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Comment Re: Not going to happen (Score 2) 79

The Zuma failure is only a rumour, and if it happened, it was caused by hardware which SpaceX was not allowed to see or touch, so it isn't their fault.

Falcon has had two full failures: CRS7 failed in flight AMOS-6 failed on the pad. Falcon has had one partial failure: CRS1 was successful but a secondary payload did not make its intended orbit and was lost. They also blew up a 'grasshopper' experimental vehicle but that is in no way comparable to a Falcon failure.

Two and a bit failures from 48 flights (or intended flight in the case of AMOS-6) is neither great nor terrible.

To be allowed to fly people, SpaceX and Boeing have to convince NASA they have less than 1/270 chance of losing crew.

Comment Re:Too ugly (Score 1) 296

I prefer the A380 to the 747, because I find the 747s hump ugly. However, the 747 blends its cockpit windows very smoothly with the shape of the nose, which the A380 doesn't. Also the A380 just looks too short for the height of its fuselage.

The A340 and 787 both look great, in my opinion. I haven't seen an A350 in the flesh yet, so can't comment on that.

Comment Why are twin jets cheaper to run? (Score 1) 296

The fundamental problem for the A380 is that twin jets are cheaper to operate than quad jets. The 777 may not carry as many passengers, but it has lower cost per passenger-kilometre than the A380, or indeed the 747 (which isn't so different in size than the 777.)

I have seen this stated many times. However, I don't really understand why. For example, this article states "those newer, more reliable [twin jet] engines have also been bigger and more efficient" but doesn't say why jet engine companies aren't also making more reliable and efficient engines for quad jets, if it is all down to newness.

I've looked online for an answer, but generally I just find speculation from people who seem no more knowledgeable than myself.

I can give an argument why quad jets should be cheaper. A plane needs to have sufficient thrust to take off and climb out after a single engine failure at the worst time (just after it is too late to abort take off.) If we call this thrust T, then a twin jet needs each engine to be capable of producing T, so it provides 2T thrust. For a quad jet, after a failure it needs T, so each of the remaining engines needs 1/3T, hence when fully operational it need only provide 4/3 T thrust. So a twin jet must be much more over provisioned than a quad.

Speculations I've seen include that four engines are extra complexity (but those big twin engines need a lot of extra complexity to be so big), extra maintenance costs, that engines disrupt lift, so you need bigger wings (and more weight) to make up the losses of having two extra engines, that with engines further outboard you need more structural strength in the wings (hence more cost and weight.)

I'm not saying these reasons are wrong, just that nobody I've seen making those arguments has convinced me they know what they're talking about. In replies, if you have expertise, or are citing someone with expertise, please make this clear.


Microsoft Partners with Signal to Bring End-To-End Encryption to Skype ( 64

Microsoft and Open Whisper Systems (makers of the Signal app) surprised many on Thursday when they said they are partnering to bring support for end-to-end (E2E) encrypted conversations to Skype. From a report: The new feature, called Skype Private Conversations has been rolled out for initial tests with Skype Insider builds. Private Conversations will encrypt Skype audio calls and text messages. Images, audio or video files sent via Skype's text messaging feature will also be encrypted. Microsoft will be using the Signal open-source protocol to encrypt these communications. This is the same end-to-end encryption protocol used by Facebook for WhatsApp and Facebook Messenger, and by Google for the Allo app.

Comment Re:Pointless (Score 1) 348

my GUESS (total non-informational guess) is that there already is an exploit (or, even apple GIVING the leos what they want) and this is all a smokescreen to keep up appearances.

I believe (again, no actual info) that the nsa has all it needs, it has enough might and power and influence to get what it wants.

I believe all encryption has been broken by the three letter agencies and we are all being led astray by false info. the narrative, if you will.

why do I believe this? just being alive for over 50 years and seeing what we have evolved into, what amazing amount of power the TLAs have and how much hunger they have to spy on everyone.

also the fact that I know, for a fact, that the government has had the ability to 'make life difficult' for any company not wanting to play ball (think CALEA) with the feds. you cannot be a business that does data comm in the US and not play ball with those bad guys (yes, I believe they are now the bad guys).

so, I will never trust a phone, ever again, no matter who makes it. I know that there are levels in silicon and firmware that even google does not get to see. carriers get some view, others get other views, but there are layers and layers. because of this, its not something I am interested in (to develop on) since its never going to be OUR devices (it never was).

from now on, pocket computers are spy devices that also offer us some services.

we need to start thinking like that, and stop believing companies who say things to further their agenda.

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