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Sunday NFL Open Thread III

by coldwarrior ( 218 Comments › )
Filed under NFL, Open thread at January 23rd, 2011 - 8:57 pm

Well, the Packers just punched their ticket to the Super Bowl…

Up next is the Jets at the Steelers. Game time temp is in the single digits to below zero.

*This is an open thread, OPEN NOT JUST FOOTBALL, discuss whatever you like…we did not put up any serious posts during the games because it would not get the exposure that we want our writers to get.*

Here is some background on the team symbol for the Steelers:

Start Here:

HypocycloidDiagram

The curve produced by fixed point P on the circumference of a small circle of radius b rolling around the inside of a large circle of radius a>b. A hypocycloid is therefore a hypotrochoid with h=b.

To derive the equations of the hypocycloid, call the angle by which a point on the small circle rotates about its center theta, and the angle from the center of the large circle to that of the small circle phi. Then

 (a-b)phi=btheta,
(1)

so

 theta=(a-b)/bphi.
(2)

Call rho=a-2b. If x(0)=rho, then the first point is at minimum radius, and the Cartesian parametric equations of the hypocycloid are

x = (a-b)cosphi-bcostheta
(3)
= (a-b)cosphi-bcos((a-b)/bphi)
(4)
y = (a-b)sinphi+bsintheta
(5)
= (a-b)sinphi+bsin((a-b)/bphi).
(6)

If x(0)=a instead so the first point is at maximum radius (on the circle), then the equations of the hypocycloid are

x = (a-b)cosphi+bcos((a-b)/bphi)
(7)
y = (a-b)sinphi-bsin((a-b)/bphi).
(8)

The curvature, arc length, and tangential angle of a hypocycloid are given by

kappa(phi) = (2b-a)/(4b(a-b))csc((aphi)/(2b))
(9)
s(phi) = (8(a-b)b)/asin^2((aphi)/(4b))
(10)
phi_t(phi) = phi(1-a/(2b)).
(11)
HypocycloidIntegers
Hypocycloids with $a/b$ an integer

And then:

The Steelmark consists of three four-pointed starlike figures within a circle. The stars in the design approximate a type of geometric figure called an astroid, a particular type of hypocycloid with four cusps.[1][2] A yellow figure is located at the top of the design, orange to the right and blue on the bottom, with the word “Steel” on the left side. The logo appears within a gray ring against a white background.

The logo was incorporated as the emblem of the Pittsburgh Steelers, initially using the same design as the Steelmark, but later modified to include the team’s full name.

Cleveland-based Republic Steel approached the owners of the Pittsburgh Steelers about placing the Steelmark logo on their helmets for the 1962 NFL season, figuring that it would be a perfect product placement for the steel manufacturers.[5] The equipment manager for the team was told to put the logo on the right side of the team’s all-gold helmets. The Steelers went 9–5 that season, their best record to that date. For their first post-season game, in the 1962 Playoff Bowl, the team changed the helmet color from gold to black and it has remained largely unchanged since, with the team the only one in the National Football League to have a logo on only one side of the helmet.[1][6] In 1963, the Steelers petitioned the American Iron and Steel Institute to be allowed to change the word “Steel” in the logo to the full team name, which was approved by the AISI.[1]

In conclusion, if one is a mathematician, then the obvious choice is the Steelers!

Enjoy the games, we will get back to the serious issues on Monday morning.

Sunday NFL Open Thread II

by coldwarrior ( 297 Comments › )
Filed under NFL, Open thread at January 23rd, 2011 - 6:15 pm

Well, the Packers just punched their ticket to the Super Bowl…

Up next is the Jets at the Steelers. Game time temp is in the single digits to below zero.

*This is an open thread, OPEN NOT JUST FOOTBALL, discuss whatever you like…we did not put up any serious posts during the games because it would not get the exposure that we want our writers to get.*

Here is some background on the team symbol for the Steelers:

Start Here:

HypocycloidDiagram

The curve produced by fixed point P on the circumference of a small circle of radius b rolling around the inside of a large circle of radius a>b. A hypocycloid is therefore a hypotrochoid with h=b.

To derive the equations of the hypocycloid, call the angle by which a point on the small circle rotates about its center theta, and the angle from the center of the large circle to that of the small circle phi. Then

 (a-b)phi=btheta,
(1)

so

 theta=(a-b)/bphi.
(2)

Call rho=a-2b. If x(0)=rho, then the first point is at minimum radius, and the Cartesian parametric equations of the hypocycloid are

x = (a-b)cosphi-bcostheta
(3)
= (a-b)cosphi-bcos((a-b)/bphi)
(4)
y = (a-b)sinphi+bsintheta
(5)
= (a-b)sinphi+bsin((a-b)/bphi).
(6)

If x(0)=a instead so the first point is at maximum radius (on the circle), then the equations of the hypocycloid are

x = (a-b)cosphi+bcos((a-b)/bphi)
(7)
y = (a-b)sinphi-bsin((a-b)/bphi).
(8)

The curvature, arc length, and tangential angle of a hypocycloid are given by

kappa(phi) = (2b-a)/(4b(a-b))csc((aphi)/(2b))
(9)
s(phi) = (8(a-b)b)/asin^2((aphi)/(4b))
(10)
phi_t(phi) = phi(1-a/(2b)).
(11)
HypocycloidIntegers
Hypocycloids with $a/b$ an integer

And then:

The Steelmark consists of three four-pointed starlike figures within a circle. The stars in the design approximate a type of geometric figure called an astroid, a particular type of hypocycloid with four cusps.[1][2] A yellow figure is located at the top of the design, orange to the right and blue on the bottom, with the word “Steel” on the left side. The logo appears within a gray ring against a white background.

The logo was incorporated as the emblem of the Pittsburgh Steelers, initially using the same design as the Steelmark, but later modified to include the team’s full name.

Cleveland-based Republic Steel approached the owners of the Pittsburgh Steelers about placing the Steelmark logo on their helmets for the 1962 NFL season, figuring that it would be a perfect product placement for the steel manufacturers.[5] The equipment manager for the team was told to put the logo on the right side of the team’s all-gold helmets. The Steelers went 9–5 that season, their best record to that date. For their first post-season game, in the 1962 Playoff Bowl, the team changed the helmet color from gold to black and it has remained largely unchanged since, with the team the only one in the National Football League to have a logo on only one side of the helmet.[1][6] In 1963, the Steelers petitioned the American Iron and Steel Institute to be allowed to change the word “Steel” in the logo to the full team name, which was approved by the AISI.[1]

In conclusion, if one is a mathematician, then the obvious choice is the Steelers!

Enjoy the games, we will get back to the serious issues on Monday morning.

Sunday NFL Open Thread

by coldwarrior ( 298 Comments › )
Filed under NFL, Open thread at January 23rd, 2011 - 2:45 pm

We have two games today. In a classic old-school rivalry the Green Bay Packers are at the Chicago Bears.

And then at 6:30pm we have the New York Jets at the Pittsburgh Steelers.

Pontification and analysis can be found over at ESPN. Its time for some football.

*This is an open thread, OPEN NOT JUST FOOTBALL, discuss whatever you like…we did not put up any serious posts during the games because it would not get the exposure that we want our writers to get.*

Here is some background on the team symbol for the Steelers:

Start Here:

HypocycloidDiagram

The curve produced by fixed point P on the circumference of a small circle of radius b rolling around the inside of a large circle of radius a>b. A hypocycloid is therefore a hypotrochoid with h=b.

To derive the equations of the hypocycloid, call the angle by which a point on the small circle rotates about its center theta, and the angle from the center of the large circle to that of the small circle phi. Then

 (a-b)phi=btheta,
(1)

so

 theta=(a-b)/bphi.
(2)

Call rho=a-2b. If x(0)=rho, then the first point is at minimum radius, and the Cartesian parametric equations of the hypocycloid are

x = (a-b)cosphi-bcostheta
(3)
= (a-b)cosphi-bcos((a-b)/bphi)
(4)
y = (a-b)sinphi+bsintheta
(5)
= (a-b)sinphi+bsin((a-b)/bphi).
(6)

If x(0)=a instead so the first point is at maximum radius (on the circle), then the equations of the hypocycloid are

x = (a-b)cosphi+bcos((a-b)/bphi)
(7)
y = (a-b)sinphi-bsin((a-b)/bphi).
(8)

The curvature, arc length, and tangential angle of a hypocycloid are given by

kappa(phi) = (2b-a)/(4b(a-b))csc((aphi)/(2b))
(9)
s(phi) = (8(a-b)b)/asin^2((aphi)/(4b))
(10)
phi_t(phi) = phi(1-a/(2b)).
(11)
HypocycloidIntegers
Hypocycloids with $a/b$ an integer

And then:

The Steelmark consists of three four-pointed starlike figures within a circle. The stars in the design approximate a type of geometric figure called an astroid, a particular type of hypocycloid with four cusps.[1][2] A yellow figure is located at the top of the design, orange to the right and blue on the bottom, with the word “Steel” on the left side. The logo appears within a gray ring against a white background.

The logo was incorporated as the emblem of the Pittsburgh Steelers, initially using the same design as the Steelmark, but later modified to include the team’s full name.

Cleveland-based Republic Steel approached the owners of the Pittsburgh Steelers about placing the Steelmark logo on their helmets for the 1962 NFL season, figuring that it would be a perfect product placement for the steel manufacturers.[5] The equipment manager for the team was told to put the logo on the right side of the team’s all-gold helmets. The Steelers went 9–5 that season, their best record to that date. For their first post-season game, in the 1962 Playoff Bowl, the team changed the helmet color from gold to black and it has remained largely unchanged since, with the team the only one in the National Football League to have a logo on only one side of the helmet.[1][6] In 1963, the Steelers petitioned the American Iron and Steel Institute to be allowed to change the word “Steel” in the logo to the full team name, which was approved by the AISI.[1]

In conclusion, if one is a mathematician, then the obvious choice is the Steelers!

Enjoy the games, we will get back to the serious issues on Monday morning.

Saturday Lecture Series:

by coldwarrior ( 72 Comments › )
Filed under Academia, Open thread, saturday lecture series, Science, Technology at January 22nd, 2011 - 8:30 am

Good morning all, today our lecture comes to us from Huntsville, Alabama (not al-Habama). Yesterday, NASA reported that the experimental NanoSail-D has successfully deployed its sail and is underway.  “This research demonstration could lead to further advances of this alternative solar sail propulsion and the critical need for new de-orbit technologies.”

.

Do check out the dashboard feature on this website:

NASA’s First Solar Sail NanoSail-D Deploys in Low-Earth Orbit

HUNTSVILLE, Ala. – Friday, Jan. 21 at 10 a.m. EST, engineers at NASA’s Marshall Space Flight Center in Huntsville, Ala., confirmed that the NanoSail-D nanosatellite deployed its 100-square-foot polymer sail in low-Earth orbit and is operating as planned. Actual deployment occurred on Jan. 20 at 10 p.m. EST and was confirmed today with beacon packets data received from NanoSail-D and additional ground-based satellite tracking assets. In addition, the NanoSail-D orbital parameter data set shows an appropriate change which is consistent with sail deployment.

“This is tremendous news and the first time NASA has deployed a solar sail in low-Earth orbit,” said Dean Alhorn, NanoSail-D principal investigator and aerospace engineer at the Marshall Center. “To get to this point is an incredible accomplishment for our small team and I can’t thank the amateur ham operator community enough for their help in tracking NanoSail-D. Their assistance was invaluable. In particular, the Marshall Amateur Radio Club was the very first to hear the radio beacon. It was exciting!”

NanoSail-D will continue to send out beacon signals until the onboard batteries are expended and can be found at 437.270 MHz. It can be tracked on the NanoSail-D dashboard at: http://nanosaild.engr.scu.edu/dashboard.htm.

It is estimated that NanoSail-D will remain in low-Earth orbit between 70 and 120 days, depending on atmospheric conditions. NanoSail-D is designed to demonstrate deployment of a compact solar sail boom technology. This research demonstration could lead to further advances of this alternative solar sail propulsion and the critical need for new de-orbit technologies. This ejection experiment also demonstrates a spacecraft’s ability, like the Fast, Affordable, Science and Technology Satellite, or FASTSAT, to eject a nano-satellite from a micro-satellite, while avoiding re-contact with the primary satellite.

“This is a significant accomplishment for both the FASTSAT and NanoSail-D projects. This accomplishment validates that we’ve met another of our primary mission objectives — successfully ejecting a nanosatellite from an orbiting microsatellite,” said Mark Boudreaux, FASTSAT project manager at the Marshall Center. “This is another significant accomplishment for our inter Agency, Industry and Governmental FASTSAT-HSV01 partnership team.”

Follow the NanoSail-D mission operation on Twitter at:

http://twitter.com/nanosaild

For additional information on the timeline of the NanoSail-D deployment visit:

http://www.nasa.gov/pdf/501204main_NSD2_timeline_sequence.pdf

To learn more about FASTSAT and the NanoSail-D missions visit:

http://www.nasa.gov/mission_pages/smallsats