A lot of rock bits are broken up as a drill bores through the earth. A special system that makes use of drilling mud is used to remove those bits so that they don’t get in the way. Today we’re going to look at why drilling mud needs to have a high viscosity.
What you will need:
A tall cup (this will represent the borehole)
A straw (this will represent the drill bit)
Sand (this will represent the rock bits)
Water (this is a liquid with a low viscosity)
Shampoo (this has a much higher viscosity than water)
► Put some sand into the cup and fill it with water. Wait for the water to penetrate through the sand.
► Place the straw into the cup so that it touches the bottom. Blow for a few seconds and then look at what the sand does.
► Repeat the above steps, but this time use shampoo instead of water. What’s the difference?
(MICHAEL KEARNEY, STAFF WRITER)
What's the science? 科學原理
Viscosity describes a liquid’s resistance to flow. Water flows easily, so it has a low viscosity. Shampoo doesn’t flow as easily, so it has a higher viscosity. Drilling mud has to have a high viscosity in order to suspend rock bits so they can be carried upwards.
Further ideas 進階點子
Cornstarch mixed with water has some strange properties. Its viscosity depends on how much pressure is applied.
Add two parts cornstarch to one part water and stir slowly. Gradually add more water and continue to stir the mixture until it acts like a liquid when you stir it slowly and a solid when you stir it quickly. Try kneading the mixture into a ball. If you continuously apply force to the ball, it will act like a solid, but once you stop applying force, the ball will “melt” before your eyes.
A special system has been developed to remove rock bits that a drill creates as it bores through the earth. The drill bit is usually hollow, and drilling mud is sent through it under pressure. The drilling mud cools down the drill bit and fills up the borehole. It carries rock bits upwards, out of the hole, to give the drill room to keep going deeper. Once the drilling mud and the rock bits are above ground, they’re separated so that the drilling mud can be pumped back down the drill bit to carry up more rock bits.
1. bore v.t./v.i.
鑽孔 (zuan1 kong3)
2. drilling mud n.
鑽井液 (zuan1 jing3 yi4)
3. viscosity n.
黏性 (nian2 xing4)
4. borehole n.
鑽井 (zuan1 jing3)，鑽孔 (zuan1 kong3)
5. drill bit n.
鑽頭 (zuan1 tou2)
6. penetrate v.i./ v.t.
穿過 (chuan1 guo4)
7. suspend v.t./v.i.
懸浮 (xuan2 fu2)
8. candidate n.
候選人 (hou4 xuan3 ren2)
9. splash n
濺出的水花 (jian4 chu1 de5 shui3 hua1)
10. cornstarch n.
太白粉 (tai4 bai2 fen3)
11. knead v.t.
搓揉 (cuo1 rou2)
Try dropping a coin into water from about a meter high. Did you notice a splash?
Now try dropping a coin into shampoo from about a meter high. The splash should be much smaller, if there is any at all. The higher a liquid’s viscosity, the more resistant it will be to splashing.
You can still eat what you want (3/5) 你想吃的還是可以吃（三） A: Foods with non-refined starch, such as brown rice, whole grain bread and oats are less easy to digest, so they will release the glucose more slowly and steadily, just like if you turn on the faucet more carefully, so that your blood sugar won’t jump up all of a sudden. B: So we should eat more non-refined starchy foods, is that right? A: Yes, so you should be eating less of foods such as white rice, noodles, white bread, cakes and cookies — because these are all refined. B: I’ve been hearing the phrase “low GI diet” a lot recently, is this
You can still eat what you want (4/5) 你想吃的還是可以吃（四） A: If you don’t want to go into a food coma after eating food, there is another thing you could try: eating more fruit and vegetables. B: Ah, I’ve tried that! For a while I wanted to lose weight, and I only ate vegetables and chicken salad for all three meals, and I ended up not being able to sleep because I was so hungry. I gave that idea up pretty quickly. A: That was a bit extreme: I’m not surprised you couldn’t see it through. Starchy foods will make you feel satiated. I’m not saying you shouldn’t eat
The original Superman Clark Kent fell for a journalist, and his son Jonathan Kent is doing the same, although this time the new Superman is falling in love with a man. On Oct. 11, to coincide with US “National Coming Out Day,” DC Comics announced that the new Superman will have a romance with male reporter Jay Nakamura. The couple will even kiss in a comic to be published next month, the publisher said, describing the new Superman as “bisexual.” As CNN commented, Jon will not be the first queer superhero when he comes out as bisexual next month, but he
A: You could try eating often but smaller portions, so that you won’t be digesting too much food at any one time, which will be easier on your stomach and your blood sugar won’t jump. You can still eat what you want. B: To be completely honest, I’ve tried that, too, with the result that I never stopped eating, haha. But I have found that if my jaw is always moving and my teeth are always biting into things, I don’t feel so sleepy when I’m studying. A: Then you should eat a low calorie food like konnyaku or