Please note:
- This page and all derivatives is/are a continued work in progress. Please send a message for any corrections and those will be considered and/or actioned as soon as possible.
- Just because the below authorities wearing Techeiles are listed doesn’t mean we have contact info on all of them. This is for informational purposes only.
- String Ratio: Rambam Ratio
- Tying Method: Rambam Method (Yemenite)
- How We Know: Picture(s)
- Date Born: March 2, 1963
- Location Born: New York
- Current Location: Efrat, Israel
Type of wearer: Founders and Organizers
Affiliation: Dati Leumi, Modern Orthodox
From https://mizrachi.org/speaker/dr-ari-greenspan/:
Dr. Greenspan is a co-founder of the Ptil Tekhelet Association. He is a US trained dentist, with a practice in Jerusalem. He is a practicing mohel, shochet and sofer, and has worked for more than 30 years on collecting Jewish traditions and mesorot from far flung Jewish communities around the globe. He pioneered the exotic kosher dinner as a means of passing along disappearing kosher food traditions. He is a frequent contributor to Mishpacha magazine, had a column on Jewish tradition in Otiyot, a children’s hebrew magazine and writes extensively for other journals. Dr. Greenspan has been producing commercial Judaic art for 25 years enjoying wood metal and glass as his media.
Scholar in Residence
He has lectured around the world for Dental groups and for many Synagogues and Jewish Schools. Some places include, San Antonio Texas, LA, NY, NJ, Chicago, St Louis, Connecticut, Florida, Georgia, Pennsylvania, Toronto, London, Germany, Bulgaria, Portugal, Croatia, Sarajevo, Addis Ababa, South Africa, India and Israel.
Multimedia and hands on Presentations include:
Tekhelet, Halachic Archeology, Halachic Adventuring, Mesorah of Exotic Kosher Animals, Search for the Perfect Etrog, History of Matzah, Anussim and Halacha and many others
Field / Profession: Educator, Business & Management
Educator at: Other
Speaking Topics: Torah, Eretz Yisrael, Jewish Education, Halacha & the Modern World
Scholar-in-Residence & Lecturer
Dr. Greenspan has lectured extensively across the globe to dental groups, synagogues, and Jewish schools. Locations have included:
San Antonio, Los Angeles, New York, New Jersey, Chicago, St. Louis, Connecticut, Florida, Georgia, Pennsylvania, Toronto, London, Germany, Bulgaria, Portugal, Croatia, Sarajevo, Addis Ababa, South Africa, India, and Israel.
His presentations combine multimedia, halachic exploration, archaeology, and hands-on workshops.
Sample Lecture Topics
Tekhelet and the Search for the Holy Snail
A multimedia journey exploring the halacha, history, archaeology, biology, and chemistry behind tekhelet. Dr. Greenspan shares the personal story of rediscovering the ancient dyeing process, including a live demonstration.
Exotic Kosher Animals
From peacocks to locusts, guinea hens to yak—this talk explores the halachic investigation into forgotten kosher animals. Discover traditions preserved in communities such as Yemen, Tunisia, and Djerba.
The Great Matzah Wars
How the Industrial Revolution clashed with ancient tradition: this lecture unpacks the dramatic halachic debates surrounding the introduction of machine-made matzah in the 19th century.
Exotic Jewish Communities
Take a halachic and cultural tour through unique Jewish communities—from Eritrea to Tunisia, Djibouti to Bahrain, and Morocco to Turkey. Stories include celebrating Yom Kippur in Addis Ababa and baking matzah in the mountains of Portugal.
The Halachic History of Coffee, Tea, Sugar, and Chocolate
Explore how these everyday staples were introduced to Jewish life, and how halacha shaped their use.
How to Tie Tzitzit
An engaging, hands-on workshop for parents and children—learn the techniques and leave with your very own handmade pair of tzitzit.
Crypto-Jews: Marranos of the Past and Anusim Today
Based on personal experience living among former Anusim in Portugal, this lecture delves into the historical and contemporary journeys of hidden Jews in Spain, Portugal, and New Mexico, including a deep dive into rabbinic responses over the centuries.
Jerusalem: A Halachic Tour of the Center of the World
An in-depth exploration of ancient and modern Jerusalem, with a focus on the Temple Mount. Includes rare, unpublished photos from beneath the Mount—its hidden gates and tunnels.
The Shofar: Halachic and Historical Insights
What animals can be used? How is a shofar made? Learn the traditions, halachot, and the fascinating history of blowing shofar on Shabbat.
Why Coca-Cola Is Forbidden During the Year and Permitted on Shabbat
A humorous yet insightful title for a session on the laws of chametz, mixtures (ta’arovot), and general kashrut—based on historical research into Rabbi Tobias Geffen’s correspondence with Coca-Cola in the 1920s.
Halachic Astronomy
A fascinating overview of timekeeping in Jewish law, how astronomy intersects with halacha, and how scholars—including Anusim and Talmudists—shaped our understanding of halachic times.
The Search for the Perfect Etrog
Uncover the halachic and botanical journey of the etrog. What is a murkav and why is it forbidden? Where do the world’s etrogim grow? Discover the “etrog wars” and the ancient significance of this symbolic fruit.
COVID-19: Pandemic, Contagion, and Disease in Rabbinic Literature
A timely lecture examining how pandemics and public health crises were understood and addressed in Jewish texts throughout history.
Personal website: www.halachicadventures.com
www.greenspandental.com
Languages: English, Hebrew
Tying Method
| Method | String Ratio | URL |
|---|---|---|
| Rambam 13 | Rambam |
Minhagim
| Minhag | Minhag SubGroup | Fully or Partially? |
|---|---|---|
| Ashkenazi | Full |
