• Frog-And More In Space 우주공간에서의 개구리

    Frog-And More In Space 우주공간에서의 개구리

    과학동아 1992년 11호

    compass orientation." Male eastern red-spotted newts (Notophthalmus viridescens) respond to the Earth's magnetic fields by using photoreceptors, a process called "light-dependent magnetoreception."In the secretions from many amphibian skins are toxins that function to protect the animal from predators, something known by native peoples who smeared the secretions of poisonous frogs on their ...

  • 쓰레기

    과학동아 1992년 09호

    overpopulation ensures that space on the planet is running out Dumping garbage where people don't live—deserts, ice fields, ocean, mountaintops—isn't the answer, either. On planet Earth everything is connected, so fouling up here louses up there — to say nothing of destroying potentially valuable ecology.In the meantime, landfills get larger. One of the world's biggest is the Fresh Kills ...

  • Genes In Action 활동하는 유전자

    과학동아 1992년 03호

    1, from one odd lamb, a Massachusetts farmer bred shortlegged sheep that couldn't jump over the stone walls around his fields.The frult fly made it possible to count genes in a chromosome (a minimum of 10,000 in the fruit fly), and find out that the individual gene has a molecular weight of 60 million (molecular weight is the sum of the atomic weights of all atoms in a molecule). Human beings ...

  • The Park Phenomenon 공원현상

    과학동아 1992년 03호

    has it all - an undulating landscape, punctuated by trees and rock outcroppings, streams and ponds, various lawns and fields. Any hunter-gatherer would be pleased, although nowadays the only hunters are unfortunately humans who prey on other humans. There are, however, plenty of gatherers from various ethnic groups harvesting such delicacies as wild garlic, lambs quarters (that's a plant), ...

  • 아인슈타인은 역시 옳았다.

    아인슈타인은 역시 옳았다.

    과학동아 1991년 06호

    exactly?This is where Gabrielse and his team came in. They had both protons and antiprotons whirled about by magnetic fields and they measured how many whirls they made in a second. The number of whirls depended on their mass and it turned out that the masses of the two types of particles were the same to within four parts in 100,000,000.From this it could be deduced that Einstein was right ...

  • 노화보다는 질병이 뇌기능 퇴화 가져와 몸은 늙어도 두뇌는 젊다

    노화보다는 질병이 뇌기능 퇴화 가져와 몸은 늙어도 두뇌는 젊다

    과학동아 1991년 06호

    정신능력이 나이에 따라 쇠퇴한다고 믿고 있다. 수학자의 가장 큰 명예인 필즈 메달(Fields medal)은 전통적으로 40세 미만의 사람들에게만 수여되고 있다. 이유는 그 나이 이후면 학문적으로 더 중요한 발견을 하지는 못할 것으로 간주하기 때문이다.지금까지 두뇌의 노화현상에 대한 규명작업은 많지 ...

  • 줄어드는 삼각주

    줄어드는 삼각주

    과학동아 1991년 02호

    Egyptians developed the calendar we still use and they developed geometry so they could lay out the boundaries of the fields after the flood.What's more, they rarely experienced food shortages, for the flood kept the land fertile. In the Bible when there was a famine in Canaan, the sons of Jacob had to go to Egypt to buy grain-there was always grain in Egypt. Of course, the fertile strip was ...

  • 우주적 위험

    과학동아 1990년 05호

    space, and, possibly even between the galaxies. Their paths twist and curve as they pass through electromagnetic fields and they end up bombarding the Earth from all directions. These cosmic rays strike our atmosphere, smashing their atoms and molecules, and forming "secondary radiation" that strikes Earth's surface and is so energetic that it passes through anything in its way, including ...

  • 대 해빙

    대 해빙

    과학동아 1989년 12호

    that something like 20,000 cubic miles of water may have poured out of the ice, all at once, to from the drumlin fields of northern Saskatchewan. The Amazon River, the largest on Earth, takes ten years to discharge 20,000 cubic miles of water into the Atlantic Ocean, but the ice-lake may have discharged it matter of a few day only. It would therefore have the effect of a river perhaps a ...

  • DNA분자를 처음 보다

    DNA분자를 처음 보다

    과학동아 1989년 06호

    where x-ray waves would be extremely difficult to focus, electrons and their waves could easily be focused by magnetic fields.In 1932, the first device used to focus electron-waves and enlarge the images of objects in that way was constructed by a German scientist, Ernst Ruska. This was an "electron microscope." It was crude at first, but over the years it was refined and imroved, until it ...

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