David A

The app I'm using says it's down almost 64 points. So, evidently the change isn't just simply the difference between the current and the opening figure. (It doesn't tally for the current against the daily high, either).

I'm looking at Kodak T-Max 100, Kodak Professional Plus-X, Ilford Delta 100 ISO, and Ilford Pan-F. There are others, but so far I haven't read reviews on them. The photos will be for publication in a scientific journal.

Many brassicas, and some members of the allium family can survive temperatures in the teens (Farenheit), and peas survive temperatures at least in the mid 20's. French beans, however, do not survive even a frost on occasion. What chemical do pea plants or brassicas contain to allow them to survive a frost?

The beetles were fairly numerous, on "monkey grass" and had a pair of long, dark gray or brown antennae. They looked a lot like ladybird beetles, but had no spots or white markings on the head, and were no more than a millimeter in length. Definitely a beetle, not an aphid, ant, or spider mite. I did not see any damage to the "monkey grass", and the beetles were shy, scurrying quickly away when I tried to look at them with a loupe.

I have an 8" Celestron Ultima telescope with a PEC fork mount. I have a suspicion that I am aligning it improperly.

My question is, when using the two-star method the instruction manual says (in regard to one of the stars) that if the star drifts south the mount is pointing too far east (that might be backwards, but it doesn't matter here). Does "south" mean actual south or south in the eyepiece? Here 'south in the eyepiece' would be down, as if the eyepiece view were a map. I use actual south in my alignment efforts, and the drive is turned on, and I do the two-star method after finding and aligning on polaris using the 'jig' supplied with the telescope.

What has been happening is once I think I've got the alignment down, point to a star with known coordinates, set the RA to the correct value for that star and try to find another star just by re-pointing the scope to its coordinates the second star isn't at that position. Usually the Declination is off. I've checked the declination on a level surface and it is right on. Is my problem simply a matter of the mount not being precisely level? Shouold I not use the little built-in level and, instead use a short torpedo level?

Good answers to any of these questions will be greatly appreciated.

Just curious, but I just want to know the compass direction of sunset on the winter solstice, and how to derive that figure. I'm at 30.5 north, but if there's a calculation to be found and you guide me to it I'll do it.

The door is a gate with two hinges. The gate is 8' X 8' and has a weight of 350 lbs. The hinges are separated by 5 feet, making them 1.5' each from the top and bottom. I want to determine the outward force on the post to which the hinges are attached, and need to know the force on the upper hinge. I am assuming the greatest force is on the upper hinge, and the lower hinge really acts as a fulcrum. A rule of thumb would be acceptable (but supply it, please!!).

I have heard that tomato plants grown from some commercially-available seedlings (say, from a feed store) produce sterile seeds. If this is true, then what about plants grown from commercially-available seeds? Obviously someone has plants that produce fertile seeds!

The new mounts have only one mounting point, while the older mounts have two. My telescope is one of the older types, and I'd like to upgrade it to a newer mount, but I haven't found out if it is possible to do that. The scope was purchased new in 1989, but I don't know if it was a 1988 or 1989 model.

I have to restrict both. So if a product lists 10 grams of fat, is that the pre-cooked amount or the amount after cooking (assuming the label is absolutely accurate and I don't trim the cut of meat).

Also, does the value listed for sodium include sodium in the molecular compounds making up the product or only that which was added during processing?

Thanks.

As I recall the world-record low temperature was -89°, at the Vostok station on Antarctica. Carbon dioxide freezes at -79°, which means it is possible that some atmospheric CO2 froze during that time. Has that event been documented? I don't recall ever hearing about it.

It was purchased used. Is there a fix? It doesn't look like it has been abused.

I want to convert various photographs to black and white, and want to determine, after conversion, the average shade of gray for the entire image. Is there a program (hopefully inexpensive) that will take the photo and return the average shade of gray. I guess the program would look at each pixel and determine the average that way. Alternately, is there a way to output the values of each pixel (I could then determine intensity myself)?

If you had a cathode and an anode near each other in a vacuum would current flow between them? If they did not spontaneous do that, would current flow between them, through the vacuum, after they were touched together (much like in arc welding)?

Let's say a particular spectrograph line is shifted 1,000 angstroms, from an original position of 4,000 angstroms. Does that imply that a line at 6,500 angstroms is shifted by 1,000 angstroms, as well? I read that visible light is affected more than radio wavelengths, and I want to clear it up. I always thought the doppler shift "moved" all wavelengths the same amount (as implied), but I saw a formula in another source that indicated the RATIO of the amount of shift versus the original wavelength was the same across the spectrum. I just want to clear it up.

I want to find a program that will return the pixel values for a bitmap or jpeg image. The x and y coordinates of the colors are irrelevant. My goal is to determine the frequency distribution of certain wavelengths.

Just curious. Cumulonimbus clouds can precipitate prodigious quantities of rain and hail. Before precipitation begins what is the mass of the cloud? What percentage of its mass typically precipitates?

Another, related, question: what is the mass of a fair weather cumulus cloud 5 x 5 x 1 km?

Dusty lanes are concentrated in the galactic equatorial regions of spiral galaxies. Why? Why isn't it disseminated more generally? Is there a mechanical reason?