A-L-E-X wrote:Source of the post I read about a particularly alarming one that fell in Portugal back in the 1800s the size of an elephant!
A-L-E-X wrote:Source of the post In the 1935 Labor Day hurricane the wind was so intense that the friction of it on the sand caused fires to occur mid-air!
A-L-E-X wrote:Source of the post I'm surprised you hadn't heard of it before, the violent winds causing the sand to cause fire sparks in the air was compared to a Van De Graaf generator.
Mr. Abner wrote:A-L-E-X wrote:Source of the post I'm surprised you hadn't heard of it before, the violent winds causing the sand to cause fire sparks in the air was compared to a Van De Graaf generator.
But there is a big difference between sparks from static electricity and actual flames from friction.
A-L-E-X wrote:Source of the post Sorry I meant sparks of fire not something akin to a forest fire lol.
Watsisname wrote:A-L-E-X wrote:Source of the post Sorry I meant sparks of fire not something akin to a forest fire lol.
Be careful of one's wording. Sparks of electricity are not the same as sparks of fire, either.
There can also be electric discharges in the ash clouds of volcanic eruptions.
Be careful of one's sources, too. Just because it is on wikipedia does not mean it is reliable, even if it has citations. Check the citations, too. The very large cryometeor in Brazil (second citation) is a broken link for example, and I can't find anything else about that event online. Some of the other reports seem more credible though.
Basically, I'm just trying to get you to apply cautious skepticism to everything you read online. Critically reviewing a claim is an important part of science regardless of whether or not you think the claim is true.
Watsisname wrote:A-L-E-X, I would recommend staying away from 25x70. Your 10x50 would be better, or try the 15x70 if you like them. To put it briefly, bigger numbers are not always better, and often quite the opposite.
The first number is the magnification, and the second number is the aperture. What 25x70 does for you compared to 15x70 is take the same amount of light (70mm aperture) and spread it out more ((25/15)^2 = 2.8x more area), which will only make the view of faint objects like galaxies worse. Higher magnification on hand-held binoculars also makes it more difficult to maintain a steady image, and most people find this uncomfortable or annoying -- a lesson learned over and over by bird watchers.
The most important thing for viewing M31 is a wide enough field of view (at least 3 degrees FOV sounds good), and light gathering power (larger aperture size). 15x70 will gather about twice as much light as 10x50, while also magnifying 50% more, so it roughly balances out to give a larger image with about the same surface brightness. 20x80 gathers 2.5x more light but spreads it over 4x as much area, so that is also worse than the 10x50. 4.7 pounds also does seem a bit heavy.
Finally, with viewing M31, what you mostly see even with a large telescope is the bright central region of the galaxy, and it's fairly featureless. The spiral bands and dust lanes are visible but they're a lot fainter. I'm not sure how we'll you'll be able to spot them with the binocs, but your 10x50 or the 15x70 sound like your best choices.
Hope that helps.