Weekly Trivia #3!

bertwert · 03-09-2016, 10:22 AM

Here is the third week of the weekly trivia!
Hopefully this weeks question is harder?
Please don't Google the answer, if you don't know it take a guess!

The units are in FEET.

Last edited by bertwert; 03-09-2016 at 11:46 AM.

**mattb123** · 03-09-2016, 10:44 AM

Can we assume the units are cubits?

Rupert · 03-09-2016, 11:32 AM - **1 Like**

Is that in inches or feet...if not I can't participate in voting. Anything metric is illegal in Texas and they monitor for violations.

Regards!

Parallax · 03-09-2016, 11:44 AM

Quote:

What is the diameter of the primary mirror in the Hubble space telescope?

Its diameter is its circumference divided by π.

What do I win?

bertwert · 03-09-2016, 11:44 AM

Originally posted by mattb123

Can we assume the units are cubits?

Originally posted by Rupert

Is that in inches or feet...if not I can't participate in voting. Anything metric is illegal in Texas and they monitor for violations.

How on earth did I forget!!!

In FEET!

bertwert · 03-09-2016, 11:45 AM - **2 Likes**

Originally posted by Parallax

What do I win?

**mattb123** · 03-09-2016, 02:53 PM

A Cubit is 0.666667 Ft, by the way.

bertwert · 03-09-2016, 02:54 PM

Originally posted by mattb123

A Cubit is 0.666667 Ft, by the way.

Or 0.268657 smoot ...

Parallax · 03-09-2016, 02:59 PM

Originally posted by mattb123

A Cubit is 0.666667 Ft, by the way.

Um, I don't think so. Do you have a source for that, or is "Ft" an abbreviation for something other than foot?
Cubit length has varied throughout history, but it's generally between about 18" and 21".
18" would indeed be just barely more than ¼ Smoot.

bertwert · 03-09-2016, 03:01 PM - **1 Like**

Originally posted by Parallax

Um, I don't think so.

He's got it reversed...

https://www.google.ca/search?q=1+cubit+to+foot

1 foot is 0.666667 cubit

**mattb123** · 03-09-2016, 03:02 PM

Originally posted by Parallax

Um, I don't think so.

Oops, you are right, I had that inverted. A Cubit is 1.5 feet.

Parallax · 03-09-2016, 03:43 PM

Originally posted by mattb123

I had that inverted.

Oh, Well there's your problem..

**mattb123** · 03-09-2016, 03:48 PM

Originally posted by Parallax

Oh, Well there's your problem..

Yep, it's been a while since I used that unit of measure.

forensicscientist · 03-09-2016, 07:33 PM

For those who have never seen the primary mirror of Hubble, I just happen to have a picture of it hanging in my office.

How you ask...well long story short: While in college I worked doing research with NASA for several years. After I got out of school, my employer (before my current gig) was a company called 'Perkin Elmer'. They made the primary mirror. This picture was hanging in the Dallas office...and on my departure from the company, my boss knew of my prior work with NASA and my fondness towards this photo....decided to give it to me as a farewell gift. I've had it hanging in my office ever since.....

And if you recall, the primary mirror was ground incorrectly. It is about 1/10000th of an inch too flat.....or about the thickness of human hair. Seeing the entire mirror gives some reference for that tidbit...When installed in the Hubble Telescope the center 'cap' seen in the image is removed to allow light to strike the secondary mirror and be reflected back thru the primary mirror and strike the various detectors.....

Now back to our regularly scheduled program.......

Paleo Pete · 03-09-2016, 07:57 PM

Originally posted by forensicscientist

1/10000th of an inch too flat.....or about the thickness of human hair.

I have to dispute that. A human hair averages .001" or 1/1000 inch according to what I've looked up. I was thinking I had measured mine and it was .006", maybe that was a sheet of paper...I just know mine has been migrating somewhere for a long time and keeps forgetting its way back...

The cellophane wrapper on a cigarette pack is .001" (1/1000") I use them for several years to find my starting point as a machinist.

I think the Hubble mirror is 9 feet, but can't remember for sure. It's been a while since I read it on their website.

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03-09-2016, 10:22 AM	#1
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173	Weekly Trivia #3! Here is the third week of the weekly trivia! Hopefully this weeks question is harder? Please don't Google the answer, if you don't know it take a guess! The units are in FEET. Last edited by bertwert; 03-09-2016 at 11:46 AM.

03-09-2016, 02:59 PM	#9
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,332	Originally posted by mattb123 A Cubit is 0.666667 Ft, by the way. Um, I don't think so. Do you have a source for that, or is "Ft" an abbreviation for something other than foot? Cubit length has varied throughout history, but it's generally between about 18" and 21". 18" would indeed be just barely more than ¼ Smoot. Last edited by Parallax; 03-09-2016 at 03:08 PM.

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03-09-2016, 10:44 AM	#2
mattb123 Site Supporter Join Date: Apr 2010 Location: Colorado High Country Photos: Gallery Posts: 10,872	Can we assume the units are cubits?

03-09-2016, 11:32 AM - 1 Like	#3
Rupert Veteran Member Join Date: Sep 2006 Location: Texas Photos: Gallery \| Albums Posts: 25,123	Is that in inches or feet...if not I can't participate in voting. Anything metric is illegal in Texas and they monitor for violations. Regards!

03-09-2016, 11:44 AM	#4
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,332	Quote: What is the diameter of the primary mirror in the Hubble space telescope? Its diameter is its circumference divided by π. What do I win?

03-09-2016, 11:44 AM	#5
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by mattb123 Can we assume the units are cubits? Originally posted by Rupert Is that in inches or feet...if not I can't participate in voting. Anything metric is illegal in Texas and they monitor for violations. How on earth did I forget!!! In FEET!

03-09-2016, 11:45 AM - 2 Likes	#6
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by Parallax What do I win?

03-09-2016, 02:53 PM	#7
mattb123 Site Supporter Join Date: Apr 2010 Location: Colorado High Country Photos: Gallery Posts: 10,872	A Cubit is 0.666667 Ft, by the way.

03-09-2016, 02:54 PM	#8
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by mattb123 A Cubit is 0.666667 Ft, by the way. Or 0.268657 smoot ...

03-09-2016, 03:01 PM - 1 Like	#10
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173 Original Poster	Originally posted by Parallax Um, I don't think so. He's got it reversed... https://www.google.ca/search?q=1+cubit+to+foot 1 foot is 0.666667 cubit

03-09-2016, 03:02 PM	#11
mattb123 Site Supporter Join Date: Apr 2010 Location: Colorado High Country Photos: Gallery Posts: 10,872	Originally posted by Parallax Um, I don't think so. Oops, you are right, I had that inverted. A Cubit is 1.5 feet.

03-09-2016, 03:43 PM	#12
Parallax Senior Moderator Loyal Site Supporter Join Date: Apr 2008 Location: South Dakota Photos: Gallery Posts: 19,332	Originally posted by mattb123 I had that inverted. Oh, Well there's your problem..

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03-09-2016, 03:48 PM	#13
mattb123 Site Supporter Join Date: Apr 2010 Location: Colorado High Country Photos: Gallery Posts: 10,872	Originally posted by Parallax Oh, Well there's your problem.. Yep, it's been a while since I used that unit of measure.

03-09-2016, 07:57 PM	#15
Paleo Pete Veteran Member Join Date: Jun 2010 Location: Texas Photos: Gallery \| Albums Posts: 2,880	Originally posted by forensicscientist 1/10000th of an inch too flat.....or about the thickness of human hair. I have to dispute that. A human hair averages .001" or 1/1000 inch according to what I've looked up. I was thinking I had measured mine and it was .006", maybe that was a sheet of paper...I just know mine has been migrating somewhere for a long time and keeps forgetting its way back... The cellophane wrapper on a cigarette pack is .001" (1/1000") I use them for several years to find my starting point as a machinist. I think the Hubble mirror is 9 feet, but can't remember for sure. It's been a while since I read it on their website.