28 research outputs found
Teaching control theory in high school
Controls is increasingly central to technology, science, and society, yet remains the “hidden technology.” Our appropriate emphasis on mathematical rigor and practical relevance in the past 40 years has not been similarly balanced with technical accessibility. The aim of this tutorial is to enlist the controls community in helping to radically rethink controls education. In addition to the brief 2 hour tutorial at CDC, we will have a website with additional materials, but particularly extensive online videos with mathematical details and case studies. We will also have a booth in the exhibition area at CDC with live demos and engaging competitions throughout the conference
The SN 393 -- SNR RX J1713.7-3946 (G347.3-0.5) Connection
Although the connection of the Chinese "guest" star of 393 AD with the
Galactic supernova remnant RX J1713.7-3946 (G347.3-0.5) made by Wang et al. in
1997 is consistent with the remnant's relatively young properties and the guest
star's projected position within the `tail' of the constellation Scorpius,
there are difficulties with such an association. The brief Chinese texts
concerning the 393 AD guest star make no comment about its apparent brightness
stating only that it disappeared after 8 months. However, at the remnant's
current estimated 1 - 1.3 kpc distance and A_v ~ 3 mag, its supernova should
have been a visually bright object at maximum light (-3.5 to -5.0 mag) and
would have remained visible for over a year. The peak brightness ~ 0 magnitude
adopted by Wang et al. and others would require the RX J1713.7-3946 supernova
to have been a very subluminous supernova event similar to or fainter than
CCSNe like SN 2005cs. We also note problems connecting SN 393 with a European
record in which the Roman poet Claudian describes a visually brilliant star in
the heavens around 393 AD that could be readily seen even in midday. Although
several authors have suggested this account may be a reference to the Chinese
supernova of 393, Scorpius would not be visible near midday in March when the
Chinese first reported the 393 guest star. We review both the Chinese and Roman
accounts and calculate probable visual brightnesses for a range of supernova
subtypes and conclude that neither the Chinese nor the Roman descriptions are
easily reconciled with an expected RX J1713.7-3946 supernova brightness and
duration.Comment: 7 pages includes 2 tables. Accepted for publication in AJ. Revised
text regarding subluminous SN