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- 윤초(閏秒)과학동아 l198806
- of Dec. 31,1987. The one before was added as the final second of June 30, 1985. This is something that is necessary not for astronomers, but for those who navigate ships, for those in charge of ...
- 우리는 지금 몇 살인가?과학동아 l198806
- Neanderthal man and modern man as different species again.Also, if Neanderthal man and modern man coexisted on Earth not for 5,000 years, but for 55,000 years, why should it have taken modern m ...
- 성단(星団)이라는 측정자과학동아 l198805
- of them, we can compare that with the luminosity they really have and calculate the distance. In a way, it might not seem this gives us anything new. A bright globular cluster is about as brigh ...
- 감마선의 시사과학동아 l198805
- fields strong enough to cause matter to spiral in tight turns that automatically emit X-rays, but the fields cannot force the matter to spiral so tightly that they will emit gamma rays. Black h ...
- 알기 어려운 쿼크과학동아 l198804
- sure of that if we've never studied them in their free state?In fact, we can't even be sure they exist at all and are not just mathematical conveniences. For instance, we know that a dollar is ...
- 우주의 비밀을 알려줄 폭발과학동아 l198804
- 만약 우주에 반(反)물질과 같은 것이 있다면 과학자들은 그것을 검출하는 방법을 곧 알아낼 것이다.한때 과학자들은 반물질이 반드시 존재해 ... we will know we have found an antistar (existing, perhaps, in an antigalaxy), and that may help us re-evaluate our n ...
- 가장 생명력이 강한 것과학동아 l198803
- evolved to that advanced stage of development 80 million years ago, bees must have formed long before that - perhaps another 80 million years before. This is of importance in connection with pl ...
- 태양계의 종말은?과학동아 l198803
- - if left to itself. The sun, however, is huge, and its gravitation is capable of collapsing it to a pygmy. It does not collapse, but that is only because it is constantly generating heat at it ...
- 옛 괴물들과학동아 l198802
- Zealand that held their heads at heights of up to 13 feet and weighed up to 500 pounds. This is a height record, but not a weight record. Up to the 1600s, the "elephant bird," or "Aepyornis," w ...
- 가솔린 바다과학동아 l198802
- case, Titan and Triton may prove to be valuable resources. To be sure, the gasoline they will supply will undoubtedly not be needed for energy purposes because the distant settlements should, p ...
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