The Observant Astronomer

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

Tuesday, November 29, 2005

The Incredible Jerusalem Compass

An advertisement for this device just came across my desk. It is for a patented, non-electronic, compass that is guaranteed to point towards Jerusalem. Indeed, according to Rav Moshe Halbershtam, "It is a fine device—mainly, that it points directly towards Eretz Yisroel, directly towards Jerusalem, directly towards the holy site of the Beis HaMikdash, directly towards the Holy of Holies—just as is taught in the Gemora."

So, until now facing in the general direction of Jerusalem has been good enough. Suddenly we need to face precisely? Is this a great circle route, or a straight line through the Earth? Will we need to reorient all our shuls? And, can you change the location it is pointing to? Does it do, say, Mecca?

UPDATE: I asked the advertiser about the claimed patents and they just directed me to the manufacturers website at There, we find, that there are only "international patents pending" and that it was invented by "Moshe" a "married student in one of Jerusalem's popular Yeshivahs". It is claimed to "defy the laws of nature". Too good to be true, I think. Anyway, anyone have $25 to blow on this and see if it really works? Additional finances for either extensive travel, or postage will be required for a full test.

FURTHER UPDATE: I have located what is apparently the patent application in question. The inventor is indeed Moshe, but he now apparently lives in New Jersey. It is listed as a "Novelty Item". As one of the anonymous commentators speculated, it is indeed a standard compass with the magnetized needle hidden and another, non-magnetized, needle suspended above it set to point east. At point 14 it points out that similar devices could be made for other locations ". For example, a compass indicating South can be marketed in Finland and Russia," etc. At point 16, it is designed to "appear to defy the laws of physics" by minimizing the space for the magnetized needle.

So, it will only work from one location. It does not point any more accurately to Jerusalem than any other compass. It just saves you having to turn 90 degrees. It is indeed incredible. Literally, too good to be true. Further commentary is left to the reader.

ANOTHER COMMENT: Correspondence seems to indicate that the advertised item moves beyond the linked patent application. Josh Waxman on parshablog has some related thoughts on how it might actually work, which also occurred to me. See my comment there for further thoughts.


Anonymous Anonymous said...

Do you think it works? It can't possibly work.

3:54 PM, November 28, 2005  
Blogger Menuval said...

"Defy the laws of nature"? Do you think "Moshe" from Yeshiva could do with a million dollars from James Randi?

3:05 AM, November 29, 2005  
Anonymous Anonymous said...

There is a serious halakhic problem here. These "rabbis" are not only perpetuating fraud, but getting good pious Jews to pray in the wrong direction!

11:24 AM, November 29, 2005  
Anonymous Anonymous said...



Now you can be TOTALLY wrong!

11:30 AM, November 29, 2005  
Anonymous Anonymous said...

Actually, I bet it's just an ordinary compass rigged to point east. So for most people it will be mostly right.

11:35 AM, November 29, 2005  
Blogger kurkevan said...

This is from the FAQ section on their website:

I understand that the Kosher Compass is very useful anywhere in the world, but does it also have usage in Israel?

It sure does. Even when you arrive to Israel, anywhere in the entire country, the Kosher Compass will point you in the precise direction of the Jerusalem.

Now can someone explain how that works??

11:17 PM, November 29, 2005  
Blogger The Observer said...

Given that the advertised item corresponds so well to the description of the "novelty item" in the patent application, and on the assumption that they are the same, they can't.

8:45 AM, November 30, 2005  
Blogger Rebeljew said...

Thi guy will test it for free and give them a million bucks US if the compass does anything to defy the laws of nature.

10:40 AM, November 30, 2005  
Anonymous Anonymous said...

Here is an email conversation I had with "Moshe." (As of this date, he has not answered my last letter)

Dear Sir

Does your compass point to Jerusalem using the "Great Circle" route, or the latitude route? For instance, if a person in Japan wanted to know the shortest distance to Jerusalem, he would place a string on a globe with one end on Japan and another end on Jerusalem and pull. The string will run north from Japan, over the North pole and then south to Jerusalem. On the other hand, if you look at a mercator map, you would say that you need to face east. This is a matter of great halachic controversy and I am curious to know which one your device follows. Perhaps is has a setting that switches between these two methods....


Dear Zev,

There may be a big conflict in the Muslim world as far as the Great Circle route , i.e. the shortest distance, but we, in Judaism follow the Torah, and therefore we are not traveling like an airplane when praying, therefore we do not have a need to face in a direction that will lead us in the shortest route, but rather, in accordance with Halacha, we face in the direction as dictated in the Shulchan Aruch.

Ones Kavanah, when praying has no limitations of distance. Our focus when praying does not travel like an airplane. The Mishnah Brurah clearly states that we are to face in the direction of Jerusalem, which for us in the U.S. is somewhat South-East.

I hope that this has answered your question.

All the best,



While you have answered my my question, you have only given one side of the equation as far as the halacha goes. Many rabbis hold (my own included,) that the halacha does indeed follow the great circle route. Of course, when the Shulchan Aruch was written there was no America or Jews living far enough away for this to make a difference. North, East, South, West, etc are not halachas but merely indicators. A perfect demonstation of this would be an example of someone standing on the North Pole. This person would be facing Due South no matter which way he is facing. Yet only one direction is correct. Se we see that the NESW equation only works for someone close to or in Eretz Yisroel. Once you get farther away, the Great Circle is really the only criteria that makes any sense.

Best of luck


When the Shulchan Aruch was written, the Ramah and other Acharonim lived in Europe, North West of Eretz Yisroel which is far enough to make a difference as far as the great circle is concerned. The Ramah, says that we face East towards Eretz Yisroel, and, the Chafetz Chaim says that we go like the Lavush, that this means to say more South Easterly direction. These geographical locations in Europe are far enough away for the Muslims to use the Great Circle theory, but we see clearly that the Acharonim did not. Also, the Bahai, use the Great circle for Europe as well, which is in fact far enough away to see them facing in an slightly North-Easter direction. Our Gedolim who lived in Europe chose not to interpret Halacha in this manner, i.e. what we call "direction" is something that even if it may be a "shorter" distance, , our intent in prayer doesn not work this way.
Of course, you have to go like your Rav,

All the best,



I'm not quite sure I understand what you are talking about. The GC Route anywhere in Europe is still roughly SE. It changes to East around the middle of the Atlantic and reaches NE by the time it hits New York.

I am thinking that perhaps you (and the muslims?) hold you have to face the city exactly. Then there would be a slight difference. Now that I think of it, this seems to be just what your device does. But if you read the Shulchan Aruch carefully, you will see that you only have to face Yerushalayim if you are already in EY. The closer you get, the more exact you have to be. My Rosh Yeshiva R. Meiselman explains this al piu mussar that you have to grow one level at a time and can't "jump" straight to the highest level of kedusha. In fact, we can be melamed zechus on those in the US who face East or SE that once you are on a different continent, you only have to face the continent. Of course, this is my own chidush, and not found anywhere. The other possibility is that they are being mekayaim "habo lehachkim yadrim" - and it worked! They are all very smart!

In any case, you seem to be aware of the issue and have probably been instructed by your rabbis and/or your own learning to design it the way you did so you certainly "have what to rely on." And it would certainly point the right direction in EY, which is the only place where you are required to face Yerushalaim anyway.

I'm curious. How does your device work? How does it know where it is? GPS?



Actually if you look into it deeper, even in Europe, the Muslims, Bahias are very exacting with the GC and they face slightly North-East.
The Shulchan Aruch as can be seen in the very beginning of siman 94, is all referring to what a person can do as far as how exact one can be. Of course, if we have a means to be more exacting, then, even better. Of course, you are right that from the U.S. it would be difficult for a human being to keep his head so straight in the direction of Yerushalyim. Even though the compass needle is facing Yerushalyim, but it would be difficult for a human beign to keep his head so straight. .
Of course, not just in EY is it obligatory to face Yerushalyim. If someone was in Jordan, Lebanon, Syria etc. they too would be obligated to face Yerushalylim, i.e. wherever it is possible.
Anyway, it is still very important to have a kosher compass for davening in various shuls where the Aron in most places is not facing EY due to the building ordinances
All the best,



Ah, yes so many ways to interpret the Torah and eilu v'eilu divrei Elikim Chayim. I always took my RY's pshat to be the only one, and now I learn of another possibility. I would still think that his fits better into the words, otherwise it would just say that you should try to do your best to face bais kodshei hakodoshim. You wouldn't need a separate posuk for each level! (See Brachos 30a). But it would seem that if you're not obligated to face Yerushaliayim in Chu"L, and you whip out your fancy little bronze kosher compass in order to do better and face Yerushalayim, that would be a violation of "chaishinan leyoraha." And I am intreagued with this concept of having to face Yerushalayim in surrounding countries. Do you have a ra'aya to this? I am interested. I'm also interested in learning how your device works. Of course, if its a secret I will understand. Still, I'm not sure why I can't just use a magnetic compass here. From magnetic north, I can easily extrapolate East or SE, whichever I want - Unless I happen to be standing in between the magnetic North Pole and the regular North Pole - but not too many Jews find themselves there too often.

BTW, if this thing really does work differently than a magnetic compass, you might want to look into other applications.......

Zev :)

10:10 PM, November 30, 2005  
Anonymous Moshe said...

Dear Zev,

I really don't know who you are, and what your pupose is, but, I will say one thing. YOu call yourself the "observant astronomer". You may be an astronomer, but I am not sure how observant you are.
When your comments hint and even lead to ridiculing Gedolei Yisroel. Then I will certainly discontinue from any connection with you. The Kosher Compass as advertised on the site is not the same compass that you thought you found in a patent application of some 5 years ago.
The KosherCompass was brought before the Gedolei Yisroel. Torah giants that you have no problem in making fun of them,and enabling others to bring Schoke and laughter in the midst of their names.
It is clear to me that this compass, which you have never even seen, but, the Gedolei Yisroel did see, certainly has no usage for you.
Those of us who will appreciate having a kosher compass to enable us to fulfill the mitzvot of Torah better, and easier,will find usage in it. As was mentioned by the Gedolei Yisroel.

10:58 PM, November 30, 2005  
Blogger The Observer said...


If the patent application referenced is not the one you are using, then it would be appreciated if you could give the correct reference. While the TES advertisement claims the compass is patented, your own website claims only "patent pending". But it also is claimed to "defy the laws of physics", which is hard to credit without some understanding of how it works. So, what is the application reference?

11:52 PM, November 30, 2005  
Blogger The Observer said...

For the record, Anonymous Zev and The Observer are not the same person. I thank Zev for publishing his correspondence here and hope that Moshe will be willing to give us a better idea of how his compass works.

11:54 PM, November 30, 2005  
Blogger joshwaxman said...

Thanks for covering this.
I wrote a bit about this over at my blog:

I contacted the distributor. I am not publish the text of the letters since I didn't ask permission to do so, from some back and forth, it seems that is will indeed work from different locations.

I think it might need some configuration, based on the presence of a knob on the side and some numbers on the face. See my blogpost for more details.

9:02 AM, December 01, 2005  
Blogger The Observer said...

After I posted last night I came up with much the same idea. For this to work there would need to be some calibration step to adjust the offset between the magnetized and non-magnetized needles. If that is the case, then fine, but you couldn't step off the plane and immediately know which way Jerusalem was, and you'd certainly have to do a lot of fiddling around in Jerusalem itself. The advertisement remains misleading.

9:38 AM, December 01, 2005  
Blogger joshwaxman said...

true. the pitfalls of ad copy.

everywhere in the world but Eretz Yisrael, you could presumably step off the plane and, having adusted it on the plane so that the correct number is on top (based on a paper that comes along with it), know where Yerushalayim is - without too much fumbling. Inside Eretz Yisrael, it is presumably more difficult - but would be based based on city; and in Yerushalayim itself - well, it only said it would point at Yerushalayim, not at the mekom hamikdash.

Still, if calibration is required, it would be nice if they mentioned this in their ad.

10:23 AM, December 01, 2005  
Anonymous Anonymous said...


I was the one who told you about this site, as a favor to you so that you could answer everyone's points including my own. But instead you choose to berate me publicly for something I didn't do. This is clearly demonstrable, as my posting above is the entirety of our correspeondence.

My main points, still unanswered are:

(a) Outside of Eretz Yisroel you are not chayav to face Jm but EY. This is not just because "ee efshar" but a separeate halachic category that has a separate limud (berachose 30). One of the gedolim in his haskama alluded to this saying that it points "towards Eretz Yisroel."

(b) Someone who would pull out this device in a shul and explain to his curious neighbors that he is being "machmir" and facing Jm in Chu"l would be considered a "yuhara" and is not allowed to do so according to halacha.

(c) Someone who lives in places that are far from EY needs to look at the Great Circle Route as opposed to the meridians. This last one is a bit hard to grasp, but the best way to explain it is to imagine someone standing on the North Pole. If he faces Jm he is facing South. Now lets say he takes a few staps back while facing in the same direction. Now what direction should he face? Well, anyone with half a brain will tell you that he should keep facing in the same direction! This is the Great Circle Route. If, however, you have to consider the meridian, he would need to start turning a little bit to the right or the left already. If the person keeps walking backwards till he reaches the meridian of Jm, you would have him turning a complete 90° while I would have facing the same way he was facing before. Another example: Let's say he starts off standing facing the paroches. Then he back up. An he keeps backing up facing the same direction and travels around the world. He will be pointing all different ways of the compass (NESW) while still be facing towards the paroches.

Now the letters of the gedolim giving their approval do not specifically deal with any of these points. We may then conclude that they could not have meant for it to be used to the extent these points would matter.

12:28 PM, December 01, 2005  
Blogger kurkevan said...

Zev (aka anonymous),
the great circle route cannot be taken as a given. On the Pacific Coast, for example, I'm pretty sure everyone faces east, even though it might be a shorter route to travel over the north pole region.

1:03 PM, December 01, 2005  
Anonymous Anonymous said...


The minhag all over the US seems to be to face East instead of the CG route. I have thought of two ways to be melemed zechus (1) The din to face EY is only on the Eastern Hemisphere. Once you're on the Western Hemisphere, it's another step removed so you only have to face the hemisphere EY is on. Of course, you would need another posuk for this innovative new din. (2) We are mekayaim the concept of "habo lahachkim yadrim," and indeed it seems to be working, albeit in a funny way on the West Coast (just kidding).

3:02 PM, December 01, 2005  
Blogger Rebeljew said...


Fact remains that it is not Observer or Zev but YOU who have ridiculed the sages by representing something to them or in their name (I do not know which) that is a bald faced lie!

The ad states clearly that your device defies the laws of physics and faces Jerusalem. Whether it uses a simple magnet as Observer says or a GPS as another comment proposed, their is no defiance of any laws of physics.

There are a few courses you could take here, Moshe:
1) You could arrogantly assert that we are all bad in some way for calling you to the carpet. That is would be unfortunate, since it would not show any strength of character.
2) You could ignore us. Ditto.
3) You could change the ad to "apparently defies the laws of physics". That is at least tenable advertising.
4) You can admit that the device has no magic powers and change the tack of the ad altogether.
5) You can take the Randi JREF challenge referenced above, get a million bucks that alot of Jewish charities would love if you can't use it, shut all us arrogant bugs up, widely embarrass Randi, a vocal atheist and get extended notariety for your device to sell like hotcakes.

Option 5 should be simple if your device conforms to its advertisement. If not, you have lied to the gedolim or in the name of the gedolim, or tricked them, publicly shaming them and you need to do something about that.

So answer the question honestly, does your device defy the laws of physics or does it not, and on what principle does it work?

11:57 AM, December 02, 2005  
Blogger joshwaxman said...


I posted the following in response to a similar comment you left at my blog:

oy vey.
give me a break!

Only someone with a huge chip on his shoulder would read it that way. No *chareidi* would read it this way. There is a difference between ad copy and genuine claims of miracles. "Defies the laws of nature" is ad copy.

They spent 11 years developing this, and there is a patent pending for it (the latter a fact mentioned in the ad). What they mean by "defies the laws of nature" is that it *seems* to defy the laws of nature in that people expect a compass to point North, not east or whatever specific direction Jerusalem lies. Obviously, they hope to patent a technological construction, rather than a miracle.

The gedolim are NOT endorsing the "miracle". They are endorsing the "better" halachic observance made possible by use of the Jerusalem compass. This is an endorsement re halacha, not regarding miracles.

I don't see anything in Moshe's response that would suggest otherwise.

Yours is an attempt to manufacture a controversy where none exists.

1:05 PM, December 02, 2005  
Blogger Rebeljew said...

11 years developing a compass with an arrow pointing in a particular direction????? I've had one for over 25 years. I think it cost me 2 bucks.

And it was Moshe, not me who relied on the sages in response to the challenge. See the comments above. He is challenged and he responds that the haskama should be enough. I cannot think of any reason that such an item would need a haskama, UNLESS the green monster made the rounds.

12:53 AM, December 04, 2005  
Anonymous Shmarya said...

I see Josh Waxman prefers spin over truth.

There are actual laws (and halkhaot) that govern advertising, JW, and TES and Moshe have violated several of them.

"Defies the laws of nature"?!?

Give me a break.

3:01 PM, December 04, 2005  
Blogger joshwaxman said...


grow up. seriously.

you are well known as a scandal-monger, so I do not know why I feel compelled to answer you - perhaps because others might be misled by you - but here goes:

first, the obvious:
"There are actual laws (and halkhaot) that govern advertising, JW, and TES and Moshe have violated several of them."


I am an independent blogger and have absolutely *no* affiliation with the company. Perhaps you remember me from our run in a while back on protocols, when you were posting nonsense on Rambam and spontaneous generation (claiming that everyone in his generation denied spontaneous generation)?

Since I have no affiliation with the company, how in the world have *I* violated any advertising laws? I am no lawyer, but I would think that to violate the law you would have to advertise something. Nor have I violated any halachot regarding advertising, since I am not advertising.

But then, you are not a lawyer either, nor a great halachist, so you are just talking out of your hat.

If you look at my reaction (over at my blog), I did three things.
1) Post about a cool gizmo being put out just in time for Chanukka.
2) Read Observant Astronomer, and worry that I was misleading people into buying something that was not as advertised, and so published a warning.
3) Corresponding with the company that was selling it, and finding out the merits of the various claims, looking at pictures of the gizmo and figuring out how it might work, and posting a mixed review.

Did you even bother reading my post?? I'll post a link to it again:

I seriously doubt that the other two parties have violated any laws or halachot either. On the other hand, there are certainly halachot of lashon hara and rechilut...

As to the actual issue, *nobody* is being fooled that there are miracles being performed here. From my perspective, one has to be either a total idiot or someone with a huge chip on his shoulder to read the advertisement and think that is what is really being claimed. From your blog and conduct in the past, I know that the latter part, at least, is true.

If you or rebeljew were really just concerned about violating advertising laws, you would have been carping about the following items on froogle for example:

There are skateboards, sunglasses, and a magic trick which "defies the laws of nature."

Do you really think the skateboard manufacturer is really claiming to defy the laws of nature?

Do not be silly.

rebeljew, I'll respond to you later.

3:37 PM, December 04, 2005  
Blogger joshwaxman said...


what is warranted here is seriousness, not jokes.

"11 years developing a compass with an arrow pointing in a particular direction????? I've had one for over 25 years. I think it cost me 2 bucks."

11 years is what they told me, as a reason they could not disclose the particulars, and when I asked whether it worked via GPS - that it was 11 years in delevopment, and patent-pending.

It is not merely a compass, but one that points to a direction other than North, and either automatically or, more likely (as I pointed out on my blog), with some reconfiguration, can point in the direction of Jerusalem. The first part, pointing in a direction other than North, was the first patent that Observant Astronomer discovered. The second, which is either the automatic or reconfiguration twist, is presumably the subject of the second patent, which is pending. I assume they wanted it to work in a user-friendly manner, which would partly account for the development time.

and so, your comment:
"11 years developing a compass with an arrow pointing in a particular direction????? I've had one for over 25 years. I think it cost me 2 bucks."

is misleading, and it seems deliberately so. Let me guess... the particular direction happens to be North, right? (because another direction would require another magnet, and why in the world would a non-Jewish manufacturer want a compass facing east??)

"I've had one for over 25 years. I think it cost me 2 bucks"

Yes, and I have a similar compass that costs the same. But that is not what is under discussion, and you know that.

"And it was Moshe, not me who relied on the sages in response to the challenge. See the comments above. He is challenged and he responds that the haskama should be enough. I cannot think of any reason that such an item would need a haskama, UNLESS the green monster made the rounds."

I never implied that it was you who relied on the Sages. What in the world are you talking about??

And yes, he does refer to the gedolim in response to a question. A challenge on an halachic matter. He writes:

"Our Gedolim who lived in Europe chose not to interpret Halacha in this manner, i.e. what we call "direction" is something that even if it may be a "shorter" distance, , our intent in prayer doesn not work this way."

this has nothing to do with the gedolim claiming to substantiate a *miracle,* as you claimed in your previous comment.

please substantiate your (somewhat dubious) claim.

and then you turn around and state:

"I cannot think of any reason that such an item would need a haskama, UNLESS the green monster made the rounds."

Well, one place to start is this halachic challenge that was made about the Great Circle, above. If there is a dispute, then haskama from certain gedolim would serve a purpose. A more likely reason for the haskamot in the ad: Most people (falsely) assume that facing East is what is required. Some newfangled device that seeks to change the direction Jews pray could be looked at with some suspicion. Haskamot could serve to allay this suspicious, and inform people that this is indeed al pi halacha.

5:00 PM, December 04, 2005  
Blogger Rebeljew said...


Let's get back to basics, 1) I liked your post on the points that you emphasized.

2) The device is likely as OA describes, a regular magnet compass, with a show face that points ina direction based on calibration. IOW, it is useless in finding Jerusalem unless you already know where it is, to point to it.

3) I have an old compass with a non magnetized needle that I can calibrate to identify any direction with accuracy, to the second. The magnetized needle indeed points North. The nonmagnet points wherever I point it.

4) I think you are cavalier in your conclusion. There are plenty of Jews who believe in magic and would read this ad as I have pointed out. Words mean things, and "defies nature" means magic. The haskamas then imply that the device works as FAQ #10 implies. That is simply not the case.

5) Great Circle and the claptrap about directions is all aside the particular point here. The haskamas are meaningless, since there is nothing to pasken. You can point the needle wherever you like, based on how you calibrate it. That is best case.

Please read my short post on this device. So far, my inquiry has gone unanswered at

7:47 PM, December 04, 2005  
Blogger Rebeljew said...

Moshe wrote:
"The KosherCompass was brought before the Gedolei Yisroel. Torah giants that you have no problem in making fun of them,and enabling others to bring Schoke and laughter in the midst of their names.
It is clear to me that this compass, which you have never even seen, but, the Gedolei Yisroel did see, certainly has no usage for you.
Those of us who will appreciate having a kosher compass to enable us to fulfill the mitzvot of Torah better, and easier,will find usage in it. As was mentioned by the Gedolei Yisroel."

Read the quote JW. Do you still not see my point?

7:54 PM, December 04, 2005  
Blogger joshwaxman said...

Sorry. I still don't see your point.

I read the quote before. This statement was a response to Zev, who was raising halachic issues. I *still* do not see this as claiming that they witnessed some miracle, or that the Gedolim are claiming that this operates miraculously.

At the *most,* you can interpret that they are verifying that it in fact *works* and points towards Yerushalayim from different locations. Which presumably it does.

You cannot correctly interpret this as meaning that the Gedolim are endorsing the magic of the product.

12:01 AM, December 05, 2005  
Blogger joshwaxman said...

in terms of your other comment:

1) thanks. :)
2) The way I assume it would work is that there is a pamphlet or piece of paper with different locations nad the correct direction to calibrate it to. Presumably, they would calibrate it before sending it to you, and you would consult the book anytime you went to a different part of the world. e.g. they would say to make sure 155 degrees points up in place X, and you would so turn it.
Obviously, this is not the same as *automatically* shifting direction, which is what one might be led to conclude by reading the advertisement.

It is *this* part that I find misleading, and which troubles me a bit, but not any hype about "defies the laws of nature," which is obviously hype of the type on can expect in ads.

3) Ah. Now I see what you meant. Perhaps they indeed do something similar, perhaps they do something similar to the first patent, though with the ability to adjustments. Look, either way, they still have some process which they are trying to patent, and which they tout. It is still a technological construct they are trying to patent, however trivial it is.

4) I don't think I am being cavalier in this assessment. I think you are underestimating the intelligence of these Jews. Even those who would believe in magic would not think that there is a patent on a magical process, and that the gedolim are giving haskamot on that. One who is mystically inclined and not a rationalist is not automatically a dope.

I think you would be hard pressed to find a Jew who reads this ad and believes this - that the device works magically or miraculously.

Also, in my response to Shmarya, I pointed out a skateboard and a pair of sunglasses which also claim to "defy the laws of nature." This goes to show that the phrase can be used by people advertising a product without the advertisers or the readers of the as actually thinking that the item works miraculously/magically.

Wouldn't the principle of dan lekaf zechut lead one to the conclusion that the makers of the KosherCompass intended it similarly.

Also, would your theoretically dopey Jew think that the skateboard works by magic? Would you support prosecution of this skateboard company for false advertising?

5) The way in which the device is intended to be used, it will point somewhat southeast from New York. Perhaps they will even automatically configure it this way. It either automatically (unlikely) or through recalibration will point to other directions than due East.

In fact, there is a section on their site:

in which they detail how one should use the koshercompass even in Shul, and not face the Ark, but rather the appropriate direction as indicated by the compass.

Most Jews do not know this. (In fact, it is a machloket Rashi/Tosafot -- see the situation in the YU Bet Midrash.) And where there is possible controversy, it certainly is helpful to have haskamot. People are more likely to buy and make use of the compass. Why object to such haskamot? People might be wary of purchasing and using the device, and this tells them that there is halachic basis and benefit to using it.

What I mentioned about the Great Circle was just in reference to *Moshe's* response on this blog.

Here are some well-meaning individuals. They came up with a cute chap, in which people will have "better" halachic observance, and the well meaning-individuals will make some money in the process. There is no sin of making a living. They package it as a fancy gift, such that people will get a somewhat useful, Judaically-oriented gift for Chanukka. It is certainly no worse than many of the other knick-knacks out there.
So why attack them? They have no intent to defraud.
The way I see it, they are caught up in the current Slifkin controversy, in which people try to draw up sides - us vs. them. But this case cannot be so categorized. The fact that they used unfortunate wording made certain people perk up their ears, and further, that they appealed to "Gedolim" as an authority really set people on edge - even as these Gedolim are cited as authorities on *halachic* matters, not on whether elephants can jump.

Can't we all just get along? :)

Kol Tuv,

12:39 AM, December 05, 2005  
Anonymous Shmarya said...

Josh Waxman –

I see your grasp of the English language (and its punctuation) is lacking. Try rereading what I wrote, pausing at the commas before and after your name.

I well remember you from Protocaols and from Bloghead, and your craven ability to apologize for important rabbis and Orthodoxy in general is legend.

RebelJew –

Josh is Steve Brizel on steroids. "Moshe" could turn out to be a convicted con man with a rap sheet a mile long and Josh would still be out there defending him. Waxman is an apologist of the worst sort. Fact will not sway him/

5:05 AM, December 05, 2005  
Blogger joshwaxman said...


for some reason I saw the comma before my name as a period. ok.

your interpretation of the advertisement as relying on a miracle still has no basis in reality. you have not explained whether you think the skateboard manufacturer also is claiming that their device works based on a miracle, and whether they have similarly violated halachot and laws on that basis.

and it is too bad that pointing out exceptional ignorance (yours in that post in protocols as a case in point) which leads people to misunderstand the words of rabbis negatively is considered apologetics ...

do you really think that Moshe will turn out to be a convicted con man with a rap sheet?

9:14 AM, December 11, 2005  
Blogger Lipman said...

I don't know what this is all about. I gather it is the same thing I've seen years ago in the possession of my Gateshead cousin, who bought it at the local môcher sforem's. It probably is same: an ordinary compass, and you have to adjust it according to where you are by turning a movable dial according to the attached list. You can buy a cheap compass and carve a mark for you place as well, or for several, if you're a frequent flyer..

5:50 AM, December 21, 2005  
Anonymous Yehuda said...

A Great Circle and a line straight through the centre of the earth is the same thing. You might have meant a Great Circle or a Mercator Projection. This has been the subject of halachic debate recently.

2:25 PM, December 27, 2005  
Anonymous Yehuda said...

I spoke with Rabbi Yosef Lieberman this past shabbos and asked him how the compass worked. He said you have to enter your location and then press a button. He said that there was a page with explanation attached.

The plot thickens...

3:16 AM, January 08, 2006  
Blogger The Observer said...


That's about what we figured must be going on, but it seems you'd need to enter an angle associated with a location, rather than just the location. The question is just how detailed their list of Jerusalem locations is.

10:23 AM, January 09, 2006  
Anonymous Anonymous said...

WE have a saying in the Gemorah, when one looks into the waters, they see their own reflection. We learn from this, that when one ridicules the other, that which they see in the other,(good or bad) is only what they themselves have.
If you see someone to be a cheat, lier, etc, then you yourself on some level have these middos as well. That is how you were able to recognize them in the other person.
I enjoyed reading this blog, and I must say that Josh Waxman, (from his comments) it is clear that he is looking for truth. Since he himslef sees truth in others, it is proof that he himself has this trait.
Certainly someone who needs to criticize another for grammatical errors, is lacking and very childish. Therefore, everything they say, must be looked at with scrutiny.
To change the topic. It is impossible to say that we should change our direction in accordance with the Great Circle and change the direction of our shuls in the U.S. to face North East, and in California, to face towards the North Pole. To change any halachah, we MUST have a source in the Rishonim. Without this, we would all be epikorsim. To say, or to hint that the Gedolei Yisroel, are not able to grasp this topic, is outright epikorsis. Everything comes from the Torah. Science, mathematics, etc. Many Rabbanim became engineers by learning the tractate Eruvin.
The only reason an airplane travels first North East from N.Y. in order to arrive to Israel, is because that is a quickest way of travel FOR AN AIRPLANE. Of course before the time of airplanes, traveling from Los Angeles to Israel via the Great Circle, would take us over the North Pole. This would have been the Longest way to travel since only an airplane can tavel in such a manner. So, therefore we should face in the direction of travel via the sea, since now this would be the quickest way to arrive?
An airplane, being a physical entity, like a boat, car, train etc, has limitations that it must travel over the surface of the earth. Therefore, since the bulge at the center of the earth is at its widest, the airplane, will fly in a North Easterly direction where the curvature is smaller. This arc will enable the airplane to avoid this buldge and thereby arrive quicker to its destination.
Our prayers (teffilot) our not physical entities nor do they have the limitations of a physical forms of travel, i.e. travelling over the surface of the earth. Nor do we have a source in the Torah stating that the "direction" for davening has anything to do with distance.
Also, to give all types of proofs that if someone is located at the North Pole, and they looked outward, there would no longer be any directions of N,S.E. or West.
This is irrelevant to us. We relate to our world in the way that the Torah tell us to.When we look in either direction, we don't see a roundish world, we relate to it in a flat manner, even though we know that it is in the shape of a globe.
We look straight ahead-North,South, East and West, and this is how our Torah tell us to relate to it. This is the Halachah, and we cannot change it. Out prayers are not physical, they do not travel like physical forms of transportation, and they do not have the limitations of these forms of transportation.
The Torah is Lo'Beshamyaim', it is here on earth and the Rabbanim were given by the Torah, the authority to explain and decide Halachic mattters. Anyone who does not agree with this authority, is an epikoris.

7:51 AM, January 13, 2006  
Anonymous Anonymous said...

Hi Observer,

Is it possible to plot the direction of Jerusalem from any place in the world-- let's call it Place X-- given the absolute locations of both places (Place X and Jerusalem)?

Thanks in advance.

10:31 AM, April 09, 2006  
Anonymous Anonymous said...

Looking over this blog,and seeing the dates, it is so interesting to read people's thoughts before the item was even available.
Now 6 months later I know so many people who have purchased this item as well as myself. It really is well made, it does appear to defy the laws of nature, and it really makes a unique gift that no one has. People are so impressed when I show them mine.

2:18 PM, May 28, 2006  
Anonymous Jo Public said...

I imagine 'anonymous' above is working for the manufacturer.

The advertising of this item appears to be a misleading Hillul Hashem (particularly as it is being sold in the Christian world eg to Catholics).

for a hint as to how it "works"

I note that many cities with large Jewish populaces are not included on the database.


10:15 AM, May 22, 2007  
Blogger DaPenguin said...

Got the below quote from the TES site. Also - I have this compass and it works as advertised. Selling now for 39.95US$. I am not affiliated with these companies. Just a happy customer.

"The $49.95, non-electrical, non-computerized device - registered for an international patent - appears to defy nature, as the magnetic needle does not always point north. It is pre-calibrated for the continental US (excluding Miami, Hawaii and Alaska). But "log book" code numbers on the inside of the brass cover encompass virtually any other location on the globe. The user recalibrates by releasing the MPR bar, rotating the rim of the compass glass until the needle is opposite the relevant code number on the dial and sliding the MPR bar towards him after recalibration. The setting doesn't have to be changed until you travel to another city in a large country or a different small country. "

1:11 AM, January 24, 2008  
Anonymous Anonymous said...

Just today I came across an ad about this Jerusalem of Gold Compass (see It says 'Instead of pointing North it will always point to Jerusalem.' This got me thinking and browsing the internet. Then I found this site that apparently has been approaching it from a scientific standpoint. Unfortunately, the communication with the designer was less than productive to gain understanding.

So, I kept reading to find more clues that would affirm my hunch. I got in a good mood. After reading every post here, the last one helped me to be convinced about its working.

Regardless of a need to practice religious acts in a certain manner, I am just curious after its working from an observer standpoint, as I am sure others are. There is a certain interesting thought process going on when trying to figure out how it works. Indeed, if one knows how it works, no explanation is needed. One could argue that the working is sufficiently explained by the ad. I want to make that clear. If I want to know what ice-cream is, I just need to know that it is edible, cold as ice, sweet and a delicacy to try. But do I need to know that it either contains milk or only water and fruit? Only if I am allergic to milk. Do I need to know how to save it for next month? Only if I am not interested in eating it right now. Do I need to know how they pack it? Only if I want to take it home. Do I need to know how they prepare it? Only if I want to make it myself.

So, the question how it works, in this case, does not ask for its use, which is clear from the ad. The question here asks for the principle that this device uses to produce that result. The intent of that question could be the reason for the miscommunication. The salesman has the right to answer however he wants, without revealing this information, because in a real sense, it is not relevant to him whether you know the 'secret', he only wants you to like the results this device produces, so he may sell it to you. These two worlds collide here, I guess.


But let's not go into the discussion, rather to note the interesting sequence of events that I experienced when I came across this device.

The thoughts I had about the principle of this device were very simple: basically it must be a compass. Period. The only thing then left to explain is its claim that it works from anywhere pointing to Jerusalem and how it 'defies' nature. This should be an exercise in thinking that anybody of scientific background should be able to do.

First stance. If this compass does point in another direction than North-South, then this means that the pointing needle is NOT the magnetic one!
Second stance. Hence, there must be a second one that moves the visible one. (I would suggest it is under the scale.)
Third stance. It can't point to Jerusalem unless it is calibrated.


The remaining and interesting question is: Can the ad be still true? How can it point to Jerusalem from any place?
The interesting thing is that the ad can be true! But it needs an explanation.


Pointing to Jerusalem obviously requires a different direction (for a compass) for any two points on the same meridian that does not pass through Jerusalem. (Check this!) If the meridian passes through Jerusalem, the direction is either North or South.

A compass that does not need calibration along a meridian would indeed defy nature. Because a compass always points North-South for any magnetic material used for the needle, because of the nature and direction of the magnetic field around the Earth and how this magnetic field influences the needle. This is common knowledge.

So, how can the ad be true. Some previous post suggested that some officials were convinced. Suppose it is just like it says.
Here is the answer that might be surprising to you.


Depending on the definition of this direction 'towards Jerusalem', this direction can be determined from any point on the globe. Suppose somebody orders this compass, he gives the salesman the information where he lives, i.e. where to send the compass. The salesman can use this information to calibrate the compass and send it to the customer 'personified'. Then, if the customer opens the box, the compass will indeed point to Jerusalem. His friend on the other side of the world, who orders the same compass, gets one that is calibrated differently! Therefore, also his compass would point to Jerusalem. Both would think that the compass does what it says... because it does. This may explain the point in the discussion where there is talk of having seen the compass '... this compass, which you have never even seen, but, the Gedolei Yisroel did see, certainly has no usage for you.' The essence of this remark is not completely to the point, but clear enough. The salesman is not going to give clues to any non potential buyer. Period. (Be honest, you'd rather use a normal compass for any purpose, including the current one. Exercise: How? Mark the compass with 'J' for Jerusalem. But think it through completely: where do you mark it and how do you use it then. If you solve this exercise, you might understand why the device under investigation is very neat solution.)


However, the ad I read said 'Please note that we are unable to ship the Jerusalem of Gold Compass to an address outside the USA.' This was also a clue to me. As others in this post have pointed out, the distance to Jerusalem from the USA is large enough that it is roughly constant, or roughly SE, depending on the definition used. But if the customers agree, there is no problem here. So, for this geographical market, there only needs to be one type of compass! No calibration required, a posteriori. This saves the salesman time ;-).


I just needed to know if somebody had solved this puzzle. Finding several blogs dedicated to this device made me smile. Maybe THAT was the intent of the design in the first place? No frustrations intended, whatsoever. So, a discussion on this topic should not degenerate. But that is just my opinion.

Again, either deliberately or not, the working of this device is not essential to those who would like to use it in the USA. On the other hand, if you have family in Israel and want to send them one, this could quickly become a disappointment if the device can not be calibrated.

If one can calibrate the device, the definition of 'the direction towards Jerusalem' is in effect left to the customer, who may always use the definition he wants. It may take some effort to accurately determine it for every place you take the device, but that is just information related, and has nothing to do with the working of the device, one may agree.

So, in the final post, the working of the knob is described, or at least affirms that the customer is able to calibrate the device. The 'log book' is an unchangeable source of information and obviously uses only one definition for the 'direction towards Jerusalem'. To be useful, it should list the directions for a sufficiently large number of cities. Then this device is perfectly in order and works all the time. Ideally, the used definition should be pointed out in the instruction manual and ideally gives references to different definitions. Being in the USA may not require any calibration if a general direction is all that is required.

So, if a customer finds the information he needs to operate the device according to his definition of 'the direction towards Jerusalem', this device works 'all over the World' and 'seemingly defies nature'. It's all true.


For me as an observer this has mostly been a fun logical puzzle, and it had me going for a while. Heartfelt thanks to Moshe.


4:16 PM, December 24, 2008  
Anonymous aryeh shore said...

The Orach HaShulchan (OH 94) brings an apologetic on how synagogues are facing east in spite of the Lavush and Taz. It is clearly a flexible topic.
The only Achron who deals with the problem is the Shulchan Aruch HaRav. He clearly says one follows the great circle. If the compass follows the rhomb line, they should bring someone who supports them.

9:34 AM, September 04, 2009  
Blogger Theo said...

This Jerusalem Compass probably works just like the Qibla Compass, which is a simple compass used by muslims to point their holiest site, Mecca.
Its magnetic needle always points north, and there is another needle, or indication marks (which has to be configurated by the owner wherever he is) that point to the Qibla (the right direction to Mecca).
It's not a novelty. Qibla compasses were invented by muslims back in the 18th century (1701-1800), and we know that always were great geographers in the Muslim world, as well great historians in the Jewish world.
Moshe has adaptated this invention not to point Mecca, of course, instead to point Jerusalem, our holiest site.
Anyway, its advertising is a little bit sensacionalistic since it claims that the compass "defy the laws of Physics".
It does not defy any physical law; on the contrary, it precisely uses physical laws in our favor. It's not magic or charlatanism. It's a little device that simply does its job. With a major propagandistic, gigantic and sensacionalistic advertising.
I don't think it changes our kivun, since kivun can be translated either as "direction" either as "intention" (min hamila kavana).
More information you can get in
Shalom uvracha,
Theo Hotz

7:56 AM, January 23, 2011  
Anonymous Anonymous said...

My Observations on the Kosher Compass

Recently (Succoth 5712) my friend showed me his Kosher Compass, also known as the Jerusalem compass, which he had received as a present. I
read the instructions and learned the details on how to use it. Basically the device is a magnetic compass that has a second pointer needle siting on top of the compass that moves with it. This needle can be set to point at any angle relative to the North Pole of the magnetic compass. Once set it will move together with the compass maintaining this constant offset.

The proper offset is a function of location. Offsets for a few locations are given on the compass case cover and also a long sheet of paper that comes with the device gives several more values for different locations.
From what I observed in setting an offset, it can be set to about one degree. Also all offsets were given as integers. When the offset is set for a given location the pointer needle is supposed to point to Jerusalem when in that location.

Knowing something about navigation and the use of compasses I became suspicious of the offsets given and the accuracy needed to point to a place a great distance away. So I decided to investigate. I found that there are a least 2 websites that give the bearing to Jerusalem from anywhere in the world. They are and Both websites give two different bearings for each location, the rhomb line bearing and the great circle bearing. There seems to be a difference of opinion on which to use. The kosherjava website gives 3 different references that discuss this matter.

There is also the website that gives offsets for a number of cities around the world. Comparing the data on the three sites. The offsets given by the kosher compass are rhomb line bearings. The numbers are truncated to the nearest integer. The kosherjava website gives these bearings to 2 decimal places, and myzmanim give the numbers rounded to the nearest integer

There is one major flaw with the offsets given. They are not corrected for magnetic declination. Any one familiar with the use of a compass knows that not correcting for magnetic declination can cause major errors in direction. There are other compass errors that are also possible, which should be considered.

For example New York City give a rhomb line bearing of 95.80 degrees east of north, myzmanim give 96 and gives 95.
These bearings are from a point in NYC to a point in Jerusalem.
I calculated the bearing to a point on the Jerusalem meridian ten miles south
of the point in Jerusalem to be 95.89 and 10 miles north to be 95.71 thus a
bearing of 95 does not point to Jerusalem but about 80 miles north on
the Jerusalem meridian! However the magnetic declination in NYC is 13.07
west of north, so that setting the offset to 95 will actually point to a place
more than 1300 miles north on the Jerusalem meridian!!

Of course you can calculate your own values for the correct bearing
Using to get the proper bearing either rhomb line if you
prefer or the great circle bearing. You can then get the magnetic declination
for your location from Then properly
combine the two numbers and you have your offset.

As far as the direction that you should face during tefilah there seems to
be a lot of leeway. It appears that you do not have to be too precise. Check
this out with your local Rabbi.

Eli Rosenthal

9:28 AM, December 07, 2011  
Anonymous Anonymous said...

I noticed that I had some typo's in the above post.
First it was Succoth 5772.
also the word is spelled rhumb.
The NYC bearing 0f 95.80 was gien by kosher java, also I recalculated it.
If the ccompass is set to 95 the true bearing will be
95-13.07 =81.93 as a result of magnetic compass error,
with the above post, I am trying to point out that the claims made fore the kosher compass

10:14 AM, December 20, 2011  
Anonymous Anonymous said...

sorry for the additional typo's int the above post -- Eli

9:27 AM, December 21, 2011  
Anonymous texas engineer said...

I have been reading the comments regarding the Jerusalem compass and have found the discussion interesting to say the least. Being orthodox and also an engineer (engineers love gadgets) I bought it more out of curiousity than anything else. I too am curious how the Jerusalem compass "decides" the direction to Jerusalem. In theory, I know how the compass works. There are two needles. A smaller magnetized needle that points to the magnetic north and a larger not magnetized needle that is set to be a certain angle (azimuth) from north that is supposed to point to Jerusalem. My question is how did the developer come up with that angle? If I calculate the angle by the great circle method (the shortest distance if I fly from my home in Houston to Jerusalem), I will be facing NE (to be precise, about 41 degrees from north)! I can assure you NO shuls in Houston face NE, they face east. If I look at a Mercator projection map (which is distorted, the earth is a sphere, not flat) Jerusalem (at latitude 31 degrees 46 minutes north) is slightly north of a true east west line from Houston (my house at latitude 29 degrees 36 minutes north).

I suspect the developer just took a Mercator projection map, drew a line from a selected city to MAGNETIC (not true) north and a line from the same city to Jerusalem, measured the angle, and put that in the user guide. But that is not the shortest distance, the great circle route is. A true shortest distance would be a line that goes THROUGH the earth to Jerusalem, but even that should follow the great circle route. So I think what the developer has done is take the traditional direction we all have faced (from the US, east) and fine tuned it to a specific angle based on Mercator projection maps.

6:19 PM, June 14, 2012  

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