Search found 5739 matches

by Amber G.
15 Apr 2019 20:58
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

^^^ LIGO took 13 years to detect the first gravitational waves. As I said here, it was being estimated that the upgrade of LIGO will make it so that we may detect 1 every week or so..(After LIGO india comes on line it may be a daily event).. Anyway .. The upgraded LIGO has just detected two likely g...
by Amber G.
12 Apr 2019 02:59
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

This may be as good time as any to share Professor Stephen Hawking’s fantastic 16-minute animated explanation of black holes:
https://www.bbc.co.uk/programmes/p03h9y3b
by Amber G.
12 Apr 2019 02:06
Forum: Military Issues & History Forum
Topic: International Aerospace Discussion - Jan 2018
Replies: 1019
Views: 141223

Re: International Aerospace Discussion - Jan 2018

The odds of a spacecraft crashing or failing in orbit are quite high, sometimes as high as 60%. So despite Beresheet not landing successfully, the Israeli team achieved a lot. Bad luck on this attempt, Good luck for the next one. (Last picture sent by Israel's moon-craft) https://pbs.twimg.com/media...
by Amber G.
11 Apr 2019 21:44
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

^^SMBH of our own galaxy will be the next candidate... It was a VERY long process .. such science takes a long time , patience and determination. The data (of the picture) was gathered about 2 years ago (2017), the computer program which analyzed the data and produced this picture was, I think was f...
by Amber G.
11 Apr 2019 07:57
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Amber ji, Here’s how my high school brain worked it out. To stop mother earth from coming in the way, let us replace it with a point of equal mass at the center of earth. Let's use a stick of negligible width to stand on to throw the ball. The other end of the stick is fixed at earths center and th...
by Amber G.
11 Apr 2019 07:49
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

11.2km/sec is escape velocity for Earth hence ball won't come back. Yep, and it will become something a "planet" (like Mangalyaan )- orbiting around the Sun. Additional point just to show how sophisticated math (computer programs) for ASAT would be. For such accuracy, one need not only co...
by Amber G.
11 Apr 2019 07:30
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

' Coriolis effect comes into play only if traversing across latitudes (e.g. long range artillery, sniper fire, ICBMs but not ball vertically going on- since it is on same latitude). This is NOT correct. Coriolis effect is valid for any rotating co-ordinate system - that is on our spinning earth. NO...
by Amber G.
11 Apr 2019 03:27
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

Why it is not symmetric? The shape (within the limit of its resolution) fits perfectly with Einstein's theory... Short answer about why one side of the image is brighter than the other: The "shadow" in the center of the picture against is a backdrop of glowing light - the light that is be...
by Amber G.
11 Apr 2019 01:45
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

^^^ The image shows a bright ring formed as light bends in the intense gravity around a black hole. This the biggest known black hole ( 6.5 billion times more massive than the Sun) ( EHT looks at gas surrounding it- it is image of a shadow. Specifically, they are looking at the event horizon - the l...
by Amber G.
11 Apr 2019 00:07
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Amber ji, ...It's a good question ... It is related to understanding suborbital and orbital paths and hence very much related to ASAT and a satellite. So, how will a ball going straight up fall 1 km away? Very confused... But, I don’t think Amber ji is wrong that a ball thrown in an atmosphere-less...
by Amber G.
10 Apr 2019 11:06
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Somebody’s been reading about Feynman. This was not a purely ballistic intercept. I find it difficult to believe microsecond accuracy is achievable over 300 km and 180 seconds flight time. Intersecting parabolas is too facile an approach. An accuracy of 1 in 5 orders of magnitude may be achievable ...
by Amber G.
10 Apr 2019 10:52
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Folks, thanks to those who took time and responded to my question about throwing the "ball straight up" a few posts above. The problem is, of course. very much related - in understanding our discussion about ASAT and provides logical thinking. The orbital motions are VERY much different th...
by Amber G.
10 Apr 2019 08:26
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Amberji, can you please explain in plainspeak if the ASAT test was more or less challenging than a BMD test? I ask because: a) I was always under the impression that the latter is more difficult considering the possibility of maneuvering reentry vehicles but am not sure anymore b) I want to underst...
by Amber G.
10 Apr 2019 07:54
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

For polar sats orbit one half is ns and other half is sn Sometimes india will be in the sn part due to rotation of earth Missed this....] Yes, also this is why I was talking about right "time-window" and "two-sets of azimuth choices" in my message above.. and actually in other d...
by Amber G.
10 Apr 2019 07:49
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Okay .. anybody still wants to take a stab at this. if you have not seen this before it will help to understand basics of This is NOT a trick questions. Neglect air-resistance etc.. assume well-known values for physical constants like g etc. If one "threw" a "ball" ** straight up...
by Amber G.
10 Apr 2019 07:39
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

ArjunPandit wrote:Is the image of Blackhole out yet?

You can watch Wednesday's press conference in English via the European Commission YouTube channel or the National Science Foundation live stream at 9 a.m. ET.
by Amber G.
10 Apr 2019 07:02
Forum: Technology & Economic Forum
Topic: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?
Replies: 14
Views: 734

Re: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?

To All - To be clear - this is absolutely NOT about any particular dhaga ( like physics or maths) or has any other motives. Just wanted to quantify about how technical discussion is perceived here. These discussion takes place in all kind of threads (particularly threads like nuclear or space relate...
by Amber G.
10 Apr 2019 03:46
Forum: Technology & Economic Forum
Topic: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?
Replies: 14
Views: 734

Re: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?

^^^ Surajji - I already answered your question (about purpose) in my intro. But you raise a good point about Physics and Maths thread - Do you (and other brfites) enjoy/participate in those kind of threads? Are such threads good or bad for BRF? Should such thread continue, become more active or disc...
by Amber G.
10 Apr 2019 00:21
Forum: Technology & Economic Forum
Topic: BR Maths Corner-1
Replies: 1748
Views: 91564

Re: BR Maths Corner-1

what do these numbers mean in real world. .. Very good question! That is what many want to figure it out. Some times people think it is a mere "coincidence" or merely a beautiful result but again it may be have a deep meaning.. What I do know, or learned in last 50 years, is many of these...
by Amber G.
10 Apr 2019 00:04
Forum: Technology & Economic Forum
Topic: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?
Replies: 14
Views: 734

Re: Is brf a place for STEM type technical discussion? Should it enable/encourages this type of discussion?

What's the purpose of a poll in a subforum that's a place for such discussions and already has both a Maths and Physics thread sitting in page 1 ? The quality of discussion is entirely on the poster body and their own willingness to self moderate. Just to gather the interest of the audience (who is...
by Amber G.
09 Apr 2019 23:44
Forum: Technology & Economic Forum
Topic: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?
Replies: 14
Views: 734

Re: Is brf a place for STEM type technical discussion? Should it enable/encourages this type of discussion?

Some personal perspective: I wanted to start this thread many times over the last few years but it is here finally. I joined BRF in 1998 and what attracted me to BRF was technical discussion just after Pokhran II I remember, our math-team (I was a coach), was visiting our ( US) senator who was quite...
by Amber G.
09 Apr 2019 23:32
Forum: Technology & Economic Forum
Topic: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?
Replies: 14
Views: 734

Re: Is brf a place for STEM type technical discussion? Should it enable/encourages this type of discussion?

I will request the admins to allow this poll for 2 weeks. In fact, I will be happy if they take part in the poll and give active feed back in form of comments. Same request for BRF-oldies/lurkers and new members. I am starting this poll in the spirit of our PM’s slogan – Jai Jawan, Jai Kisan, Jai Vi...
by Amber G.
09 Apr 2019 23:30
Forum: Technology & Economic Forum
Topic: Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?
Replies: 14
Views: 734

Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion?

Is BRF a place for STEM type technical discussion? Should it enable/encourages this type of discussion? In your opinion , what should be the role of technical/scientific discussion in BRF? All things considered , at present, in your opinion, what is the quality of such discussions. Please choose on...
by Amber G.
09 Apr 2019 11:48
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

Meanwhile - Potential BIG News regarding Gravitational Waves. Just a a week into the 3rd LIGO Observing Run and first candidate has been posted to GraceDB - the GravitationalWave candidate event database: say hello to S190408an! More info, including a map of its likely sky location, at https://grace...
by Amber G.
09 Apr 2019 09:07
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Have not had chance to go through messages in details here.. some comments, more to come as I get a chance. (Plan to respond to Tanaji and Cain Marko later) but few quick responses: 1. Orbit direction of satellites as viewed from Hasaan MCF, Bengaluru Kerala for all PSLV launches for SSO is from Nor...
by Amber G.
09 Apr 2019 05:12
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

Subir Sachdev (Harvard) along with Dam Thanh Son (UChicago) , and Xiao-Gang Wen (MIT) share the 2018 Dirac Medal for their work on "novel phases in strongly interacting many-body systems." Congrats! Subir Sachdev was born in India and was at IIT Delhi as a student in late 70's. Ceremony w...
by Amber G.
09 Apr 2019 01:20
Forum: Technology & Economic Forum
Topic: Physics Discussion Thread
Replies: 2461
Views: 73867

Re: Physics Discussion Thread

Yes, nice picture .. The way I would explain it in layman terms - though accurately: No need to think about a string, just imagine once the ball is released (and the ball has no rocket thrust etc) the ball will remain in a figure called conic-section (which is a hyperbola, or a parabola or an ellips...
by Amber G.
08 Apr 2019 04:21
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

UlanBatori and AmberG , please stop responding to each other in this thread. Your fight is threatening to derail this thread. Put each other on the ignore list if you want and then continue engaging with others. Agreed. Folks - Unless the the question is directly addressed to me, or continuing/clar...
by Amber G.
08 Apr 2019 02:46
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

No it sadly does not [help], Amberji. Fine, sorry I can't waste more time to help you understand. Meanwhile please keep words like "cra*" and rudeness away. No need for that. End of this unsolicited "discussion" please, it is embarrassing to have to explain such things to people...
by Amber G.
08 Apr 2019 02:42
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Try actually throwing a ball straight up. It stops at the top and comes back down into your hands ... Hey UB, I have a challenge for you,. See if you can answer the following *simple* question in straight forward manner -- without resorting to insults and other irrelevant comments. If one "thr...
by Amber G.
07 Apr 2019 11:49
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

technically proficient civilians like space enthusiasts are already getting way too much info from the drdo video like: "It also lists an azimuth, elevation and range: az 168.981 deg, elev 41.758 deg, range 414.485 km. This would place the IR camera on the coast near 21.345 N, 86.912 E, give o...
by Amber G.
07 Apr 2019 10:28
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

... Hitting a satellite in orbit is same as tossing a ball up as a bird is flying fast, as I mentioned (and iirc some pompous entity of course twisted into something else :rotfl: ). Pompous entity? :rotfl: :rotfl: Honestly I must admit that I avoid UB's analysis in anything related to science - spe...
by Amber G.
07 Apr 2019 09:27
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

I am going to plug my article in here. But I Am not feeling any shame in this. I had written this with no insider knowledge. Saurav Jha did provide some quality inputs about the KKV. Every point we made has turned out to be correct. Feeling proud. All You Need To Know About The PDV MK-II: India’s S...
by Amber G.
07 Apr 2019 09:19
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

AmberG- the ASAT-Microsat impact discussion above reminds me of the question you had posted a couple of years ago on the ISRO thread about the direction of an orbiting satellite which is 'impacted' tangential to and normal to its orbit :) Yes, and thanks for pointing it out. Intersting (and in some...
by Amber G.
07 Apr 2019 09:07
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

From this video, at about 26:00... DRDO director Satheesh Reddy specifically says that the satellite was impacted almost head on (or at a very shallow angle). This was to done to maximize debris that would lose kinetic energy and come down into atmosphere. Posting this here since there was some spe...
by Amber G.
07 Apr 2019 00:02
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

Amber Ji, was waiting for you to comment. Would you be able to comment on the following notions I figure? 1. The new perigee of any piece cannot be lower than the impact point (because the object returns there.. DUH! 2. If debris is thrown all around (from an almost circular orbit), most of them wi...
by Amber G.
06 Apr 2019 23:45
Forum: Military Issues & History Forum
Topic: Indian ASAT Test
Replies: 855
Views: 95510

Re: Indian ASAT Test

From the following article: All You Need To Know About The PDV MK-II: India’s Satellite Killer By Indranil Roy About debris: The test parameters were chosen with extreme caution to minimize the hazard of debris after the impact. Although the missile can take out a satellite at 1000 km, the satellite...

Go to advanced search