherwise think that the boat would list or sail backwards. In fact, sailing ships have a keel that stops them from being just pushed sideways. Therefore, they can only go forwards or backwards.
When the ship faces into the wind at an angle instead of head on, it's possible to set the sails so that the force of the wind
is pushing a little bit back and a lot sideways. So let's say the wind is coming from the north and the ship is facing
northwest. A good sailor can set up the sail
so that the force on the sails is a little bit south and a lot west.
Since the ship can only go forwards or backwards, the western force overcomes the southwards force, and the ship goes a lot west and a little north. If you then turn the ship northeast, you can go a lot east and a little north. Now you're farther north than you started, even though the wind is blowing from the north. If you turn your bow directly into the wind however, you will go backwards as your sails cannot catch the wind. This is an excellent way to cut your speed.
The sailors competing in America's Cup all possess incredibly precise intuition—built from years of practice—regarding the degree they should be to the wind. It is thrilling to watch them compete and race towards their goal. Although the excitement is over for the year, they'll be back next year for an intense competition that promises to be exhilarating!
Since the ship can only go forwards or backwards, the western force overcomes the southwards force, and the ship goes a lot west and a little north. If you then turn the ship northeast, you can go a lot east and a little north. Now you're farther north than you started, even though the wind is blowing from the north. If you turn your bow directly into the wind however, you will go backwards as your sails cannot catch the wind. This is an excellent way to cut your speed.
The sailors competing in America's Cup all possess incredibly precise intuition—built from years of practice—regarding the degree they should be to the wind. It is thrilling to watch them compete and race towards their goal. Although the excitement is over for the year, they'll be back next year for an intense competition that promises to be exhilarating!
Wednesday, October 24, 2012
Bay Area Science Festival
The Bay Area Science Festival is a week-long celebration of science that kicks off later this week. UC Berkeley and Science@Cal are involved in a number of exciting events, beginning with not one, but two star parties on Friday (one at the Lawrence Hall of Science for everyone, and a second teen-exclusive event at the YMCA Teen Center in downtown Berkeley).
You can also hike the Hayward Fault with UC Berkeley seismologists, explore what you eat at local farmers' markets, learn about the amazing things plants can do, enjoy the chemistry of brunch, investigate the intersection of art and science at a two-night exclusive gallery gala in downtown Berkeley, and join 25,000 others for the big finale at AT&T Park on November 3rd.
Many of these events are free. For a few of them, a small fee applies and / or registration is required.
Details of Science@Cal's participation in these events can be found on their website here.
The main festival webpage, featuring other events taking place across the Bay Area, is at Bay Area Science.
Also, save the date for the next Science@Cal lecture, November 17th, featuring Prof. Rosemary Gillespie, Director of the Essig Museum of Entomology, talking about evolution on remote islands.
Science Education Kickstarter
Wonderfest, the nonprofit San Francisco Bay Area Beacon of Science, has just begun a Kickstarter campaign to support a new, online, video series called "Radical Physics." Alex Filippenko, one of the world's most highly cited astronomers and a professor at UC Berkeley, will be part of the series.
You can take part by contributing as little as $1. And if you want a tangible reward, you can pledge $10 or more. All contributions (including big ones!) will be very welcome, and are tax deductible.
To appreciate this campaign -- and the educational need for Radical Physics -- please see the following web page. If you wish, watch the short-and-fun video and check out the various rewards of the Energy Radical Physics Video Series.
Wednesday, September 12, 2012
Pi Art in the Sky
If you look up into the sky today in the SF Bay Area, you will see skywriting planes creating an art installation called "Pi in the Sky." What is this? Why pi?
This artistic presentation of sky calligraphy will be the world's largest ephemeral art installation. Five synchronized planes will draw the first 1000 digits of the infinite sequence of pi (π, 3.14…), the ratio of a circle's circumference to its diameter.
Though created by an SF-based artist (ISHKY) as a community-building civic art experience, this event also provides an interesting educational opportunity, reminding us of the importance of math and science in our lives.
It is supported by piZone.org, a crowd-source resource that uses pi to educate and engage students and the public to become more interested in math and science with interactive games, educational videos, activities/demos, and pi art. For more information, see the press release here.
We invite you to pi-ticipate!
Share the pi with people in the Bay Area and beyond.
Estimated Flight Times and Cities
San Jose ~11:30
Oakland ~12:00
San Francisco ~12:10
Palo Alto ~12:30
San Jose ~12:40
This artistic presentation of sky calligraphy will be the world's largest ephemeral art installation. Five synchronized planes will draw the first 1000 digits of the infinite sequence of pi (π, 3.14…), the ratio of a circle's circumference to its diameter.
Though created by an SF-based artist (ISHKY) as a community-building civic art experience, this event also provides an interesting educational opportunity, reminding us of the importance of math and science in our lives.
It is supported by piZone.org, a crowd-source resource that uses pi to educate and engage students and the public to become more interested in math and science with interactive games, educational videos, activities/demos, and pi art. For more information, see the press release here.
We invite you to pi-ticipate!
Share the pi with people in the Bay Area and beyond.
Estimated Flight Times and Cities
San Jose ~11:30
Oakland ~12:00
San Francisco ~12:10
Palo Alto ~12:30
San Jose ~12:40
Friday, August 31, 2012
Lick Observatory Event
On Saturday, September 15, at Lick Observatory--located at Mt. Hamilton, about an hour drive from San Jose--there will be a "BBQ with the Stars." In addition to the barbeque dinner, there will be live music, entertaining and informative astronomy lectures, and viewing through the observatory's large historic telescopes. Professor Alex Filippenko will be one of the main speakers, along with Sandra Faber (Interim Director, University of California Observatories), Professor Geoff Marcy (the world's leading hunter for planets orbiting other stars, and Timothy Ferris (one of the world's best science writers).
Dinner catered by Bruno's Barbeque (with vegetarian options) will be served from 5 to 7 p.m., followed by astronomy talks and viewing through the large telescopes from 7:30 to 10:30 p.m. The talks will be at a level suitable for the lay public, including kids. There will be plenty of time to ask questions of the astronomers, too. Musical entertainment will be provided by Silicon Valley's Dr. West playing live 1970s music, and classical guitar duo Equilibrium.
Tickets to this very special event are limited and must be purchased in advance by calling the UC Santa Cruz Ticket Office at (831) 459-2159 or online at www.SantaCruzTickets.com . Admission is only $60 per person (plus a small ticket service fee), and proceeds benefit Lick Observatory's extensive public programs. Hope to see you there!
Dinner catered by Bruno's Barbeque (with vegetarian options) will be served from 5 to 7 p.m., followed by astronomy talks and viewing through the large telescopes from 7:30 to 10:30 p.m. The talks will be at a level suitable for the lay public, including kids. There will be plenty of time to ask questions of the astronomers, too. Musical entertainment will be provided by Silicon Valley's Dr. West playing live 1970s music, and classical guitar duo Equilibrium.
Tickets to this very special event are limited and must be purchased in advance by calling the UC Santa Cruz Ticket Office at (831) 459-2159 or online at www.SantaCruzTickets.com . Admission is only $60 per person (plus a small ticket service fee), and proceeds benefit Lick Observatory's extensive public programs. Hope to see you there!
Sunday, August 12, 2012
How has NASA affected you?
What has NASA done that has affected you? Well, do you like to hang glide? NASA developed the materials. Runs marathons? Own a home? NASA created the fabric that insulates and protects both runners and inhabitants. What else did they do? Well, there's a nifty site called WTF NASA that will tell you. You can decide, as you click through the links, whether the facts "Fail to Launch" or maybe "That Rockets!"
Saturday, August 11, 2012
Moon Disaster
This is the first page of a speech written by Bill Safire for President Nixon to read if the moon landing went poorly and the astronauts were unable to return. As we know, thankfully it was unnecessary but it's still a poignant insight into the fears and uncertainty of space exploration.
Friday, August 10, 2012
Annual Perseid Meteor Shower
The annual Perseid meteor shower is coming on Saturday night, and I encourage you to view it. (Friday and Sunday nights should be okay, too, but not quite as good.) The shower peaks around 2-4am PDT on Sunday, August 12 (that is, Saturday night, August 11). Try to get as far away from city lights as possible. No binoculars or telescopes are needed; just view the sky with your unaided eyes from as dark a location as possible, away from city lights. Dress warmly, and bring a hot beverage if you wish. You can lie down on a blanket or a lawn chair, for comfort. Looking anywhere in the sky is fine, but views to the northeast should provide the most meteors.
There are many good references with viewing tips, etc. From Astronomy.com:
"If you ask most skygazers to name their favorite meteor shower, the odds are good that `Perseid' will be the first word out of their mouths. This annual shower seemingly has it all: It offers a consistently high rate of meteors year after year; it produces a higher percentage of bright ones than most other showers; it occurs in August when many people take summer vacation; and it happens at a time when nice weather and reasonable nighttime temperatures are common north of the equator. No other major shower can boast all four of these attributes.
And this year’s Perseid meteor shower promises two other significant advantages. First, it occurs when the Moon is at a waning crescent phase, which means bright moonlight won’t diminish the number of visible meteors. And second, the shower peaks on a Saturday night, August 11/12, so most people can afford to sleep in or at least relax the following day... The crescent Moon, which rises shortly after 1 a.m., won’t have much impact because the shower consistently produces lots of bright meteors. Observers under clear dark skies likely will see 60 to 80 meteors per hour -— an average of at least one per minute —- in the hour or two before twilight starts to break shortly after 4 a.m. local daylight time. By then, the brilliant planets Venus and Jupiter will add to one of the finest predawn shows of 2012."
Have fun, and I hope you have clear skies!
There are many good references with viewing tips, etc. From Astronomy.com:
"If you ask most skygazers to name their favorite meteor shower, the odds are good that `Perseid' will be the first word out of their mouths. This annual shower seemingly has it all: It offers a consistently high rate of meteors year after year; it produces a higher percentage of bright ones than most other showers; it occurs in August when many people take summer vacation; and it happens at a time when nice weather and reasonable nighttime temperatures are common north of the equator. No other major shower can boast all four of these attributes.
And this year’s Perseid meteor shower promises two other significant advantages. First, it occurs when the Moon is at a waning crescent phase, which means bright moonlight won’t diminish the number of visible meteors. And second, the shower peaks on a Saturday night, August 11/12, so most people can afford to sleep in or at least relax the following day... The crescent Moon, which rises shortly after 1 a.m., won’t have much impact because the shower consistently produces lots of bright meteors. Observers under clear dark skies likely will see 60 to 80 meteors per hour -— an average of at least one per minute —- in the hour or two before twilight starts to break shortly after 4 a.m. local daylight time. By then, the brilliant planets Venus and Jupiter will add to one of the finest predawn shows of 2012."
Have fun, and I hope you have clear skies!
Monday, August 6, 2012
Exploring with Curiosity
Late last night, the NASA "Mars Science Laboratory
(MSL)" mission gently landed its fully robotic "Curiosity"
rover in a crater on Mars. It was launched on November 26, 2011. The rover
is aptly named.
The mission's primary purpose is to determine whether Mars could ever have supported life, but this does not yet extend to detecting current life itself.
The mission's primary purpose is to determine whether Mars could ever have supported life, but this does not yet extend to detecting current life itself.
This is by far the largest rover to date: 10 feet long (not
including the arm), 9 feet wide, and 7 feet tall, weighing 2000 pounds. If
you’re having a tough time visualizing that, it's about the size of a typical
car.
The mere landing of a vehicle this size, not to mention the execution of its experiments, will be a veritable marvel of modern mathematics, science, technology and engineering. The landing sequence had multiple steps addressing various challenges (some introduced by prior steps), designed to slow the vehicle from 13,000 mph upon hitting the thin atmosphere to a soft landing in 7 minutes, each of which had to work flawlessly or the whole enterprise would fail! Furthermore, because it takes 14 minutes for electromagnetic signals to travel one way between Earth and Mars, the entire landing had to have been accomplished via autonomous robotics, without any direct human intervention. By the time mission control received indications of entry into the thin Martian atmosphere, the Curiosity rover had already been sitting on the surface of Mars for at least 7 minutes. Yikes!
If interested, take a look at the following two videos about the astounding landing sequence:
"Video: Curiosity's Landing" a simple, excellent, non-narrated video -- just gets your heart racing!
"Video: Curiosity's Seven Minutes ofTerror" which is narrated by JPL scientists; includes fascinating context about the design decisions that had to be made.
Another good site is"Fast Facts" which includes basic info, simply presented, with links for digging deeper.
The mere landing of a vehicle this size, not to mention the execution of its experiments, will be a veritable marvel of modern mathematics, science, technology and engineering. The landing sequence had multiple steps addressing various challenges (some introduced by prior steps), designed to slow the vehicle from 13,000 mph upon hitting the thin atmosphere to a soft landing in 7 minutes, each of which had to work flawlessly or the whole enterprise would fail! Furthermore, because it takes 14 minutes for electromagnetic signals to travel one way between Earth and Mars, the entire landing had to have been accomplished via autonomous robotics, without any direct human intervention. By the time mission control received indications of entry into the thin Martian atmosphere, the Curiosity rover had already been sitting on the surface of Mars for at least 7 minutes. Yikes!
If interested, take a look at the following two videos about the astounding landing sequence:
"Video: Curiosity's Landing" a simple, excellent, non-narrated video -- just gets your heart racing!
"Video: Curiosity's Seven Minutes ofTerror" which is narrated by JPL scientists; includes fascinating context about the design decisions that had to be made.
Another good site is"Fast Facts" which includes basic info, simply presented, with links for digging deeper.
Friday, July 27, 2012
Astronomy Picture of the Day
Two accomplished astronomers run Astronomy Picture of the Day and put up interesting and
gorgeous astronomy pics every day. They have been at it since 1995, and
haven't skipped a single day. The look of the website hasn't changed
much -- basic HTML, but the one paragraph of text below the picture often
gives an insight into our universe and modern astronomy. Their forums
are pretty cool too, for those interested.
Wednesday, July 11, 2012
Higgs Boson Explained
Following in the wake of CERN's July 4th announcement, this video comes from the channel of MinutePhysics explaining the Higgs Boson.
From the video:
"The fact that the Higgs Boson is so independent from the rest of the Standard Model is why it's the last piece of the puzzle to be discovered - and if it turns out to be exactly what was predicted, the Standard model will be complete."
Wednesday, July 4, 2012
Saturday, June 30, 2012
Leap Second: Today is the Longest Day of the Year
Due to the gradual slowdown in Earth's rotation, a team at the Paris Observatory is adding a "leap second" just before
midnight. Experts
at the International Earth Rotation and Reference System Service make
the adjustment when the planet's movement falls out of sync with atomic
clocks used to measure time.
"Today, time is constructed defined and measured with atomic clocks" said Noel Dimarcq, director of the SYRTE time-space reference system at the Paris Observatory. "This allows us to ensure that everyone on Earth is on the exact same time," Daily Mail quoted Dimarcq as saying.
Today's final minute (Greenwich Time), with its added second, will compensate for the sloshing of oceanic tides on the continental shelves, which slows Earth's rotation ever so slightly. It's been four years since a leap second has been added.
"Today, time is constructed defined and measured with atomic clocks" said Noel Dimarcq, director of the SYRTE time-space reference system at the Paris Observatory. "This allows us to ensure that everyone on Earth is on the exact same time," Daily Mail quoted Dimarcq as saying.
Today's final minute (Greenwich Time), with its added second, will compensate for the sloshing of oceanic tides on the continental shelves, which slows Earth's rotation ever so slightly. It's been four years since a leap second has been added.
Wednesday, June 20, 2012
Closure of 70 of California's State Parks
The First 70 Trailer from Heath Hen Films on Vimeo.
On July 1st, up to 70 of California’s 279 state parks may be closed due to budget cuts enacted by the Governor and Legislature. This closure will affect 25% of California's beautiful parks will erode the state’s commitment and legacy to irreplaceable natural, cultural, and historic resources. Additionally, closing state parks will impact California’s travel and tourism industry and reduce much-needed revenues for local businesses. As the parks are shut down they will no longer be considered in the state's eyes as an asset, which will allow for lobbyists to push to have state protection of the parks removed. This will allow for timber, mining, and real estate interests to purchase bits of the parks. Although this will profit them immensely, it will devastate the national landmarks and leave the land ravaged.
Monday, June 4, 2012
Transit of Venus!
There
will
be
a
"transit
of
Venus"
on
Tuesday,
June
5,
visible
from
throughout
the
USA.
(It
will
occur
on
June
6
in
Asia,
across
the
International
Date
Line.)
Venus
will
look
like
a
tiny
black
dot
on
the
Sun.
The
last
time
this
occurred
was
in
June
2004.
After
June
5,
2012,
to
see
the
transit
of
Venus
anywhere
on
Earth
you'll
need
to
wait
until
the
year
2117,
and
then
2125
–
no
kidding!
(The
previous
pair
of
Venus
transits
was
in
1874
and
1882.)
So,
I
suggest
you
see
it!
A transit of Venus occurs when Venus passes right between Earth and the Sun: it looks like a tiny black dot, about 1/30th the size of the Sun (more technically, about 1 arcminute in diameter), slowly going across the Sun. You'll be able to just barely see it with the unaided (but protected) eye, but a far better, magnified image will be visible if you look through binoculars (properly filtered) or a telescope (again, properly filtered). If you wish, you can get very nice, appropriate equipment at many stores, such as Scope City. Wherever you live, local amateur astronomy organizations and science centers will set up telescopes for public viewing, you'll just have to check online for locations. The Chabot Space and Science Centerin the Oakland hills is one such example.
In the Pacific Daylight Time (PDT) zone, the transit starts on June 5 at about 3:07 pm, though it will be hard to notice until around 3:24 pm. Mid-eclipse will be at 6:27 pm. In the San Francisco Bay Area, sunset occurs around 8:28 pm. The transit ends at 9:47 pm PDT, after sunset in California. As with the partial lunar eclipse above, if you are in other time zones, adjust the times accordingly. These times are, of course, approximate to within a few minutes, however they will depend slightly on your exact location within a time zone. So, progressively less of the transit will be visible the farther east you go in the USA.
Suppose you consider the Sun’s disk to be like the face of a clock when you look directly at it. As seen from San Francisco and most of the USA/Canada, Venus will begin to transit at roughly the 12 o’clock position (i.e., near the top of the Sun), but around sunset, Venus will be near the 4 o’clock position. More information on the event can be found at transitofvenus.org, and eclipse.gsfc.nasa.gov/OH/transit12.html.
Transits of Venus are historically important because observations of them in 1761 and 1769 from many different locations on Earth led to the first accurate (to within 2%) estimate of Earth's distance from Venus, and hence of Earth’s distance from the Sun (the “Astronomical Unit”) since the relative distances were already known. Viewed from a given location on Earth, the exact position of Venus’s silhouette depends on Venus’s distance, so one can solve for the distance using a bunch of measurements. Transits of Venus are important now because they illustrate the technique with which thousands of exoplanets are being found by the Kepler spacecraft: the total brightness of a star periodically drops a tiny bit while an exoplanet transits across its disk, as seen by us. If you monitor a star’s brightness and notice a slight periodic dimming, you’ve probably detected an exoplanet.
If you are planning on looking directly at the Sun, remember that you need proper eye protection or you could permanently damage your eyes! Use "Shade 14 welder's glass" (available at welding supply stores) or some other safe filter which blocks 99.999% of the Sun's rays at visible, ultraviolet, and infrared wavelengths. Appropriate "eclipse glasses" can also be found and purchased online for just a few dollars (comparable to Shade 14 welder's glass, but less durable). Regular sunglasses or smoked glass won't suffice by a long shot.
Without magnification, the black silhouette of Venus will be barely visible to the naked eye, or possibly even invisible, depending on your visual acuity. A magnified view will be much better. If you have a sufficiently small pair of binoculars, you can securely tape a piece of Shade 14 glass across the front end (so that light goes through the filter before entering the binoculars). Many local amateur astronomy clubs and science centers will have properly filtered telescopes for public viewing, providing a magnified image. I encourage you to visit them and watch the transit safely.
Source: culture-and-current-affairs.com
A transit of Venus occurs when Venus passes right between Earth and the Sun: it looks like a tiny black dot, about 1/30th the size of the Sun (more technically, about 1 arcminute in diameter), slowly going across the Sun. You'll be able to just barely see it with the unaided (but protected) eye, but a far better, magnified image will be visible if you look through binoculars (properly filtered) or a telescope (again, properly filtered). If you wish, you can get very nice, appropriate equipment at many stores, such as Scope City. Wherever you live, local amateur astronomy organizations and science centers will set up telescopes for public viewing, you'll just have to check online for locations. The Chabot Space and Science Centerin the Oakland hills is one such example.
In the Pacific Daylight Time (PDT) zone, the transit starts on June 5 at about 3:07 pm, though it will be hard to notice until around 3:24 pm. Mid-eclipse will be at 6:27 pm. In the San Francisco Bay Area, sunset occurs around 8:28 pm. The transit ends at 9:47 pm PDT, after sunset in California. As with the partial lunar eclipse above, if you are in other time zones, adjust the times accordingly. These times are, of course, approximate to within a few minutes, however they will depend slightly on your exact location within a time zone. So, progressively less of the transit will be visible the farther east you go in the USA.
Suppose you consider the Sun’s disk to be like the face of a clock when you look directly at it. As seen from San Francisco and most of the USA/Canada, Venus will begin to transit at roughly the 12 o’clock position (i.e., near the top of the Sun), but around sunset, Venus will be near the 4 o’clock position. More information on the event can be found at transitofvenus.org, and eclipse.gsfc.nasa.gov/OH/transit12.html.
Transits of Venus are historically important because observations of them in 1761 and 1769 from many different locations on Earth led to the first accurate (to within 2%) estimate of Earth's distance from Venus, and hence of Earth’s distance from the Sun (the “Astronomical Unit”) since the relative distances were already known. Viewed from a given location on Earth, the exact position of Venus’s silhouette depends on Venus’s distance, so one can solve for the distance using a bunch of measurements. Transits of Venus are important now because they illustrate the technique with which thousands of exoplanets are being found by the Kepler spacecraft: the total brightness of a star periodically drops a tiny bit while an exoplanet transits across its disk, as seen by us. If you monitor a star’s brightness and notice a slight periodic dimming, you’ve probably detected an exoplanet.
If you are planning on looking directly at the Sun, remember that you need proper eye protection or you could permanently damage your eyes! Use "Shade 14 welder's glass" (available at welding supply stores) or some other safe filter which blocks 99.999% of the Sun's rays at visible, ultraviolet, and infrared wavelengths. Appropriate "eclipse glasses" can also be found and purchased online for just a few dollars (comparable to Shade 14 welder's glass, but less durable). Regular sunglasses or smoked glass won't suffice by a long shot.
Without magnification, the black silhouette of Venus will be barely visible to the naked eye, or possibly even invisible, depending on your visual acuity. A magnified view will be much better. If you have a sufficiently small pair of binoculars, you can securely tape a piece of Shade 14 glass across the front end (so that light goes through the filter before entering the binoculars). Many local amateur astronomy clubs and science centers will have properly filtered telescopes for public viewing, providing a magnified image. I encourage you to visit them and watch the transit safely.
Saturday, June 2, 2012
Upcoming Partial Lunar Eclipse
On
the
morning
of
Monday,
June
4,
there
will
be
a
partial
eclipse
of
the
full
moon
in
the
few
hours
before
sunrise.
About
a
third
of
the
Moon
will
enter
the
Earth’s
dark
shadow,
starting
at
3:00
am
PDT
and
ending
at
5:06
am
PDT
(mid-‐eclipse
at
4:03
am
PDT).
No
optical
aid
is
needed
to
view
the
eclipse,
though
binoculars
or
telescopes
will
provide
a
magnified
view.
There
is
no
danger
when
viewing
a
lunar
eclipse
with
the
naked
eye,
binoculars,
or
telescopes;
filters
are
not
needed
(unlike
the
case
for
a
partial
solar
eclipse).
Just
go
outside
wherever
you
are,
and
take
a
look!
But
some
local
astronomy
clubs
and
science
centers
(such
as
the
Chabot Space and Science Center in
the
Oakland
hills)
will
hold
official
public
viewing
sessions;
check
online.
The entire easily visible part of the eclipse (when the Moon is in the Earth’s “umbra,” or full shadow) will be visible from California. As seen from the central USA, moonset will occur during the eclipse. The eastern US will basically miss out on this eclipse, since it will begin around or after moonset. West of California (say, in Hawaii), the entire eclipse [penumbra (partial, bright shadow) and umbra (full, dark shadow)] will be visible with the Moon high in the sky. For more information, see http://eclipse.gsfc.nasa.gov/OH/OH2012.html#LE2012Jun04P (courtesy of Fred Espenak, NASA’s GSFC.
The entire easily visible part of the eclipse (when the Moon is in the Earth’s “umbra,” or full shadow) will be visible from California. As seen from the central USA, moonset will occur during the eclipse. The eastern US will basically miss out on this eclipse, since it will begin around or after moonset. West of California (say, in Hawaii), the entire eclipse [penumbra (partial, bright shadow) and umbra (full, dark shadow)] will be visible with the Moon high in the sky. For more information, see http://eclipse.gsfc.nasa.gov/OH/OH2012.html#LE2012Jun04P (courtesy of Fred Espenak, NASA’s GSFC.
Monday, May 21, 2012
Photos: Yesterday's Eclipse
DiscoveryNews: Eclipse Over Idaho
Gardnerville, Nevada. (Photo: Cathleen Allison / AP via The Guardian)
DiscoveryNews: Eclipse in Gilbert, AZ as seen through a Fox 10 News camera.
Friday, May 18, 2012
Rare Annular Eclipse
A rare "annular eclipse" of the Sun will occur in our area (northern California) in the late afternoon of May 20, 2012. I encourage you to see it, regardless of whether you can be within the narrow path where the "ring of fire" will be visible. (You will at least see a deep partial eclipse of the Sun, if you are in the western US.)
An annular solar eclipse occurs when the Sun, Moon, and Earth are lined up, but the Moon is farther than average from Earth, so it looks a bit too small to fully cover the Sun. Thus, if you are at one of the right places (see the below map), the Sun will form a ring, or annulus, around the Moon. It's a special form of a partial solar eclipse that's cool to see (though not nearly as dramatic and mind-blowing as a total solar eclipse). You can view a map showing the eclipse path in detail here.
Online, you can zoom in on it and find specific locations from which the eclipse will be visible. Click on the location to find times, etc. Note that "UT" is "Universal Time" (the time in Greenwich, UK), and right now it is 7 hours ahead of PDT. So, for example, I find that in northern CA, the middle of the eclipse will occur around 6:28 pm PDT on May 20 (1:28 am UT on May 21), and the annular phase will last about 4.5 minutes if you are near the "centerline." (Note: the non-annular partial phases will last much longer, a couple hours total: 5:20 pm to 7:34 pm, plus or minus a few minutes, depending on exactly where you are.)
The centerline (from which the Moon will appear perfectly centered on the Sun at mid-eclipse) is the orange curve, and the blue lines mark the northern and southern edges of the path of annularity; outside the blue lines, you'll see a partial solar eclipse but not a complete annulus or ring. So, try to go to a favorable location, within the brown swath. Choose your location wisely! You can find a summary graph that shows the percent cloudiness along the path here.
Oroville in CA (near Chico) has great odds, it seems: just 11% cloudiness. But it isn't super close to the centerline; Redding and Mt. Shasta are closer, but have somewhat worse odds. If you are between the two red lines, you'll see a complete "ring of fire." Outside that band, you'll see a partial eclipse, but not a full ring. You don't have to be right on the centerline, by the way -- just within the swath, if you want to see the "ring of fire," though it will last longer if you are closer to the centerline.
More info about weather patterns is given here at the following websites:
http://home.cc.umanitoba.ca/~jander/ase2012/ase12intro.htm
http://home.cc.umanitoba.ca/~jander/ase2012/climate.htm
Have fun viewing the annular eclipse, but be sure to view it safely! And if you can't get to the path of annularity (the brown swath in the map), at least view the regular partial eclipse from wherever you happen to be at the time (late afternoon on May 20), if it's visible.
An annular solar eclipse occurs when the Sun, Moon, and Earth are lined up, but the Moon is farther than average from Earth, so it looks a bit too small to fully cover the Sun. Thus, if you are at one of the right places (see the below map), the Sun will form a ring, or annulus, around the Moon. It's a special form of a partial solar eclipse that's cool to see (though not nearly as dramatic and mind-blowing as a total solar eclipse). You can view a map showing the eclipse path in detail here.
Online, you can zoom in on it and find specific locations from which the eclipse will be visible. Click on the location to find times, etc. Note that "UT" is "Universal Time" (the time in Greenwich, UK), and right now it is 7 hours ahead of PDT. So, for example, I find that in northern CA, the middle of the eclipse will occur around 6:28 pm PDT on May 20 (1:28 am UT on May 21), and the annular phase will last about 4.5 minutes if you are near the "centerline." (Note: the non-annular partial phases will last much longer, a couple hours total: 5:20 pm to 7:34 pm, plus or minus a few minutes, depending on exactly where you are.)
The centerline (from which the Moon will appear perfectly centered on the Sun at mid-eclipse) is the orange curve, and the blue lines mark the northern and southern edges of the path of annularity; outside the blue lines, you'll see a partial solar eclipse but not a complete annulus or ring. So, try to go to a favorable location, within the brown swath. Choose your location wisely! You can find a summary graph that shows the percent cloudiness along the path here.
Oroville in CA (near Chico) has great odds, it seems: just 11% cloudiness. But it isn't super close to the centerline; Redding and Mt. Shasta are closer, but have somewhat worse odds. If you are between the two red lines, you'll see a complete "ring of fire." Outside that band, you'll see a partial eclipse, but not a full ring. You don't have to be right on the centerline, by the way -- just within the swath, if you want to see the "ring of fire," though it will last longer if you are closer to the centerline.
More info about weather patterns is given here at the following websites:
http://home.cc.umanitoba.ca/~jander/ase2012/ase12intro.htm
http://home.cc.umanitoba.ca/~jander/ase2012/climate.htm
Have fun viewing the annular eclipse, but be sure to view it safely! And if you can't get to the path of annularity (the brown swath in the map), at least view the regular partial eclipse from wherever you happen to be at the time (late afternoon on May 20), if it's visible.
Wednesday, May 9, 2012
Do You Feel the Attraction?
Why are people so drawn to magnets? (Bad pun, I know.) Magnets truly are fascinating, and a mini-movie was filmed at the NASA Space Sciences Laboratory, UC Berkeley, in 2007 showing just the amazing research that goes on regarding magnetic forces. Everything shown in the movie takes place around those laboratories as the scientists describe their research and discoveries. These scientists develop and conduct experiments and instruments to study the magnetic fields above the sun and to create theoretical models.
The site describes the movie saying, "Magnetic Movie is the aquavit, something not precisely scientific but grants us an uncanny experience of geophysical and cosmological forces." Take a gander at the short movie, it's beautifully artistic and cleverly done.
The site describes the movie saying, "Magnetic Movie is the aquavit, something not precisely scientific but grants us an uncanny experience of geophysical and cosmological forces." Take a gander at the short movie, it's beautifully artistic and cleverly done.
Tuesday, May 8, 2012
Super Moon, Part Two
I hope everyone got a chance to check out the moon last Saturday! Here's a picture of it taken in North Berkeley with the moon over the Berkeley campus:
Monday, May 7, 2012
Map it out: An Interactive Map of the World
This morning I found a cool site featuring an interactive map called the Antipodes Map. What you can do is find your home (or any other place on the map) and the map will show its antipode - meaning the spot on the earth of which it is diametrically opposite. As the site explains, "Two points which are antipodal to one another are connected by a straight line through the centre of the Earth."
Therefore, if you click on, or move the original map, you can set a marker on a desired location. The antipode map will automatically show its antipodal location. So what can you use this for? Well, most importantly, it will show you where if you dug straight through the earth you'd end up (provided of course you were able to withstand all the radiation, heat, and intense compression you would experience).
Therefore, if you click on, or move the original map, you can set a marker on a desired location. The antipode map will automatically show its antipodal location. So what can you use this for? Well, most importantly, it will show you where if you dug straight through the earth you'd end up (provided of course you were able to withstand all the radiation, heat, and intense compression you would experience).
Friday, May 4, 2012
"Super Moon"
Tomorrow, Saturday May 5, there will be a "super moon." This means that the moon will be full when it happens to be at "perigee," which is the closest approach to Earth in its elliptical orbit. The full moon will look unusually large, about 14% larger than when it is at "apogee" (the farthest point
from Earth in its elliptical orbit).
If you are interested in seeing it, try to look for it around moonrise, shortly after sunset (around 8pm), when it is close to the horizon. Furthermore, a psychological effect (still not fully understood) makes it look even bigger then. No Shade 14 glass or any other equipment is needed to safely view the moon (but not the Sun!).
from Earth in its elliptical orbit).
If you are interested in seeing it, try to look for it around moonrise, shortly after sunset (around 8pm), when it is close to the horizon. Furthermore, a psychological effect (still not fully understood) makes it look even bigger then. No Shade 14 glass or any other equipment is needed to safely view the moon (but not the Sun!).
Wednesday, May 2, 2012
The Most Astounding Fact, Part Two
On March 5 I posted a link to a video featuring Neil DeGrasse Tyson, titled The Most Astounding Fact. In the past month or so, this video has appeared repeatedly on Facebook as a beautiful and inspirational speech regarding the universe. Well, now the artist behind Zenpencils has taken that video and cartoonized it, and I think it's worth a look. Take a look here.
From the Zenpencils website: "I kept putting off trying to adapt this quote because it was too intimidating. I knew that it would require me to draw stars and planets which I’m not very comfortable with, but I loved the quote so much that I just had to try it. I spent a lot longer than usual working on the cosmic scenes and I’m pretty happy with how they turned out. I guess I was also inspired by the film The Tree of Life which connects the story of a family with the history of the Universe."
From the Zenpencils website: "I kept putting off trying to adapt this quote because it was too intimidating. I knew that it would require me to draw stars and planets which I’m not very comfortable with, but I loved the quote so much that I just had to try it. I spent a lot longer than usual working on the cosmic scenes and I’m pretty happy with how they turned out. I guess I was also inspired by the film The Tree of Life which connects the story of a family with the history of the Universe."
Tuesday, April 24, 2012
Planet Earth
In anticipation of Planet Earth's return to BBC America, this video was released featuring young fans reading scripts and voicing over action on the screen. These are supposed to be narrator auditions for the Planet Earth series, and some of their youngest fans decide to try their hand at relaying wilderness scenes. However, Sir David Attenborough - the regular narrator - is a tough act to follow, even for kids. The results are hysterical.
Sunday, April 22, 2012
28th National Space Symposium
Last week was the 28th National Space Symposium attended by over 3,000 space professionals. The keynote speech was given by Dr. Neil deGrasse Tyson, director of the Hayden Planetarium and the host of COSMOS. It is an inspiring forty minutes of speech by Dr. Tyson, followed by twenty minutes of Q&A. It is definitely worth listening to, especially in a time when NASA is quickly losing all of its funding. Enjoy!
Thursday, April 19, 2012
The Retirement of Discovery
The space shuttle Discovery took one last flight leaving from NASA's Florida spaceport this past Tuesday (April 17). After thirty years of service, it is going on permanent display at the Smithsonian Institution's National Air and Space Museum just outside Washington, D.C. Discovery was the leader of NASA's space shuttle fleet and, having launched in 1984, the oldest of the three shuttles remaining. Both Columbia and Challenger debuted earlier, but were lost along with their crews in tragic accidents.
Discovery is known as the world's most often flown spacecraft, having flown thirty-nine space missions and traveling a distance that is the equivalent of over 300 flights to the moon and back. Even more impressively perhaps is that it is the shuttle responsible for deploying the Hubble Space Station in April, 1990.
Eager viewers were able to snap photos on Tuesday as Discovery made its last flight, seen here on top a modified Boeing 747 jet.
Discovery is known as the world's most often flown spacecraft, having flown thirty-nine space missions and traveling a distance that is the equivalent of over 300 flights to the moon and back. Even more impressively perhaps is that it is the shuttle responsible for deploying the Hubble Space Station in April, 1990.
Eager viewers were able to snap photos on Tuesday as Discovery made its last flight, seen here on top a modified Boeing 747 jet.
Wednesday, April 4, 2012
Scientists develop ultra-thin solar cells
Today, Austrian and Japanese scientists have unveiled solar cells thinner than a thread of spider silk. These cells are still flexible enough to be wrapped around a single human hair. In the article on Physorg, Sekitani, from the University of Tokyo and one of the lead researchers, said the team hoped to increase the rate at which the device converts sunlight into electricity and put it to practical use in around five years.
So, what impact does this have on solar energy powered cars? Couldn't a car store the energy saved all day to charge the battery for later use?
Ignoring clouds, the daily average irradiance for the Earth is approximately 250 W/m2 . A Toyota Camry is 4.805m long and 1.820m wide, for a total top area of ~8.75m2 . That means every hour in the sun absorbs 2188W. Eight hours in the sun would get you 17,504 Wh.
But we have to take inefficiency in solar tech into account, which is currently around 10-20% efficient for most commercially available types. So we're only getting at most 3500Wh or 3.5kWh. Also that assumes no clouds and direct overhead sunlight, which is not often available, but for the purpose of the calculation we'll comply with. The Tesla Model S gets about 3.5 miles/kWh from it's battery back.
So covering your entire car with solar cells and leaving it in the sun for an entire day would get you at most 12.25 miles, but probably a lot less as not all the cells would be lit at the same time, the sun wouldn't be directly overhead, and there could be inclement weather, etc.
Now we just need to get the battery tech up to spec with the solar cell tech. It's no accident that the Oil & Gas giants have been scooping up patents to improved battery technology for years now. E.g. Chevron owning the large format NiMH patents. The truth is that while there is lots of anticompetitive and borderline illegal behavior in the industry. After all, it's a fiercely competitive industry so not unexpected. However, generally things are improving.
Plenty of technology has been developed over the last 10 years that is well outside the grasp of the Oil conglomerates and the $/kWh (cost per kilowatt hour) of renewables is steadily declining as the non-renewables costs are steadily increasing. Renewables will probably reach price parity with non-renewables for large-scale energy generation in the next 5 years or so and forward thinking countries like Canada, Germany, Denmark, etc... are certainly speeding up the process with their generous renewables subsidies too. So fret not, renewables are here to stay.
So, what impact does this have on solar energy powered cars? Couldn't a car store the energy saved all day to charge the battery for later use?
Ignoring clouds, the daily average irradiance for the Earth is approximately 250 W/m2 . A Toyota Camry is 4.805m long and 1.820m wide, for a total top area of ~8.75m2 . That means every hour in the sun absorbs 2188W. Eight hours in the sun would get you 17,504 Wh.
But we have to take inefficiency in solar tech into account, which is currently around 10-20% efficient for most commercially available types. So we're only getting at most 3500Wh or 3.5kWh. Also that assumes no clouds and direct overhead sunlight, which is not often available, but for the purpose of the calculation we'll comply with. The Tesla Model S gets about 3.5 miles/kWh from it's battery back.
So covering your entire car with solar cells and leaving it in the sun for an entire day would get you at most 12.25 miles, but probably a lot less as not all the cells would be lit at the same time, the sun wouldn't be directly overhead, and there could be inclement weather, etc.
Now we just need to get the battery tech up to spec with the solar cell tech. It's no accident that the Oil & Gas giants have been scooping up patents to improved battery technology for years now. E.g. Chevron owning the large format NiMH patents. The truth is that while there is lots of anticompetitive and borderline illegal behavior in the industry. After all, it's a fiercely competitive industry so not unexpected. However, generally things are improving.
Plenty of technology has been developed over the last 10 years that is well outside the grasp of the Oil conglomerates and the $/kWh (cost per kilowatt hour) of renewables is steadily declining as the non-renewables costs are steadily increasing. Renewables will probably reach price parity with non-renewables for large-scale energy generation in the next 5 years or so and forward thinking countries like Canada, Germany, Denmark, etc... are certainly speeding up the process with their generous renewables subsidies too. So fret not, renewables are here to stay.
Sunday, April 1, 2012
Wind Map
Earlier today I came across something incredibly cool: a US Wind Map. It is an interactive map of the US with forecast winds shown across the country. These near-term forecasts are updated once per hour, with data from the National Digital Forecast Database. The website describes it as a "living portrait."
There are handy keys detailing the wind speeds on the side bar, along with a note of the top and average speeds. It's unfortunate that it isn't shown where the top speed occurs.
The site proudly states that it is not associated with any corporation and is, in fact, a personal art project. A disclaimer expounds, "We've done our best to make this as accurate as possible, but can't make any guarantees about the correctness of the data or our software. Please do not use the map or its data to fly a plane, pilot a boat, or fight wildfires." So while the map may be fun to look at, don't use it for anything serious!
There are handy keys detailing the wind speeds on the side bar, along with a note of the top and average speeds. It's unfortunate that it isn't shown where the top speed occurs.
The site proudly states that it is not associated with any corporation and is, in fact, a personal art project. A disclaimer expounds, "We've done our best to make this as accurate as possible, but can't make any guarantees about the correctness of the data or our software. Please do not use the map or its data to fly a plane, pilot a boat, or fight wildfires." So while the map may be fun to look at, don't use it for anything serious!
Monday, March 19, 2012
Jupiter and Io
The image above depicts Jupiter and its moon, Io. The tiny red dot on the surface of Io is a volcano, while the blue above it is the volcanic emissions. According to NASA, "The Io image, taken on March 1st 2007, is an approximately true-color composite taken by the panchromatic Long-Range Reconnaissance Imager (LORRI), with color information provided by the 0.5 µm (“blue”) and 0.9 µm (“methane”) channels of the MVIC."
Since Io 's discovery by Galileo in 1610, it has continuously been both confusing and amazing scientists. First of all, it's larger than our own moon, and is also the most volcanically active object in the solar system. Io is home to volcanoes that erupt liquid sulfur dioxide, and has a molten iron/iron sulfide core due to the immense tidal heating associated with orbiting so closely to Jupiter at roughly 350,000 km. This happens because the gravitational field of Jupiter is so powerful that it squeeze Io, and that the magma inside Io is pushed outside because of the amount of pressure it induces.
The magnetosphere of Jupiter sucks off the dust and gasses emanating from Ionian eruptions at a rate of about 1 tonne per second. It has no magnetic field of its own, but instead has a magnetosphere created by Jupiter's. This is turn induces an electrical current along the magnetic lines of force from Jupiter's north pole, through Io, and back to Jupiter's south pole, which in turn creates an auroral glow similar to Earth's aurora. It's orbit is encased in a plasma torus of high-energy radiation and ionized sulfur, sodium, oxygen, and chlorine. Io's orbit is eccentric, since Io has the moons Europa, Ganymede, and Callisto pulling it back.
Thursday, March 15, 2012
Happy (Belated) Pi Day!
In honor of Pi day, I thought I'd introduce you to a website dedicated to your favorite mathematical concept: Pi! The wife of one of my favorite professors at Cal, Alex Filippenko, created a website designed an educational and entertaining website, piZone.org, in order to promote National Pi Day as a day to celebrate the fun facts, trivia, and uses of pi.
From an email I received from Alex:
The site has various videos, interactive games, and even pi-related t-shirts –- everything a person needs to celebrate pi. Moreover, you can enter to win an iPad (whichshe calls a "Pi-Pad") or t-shirts; click on the "Play" button, or "like" piZone on Facebook. (No purchase is necessary to win.)
The website is her social mission, and it was created as a crowd-source resource. Under the "pi it forward" program, $3.14 from every t-shirt sale goes to provide a pi-related t-shirt to a K-12 teacher.
I invite you to visit the website or Facebook (piZone) and help share the pi.
-Alex
Check out the site, it's pretty pi-tastic! And, because I can't resist, in honor of Pi day, my favorite Pi riddle:
Question: What do you get if you divide the circumference of a jack-o-lantern by its diameter?
Answer: Pumpkin Pi!
Monday, March 12, 2012
Introducing TED-Ed:
TED Talks is rolling out their new program: TED-Ed. This is set to be a series of TED Talks, under ten minutes in length, whose intention is to potentially rival Khan Academy.
I think the idea is fabulous, and the more well funded, educational services out there and accessible by students, the better. From the video description: TED-Ed's mission is to capture and amplify the voices of great educators around the world. We do this by pairing extraordinary educators with talented animators to produce a new library of curiosity-igniting videos.
In fact, they make it simple for you to nominate a teacher or animator. This can be done here.
I think the idea is fabulous, and the more well funded, educational services out there and accessible by students, the better. From the video description: TED-Ed's mission is to capture and amplify the voices of great educators around the world. We do this by pairing extraordinary educators with talented animators to produce a new library of curiosity-igniting videos.
In fact, they make it simple for you to nominate a teacher or animator. This can be done here.
Monday, March 5, 2012
The Most Astounding Fact
Neil DeGrasse Tyson was asked by a reader of TIME magazine, "What is the most astounding fact you can share with us about the Universe?" This is his video response, an incredible and humbling take on the universe:
Saturday, February 11, 2012
Under the Microscope
The human body is an amazing instrument with the ability to heal itself from a variety of different maladies. A T cell (depicted in the video above) is one of the immune system's responses to external threats. These cells identify and attack diseased cells in order to eradicate them from the host's body. A cytotoxic T cell, which is what the above cell is classified as, exists with the single purpose of going around looking for cancerous cells, whereupon is eradicates them without causing any damage to the healthy cells in the area.
Thursday, February 9, 2012
The Vastness of the Universe
How big is the Universe? Well, what do you want to compare it to? After all, it's all relative. It's interesting to note that between the Planck length and the size of the known universe, humans (magnitude 100) are at about 65%, which means we're pretty huge.
A website developed by Cary Huang called Scale of the Universe allows for an interactive experience, whereupon the user can scroll in and out, all the way from Quantum Foam to the very edges of the observable universe.
I love the diversity of objects included, and the animations and text descriptions round out the experience nicely. It's an awe inspiring depiction of humans and our impact, but also of the limitations of what we know and can experience.
A website developed by Cary Huang called Scale of the Universe allows for an interactive experience, whereupon the user can scroll in and out, all the way from Quantum Foam to the very edges of the observable universe.
I love the diversity of objects included, and the animations and text descriptions round out the experience nicely. It's an awe inspiring depiction of humans and our impact, but also of the limitations of what we know and can experience.
Monday, February 6, 2012
The Earth at Night
This is an image of the world at night, thanks to NASA's Visible Earth, 2001. The various colors that can be seen are city lights, natural gas flares, wildfires, and lights from fishing fleets. (Disclaimer: Obviously, this is a compiled image since the earth is never all dark at once, nor is it flat...)
Thursday, February 2, 2012
Tuesday, January 24, 2012
Tuesday, January 17, 2012
Hand Sanitizer
Hand sanitizers claim to kill ~99% of bacteria. How does this work? Well, alcohol kills bacteria exponentially. For example, after x amount of time, 90% are dead. After 2x that time, 99%, 3x, 99.9%, and so on. As you can see from that math, you'll never 100% sterilize something using alcohol - at least not in a practical way. However, as far as getting germs off your hands, 99.9% is good enough. You're not looking to sterilize your hands (which is impossible), you're looking to cut down the risk of infection.
The 10% survivors in each instance aren't resistant, they're just lucky. Maybe they didn't get the full exposure to the alcohol, they had a little extra water in them, or they were in a clump. The effectiveness of a sanitizer is always dependent on the surface to which it is applied. If the alcohol can't get to the bacterium, it can't kill it. As such, human skin provides a lot of nooks and crannies in which bacteria could not be reached by the alcohol very well. This is why alcohol based hand rubs are only recommended on non-soiled hands. They aren't designed to penetrate dirt and gunk. Just like the ratio of bleach to water has to increase depending on the amount of blood (or protein) in a spill.
Also, while alcohol kills everything, it doesn't efficiently kill everything. Bacterial spores, bacteria with thick capsules, and nonenveloped viruses are fairly resistant to alcohol. For this reason, alcohol is never used as the only method when something needs to be completely sterile - we use fire, 10% bleach, formaldehyde, gamma rays, or autoclaving instead. Labs also use the aseptic technique when surfaces need to be 100% sterile. Please see the CDC take on handwashing and hand sanitizer.
Saturday, January 7, 2012
Methuselah
Methuselah is the oldest known living non-colonal organism in the world. It is 4,842 years old. It can be found in the Bristlecone Pine Forest near Death Valley. However, while it is open to tourists, nowhere does it say which tree is Methuselah; it's kept anonymous for its own security. According to the Wikipedia page, " Methuselah's exact location is undisclosed as a protection against vandalism." So while unlikely that the tree above is Methuselah, it is probably very similar to this one.
In 1964, when scientists were first beginning to realize just how old these trees were, they decided to do some core sampling. A graduate student doing the samples ended up getting his drill bit stuck in one of the trees. Rather than just leave it there, he decided to cut down the tree to retrieve it. Upon inspecting the age rings of said tree, it became apparent that the tree, nicknamed Prometheus, was well over 5,000 years old. This controversial felling is featured in an episode of Radiolab, appropriately titled "Oops."
Sunday, January 1, 2012
Subscribe to:
Posts (Atom)