Japan Earthquake May Have Shifted Earth's Axis 253
Zothecula writes "Using a complex model to perform a theoretical calculation based on a US Geological Survey, Richard Gross of NASA's Jet Propulsion Laboratory has determined that by changing the distribution of the Earth's mass, the earthquake that devastated Japan last Friday should have sped up the Earth's rotation, resulting in a day that is about 1.8 microseconds (1.8 millionths of a second) shorter."
On the positive side... (Score:5, Funny)
... the work day got about 0.6 microseconds shorter, woo! Oh, wait....
Re:On the positive side... (Score:5, Funny)
That's coming out of your paycheck.
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Can we all face the fact this is a HUGE government coverup?
I think we now have proof that there is a Godzilla, and this is all Godzilla related turmoil. Sheesh..can we not get a senate investigative committee together?
I mean, if they're willing to put so much time, money and effort into steroids in baseball, surely we rate at least as much time into the Godzilla effect?
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AIUI deviations between the earths rotation and the SI second are grouped up and presented in the form of leap seconds (which may be either positive or negative) at midnight UTC. Whether these come during the working day or not will vary depending on where you live.
2 microseconds per day is a pretty small change though. Other changes such as the gradual slowing of the earths rotation will have a far more significant impact on the frequency of leap seconds (assuming that is that the proposal to make civil ti
Damn! (Score:2)
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It won't add up to a whole second for about 1711.2 years.
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So what? Some of us prefer to be ahead of time.
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Isn't a second defined to be 1/60th of a minute which is 1/60th of an hour, which is 1/24th of a day? And a day is the amount of time it takes for the sun to revolve around the earth. For this reason, it won't add up at all since this change will have redefined what a second is.
- queue sound of crickets chirping -
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Isn't a second defined to be 1/60th of a minute which is 1/60th of an hour, which is 1/24th of a day? And a day is the amount of time it takes for the sun to revolve around the earth. For this reason, it won't add up at all since this change will have redefined what a second is.
- queue sound of crickets chirping -
Is there a bunch of crickets lined up waiting to make sound?
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Yes. It's not easy to keep them all in order, and training them is not the easiest thing to do either. Not even bringing the relatively short lifespan of them into it!
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But either statement is not related (regardless of your frame of reference). One governs year, the other day.
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And what does that have to do with the heliocentric or geocentric rotation? That's on the scale of a year, not a day. We are apparently thinking of different yet similar things here...
further to the point though - the argument is garbage. Gravity, inertia etc all back up the fact that it is the earth moving about the sun, with the other planets. Your perspective doesn't change fact, only color your perception of it.
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Straignt-line unaccelerated motion is relative. Rotation is absolute. You can tell from the forces involved.
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No. The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom (at rest and at 0K). Which will not have changed due to an earthquake.
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I'm just hoping it means I won't have to adjust my watch so often any more.
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And the Earth's rotation isn't constant anyways. http://www.cv.nrao.edu/~rfisher/Ephemerides/earth_rot.html [http] The second is (as posted by others) constant.
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If kids go home and spouting off facts like the earth does not rotate around the sun, parents tend to get really upset and start complaining.
One of my most profound insights into my (American) education came when my high school physics teacher explained that to me. Teachers don't just teach kids facts; they have to teach kids truths that their parents accept, or be very prepared to explain gravitation to an well-meaning but under informed parent.
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We're moving to metric where it makes sense, slowly - liquid volume, weight, most scientific measurements - but staying with Imperial where that makes sense - namely, length.
SI/Metric make sense when you're doing lots of complex computations and unit conversion, but when you're measuring a 2x4, it's far easier to divide 4' 3 3/8" by 2 than it is to divide 1.267 meters by 2.
(I have no idea if those measurements are close, I pulled them out of the air.)
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One day, some day, the US elementary education system will move to the metric system. But as long as parents expect teachers to teach what they know and use, it will never happen.
Never! You can have my feet when you pry them from my cold, dead legs!
Know your reader (Score:5, Funny)
Did I read that correctly? Did the summary explain to us what a microsecond is?
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If the Système international had a swimsuit edition there'd be much more interest in science. Among males, anyway. But hey, I'd go for equal time for guys in Speedos if it'll bring more females into science.
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http://www.google.com/images?q=ubuntu+calendar [google.com]
(Likely NSFW) It didn't work too well with Ubuntu, apparently.
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It's enough for most of us to abstract that out. There is one AU of distance between the Earth and the Sun, mm is
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mm is larger than a nm is larger than a um.
Hah. Way to illustrate the point.
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A biologist ... He is not dumb, after all, he is a biologist. It would have taken him less than two minutes to understand the exponent notation
I'm sorry how does one work in a science related field and not understand exponent notation - and even if they did why would it take anywhere near two minutes for them to understand it?
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thats kinda scary to me.. i just went and looked up the math requirements for Cell Biologist degree.. basically intro to calc one and some stats classes, but then based on the number of chem classes they should know exponent notation..
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You're forgetting about leap microseconds!
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Yes, but how many microseconds are in a microscope?
What's a second? (Score:2)
1.8 microseconds (1.8 millionths of a second)
Second? I don't care for a second, the second is the first loser!
What I want to know is who is on first.
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Did I read that correctly? Did the summary explain to us what a microsecond is?
Only on Slashdot will a summary explain an easily parsed term, yet another summary will simply assume a technical word from some obtuse field known to a few hundred people is common knowledge (and so be left uninterpreted).
Damn "fair and balannced" journalists. (Score:2)
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Nope, your apple isn't going to do it (Score:2)
Simple equal and opposing forces.
Now, on the other hand, if you lay down on the floor from a standing position, you have had an impact on speeding up the rotation of the Earth.
Ultimately the net effect of all of us moving ourselves (and apples) around all day has little cumulative effect. However, if you engage in the fun activity of burning petrol in your automobile, which was once deep in the ground, you have actually contributed to change in the Earth's rotation. Also, if you climb a hill, pick up a ha
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Does the axis shift if it can't be measured?
That depends on whether we're trying to prove that our policies are "stable and determined" or "flexible and intelligent" today. It's all a matter of communication priorities you see.
Just when you think you're having a good day... (Score:5, Funny)
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We got shifted by our own planet. Go figure.
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Shifting the axis? (Score:5, Informative)
Apparently, the axis that shifted is that of mass, called the Figure Axis, meaning the axis of symmetry in the Earth's mass distribution. We're still rotating in the same direction (defined by an axis which is not the Figure one), though.
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It's like what happens when a figure skater moves their arms closer to their body. Their mass has shifted and they don't wobble but they do spin faster.
Since the earth didn't actually gain any new mass, I assume it had been slowing down as subduction shifted the crust in the build-up to the quake. Correct? Or did the shape of the globe change such that the north and south poles are now a tiny bit further apart, while the circumference at the equator shrank?
Doom, doom, DOOOOOOOM! (Score:3)
Eh, it's just God setting us up for 2012. Just needed to tweek the axis a bit before he could start destroying us all. It's like tuning a set of rabbit ears on an old television.
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>>>It's like tuning a set of rabbit ears on an old television.
Old??? Hey! Some of us still use "rabbit ears" aka antennas, you insensitive clod!
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Ditto. I use OTA for my DTV feeds since I am under 20 miles from the transmitters. :)
Comment removed (Score:5, Informative)
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The older I get and the more I learn, the more I appreciate straightforward explanations of things in laymans terms.
My noggin only has so much storage. Having to remember the academically approved (sometimes obscure) technical terms for every phenomena in physics is a burden.
GPS affected? (Score:3, Interesting)
But seriously, does this have an effect on GPS? GPS satellites need to be corrected for relativistic effects that cause their clocks to tick 38 microseconds/day different than the ground; which would cause error to accumulate at 10km/day. Does 1.8 microsecond difference in our day cause error to accumulate in GPS at the rate of 0.5km/day if not fixed?
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You're certainly right to an extent. What you imply is a special event is in fact the daily bread and butter of keeping up a positioning system satellite constellation. The GPS system's frame of reference is being constantly kept in sync with Earth's rotation. After all, the satellites are simply orbiting the Earth in some arbitrary orbits, and the ground stations constantly monitor their orbits. The orbital data -- the ephemerides -- are broadcast to GPS receivers. The net effect of changing Earth's rotati
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A very small and temporary one. When effects like this are discovered, the ground stations uplink corrections to the birds which then downlink them to your GPSr.
This opens up possibilities (Score:2)
In the news: Angular momentum conserved! (Score:5, Interesting)
Newton still right!
Basic principles of mechanics remain sound!
Film at eleven.
The speed of the Earth's rotation changes every time I ride an elevator, too. (Please resist the temptation to make a fat joke here; it's too obvious to be worth the trouble.) On a more impressive scale, there's a significant and variable amount of angular momentum stored in the atmosphere. Changes in major air currents year over year (things like El Nino, for instance) can change the length of the day by close to a millisecond: hundreds of times more than this little earthquake.
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The speed of the Earth's rotation changes every time I ride an elevator, too.
That depends on the type of elevator.
If it's counterweighted, not so much, and possibly not at all if it's balanced for the payload of one passenger weighing the same as you.
If it's a telescoping or wall-riding type, far more, because then the mass of the elevator itself also counts.
Nice to refocus on a longer term view but... (Score:2)
If you live on a mostly island nation, there is nowhere to run , nowhere to hide
Personally, as an atheist, i'm tempted to pray for my (potentially future) friends over there
Different cultures, they don't matter...
Even now in the 21st century on earth we can have our "chestnuts" rattled quite easily
5.2,5.3 richter here in athens feels like nothing at all to worry about....
and btw, don't forget our new zealand friends who are f
immeasurably small (Score:2)
hmm second shift (Score:2)
Great (Score:2)
Now my iPod *really* won't wake me up in time!
Will this affect GPS? (Score:2)
Re:It's a dupe! (Score:4, Funny)
"People of Earth, at 18:00 GMT March 10 we all jump at the same time and regain our microsecond!"
Hm, maybe I should have changed the date on that one.
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Great! I can go home a few microseconds early today. [slashdot.org]
Hope this works, I need the karma!
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Now i will live more miliseconds.
not too smart this one, kinda like what's heavier a pound of feathers or a pound of bricks.
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We do use imperial in the UK for a few things - speed limits, beer - but most measurements are metric now.
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It doesn't help that there are about six completly different measuresments call the 'ton' or 'tonne.' The metric system was introduced to replace the terrible mess of often contradictory units that were in use before - and remain in use in the UK, and just about nowhere else.
We do use imperial in the UK for a few things - speed limits, beer - but most measurements are metric now.
Fortunately the US has adopted a simpler, more consistent set of measurements. For example, my car gets 40 rods to the hogshead, and that's the way I likes it!
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A pound of bricks is heavier.... Try dropping it on your toes :-P
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Each time a meteorite hits the moon, it shifts it slightly which might likely have a bigger impact on earth than human activity does (affecting tides and waves). Also dinosaurs were MUCH bigger that humans. Defecating Brachiosaurus were likely the first cause of global warming (being endotherms).
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On the grand scale of things, we don't play that big of an impact on a geological scale. Mother nature is a lot more awesome than anything we could come up with.
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Well, I guess he could be wrong, or you could be wrong?
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Just because water rose up due to a plate under it rising doesn't mean something else that was heavier didn't go under that plate. That would decrease the moment of inertia. After all, this was due to a plate sliding under another plate.. (Not saying that is just what happened, but there may be other factors.)
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As the article explains, the water is moved closer to the earth's axis despite being at a higher altitude. The north pole, for instance, is zero distance from the axis.
This is due to the majority of reservoirs being further away from the equator than the majority of the water sources and thus water is being moved closer to the axis.
Melting land-based ice caps certainly would slow rotation, but this is because they are at the poles, not because they are higher up.
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Also, what if someone wanted to deliberately slow down the earth's rotation? Say, by turning a motor against it?
I did a quick back-of-the-envelope calculation that suggests someone could slow down the earth's rotation by 5% by spending $30 billion on electricity to turn a motor in the appropriate direction.
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I didn't mean the rotor would press against the earth (like a moving gear). If you just attached it to a frame and had electricity flow in to power it, then the alternating magnet on the stator would apply a moment on the magnet, and a moment in the opposite direction on the frame. As long as the frame doesn't rotate relative to the ground, there is another opposite moment at its interface with the earth's surface.
Or did I just really doze off in my reasoning there?
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Well, if you climb a mountain, or move towards the equator, you will slow down the earth's rotation.
This in turn reduces the centrifugal force, and makes everybody slightly heavier.
Lawsuits will follow.
Lake Victoria (Score:2)
The largest hydroelectric power plant reservoir in the world is actually a natural lake, lake Victoria in Uganda. This lake serves the reservoir for the Nalubaale (formerly Owens Falls) dam [nasa.gov].
The large total volume of water and the fact that it's located at the equator makes it the reservoir with most influence on the earth's rotation rate.
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That's not 'sleeping', that's 'dead'.
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Nope, that's a euphemism.
Which, in this case "That's not 'sleeping', that's 'dead'." still applies. :-P
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He's not dead, he's just pining for the Chryslers.
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You'd have to be on crack [huffingtonpost.com] to make that kind of mistake.
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http://en.wikipedia.org/wiki/Angular_momentum#Conservation_of_angular_momentum [wikipedia.org]
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The leap year is to correct for the Earth's not revolving around the Sun in an even number of days. It has nothing to do with compensating for the Earth's rotation. The leap second, however, is used to compensate for the Earth's not rotating exactly 360 degrees in one "day."
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