Stars

Question

I read about a young woman astronomer who died young, but came up with the theory that light from stars that we see now originated thousands of years ago I cannot remember her name but Tinkling or something like that comes to mind. Can you tell me her name?

Answer

Fran, Are you thinking of Henrietta Swan Leavitt? http://www.womanastronomer.com/hleavitt.htm

Her studies of Cepheid variable stars helped astronomy ENORMOUSLY, and helped to calculate how many years the light from many stars travelled to reach us. Study the 4th paragraph in the main article in the link I just posted, the one which begins with "Another area of research that Leavitt pursued..."

Also, she did die at a fairly young age. (Much too young for the good of the astronomy community. She was incredibly gifted. Who knows how far our understanding of the universe might have advanced, if she had lived for 20 or 30 more years? Maybe we would have reached the level of understanding that we have today, about the universe, by the 1970s or 1980s. By now, we could be incredibly advanced.... it is terrible that she died so young).

I don't know where you got the name Tinkling... maybe from her boss, Edward Charles PICKERING? http://en.wikipedia.org/wiki/Edward_Charles_Pickering

I hope this is helpful. Keep Looking Up! -Ed

Question

My niece majored in astrology; she said turbulence like that of a tornado is one cause of violent color changes and violent flickering from stars;what's your opinion? Darlene

Answer

Hi Darlene, I didn't know any college had a major in astrology (fortune telling) ...because that's all astrology is...like numerology, ouiga boards, gypsy fortune telling, palm reading...they are all in the same catagory....ie. junky trash not to be believed in. OR, perhaps you meant something completely different....astronomy; the scientific study of the heavens. That's completely different than the pseudo-religion of astrology. They are completely different so you have to keep them straight, and completely apart.

Well, it's not "my opinion"....it's factual. Ahhh, yes, she is right. She is correct in that atmospheric turbulence is the main cause of twinkling and apparent color changes in the stars, but it doesn't take tornadic jet stream violence to do it....even the excess heat coming off a tarred black "neighbor's roof" is enough (heat waves) to cause the background stars to sintillate wildly...(the real scientific word for 'twinkling'). Astronomers refer it to the "seeing" conditions. It can be perfectly clear, but IF there is the jet stream core right overhead, some astronomers put their equipment away for the night because the "seeing" is very bad....and that means poor resolution of all the objects. For instance, instead of superb 0.5 arc-second resolution, you might only have 4 to 5 arc-second resolution due to atmospheric turbulence, so the clear night is a complete waste of time....a real waste of a beautiful moonless, clear night. It happens more often than one thinks. On the Earth's surface, we reside as if at the bottom of a 'swimming pool'...the atmosphere. If someone is 'swimming' in the pool, then that affects our looking up thru the atmosphere, so we need a 'calm swimming pool' above us to see the heavens....as they are. That was why we put the Hubble Space Telescope up in orbit, so it is not affected by the atmosphere, so we can achieve very high resolution (definition) of the heavenly objects. And it's well worth it, if you've viewed any of the Hubble Telescope pictures.

If we didn't have an atmosphere, then the stars would remain bright steady pin-points all the way down to the horizon, (like on the lunar surface)...and they would immediately disappear behind the horizon unaffected. There would be no horizon haze to dim them down, no twinkling, no violent color changes....in addition, no rainbows, no haloes, no circumzenithal arcs, no corona's....none of that atmospheric stuff. In effect, anything you see from the ordinary and steady pin-points of starlight, you can be assured that it's the atmosphere interfering with our view of the heavens.

Hope this helps, Clear Skies, Tom Whiting Erie, PA

FOLLOW UP: Most common cause of bad "seeing" is the jet stream up at altitude overhead, followed by an unstable lower atmosphere (approaching or receding low pressure system), immediately before cold front passage, high horizontal winds, and lastly, observing around a lot of buildings that give off heat waves at night, but these settle down around midnight local time. That's why we astronomers with portable telescopes prefer to set up on a rural flat grassy area as opposed to a cement or asphalt parking lot which is radiating heat waves from the daytime sun exposure.

 Best seeing conditions are usually with a high pressure system directly overhead, then the upper air is slowly descending overhead with relatively stable, clear sky conditions. And some nights, a 

slightly hazy sky means very stable conditions, and therefore excellent "seeing" at the sacrifice of a very slight haze layer above you. Clear skies, Tom

ADDITIONAL FOLLOW UP; Oh, and if your question was meant as a "tornado" forecaster just using 'astronomical seeing'... you can forget about that. Tornadoes require a thunderstorm (first requirement) and anytime conditions are ripe for thunderstorm formation, you're going to have a very unstable atmosphere and subsequent bad seeing all around the area of thunderstorm formation; irrespective of whether a tornado forms, or not. And as you know, not every thunderstorm produces a tornado. Clear skies, Tom

Question

QUESTION: Hi I was wondering if you can answer this question. why do all stars seem like there the same distance from earth. And does this have anything to do with the oblers paradox?

ANSWER: Hi Mike,

All the stars seem like they're at the same distance from earth because they're all so far away. Although it takes about 8 minutes for light to travel to earth from the sun (93 million miles away), light takes over 4 years to travel to even the nearest star. For most stars that we see, light has been travelling for hundreds or even thousands of years. When things are all so very far away, we can't easily tell they're all at different distances from us. To determine distances, there are a lot of "tricks" astronomers use - but that's another whole question!

The star's distances have little to do with Olber's paradox. That paradox states that if the universe were infinite and filled with stars, in no matter which direction we'd look (even if the stars were very far away), we'd see a star, and the night sky would be very bright. In reality, the universe is not infinite in size or age (current estimates put it at 13.7 billion years old), it is expanding, and stars don't live forever (they die and are slowly replaced with new stars). These things combine to make the night sky dark, instead of completely filled with stars.

Hope that helps.

Prof. James Gort

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QUESTION: Professor,

 Thank you for you quick and very informative response. If I read some other tings that don't quite make a lot of sense, Ill be sure to ask you! Thanks again,Mike

Answer

Hi Mike,

No problem. I'll always try the best I can to make sense of it. But believe me, there are some areas where no one has the answers or can make sense of it - although some try! But I'll always let you know what's fairly well known; if not known - what's the best explanation; and if there is disagreement among the experts (and there's plenty of that!), I'll try and explain the difficulties.

Cheers,

Prof. James Gort