Apparently, I’m on a physics kick as of late.
[Via Science Punk]
Apparently, I’m on a physics kick as of late.
[Via Science Punk]
April 11, 1954 was the most uneventful and boring day of the 20th century. Every day something of significance occurs, but nothing remarkable had happened on the said day in 1954, according to experts who inserted over 300 million important events of the century into a computer search programme to calculate.
This is kind of amazing. I’d love to see this parsed based on specific dates — for example, what was the most boring day (according to this algorithm) during my life? I’m sure there are a few dates in high school or college that come to mind.
[Via Daily Dish]
NPR’s science and culture blog has an interesting post up about why Pluto isn’t a planet and we should get over it. It’s something that I’ve been arguing about for a long time.
There are an estimated 70,000 KPOs (Kuiper Belt Objects) out there larger than 100 meters. More importantly, at least 3 KPOs are large enough for gravity to work its symmetric magic and pull rock and ice into a sphere. These are the newest class of solar system’s inhabitants the Dwarf Planets: Huamea, Makemake and, yes, Pluto.
With the discovery of the KPOs and, in particular, the KPO Dwarf Planets, Pluto lost any claim to being special. It was just one cinder-block in a field of cinder-blocks left over from building our solar system. It wasn’t even the biggest cinder block. In 2005 the dwarf planet Eris was found orbiting the Sun at distances beyond the Kuiper Belt in yet another new region of the solar system that astronomers call the Scattered Disk.
Face it, Pluto isn’t special.
[via Daily Dish]
Hah! Apparently, the American Museum of Natural History gets a lot of unhappy letters from children, unhappy that Pluto is no longer considered a planet.
Interestingly enough, the IAU has had a definition for what should be considered a planet that has been used since 2006:
The definition of “planet” set in 2006 by the International Astronomical Union (IAU) states that in the Solar System a planet is a celestial body that:
1. is in orbit around the Sun,
2. has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
3. has “cleared the neighborhood” around its orbit.
Oh man, a physics student at UC Davis has proposed that the number 1027 carry the prefix of “hella-“. As in a hellawatt, a hellagram, or a hellameter.
From the Urban Dictionary:
Originated from the streets of San Francisco in the Hunters Point neighborhood. It is commonly used in place of “really” or “very” when describing something.
The Fillmore is hella better than the Mission.
It’s amusing, but as someone who’s always found this distinctly Northern Californian word annoying, I can’t help but shake my head.
Regardless, if you’re interested in that sort of thing, you can join the group on Facebook.
(Via Cosmic Variance.)
Update: January 3rd, 2011 – A final update on 2010 numbers posted right here.
Damage in Santiago, Chile. Photo by Reuters/Marco Fredes
After the massive earthquake this past weekend in Chile, MSNBC published a sensationalistic piece entitled, “Is nature out of control?” The Wall Street Journal asked if three massive earthquakes around the world in two months are related and a cause for alarm. The mainstream media, always searching for sensationalistic or fear mongering news, has latched onto the question; are we seeing more earthquakes than normal?
Well, not really.
To better understand why, let’s take a look at how many earthquakes occur each year on average. The USGS has a fascinating page of earthquake facts and statistics, with the following table:
|8 and higher||1 ¹|
|7 – 7.9||17 ²|
|6 – 6.9||134 ²|
|5 – 5.9||1319 ²|
|4 – 4.9|| 13,000
|3 – 3.9|| 130,000
|2 – 2.9|| 1,300,000
¹ Based on observations since 1900.
² Based on observations since 1990.
For our analysis, let’s take earthquakes based in the magnitude 6.0 – 6.9 range. Why am I picking earthquakes in the M6 range? It’s arbitrary. You can repeat this process for earthquakes of any range. Based on data recorded since 1990, we’d expect to see an earthquake within this magnitude range occur every 2.7 days or so.
So here we are, on March 1st, 2010, the 60th day of the year. How many earthquakes in the M6.0 – M6.9 range have we had this year? According to this handy search tool from the USGS, there have been 25 earthquakes of M6.0 – M6.9 in 2010.
That works out to roughly one earthquake in the magnitude 6 range every 2.4 days. That doesn’t seem totally unreasonable or a reason for alarm, but we should do some further work to put it in context.
Total results: 21
Mean (average): 2.67143
Standard deviation: 0.41732
So, the number of magnitude 6 earthquakes that we’ve had in 2010 falls within one standard deviation of the mean. If we were to plot up a graph, it’d look like this. The error bars represent one standard deviation.
Awesome! Well, what about those ranges of values that fall outside of one standard deviation from the mean? For those that don’t understand how statistics works, check out the following bell curve from Wikipedia.
This shows roughly the percentage of values that you’d expect to fall within a specific standard deviation away from the mean value.
Dark blue is less than one standard deviation from the mean. For the normal distribution, this accounts for about 68% of the set (dark blue), while two standard deviations from the mean (medium and dark blue) account for about 95%, and three standard deviations (light, medium, and dark blue) account for about 99.7%.
So, if we modify our graph to show an error bar of 2 standard deviations, you’ll notice that every result since 1990 fits inside this model! Statistically speaking, you would expect to find 95% of all results falling within two standard deviations of your average. Simply put, there is absolutely nothing strange happening.
In fact, thanks to this normal curve you can basically predict, with a 99.7% chance of success (three standard deviations), that an earthquake of equal to or greater than M6.0 will occur somewhere around the world within the next 3.5 days. Update: Proven correct! A M6.4 earthquake occurred in Taiwan on March 3rd.
Alright, so what’s with all the coverage on earthquakes? It sure seems like a lot is happening, right? We can attribute this to observer bias. The massive devastation in Haiti warranted a large amount of news coverage. Because this is so fresh in everyone’s mind, people are more likely to notice any news or information related to earthquakes anywhere in the world. An earthquake of M6.0 or greater, usually garners international attention.
It’s the same principle that happens whenever you acquire some new toy, gadget, or piece of clothing. Suddenly, you notice that particular item around all the time. It’s like everyone has it.
So, bottom line, the Earth isn’t becoming more active, more dangerous, or even “out of control.” Despite the fear mongering and what esteemed mainstream media networks would have you believe, the simple reality is that the numbers prove things are happening at an expected rate. Keep that in mind the next time a large earthquake happens and everyone is wondering why the Earth seems so active!
Update (April 21, 2010): Chris Rowan at Highly Allochthonous has a great post on yearly earthquake averages and variability with larger magnitudes.
In the last 28 years, there have been on average around 13 such ‘significant’ earthquakes a year, with a magnitude 8 occuring about every year and a half. This average rate is marked by the grey line on the plot: if we extraplolate the six major earthquakes recorded in the first four months, 2010 is on course to experience 18 major earthquakes, a little above average but well within the variability shown by the whole dataset (and it’s actually closer to the centennial average of 16 major quakes a year reported by the USGS above).
Just saw this absolutely ridiculous article posted on Digg, by way of the Guardian: “Water vapour caused one-third of global warming in 1990s, study reveals.”
That’s gotta be one of the more sensationalist titles ever written in the climate change debate, which will help fuel and legitimize claims made by climate change deniers. Anyway, the article does have some interesting nuggets and things that should be discussed.
Scientists have underestimated the role that water vapour plays in determining global temperature changes, according to a new study that could fuel further attacks on the science of climate change.
The research, led by one of the world’s top climate scientists, suggests that almost one-third of the global warming recorded during the 1990s was due to an increase in water vapour in the high atmosphere, not human emissions of greenhouse gases. A subsequent decline in water vapour after 2000 could explain a recent slowdown in global temperature rise, the scientists add.
Basically, scientists need to do a better job modeling how water vapor plays a role in climate change. That said, there are few interesting things to consider, that this article fails to mention:
The second thing to consider is the relative impact each of these gases have on trapping heat. In general, all greenhouse gases are compared to CO2 (which has a value of 1.0). This is called the global warming potential.
Methane is 25x stronger at trapping heat than carbon dioxide! Again, the atmospheric concentration of both of these gases is increasing. What is water vapor’s effect on trapping heat?
A GWP is not usually calculated for water vapour. Water vapour has a significant influence with regard to absorbing infrared radiation (which is the green house effect); however its concentration in the atmosphere mainly depends on air temperature. As there is no possibility to directly influence atmospheric water vapour concentration, the GWP-level for water vapour is not calculated.
This video of The Known Universe is from the American Museum of Natural History’s Hayden Planetarium in New York City, and zooms out from the mountains of Tibet, showing every single satellite (artificial and not), star, and known galaxy in the universe. Absolutely incredible!
My immediate reaction on seeing this video was thinking back to the Powers of 10 video that I saw in a junior high math class, probably around 1995 or so.