関連する実験動画
Updated: Jul 9, 2026
11:41
Magnetic Tweezers for the Measurement of Twist and Torque
Published on: May 19, 2014
日光斑の半陰のフィラメントの回転の動き
K Ichimoto1, Y Suematsu, S Tsuneta
1National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Toyko 181-8588, Japan. ichimoto@solar.mtk.nao.ac.jp
Science (New York, N.Y.)
|December 8, 2007
まとめ
太陽の斑点の半陰の明るい繊維は,明らかに回転する動きを示しています. この現象は3次元放射伝送の人工物であり,実際の光線の回転ではありません.
科学分野:
- ソーラー物理学 ソーラー物理学
- 天文学 (astronomy) 天文学 (astronomy) とは,天文学 (astronomy) とは,天文学 (astronomy) とは,天文学 (astronomy) とは
- プラズマ物理学 プラズマ物理学
背景:
- 太陽斑の半陰は,放射的に伸びた線状のフィラメントを特徴としています.
- これらのフィラメントは,Evershed流として知られる,外向きのガス流れを示します.
研究 の 目的:
- 太陽の斑点の半状フィラメントにおける観察された回転運動の性質を調査する.
- これらの動きが実際のフィラメントのねじれか,または異なる物理的過程を表しているかどうかを判断する.
主な方法:
- ヒノード衛星の太陽光望遠鏡からの高解像度太陽画像の分析.
- 糸状構造とその動態の観察と特徴付け.
主要な成果:
- 半暗黒の明るい繊維の中で,見かけのねじれ動きを発見した.
- 観測された歪みは,太陽斑円盤の中央線に垂直した半陰に限定されています.
- 表面の回転の方向は一貫して,四肢側から円盤中心側までである.
結論:
- 観察された歪みは,フィラメントの物理的な回転ではありません.
- それは,半陰の繊維のダイナミクスの表れである.
- 観測された現象には3次元放射伝送効果が寄与しています.
関連する概念動画
01:19Magnetic Field Lines
The representation of magnetic fields by magnetic field lines is very useful in visualizing the strength and direction of the magnetic field. Each of the magnetic field lines forms a closed loop. The field lines emerge from the north pole (N), loop around to the south pole (S), and continue through the bar magnet back to the north pole.
Magnetic field lines follow several hard-and-fast rules:
Magnetic field lines follow several hard-and-fast rules:
01:26Divergence and Curl of Magnetic Field
The magnetic field due to a volume current distribution given by the Biot–Savart Law can be expressed as follows:
01:25Magnetic Field due to Moving Charges
A stationary charge creates and interacts with the electric field, while a moving charge creates a magnetic field.
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
Consider a point charge moving with a constant velocity. Like the electric field, the magnetic field at any point is directly proportional to the magnitude of the charge and inversely proportional to the square of the distance between the source point and the field point. However, unlike the electric field, the magnetic field is always perpendicular to the plane containing the line...
01:24Gyroscope: Precession
Precession can be demonstrated effectively through a spinning top. If a spinning top is placed on a flat surface near the surface of the Earth at a vertical angle and is not spinning, it will fall over due to the force of gravity producing a torque acting on its center of mass. However, if the top is spinning on its axis, it precesses about the vertical direction, rather than topple over due to this torque. Precessional motion is a combination of a steady circular motion of the axis and the...
01:13Angle of Twist: Problem Solving
An electric motor applies a torque of 700 N·m to an aluminum shaft, triggering a stable rotation. Two pulleys, B and C, are subjected to torques of 300 N·m and 400 N·m, respectively. The modulus of rigidity is provided as 25 GPa. With the knowledge of the length and diameter of each segment, the twist angle between the two pulleys can be computed. First, a section cut is made between pulleys B and C, and the cut cross-section is analyzed using a free-body diagram. Given that the torque exerted...
01:16Magnetic Field Of A Current Loop
Consider a circular loop with a radius a, that carries a current I. The magnetic field due to the current at an arbitrary point P along the axis of the loop can be calculated using the Biot-Savart law.