Using technological aids to determine halachic status

may as well be part of the copepod department
Can we use technological aids to ascertain facts in order to determine halachic status? What if you need a magnifying glass or microscope to see a bacterium? (Copepods are macroscopic, so you don't need a microsocope.) What if you need a buglight to see insects? What if you need a telescope to observe some phenomenon, say to observe the new moon for the purpose of kiddush hachodesh, back when we were still doing this?

Muslims given OK for telescopes

IRANIAN supreme leader Ayatollah Ali Khamenei has put an end to a major religious question here by authorising the use of a telescope to observe the moon and declare an end to the Muslim fasting month of Ramadan.

In a ruling that could prevent a repeat of last year's confusion over when to celebrate the Eid holiday, Mohsen Rezai - a close aide to the all-powerful leader - announced to the press that Khamenei had ruled that "looking at the moon with technical aids is valid".

In an annual ritual, Muslims scan the sky for the crescent of a new moon that signals the start of Eid al-Fitr, a three-day feast celebrating the end of Ramadan and its dawn-to-dusk of grumbling stomachs.

But religious dignitaries generally prefer to do their moon-spotting with the naked eye - something that is not always practical given the presence of cloudy skies and even modern curses such as light pollution or smog.

Not to mention that many of Iran's grand ayatollahs are advanced in years, with their eyesight not what it used to be.

Last year some clerics in the holy city of Qom announced the end of Ramadan a day before the office of the supreme leader, sparking plenty of confusion.

We actually do have a precedent for this. Rabban Gamliel had a telescope which could see 2000 cubits on land and 2000 cubits on water, which he used to determine techum shabbat.

Mishna, Eruvin 41b:

פעם אחת לא נכנסו לנמל עד שחשיכה אמרו לו לרבן גמליאל מה אנו לירד אמר להם מותרים אתם שכבר הייתי מסתכל והיינו בתוך התחום עד שלא חשיכה:

...One time they did not enter the port when it became dark (and therefore Shabbat). They said to Rabban Gamliel, 'May we disembark?' He said to them, 'You are permitted, for I had already looked and we were within the techum while it was not yet dark.'

Eruvin 43b:

תנא שפופרת היתה לו לרבן גמליאל שהיה מביט וצופה בה אלפים אמה ביבשה וכנגדה אלפים בים
הרוצה לידע כמה עומקו של גיא מביא שפופרת ומביט בה וידע כמה עומקו של גיא

It was taught in a brayta: Rabban Gamliel had a telescope that he would look through and see in it 2000 cubits on land, and corresponding to this, 2000 cubits on the sea.
One who wishes to know how much is the depth of a valley should bring a telescope and look through it, and he will know the depth of the valley.

Elsewhere (in Rosh HaShana 24b-25a), we see that Rabban Gamliel used his astronomical knowledge to ascertain the validity of testimony for declaring the New Moon.