, but this code // executes before the first paint, when

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is not yet present. The // classes are added to so styling immediately reflects the current // toolbar state. The classes are removed after the toolbar completes // initialization. const classesToAdd = ['toolbar-loading', 'toolbar-anti-flicker']; if (toolbarState) { const { orientation, hasActiveTab, isFixed, activeTray, activeTabId, isOriented, userButtonMinWidth } = toolbarState; classesToAdd.push( orientation ? `toolbar-` + orientation + `` : 'toolbar-horizontal', ); if (hasActiveTab !== false) { classesToAdd.push('toolbar-tray-open'); } if (isFixed) { classesToAdd.push('toolbar-fixed'); } if (isOriented) { classesToAdd.push('toolbar-oriented'); } if (activeTray) { // These styles are added so the active tab/tray styles are present // immediately instead of "flickering" on as the toolbar initializes. In // instances where a tray is lazy loaded, these styles facilitate the // lazy loaded tray appearing gracefully and without reflow. const styleContent = ` .toolbar-loading #` + activeTabId + ` { background-image: linear-gradient(rgba(255, 255, 255, 0.25) 20%, transparent 200%); } .toolbar-loading #` + activeTabId + `-tray { display: block; box-shadow: -1px 0 5px 2px rgb(0 0 0 / 33%); border-right: 1px solid #aaa; background-color: #f5f5f5; z-index: 0; } .toolbar-loading.toolbar-vertical.toolbar-tray-open #` + activeTabId + `-tray { width: 15rem; height: 100vh; } .toolbar-loading.toolbar-horizontal :not(#` + activeTray + `) > .toolbar-lining {opacity: 0}`; const style = document.createElement('style'); style.textContent = styleContent; style.setAttribute('data-toolbar-anti-flicker-loading', true); document.querySelector('head').appendChild(style); if (userButtonMinWidth) { const userButtonStyle = document.createElement('style'); userButtonStyle.textContent = `#toolbar-item-user {min-width: ` + userButtonMinWidth +`px;}` document.querySelector('head').appendChild(userButtonStyle); } } } document.querySelector('html').classList.add(...classesToAdd); })(); Calvin Prof Excited About Eclipse - News & Stories | 黄大仙高手论坛

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Calvin News

Calvin Prof Excited About Eclipse

Wed, Jun 05, 2002
N/A

Calvin College astronomy professor will be watching the West Michigan sky with interest on Monday, June 10. That's when a partial solar eclipse is expected to create an unusual sunset.

In West Michigan, the moon will begin to obscure the sun at 8:30 pm. By 9:08 pm, the moon will cover 26% of the sun, making the setting sun look like a cookie with a bite taken out of it. The show ends at 9:20 pm when the sun sets.

Haarsma notes that to see this show, you'll need to be at a location where the horizon is clearly visible. And she adds "Do not look directly at the sun!" Says Haarsma: "Even a setting, partially eclipsed sun is bright enough to damage your eyes. Instead, poke a pin through an index card, and hold the card between the sun and a white piece of paper. An image of the sun will
appear on the paper, and you can look at the paper safely."

The eclipse will be most dramatic in the middle of the Pacific Ocean, where the moon will block the central portion of the Sun, leaving a circular ring of light at the edges (a phenomenon called an "annular" eclipse).

Haarsma notes that solar eclipses are possible because although the sun is about 400 times larger than the moon, it is also about 400 times farther away. From our point of view, the sun and the moon seem to be about the same size.

But since the moon orbits earth in an ellipse and the earth orbits the sun in an ellipse there are times when the moon happens to appear the same size as or bigger than the sun (making total eclipses possible) and times when the moon appears smaller (making annular eclipses possible).

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