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BYTEBACK
Cosmology
Would Ms. Fatima Sajid please answer my questions:
1. Which planets cross the sky from East to West?
2. Which planets do not cross the sky but do appear on Earth’s horizon and can be seen?
3. Are there any morning stars or evening stars which rise but again sink back? In what months can we see them in Pakistan?
4. I have seen some stars at night which, over a period of time, cross ahead of the others in their front. Am I correct? Which are those stars and are they faster in speed than the others?
DR N. A. BALOCH
Sindh University Old Campus
Hyderabad
Fatima Sajid replies: I’ll try to answer the questions as best as I can:
1. All the planets whose orbits lie outside the Earth’s orbit cross the sky from East to West. These are, counting from inside: Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. (I wonder what exactly you mean by “cross the sky”... because these planets cross the sky surely but only over several months... not in seconds or minutes.)
2. The planets Mercury and Venus, with orbits inside Earth’s orbit, do not cross the sky but do appear on Earth’s horizon and can be seen.
3. Usually, what is meant by morning or evening stars is Venus and sometimes Mercury because these two planets appear only before sunrise or for a while after sunset. Mercury rises only about 20 degrees above the horizon and Venus almost 40 degrees. Every celestial body, like the sun, rises and falls because of Earth’s rotation on its axis. When Venus is visibile at about 45 degrees altitude above the horizon, it will set in about three hours because the Earth’s rotation rate is about 15 degrees per hour. Everyone on Earth can see Venus and Mercury when they are visible, of course in their own time zones. On a given day, if Venus is visible from, say, the United States, it is also visible from Pakistan or any other country, just at different times. Visibility of Venus varies from month to month because of Venus’ and Earth’s relative orbital displacement. Given the fact that Venus completes its journey around the Sun in about six months, its visibility varies accordingly. For a few months, it is visible in the East during hours before dawn, and then goes behind the sun to come up again in the West in the hours after sunset.
4. The astronomical bodies which move in a human lifespan against the background stars are the planets of our solar system. The stars are so far away that it takes thousands even millions of years for their relative positions to change as seen from Earth. They are all located in a three-dimensional space and move in different orbits at different speeds. But since they are so far away even when one of them moves a light year (9 trillion kilometres) they hardly appear to have moved at all except to professional astronomers using accurate positioning and telescopes.
The “stars” that we see crossing ahead of the others are actually the planets visible to the naked eye (Mercury, Venus, Mars, Jupiter and Saturn.)
IE doesn’t work
I had been using WinXP. Suddenly its integrated IE browser has stopped opening any websites. I tried using proxy but it didn’t help. Other application such as MSN Messenger runs fine.
OBAID MUNAF
obaid3d@hotmail.com
Editor replies: This problem is very common with IE. If you’re getting the getting an error, “Windows cannot open the Page”, then your Explorer’s files have been corrupted. Try one of the solutions to fix this problem: Go to Add/Remove in Control Panel; double click on Internet Explorer. It will give you an option to repair this application. If that doesn’t work, reinstall WinXP, or choose any other browser, such as Opera 6.0, which is available on most installers CDs.
Cable net blues
Since I started using cable net, my Win98SE OS began showing errors. I can’t run game on my system, whereas the same the same OS.
UMAIR SAEED MEMON
Editor replies: It appears that both the problems are inter-related. It happens when your system files get corrupted making your operating system unstable. The unstable system architecture leads to crashing all the drivers. As a result, you get all sorts of errors and often experience system crashes. This may be playing havoc with your games too. The problem may also have stemmed from viruses which are usually found on cable networks, or from bad drivers for your Lan card which result in destabilizing the OS.
We’d suggest to reinstall your OS after completely formatting your Root Partition. And since you are always hooked up to LAN, it is recommended to have an updated antivirus program running on your system. In case, the problem persists, get your hardware checked by an expert hardware technician.
Installation problems
I tried to install Norton Anti Virus. At completion, I got the “run time error” message. After that I could not open the anti virus. I couldn’t even see it in Add/Remove programs. I deleted the folder directly. On booting again I got a message that some file is missing in the anti virus program.
I also tried to go to Regedit. But the window opens and closes too quickly, giving me no time to do anything.
Then I went directly to Windows where I found Regedit. I checked its Properties and then went to hidden, read-only and archive. After that I can’t find the icon of Regedit. I am using Win98 on a P II, branded IBM system.
SAIMA
Islamabad
Editor replies: Seems like your system is infected with one of the Yaha variants. This virus kills the antivirus system first and does not let it load again.
Deleting the directory won’t help as your problem is virus activity, and plenty of it from the looks of it.
You can reinstall Windows and replace the System files that have been affected. This will replace the affected files and replace most of your original files. After you download Symantec ActiveX control onto your PC, try online scanning at
