The Observant Astronomer

The passing scene as observed by an observant Jew, who daylights as an astronomer.

Tuesday, April 19, 2005

Cleaning your computer for Pesach

Zman Biur offers practical advice.

Monday, April 18, 2005

Rabbi Blumenkrantz and Homeopathy

This is the time of year when the observant American Jew is busy consulting the various guides to kashrus on Pesach. One of the most thorough, and stringent ones, is the annual publication by Rabbi Avrohom Blumenkrantz.

In the chapter on medicine, he devotes two pages to the question of homeopathic remedies. For the most part, this year's text is the same as in previous editions with the following remark on page 11-364 following a full discussion of the extent of the dilutions involved:
Since homeopathy is very effective, nontoxic, cheap, and in most instances easily accessible to the layman without prescription more and more frum people are using it.

This year he adds a new paragraph at the end (page 11-365):
Whenever we wrote that homeopathic medications may be used is[sic] only if at least some of molecules[sic] from the original "medication" are still in existence in the dilution. But if the dilution is such that there is[sic] no molecules left from the "medicine"- then one would NOT be allowed to use it. See Below.

"Below" refers to an article dated Adar 5765, entitled Some Halachic Concerns Regarding "Alternative Health" by Rav Menachem Kelinman, author, Hisna'ari Mal'Ofor which points out the often forbidden roots of various alternative-healing practices, including homeopathy. The prohibitions involved relate to serious issues of Avodah Zarah, kishuf (sorcery) and k'fira.

It appears that Rabbi Blumenkrantz is reconsidering his support for homeopathy. It will be interesting see if the contradiction has been removed from next year's edition.

Friday, April 08, 2005

Washing Dirty Laundry

As I was folding the midweek laundry, I was contemplating the remarkable skill of the lady who owns the laundromat we frequent. Now you may wonder why a laundromat, but the reason is quite simple. It is more convenient to go there than to do the laundry in house. At home, the nearest place to install a washing machine is down two flights of stairs in the nethermost depths. This is very common in North America, at least in the parts where there are basements.

It is a dirty secret, but the reason for this is that it seems impossible for North American washing machines to be housebroken. The American family lives in fear of their washing machine spontaneously spilling its load, flooding the room, seeping through the floor, melting the plaster, and ultimately destroying the homestead. So, banished it must be to the basement, to minimize harm from the inevitable disaster.

British washing machines don't seem to have this problem. In Britain one has one's washing machine in a room within the living area; usually either in, or adjacent to, the kitchen. One switches easily from dinner to laundry without the need to haul heavy loads up and down endless, narrow stairwells.

Similarly in Israel, but, given the standard construction of Israeli apartment buildings, an unruly washing machine poses no risk in any event. After all, the standard way of washing tile floors there is to dump a bucket of water on it and push the water and dirt down the conveniently placed drain.

But American washing machines are simply too dangerous to keep in the kitchen. So, faced with all those stairs, we take the simpler alternative of twice-weekly visits to the local laundromat. There we can take advantage of the efficiency of parallel processing, doing all the laundry in the time required for but a single load in the serial-style basement laundry. The remaining bottleneck is folding.

Which brings me back to the remarkable skill of the laundromat owner. Here is a woman who is able to quickly transform a mound of dry laundry into an identically sized stack of precisely folded garments. Through regular practice and a focus on the essential point, an unruly situation, an unstable pile, is brought to order.

Thursday, April 07, 2005

On Time Zones

Beside the disruption of changing the clocks twice a year, one of the reasons for objecting to Daylight Saving Time is that many of us are on DST year round anyway, so the change puts us on double DST in the summer.

To understand this, consider this time-zone map on the UK Met office site:

Time zone map

The faintly coloured vertical bands are the nominal time zones, 15 degrees wide, centered at 15 degree spacings starting with the Greenwich meridian. On the central meridian of each zone, the mean sun is due south at local noon. At the eastern boundary of each zone, local noon is at 11:30 AM zone time. At the western boundary, local noon is at 12:30 PM zone time.

The darkly coloured regions are the actual time zones. What is interesting is that most of them are systematically shifted to the west. For a striking example of this consider Spain. It ought to be in the GMT zone, like Britain due north of it. Yet it is in the zone GMT+1, so local mean noon in Madrid is at 1:15 PM. Asian Russian time zones are all systematically displaced 15 degrees to the west---year-round DST, except in the summer when they also go ahead one hour.

In North America the western boundaries of both the Eastern (GMT-5) and Central (GMT-6) time zones lie at roughly the central meridians for the Central and Mountain (GMT-7) time zones, so the western parts of these zones are already half-way to DST even when standard time is in effect. This westward bias is why Indiana, Arizona, and eastern Saskatchewan don't join in the annual jump to the west. They're already there.

Not every country deals with this the same way. China just puts the whole country on Beijing time. For the far west, that is triple DST. India and Iran, on the other hand, since they straddle the boundaries between two time zones, take the sensible option of shifting themselves a further half-hour from the nominal time zone in their western halves. This way they can keep noon at roughly 12:00 everywhere without requiring two time zones for the country.

If you must know who's going on or off DST when check out the links from here.

UPDATE: (15:30) CNN is reporting an AP report that the U.S. Congress is considering an amendment to energy legislation to extend Daylight Savings Time by two months, to run from the beginning of March to the end of November(!). Good luck to anyone in the western edges of the time zones who want to get in shacharis before work, especially in November. In Detroit, you won't be able to put on tefillin until ~7:30. I hope the kids enjoy the sunrise as they walk to school. How much energy can you really save if it is pitch black when you get up? Has this really been thought through, or is this a mindless reaction to rising oil prices?

Tuesday, April 05, 2005


I've started up a blogroll off to the left there connecting with whom I frequently reading. Don't feel left out if you're not there. I imagine I'll be adding to it as things go on.

Google sued for loss of productivity

but can anyone explain why Massachusetts has high resolution imagery of every tree, right up to its borders?

Friday, April 01, 2005


It's here again. The dreaded spring weekend where, by government decree, we lose a valuable hour of Pesach cleaning time. Unless you are fortunate enough to live in enlightened places like Indiana, Arizona, or Saskatchewan. My kids can't get up on time for school as it is, how am I to get them out of bed an hour earlier come Monday?

The whole thing is a fraud anyway. The British are more honest about it, calling it just plain "Summer Time", but here we get a Madison Ave. getting into the act with this prattle about saving daylight. No. Someone decided that it would be a good idea for people to get up earlier in the summer, to take advantage of all that beautiful extra sunshine. But, people, being people, stubbornly insisted on keeping to their usual schedules, so the whole thing had to be legislated into existence.

It is bad enough that it starts in April, but why does it have to go all the way to the end of October? Where is the logic in starting just after the vernal equinox, but having it go half-way to the winter solstice? If it really has to do with the amount of daylight, we ought to turn it off two months earlier, i.e. at the beginning of September. If we really must put up with this, let the clocks go back the day before school starts.

Meanwhile, the Kazaks have the right idea: Abolish Daylight Savings Time.

Things crossing my desk

The latest issue of Tidbits contains a whole slew of product announcements from Apple. I particularly like the furry iBook.

On a more serious note, it seems that one of astronomy's holy mountains is the center of a new dispute regarding truth.

In the "What the heck is that?" department, Neuhaeuser et al. report on the direct observation of a ~2 Jupiter mass object moving through space with the young star GQ Lupi. The 140 pc distance quoted is the distance from us. The substellar companion is ~100 AU from the star itself. (For comparison, the Earth is 1 AU from the Sun; Neptune is 30 AU.) The orbital period of this object is of order 1000 years, so don't hold your breath waiting for it to move. The only reason we can see the thing at all is because it only ~1 million years old, and so still rather hot.