How Quicksand Works

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With quicksand, the more you struggle in it the faster you will sink. If you just relax, your body will float in it because your body is less dense than the quicksand.

How many times have you watched a movie where the hero is sucked down into a pit of quicksand, only to be saved at the last minute by grabbing a nearby tree branch and pulling himself out?

If you believed what you saw in movies, you might think that quicksand is a living creature that can suck you down into a bottomless pit, never to be heard from again. But no — the actual properties of quicksand are not quite those portrayed in the movies.

Quicksand is not quite the fearsome force of nature that you sometimes see on the big screen. In fact, the treacherous grit is rarely deeper than a few feet.

It can occur almost anywhere if the right conditions are present. Quicksand is basically just ordinary sand that has been so saturated with water that the friction between sand particles is reduced. The resulting sand is a mushy mixture of sand and water that can no longer support any weight.

If you step into quicksand, it won’t suck you down. However, your movements will cause you to dig yourself deeper into it. In this article, you will learn just how quicksand forms, where it’s found and how you can escape its clutches if you find yourself hip-deep in it.

Next, we’ll find out how the ground shaking beneath your feet can lead to sand slipping beneath your weight.
What’s Quicksand?

Quicksand is an interesting natural phenomenon — it is actually solid ground that has been liquefied by a saturation of water. The “quick” refers to how easily the sand shifts when in this semiliquid state.

Quicksand is not a unique type of soil; it is usually just sand or another type of grainy soil. Quicksand is nothing more than a soupy mixture of sand and water. It can occur anywhere under the right conditions, according toDenise Dumouchelle, geologist with the United States Geological Survey (USGS).

Quicksand is created when water saturates an area of loose sand and the ordinary sand is agitated. When the water trapped in the batch of sand can’t escape, it creates liquefied soil that can no longer support weight. There are two ways in which sand can become agitated enough to create quicksand:

Flowing underground water – The force of the upward water flow opposes the force of gravity, causing the granules of sand to be more buoyant.
Earthquakes – The force of the shaking ground can increase the pressure of shallow groundwater, which liquefies sand and silt deposits. The liquefied surface loses strength, causing buildings or other objects on that surface to sink or fall over.

Vibration tends to enhance the quickness, so what is reasonably solid initially may become soft and then quick, according to Dr. Larry Barron of the New South Wales Geological Survey.

The vibration plus the water barrier reduces the friction between the sand particles and causes the sand to behave like a liquid. To understand quicksand, you have to understand the process of liquefaction. When soil liquefies, as with quicksand, it loses strength and behaves like a viscous liquid rather than a solid, according to the Utah Geological Survey. Liquefaction can cause buildings to sink significantly during earthquakes.

While quicksand can occur in almost any location where water is present, there are certain locations where it’s more prevalent. Places where quicksand is most likely to occur include:

Riverbanks
Beaches
Lake shorelines
Near underground springs
Marshes

The next time you’re at the beach, notice the difference in the sand as you stand on different parts of the beach that have varying levels of moisture. If you stand on the driest part of the beach, the sand holds you up just fine. The friction between the sand particles creates a stable surface to stand on.

If you move closer to the water, you’ll notice that the sand that is moderately wet is even more tightly packed than the dry sand. A moderate amount of water creates the capillary attraction that allows sand particles to clump together. This is what allows you to build sand castles.

But beach sand could easily become quicksand if enough water were thrust up through it. If an excessive amount of water flows through the sand, it forces the sand particles apart. This separation of particles causes the ground to loosen, and any mass on the sand will begin to sink through it. In the next section, you will find out how to save yourself if you happen to fall into a pit of quicksand.

What’s Up in Grade 4? (Psst! There’s Videos!)

So, I wanted to share some things that we have been doing in school lately. It’s been awhile and, while I am sure you have been hearing lots and lots about school at home (especially about my evil twin brother, Bob), I thought I would share some things with you. But don’t think that this is just for the parents. Au contraire, mon frere! Gather the kids and check it out!

In Language Arts, we have been doing a author study on the really cool and very interesting author, Chris Van Allsberg. He writes these fascinating books that are fantasy based. As part of this, we have been learning that fantasy books have three characteristics: they are usually based in the present, they take place in normal places but strange things happen and they have an element of magic in them like animals that talk. We have read a number of his books in class and have also talked about theme where the author writes a book to share a main idea. This is a tougher concept for the students to grasp as it is not very easily discerned. However, the books are a lot of fun with just enough of a twist to them to keep the kids interested. After the Thanksgiving break we will be starting our Home Reading program.

In Science, as you probably know, our class is doing a unit on Animal Habitats and Communities. As part of this unit, students are going to be assembling terrariums. The terrariums are homes for various plants and animals that typically live in or on the forest floor. Observing what happens in the terrariums gives students a chance to learn about the habitats and adaptations of animals that live in this type of environment as well as gain knowledge about the role these plants and animals play in the larger ecosystem.

We need your help in making this the best learning experience possible. Your child will need a variety of supplies in order to build their terrariums. The supplies they will need are inexpensive but I wanted to give you a heads up so you will have time to collect the items to send with your child. As you collect the items, you can send them with your child so they are ready to go once we begin to build the terrariums.

For Tuesday, Oct. 15th

Your child will need:

  • A small trowel
  • Boots
  • A small plant
  • Small amount of grass seed or birdseed
  • 1 small plant such as strawberry plant, sweet alyssum, violets or other small garden plants which you can get fairly cheaply at Home depot, Walmart, Rona or a garden place.

We started today looking at the soil that your child brought in. We found some very cool things in the soil which were unexpected. We will talking more about soil and the importance of soil in the food chain, setting up an experiment with soil and starting our Terrarium habitats on Tuesday.

Here are some pictures from our look at soil:

Speaking of habitats, we have learned a lot about habitats and I found this cool video that I thought everyone would enjoy!


Finally, I found this awesome video on Science experiments you can do at home…and it has Oobleck in it!!! I don’t think you are ever too old for Sesame Street, especially when it’s done this way!

What Do You Mean, Pluto Isn’t A Planet?

For the last couple of days, we have been scientists questioning, observing, and analyzing. It’s been a lot of fun and the students have had a great time doing some fun experiments including testing the flight of paper airplanes. Yesterday, we continued as scientists as we studied a mysterious substance found in my backyard, called Oobleck. This mysterious green substance has some very unique properties which we took some time exploring as you no doubt discovered when they came home covered in dust! It does wash out, I promise. We started by talking about what properties are and how we can observe the properties of objects. Then I showed them the Oobleck! Kids had a great time mucking around. In doing this, the students discovered that Oobleck was not quite what it initially appeared to be! After a few minutes, students took some time to write down 5 unique properties of this Oobleck.

Yesterday, we set up a scientific convention. Scientists all over the world get together in conventions to discuss and debate important scientific discoveries and questions to come to a consensus on various issues. Scientists use these conventions to come to an agreed upon truth about various scientific issues and thus are very important in the advance of science. The example I gave to the students was the scientific convention where scientists came to an agreement that Pluto was to be demoted to the category of dwarf planet and was not to be in the same category as our other planets. There was a huge debate and lots of arguing but at the end of the day, scientists had come together and agreed to change Science.

So we had our own little convention today to come up with some truths about this mysterious substance. It was a great time arguing and voting. The kids came up with some great points. Here are some pictures from the convention:

We’re going to be doing some neat things in the next couple of days in Science so keep an eye out here for more news! In the meantime, here is a nice video by one of my favorite scientists, Bill Nye, talking about why Pluto isn’t a planet.

Also, I found this great article with pictures showing what we would see in our night sky if the other planets in the Solar System were as close as our Moon is to Earth. The first one is Mars:

Our moon is a pretty big object. It’s big enough to be a respectable planet in its own right, if it were orbiting the sun instead of the Earth. (Actually, it is orbiting the sun in a nearly perfectly circular orbit, that the Earth only slightly perturbs… but that’s a topic for another day.) The Moon is a quarter the diameter of the Earth. Only Pluto has a satellite that is larger, in proportion to the size of the planet it orbits.

But what if the Moon were size of Mars, instead? It would like the picture above. Check out how some of the other planets of the Solar System would look in our sky, if they took the Moon’s place.

What if we had a planet instead of a Moon?

At a distance of about 240,000 miles, the Moon occupies a space in the night sky about half a degree wide. By sheer coincidence, this is almost exactly the same size the sun appears, which is why we occasionally get total solar eclipses. (We don’t get a total eclipse every time the Moon passes in front of the sun because the Moon is sometimes a little closer to the Earth and sometimes a little further away, so it will cover more or less of the sun during any eclipse.)

But it’s interesting to imagine what the night sky might look like if one of the Solar System’s planets were to replace our moon. (We’d have to ignore things like tides and gravitation, but that’s the advantage of doing things in the mind’s eye.) So what would we see if we were to replace the moon with Mars? The red planet is almost exactly twice the size of the Moon, so it would appear twice as big in the Earth’s sky. It would be easy to see with the naked eye details on the surface of the planet that were previously visible only through telescopes. You could watch the ice caps grow and shrink during the changing seasons, see dust storms form and move across the planet and make out features like Vallis Marineris and Olympus Mons.

What if we had a planet instead of a Moon?

Venus is three and a half times larger than the Moon. It would be nearly as large in our sky as the Earth appeared to the Apollo astronauts, when they were walking on the surface of the Moon. There wouldn’t be too much to see, other than vague swirling patterns in the dense, ivory-colored cloud cover. (We’re pretending, of course, that Venus would still have the same atmospheric conditions if it were in essentially the same orbit as the Earth.) It would be an amazingly bright object, however — much brighter than our moon. Not only does Venus reflect six times more light than the Moon, it covers an area 40 times larger… so the night skies would seem as bright as daylight.

What if we had a planet instead of a Moon?

Neptune is more than fourteen times larger than the Moon — and now we’re talking about something that would look really impressive. It would loom like an enormous blue balloon in the night sky. And dominate the daytime sky, as well. All other things being equal, an eclipse of the sun would seem to last forever. Once the sun disappeared behind the edge of the “moon” earth would be plunged into darkness for over an hour and half.

What if we had a planet instead of a Moon?

Uranus, which is nearly the same size as Neptune, would provide a very similar view.

What if we had a planet instead of a Moon?

Saturn would be an astonishing sight. Almost 35 times larger than the Moon, this golden globe would cover nearly 18 degrees of the sky. We’d be a little further away from Saturn than its satellite Dione. In fact, we’d be more likely to be a satellite of Saturn ourselves than the other way around. The rings would stretch nearly from horizon to horizon.

What if we had a planet instead of a Moon?

Jupiter would trump them all. Forty times larger than the Moon, Jupiter would stretch 20 degrees across the sky. It would also look a little different from the telescopic and spacecraft photos we’re used to seeing. This close, we’d be looking “up” at the northern hemisphere and “down” at the southern hemisphere, so the cloud bands would be distinctly curved in perspective. In fact, we’d not be able to see the north and south poles of the planet.

To visualize Jupiter taking the place of our Moon, we really have to use our imaginations. Since we’d be about the same distance from Jupiter as its satellite Io, the earth would be subject to the same tidal stresses caused by Jupiter’s immense gravitation. We might have a much more volcanic-looking landscape around us. There might also be little evidence for life since we’d also be in the midst of Jupiter’s deadly radiation field. But as I said at the beginning, we have to make some allowances for imagination!

Science, Airplanes, and Experiments, Oh My!

Our first full day of school and it was jam packed. We had a great day doing a variety of things. We started with some handwriting review and went into some math review. We have also been focusing a lot of the correct procedures for doing things during the day, particularly in paying attention and following directions. The first few days of school are always about procedures and other things that make the school days go smoother. This amazing class is well on it’s way and students have already earned lots of stars towards their first prize!

For Science, we had a couple of great activities focusing on how to work as a group and the scientific method. We are going to be doing lots of group work and science experiments this year with a focus on doing science like real scientists. So….. we made paper airplanes. I know. I know. I was just talking about teaching the students to do science like real scientists and now I’m saying that they spent science making paper airplanes? That’s right! But it does have to do with science. Making paper airplanes was the first part of our experiment to see if and how we can make a paper airplane fly farther. On Friday, we will be going through the scientific method to answer that question, make a hypothesis, run trials to test our hypothesis, create an independent variable and a constant variable and analyze our results. Having said that, the kids had a blast making and designing their paper airplanes. At the end of the day today, we tested which one of the two they made flew the best to determine which one they will actually use for the experiment.

One of the other things we did is talk about how to work well as a group. To do that, the students had a challenge where they had to move cups into a pyramid shape using only a rubber band and string. It was so much fun watching them and they all accomplished the task with flying colours though they did seem a little skeptical at first! Here are some pictures from the challenge:

 

More Moon Phases!

We have had lots of fun with moon phases but now it is time to show what we have learned about the moon and it’s phases.

On Tuesday, we will be having a little quiz about the moon and it’s phases. I have embedded the page below that we will be using for the quiz. While it is a long document, we will only be using the last page for the quiz. Students can use this to help them get ready for the quiz.

I also learned a very cool trick for figuring out whether a moon is waning or waxing. Draw a line on the moon in your head from top to bottom between the light part and the dark part. If the line and the lighted part make the shape of a “b”, then the moon is waxing. If the line and the lighted part make the shape of a “d”, the moon is waning.

Moon Phases Quizzes

For homework this month, students will be required to track the moon phases. Students should do this each night. There are lots of resources available to help with this, even if the night is cloudy. However, having a chance to go out and look at the sky at night is a great opportunity to learn about all the things in the night sky. If you have an ipad or ipod touch, there is a very nice app called, “Skyview”, that will tell you more about all the objects in the night sky above your head. It is a really cool app.

Each child has a received a copy of the calendar. I have also embedded one below in case of mishap. Please ensure that the calendar is done neatly. The calendars are for marks. I am looking for accuracy, neatness and detail. I don’t mind some creative license in creating a nicely designed moon with craters etc. I do not want a messy picture, however.

Calendarmonthvt-EnchantedLearning
 

The Moon’s Phases Part II

Did you know the word “Month” comes from the word Moon?

So we talked more about the Moon’s phases today. We had a lot of fun moving the desks out of the week and setting up our “Sun” lamp in the middle of the room. Using some styrofoam balls and popsicle sticks, we made “Moon’s On A Stick” to simulate the movement of the moon around the Earth. Our heads being the Earth, we were able to get a good idea as to how the Moon gets it’s phases. Here is one of the videos we watched to show the phases.


You can also see a great page on the Moon’s phases that you can play with by clicking HERE.

Here are some other ways to visualize the size and distance of the Moon.


 

The April Sky

Here is the next video in the Series, “Tonight’s Sky”. These videos do a great job detailing the various events, constellations, and planets you can see in the  night sky this month. Take some time on a nice clear night and go outside to see some of God’s wonder! I also added some videos about the space shuttle as we had some questions today about how it worked.


 

This video shows the last launch of the Space Shuttle!

Cool video about possibly living on the moon!

Views of Earth from Space!

I recently came across this really cool article from the Mental_Floss Blog, showing the Earth from different places in space. One of the coolest is the last one, which is the most distant picture of our planet ever taken. The series of photos is breathtaking and amazing as it illustrates our small place in this universe.

Here is the article.

n January 2012, the newly launched weather satellite NPP Suomi had gathered enough swaths of data to cover the entire Earth. To commemorate this, the mission team assembled this into a map and projected it over the globe:

NPP’s “Blue Marble,” western hemisphere, data acquired from about 824km altitude

It’s a synthetic view; NPP flies too close to ever see this much of Earth at once. But there are spacecraft that do get that vaunted view—and more besides. Let’s look at the Earth from increasingly more distant viewpoints…

35,786 km

GOES-7 image of Hurricane Andrew making landfall in 1992, from Geosynchronous Orbit, 35,786 km altitude

45,000 km


The original “Blue Marble” photo, taken by Apollo 17 during transearth cruise, 45,000km altitude

55,831 km

Mercury-bound MESSENGER got this during an Earth gravity assist flyby, at a distance of 55,831 km

384,000 km

The most famous of the Earthrise photos: Earth rising over the lunar limb as viewed from Apollo 8, distance of about 384,000 km

384,000 km


The USAF’s Clementine spacecraft looks back from the moon, about 384,000 km away

384,000 km

Lunar Reconnaissance Orbiter looks back at Earth from lunar orbit, about 384,000 km away

400,000 km


The NEAR spacecraft, en route to 433 Eros, took this during a flyby of Earth, at a distance of 400,000 km

2 – 2.7 million km


Taken by Galileo during its first Earth gravity-assist flyby, between 2 and 2.7 million km away

2.6 million km

Mariner 10 looks back during departure, at a distance of 2.6 million km; a composite of two images, one of Earth and one of the Moon, moved together to show relative scale

3.5 million km

2011 Mars Odyssey looked back at Earth from 3.5 million km, in a view that shows the true size and distance relationship between Earth and Moon

6.2 million km

Taken during Galileo’s second Earth gravity-assist flyby, about 6.2 million km away; the Earth and Moon are truly in conjunction

11.66 million km


Voyager 1 took this at a distance of 11.66 million km, while departing Earth; it’s the first view showing both Earth and Moon together in a single frame without compositing and without being in orbit around either

From Mars

The Mars Exploration Rover A, “Spirit,” saw Earth in the predawn sky on Sol 63 of its mission; the first image of Earth from the surface of another planet

142 million km

Mars Reconnaissance Orbiter took this from Mars orbit, at a distance of 142 million km

183 million km

MESSENGER, looking back at Earth from Mercury, at a distance of 183 million km

183 million km

Also MESSENGER, this is a solar system portrait from Mercury; the Earth image is part of this

1.5 billion km


Cassini took this from Saturn orbit, at a distance at the time of 1.5 billion km. Look carefully through the rings; there’s a bright star in there. It’s Earth.

1.5 billion km


Enhanced zoom on the Earth from the previous frame

6 billion km

February 14, 1990, Voyager 1 set a record that still stands for the most distant image of Earth. It is over 6 billion km away. This montage is a solar system family portrait, showing six of the planets. Mercury was too close to the Sun to be visible at this range. They attempted to photograph Mars, but it was too faint for Voyager’s camera.

6 billion km


Enhanced, enlarged view of Earth from the solar system portrait; Carl Sagan called this image the “Pale Blue Dot.” It is the most distant view we’ve ever recorded of ourselves.

Read the full text here: http://www.mentalfloss.com/blogs/archives/117388#ixzz1mtNPYAxw
–brought to you by mental_floss!

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