space

已查看 185 次
跳至第一个未读帖子

gippgig

未读,
2015年6月1日 02:34:502015/6/1
收件人 Bla...@hacdc.org

Bobby Baum

未读,
2015年6月29日 04:48:112015/6/29
收件人 Bla...@hacdc.org

gippgig

未读,
2015年8月5日 02:47:592015/8/5
收件人 Blabber

gippgig

未读,
2015年10月9日 01:14:402015/10/9
收件人 Blabber
A private lunar lander now has a launch reservation:
www.washingtonpost.com/news/the-switch/wp/2015/10/07/the-first-ever-private-mission-to-the-moon-just-got-a-lot-closer-to-reality/
However, there has already been a private mission to the moon (not a lander) - when a launch failure in the 1990s left the AsiaSat 3 comsat in the wrong orbit engineers were able to get it into a usable orbit by sending it to the moon for a gravity assist.

gippgig

未读,
2016年4月21日 16:59:422016/4/21
收件人 Blabber

gippgig

未读,
2016年5月5日 04:10:072016/5/5
收件人 Blabber

gippgig

未读,
2016年5月10日 16:55:192016/5/10
收件人 Blabber

Bobby Baum

未读,
2016年8月1日 21:22:462016/8/1
收件人 Blabber
Achieving Science with CubeSats: Thinking Inside the Box
www.nap.edu/download/23503

gippgig

未读,
2017年2月4日 20:29:512017/2/4
收件人 Blabber
Serious planning for an interstellar mission:
First trip to the stars
Nature Vol. 542 issue 7639 p. 20 (Feb. 2)
Also see www.spacedaily.com/reports/Full_Braking_at_Alpha_Centauri_999.html

gippgig

未读,
2017年7月13日 22:14:012017/7/13
收件人 Blabber
...and how to use solar gravitational lensing for interstellar communication:
arxiv.org/pdf/1706.05570.pdf

gippgig

未读,
2017年8月26日 22:25:492017/8/26
收件人 Blabber

gippgig

未读,
2017年12月30日 17:31:022017/12/30
收件人 Blabber

nancy lessons

未读,
2017年12月31日 03:38:482017/12/31
收件人 Blabber
This is awesome, thanks for sharing this info!
Nancy

On Sat, Dec 30, 2017 at 5:31 PM, gippgig <gip...@gmail.com> wrote:

--
--
Like what we do? Support HacDC by becoming a member. Learn more here: http://hacdc.org/membership/
--
You received this message because you are subscribed to the HacDC "Blabber" group.
To post to this group, send email to Bla...@hacdc.org
To unsubscribe from this group, send email to
Blabber+u...@hacdc.org
For more options, visit this group at
http://groups.google.com/a/hacdc.org/group/Blabber
---
You received this message because you are subscribed to the Google Groups "Blabber" group.
To unsubscribe from this group and stop receiving emails from it, send an email to Blabber+u...@hacdc.org.

gippgig

未读,
2018年2月2日 17:09:482018/2/2
收件人 Blabber
www.sciencemag.org/news/2018/01/amateur-astronomer-dicovers-revived-nasa-satellite
Receiving satellite telemetry would be an interesting and potentially useful project - still-functioning satellites are often abandoned because the pros don't have time to listen to them. This would also be a good way to get HARC and the rest of HacDC to work together.

Bobby Baum

未读,
2018年2月3日 16:59:122018/2/3
收件人 Blabber

gippgig

未读,
2018年3月6日 15:53:442018/3/6
收件人 Blabber

gippgig

未读,
2018年3月12日 18:16:392018/3/12
收件人 Blabber

gippgig

未读,
2018年5月21日 21:59:252018/5/21
收件人 Blabber

gippgig

未读,
2018年10月11日 16:47:372018/10/11
收件人 Blabber
Moons could have moons: arxiv.org/abs/1810.03304

gippgig

未读,
2018年10月20日 01:00:022018/10/20
收件人 Blabber
NASA Image and Video Library: images.nasa.gov

gippgig

未读,
2018年11月7日 21:28:452018/11/7
收件人 Blabber
Was the interstellar object Oumuamua a solar sail?
arxiv.org/pdf/1810.11490.pdf

Julia Longtin

未读,
2018年11月7日 21:58:162018/11/7
收件人 Bla...@hacdc.org
i hope so! :)

On Thu, Nov 8, 2018 at 2:28 AM gippgig <gip...@gmail.com> wrote:
Was the interstellar object Oumuamua a solar sail?
arxiv.org/pdf/1810.11490.pdf

--

Bobby Baum

未读,
2018年11月7日 22:06:592018/11/7
收件人 Bla...@hacdc.org
Idle speculation - if it was a starship maybe it ignored us because we
failed its intelligence test; perhaps hitting it with a pulsed
neutrino beam would have caused a response.

Tom Iddings

未读,
2018年11月7日 22:45:362018/11/7
收件人 Bla...@hacdc.org
Oh yeah. Tangentially this made me start thinking about what levels of signal collection sensitivity vs. signals broadcasting power two species need to develop to reliably be able say hello and expect a response. Like a modified drake equation whose product is the probability of making radio contact with an intelligent species. What sort of systems would SETI need to build that would push the probability of contact with a suitably advanced species towards 1, if the other variables are supportive?
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

Bobby Baum

未读,
2018年11月7日 22:55:362018/11/7
收件人 Bla...@hacdc.org
Expecting aliens to try to make contact using radio is an example of
what I call Earthism - assuming that everything else is like us. (Note
that in the case where it has been tested, Earthism is totally wrong -
contrary to previous belief, extrasolar planetary systems are often
totally unlike our own.) I think aliens would most likely use visible
light - it's the frequency range at which stars radiate most strongly
so creatures' eyes are most likely to detect visible light, it can
propagate long distances, and there is no need to build a transmitter
- just modulate the light from your star (i.e., with something like
giant Venetian blinds). I wonder if we've already detected an
extraterrestrial signal and written it off as an irregular variable
star.

Tom Iddings

未读,
2018年11月7日 23:21:582018/11/7
收件人 Bla...@hacdc.org
I agree that the problem is what sort of signals to look for. Maybe
interstellar civilizations like to communicate by modulating the
brightness of stars at high frequency.
> --
> --
> Like what we do? Support HacDC by becoming a member. Learn more here: http://hacdc.org/membership/
> --
> You received this message because you are subscribed to the HacDC "Blabber" group.
> To post to this group, send email to Bla...@hacdc.org
> To unsubscribe from this group, send email to
> Blabber+u...@hacdc.org
> For more options, visit this group at
> http://groups.google.com/a/hacdc.org/group/Blabber
> ---
> You received this message because you are subscribed to the Google Groups "Blabber" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to Blabber+u...@hacdc.org.
>

--

Tom Iddings

Nicolas Sabharwal

未读,
2018年11月8日 10:02:542018/11/8
收件人 Bla...@hacdc.org
It looked like a rock.

Zachary Huberty

未读,
2018年11月8日 10:16:392018/11/8
收件人 Bla...@hacdc.org
What a troll
ZACHARY J. HUBERTY
202-590-0915
 
 

James Sullivan

未读,
2018年11月8日 11:01:152018/11/8
收件人 Bla...@hacdc.org

Radiation strength versus frequency depends on what type of star it is.  Even our own sun with significant human-visible light spectrum emissions puts out plenty of radiation at the H-alpha frequency in the IR band.  The below image shows solar spectral distribution at the lower atmosphere.  Significant amounts of IR get sucked up by the air, while the visible light passes through.  Stars of different composition and temperature (and age, size, mass, etc.) radiate differently.  (Not sure if image will survive email.  Figure 4 here: http://environ.andrew.cmu.edu/m3/s2/02sun.shtml )

http://environ.andrew.cmu.edu/m3/s2/graphics/embedded/fig4.gif

See y’all next month!

--

Kevin Cole

未读,
2018年11月8日 11:32:112018/11/8
收件人 HacDC Public Discussion
On Wed, Nov 7, 2018 at 10:55 PM Bobby Baum <gip...@gmail.com> wrote:

I think aliens would most likely use visible
light - it's the frequency range at which stars radiate most strongly
so creatures' eyes are most likely to detect visible light, it can
propagate long distances, and there is no need to build a transmitter
- just modulate the light from your star (i.e., with something like
giant Venetian blinds). I wonder if we've already detected an
extraterrestrial signal and written it off as an irregular variable
star.

This is yet another case of "Earthism": It presumes that life capable of (and interested in) searching for other life that is equally capable of (and interested in) the same, becomes aware of their environment using the same sorts of sensors we're used to on this planet, and that they would reach for the same set of tools...

It might be fair to say -- with the caveat "as 'far' (pun intended) as we KNOW" -- radiation is the best long-distance carrier of information. But who's to say that these extraterrestrials are "wired" to perceive, and classify / separate the same frequencies of it that terrestrial life forms do?


Enrique Cobas

未读,
2018年11月8日 20:49:292018/11/8
收件人 Bla...@hacdc.org
Modulated gravity waves or neutrino beams might penetrate through dust clouds and other obstacles better than light. Maybe something we aren't aware of yet. Or my default hypothesis which is that since the speed of light is pretty slow and distances so large they just don't see the point in reaching out.

Tom Iddings

未读,
2018年11月8日 22:45:222018/11/8
收件人 Bla...@hacdc.org
I guess my original point was just that a civilization might become technologically advanced enough to sense and analyze the entire bandwidth in every direction of all available signals travelling at /c/, such that they'd be almost guaranteed to hear any sort of deliberate and sustained ping out to a certain distance and amplitude. There isn't much point to talking to aliens but there isn't much risk either, and it's not too unlikely that any real interplanetary extrasolar aliens are possessed of the same curiosity that drives SETI.

David Prentiss

未读,
2018年11月9日 10:37:252018/11/9
收件人 Bla...@hacdc.org
heavensgate.jpeg

--

gippgig

未读,
2019年1月18日 23:54:072019/1/18
收件人 Blabber

Kevin Cole

未读,
2019年1月19日 10:20:002019/1/19
收件人 HacDC Public Discussion
On Fri, Jan 18, 2019 at 11:54 PM gippgig <gip...@gmail.com> wrote:


The article appears to have missed the obvious (or maybe I did) -- the URL https://technosearch.seti.org/

And, bragging rights / street cred: I *was* user #45 of SETI@Home before they screwed up their database and bumped me to user #27114. (I attended a conference where Jill Tarter announced the beta version would launch shortly after the conference.) I've been running SETI@Home somewhere(s) for a very long time.


C'est moi:



gippgig

未读,
2019年1月24日 22:13:092019/1/24
收件人 Blabber

gippgig

未读,
2019年1月28日 21:30:452019/1/28
收件人 Blabber

gippgig

未读,
2019年2月2日 15:29:042019/2/2
收件人 Blabber

gippgig

未读,
2019年2月5日 01:30:252019/2/5
收件人 Blabber

gippgig

未读,
2019年2月11日 18:11:002019/2/11
收件人 Blabber

gippgig

未读,
2019年2月22日 01:46:522019/2/22
收件人 Blabber

gippgig

未读,
2019年3月18日 18:51:432019/3/18
收件人 Blabber

gippgig

未读,
2019年3月27日 20:30:582019/3/27
收件人 Blabber
The halo drive - new way to use black holes for propulsion: arxiv.org/abs/1903.03423

gippgig

未读,
2019年4月1日 20:02:192019/4/1
收件人 Blabber

gippgig

未读,
2019年4月10日 00:45:402019/4/10
收件人 Blabber

gippgig

未读,
2019年5月20日 22:56:452019/5/20
收件人 Blabber

gippgig

未读,
2019年5月21日 19:56:502019/5/21
收件人 Blabber
USC students have apparently reached space with their Traveler IV rocket. Details are sketchy.

gippgig

未读,
2019年5月23日 20:39:412019/5/23
收件人 Blabber

gippgig

未读,
2019年6月6日 20:53:222019/6/6
收件人 Blabber
Interesting story: The Taurus launches of OCO & Glory, at a total cost of over $700,000,000, failed because of fraud - a manufacturer supplied substandard metal & falsified test reports
www.nasa.gov/sites/default/files/atom/files/oco_glory_public_summary_update_-_for_the_web_-_04302019.pdf

gippgig

未读,
2019年6月7日 03:23:582019/6/7
收件人 Blabber

gippgig

未读,
2019年6月8日 16:46:072019/6/8
收件人 Blabber

gippgig

未读,
2019年7月6日 16:09:232019/7/6
收件人 Blabber
Monitor telemetry from The Planetary Society's Lightsail 2 spacecraft (possibly even before the controllers see it!):
www.planetary.org/explore/projects/lightsail-solar-sailing/lightsail-mission-control.html

gippgig

未读,
2019年7月8日 17:13:382019/7/8
收件人 Blabber

gippgig

未读,
2019年7月9日 00:05:552019/7/9
收件人 Blabber

gippgig

未读,
2019年7月26日 01:42:182019/7/26
收件人 Blabber
www.spacedaily.com/reports/Oumuamua_Is_Not_an_Alien_Spacecraft_999.html
(with link to Nature Astronomy paper The Natural History of 'Oumuamua)

gippgig

未读,
2019年8月8日 20:39:572019/8/8
收件人 Blabber

gippgig

未读,
2019年9月13日 17:13:562019/9/13
收件人 Blabber

gippgig

未读,
2019年10月12日 18:31:202019/10/12
收件人 Blabber
Planets around supermassive black holes?: arxiv.org/abs/1909.06748

gippgig

未读,
2019年10月23日 20:04:382019/10/23
收件人 Blabber
Helical engine uses relativistic effects to produce acceleration without propellant:

gippgig

未读,
2019年11月6日 16:11:212019/11/6
收件人 Blabber
Build a cubesat simulator: cubesatsim.org/wiki

gippgig

未读,
2019年11月22日 15:56:042019/11/22
收件人 Blabber

gippgig

未读,
2019年11月29日 15:09:202019/11/29
收件人 Blabber
Old story, but interesting:

gippgig

未读,
2020年1月6日 16:54:142020/1/6
收件人 Blabber
Recalibration may have eliminated evidence for accelerating universe expansion

gippgig

未读,
2020年1月6日 17:05:152020/1/6
收件人 Blabber

gippgig

未读,
2020年1月23日 17:55:102020/1/23
收件人 Blabber

gippgig

未读,
2020年1月30日 23:34:002020/1/30
收件人 Blabber
Asteroid skimmed within 37 miles of Earth but gained speed from a gravity assist: arxiv.org/abs/1912.01895

gippgig

未读,
2020年2月6日 18:47:152020/2/6
收件人 Blabber

gippgig

未读,
2020年2月19日 17:43:322020/2/19
收件人 Blabber
NASA is asking the public for ideas on an avoidance sensor for a Venus rover: www.nasa.gov/exploring-hell-venus-rover-challenge

gippgig

未读,
2020年2月19日 19:18:362020/2/19
收件人 Blabber

gippgig

未读,
2020年2月27日 23:22:502020/2/27
收件人 Blabber

gippgig

未读,
2020年2月27日 23:30:252020/2/27
收件人 Blabber

gippgig

未读,
2020年4月16日 03:31:402020/4/16
收件人 Blabber

gippgig

未读,
2020年4月19日 01:48:322020/4/19
收件人 Blabber
已删除帖子
已删除帖子

gippgig

未读,
2020年8月13日 15:43:122020/8/13
收件人 Blabber

gippgig

未读,
2020年10月30日 18:28:002020/10/30
收件人 Blabber、gippgig

gippgig

未读,
2020年10月31日 04:38:242020/10/31
收件人 Blabber、gippgig
The Resilience of Habitable Climates Around Circumbinary Stars
JGR Planets Vol. 125 Issue 9 e2020JE006576   doi: 10.1029/2020JE006576

gippgig

未读,
2020年11月11日 03:09:442020/11/11
收件人 Blabber、gippgig

gippgig

未读,
2020年12月31日 16:27:012020/12/31
收件人 Blabber、gippgig

gippgig

未读,
2021年1月15日 18:02:122021/1/15
收件人 Blabber、gippgig

gippgig

未读,
2021年2月13日 04:34:022021/2/13
收件人 Blabber、gippgig

gippgig

未读,
2021年2月14日 21:53:592021/2/14
收件人 Blabber、gippgig
Origami-Inspired Antenna Technology for Use in Small Satellites

Alberto Gaitan

未读,
2021年3月5日 11:43:432021/3/5
收件人 HacDC Public Discussion
"Current assessments of galactic rotation curves are based upon a framework of Newtonian accounts of gravity, a new paper published in EPJ C, by Gerson Otto Ludwig, National Institute for Space Research, Brazil, suggests that if this is substituted with a general relativity-based model, the need to recourse to dark matter is relieved, replaced by the effects of gravitomagnetism."

Factoring in gravitomagnetism could do away with dark matter


On Sun, Feb 14, 2021 at 9:54 PM gippgig <gip...@gmail.com> wrote:
Origami-Inspired Antenna Technology for Use in Small Satellites

--
--
Like what we do? Support HacDC by becoming a member. Learn more here: http://hacdc.org/membership/
--
You received this message because you are subscribed to the HacDC "Blabber" group.
To post to this group, send email to Bla...@hacdc.org
To unsubscribe from this group, send email to
Blabber+u...@hacdc.org
For more options, visit this group at
http://groups.google.com/a/hacdc.org/group/Blabber
---
To unsubscribe from this group and stop receiving emails from it, send an email to Blabber+u...@hacdc.org.

gippgig

未读,
2021年3月17日 16:30:232021/3/17
收件人 Blabber

gippgig

未读,
2021年3月19日 18:51:342021/3/19
收件人 Blabber、gippgig

gippgig

未读,
2021年3月29日 14:59:592021/3/29
收件人 Blabber

gippgig

未读,
2021年7月21日 01:18:152021/7/21
收件人 Blabber、gippgig

gippgig

未读,
2021年7月22日 04:29:302021/7/22
收件人 Blabber、gippgig

gippgig

未读,
2021年7月23日 04:00:512021/7/23
收件人 Blabber、gippgig

gippgig

未读,
2021年7月23日 19:55:022021/7/23
收件人 Blabber、gippgig

gippgig

未读,
2021年7月26日 15:18:502021/7/26
收件人 Blabber、gippgig

gippgig

未读,
2021年8月13日 01:54:132021/8/13
收件人 Blabber

gippgig

未读,
2021年8月16日 03:57:312021/8/16
收件人 Blabber、gippgig
Searching for life on Mars and its moons

gippgig

未读,
2021年8月17日 14:17:092021/8/17
收件人 Blabber、gippgig

Bobby Baum

未读,
2021年8月17日 15:05:402021/8/17
收件人 Blabber
Oops, deleted the s - that should have been space

gippgig

未读,
2021年9月10日 16:16:402021/9/10
收件人 Blabber、gippgig

gippgig

未读,
2021年10月6日 04:35:012021/10/6
收件人 Blabber、gippgig

gippgig

未读,
2021年10月8日 14:15:582021/10/8
收件人 Blabber、gippgig
已删除帖子
正在加载更多帖子。
0 个新帖子