imatfaal

Actually I am struggling to see an easy solution - I am pretty sure that with enough leg work I could manage a complex very involved answer; but these sorts of questions tend to resolve to a few lines of proof.  Just cannot see it yet - maybe I have missed something obvious

That's so useful

Is Mary Winehouse a bastard mix of Amy Winehouse and Mary Whitehouse?  A great soulful voice who sings about censorship and the decline of family values

if you sit in quiet room and listen to your favourite tune on FM radio, DAB radio, tape, cd, bad encrytion, good encryption, etc.  You will notice a difference but you pay your money and take your choice of where you draw the balance between money and fidelity.

24 minutes ago, zapatos said:

Primarily because the US does not regularly threaten nuclear strikes against North Korea.

Does quite a lot of threatening in general.  And it invades a lot more countries.  I didn't say that it didn't apply in the initial formation too.  It is just that if your government start talking about regime change as the endgame of a large scale military intervention then how can you still claim the moral high ground. And how can you dismiss North Korea's ravings as solely rampant paranoia when said country's integrity and sovereignty is threatened by an elected representative of the highest level.

On 01/08/2017 at 6:06 PM, Ten oz said:

America must not ignore the threat gathering against us. Facing clear evidence of peril, we cannot wait for the final proof, the smoking gun that could come in the form of a mushroom cloud. - George W. Bush discussion Iraq
 

Can someone explain why the above does not work just as well as follows:

North Korea must not ignore the threat gathering against us. Facing clear evidence of peril, we cannot wait for the final proof, the smoking gun that could come in the form of a mushroom cloud.

2 hours ago, iNow said:

Exactly. Also, my wife is usually pretty down with this sort of thing. She wouldn't normally need convincing. It's mostly just that we're in new infant territory right now so even "simple" trips to the grocery store require us to put on our war paint and work up the courage for the ride ahead. I'm making progress, though.

It is the fodder of life long memories - who wants kids to remember the trip to disneyland when they could have great memories of the trip to see the sun go dark

To be honest I think the idea of packing up the station wagon and heading of to see the total eclipse of the sun with wife, curious 4 year-old, and 8-week babe in arms (congrats to you and la iNow btw) sounds like the beginning of a Great American Novel.  And as if to prove my point: I reached up to grab the nearest John Irving I could find - the first chapter is called The Inadequate Lamp Shade (clearly a reference to the eclipse) and the first line is "One night when she was four and sleeping..."   (Admittedly it goes a bit dark from then on in). 

A bibliomancy for the 21st century - do things if they might make a good plot for a novel

On 04/08/2017 at 10:37 AM, Endy0816 said:

Not likely based on population sizes and growth.

Agree on that.  But from a purely mercenary viewpoint it might be worth learning.  I was offered a 7 figure salary to work in one of the Gulf states - in my industry English is used almost exclusively so I wouldn't have needed to be able to already speak Arabic (expected to learn eventually).  However in many other industries you can change your salary by an order of magnitude by working in the Gulf - but you need good Arabic (and to tick other boxes too).  I value my way of life too highly to move to a brutal dictatorship - but many others value the ability to provide a much more affluent lifestyle for themselves and family as more important..

22 minutes ago, PrimalMinister said:

I was told that if an astronaut travelled away from the planet near the speed of light and then came back a year later everyone on earth has aged 20 years. What is happening here? He has travelled into the future (despite never leaving the present).

Which is exactly why we use less poetic, or preferably mathematical descriptions.  Time has been dilated - each tick of his clock has, from an earthbound perspective, taken longer.  If he had kept a (impossibly good) telescope trained on the earth he would not have seen any discontinuities or jumps into the future - just a (quite complicated and let's not go there quite now) change in the way time passes.  If the earth-bound scientists had kept a telescope trained on him again they would has seen him do everything he did with no jumps or gaps. 

24 minutes ago, PrimalMinister said:

In the case of atomic clocks, one travelling round in a satellite and one on earth, how do we know the clock in the satellite is travelling into the future instead of just ticking faster?

Not sure that your question isn't a false dichotomy. 

Firstly we like relativity as an explanation as the calculation of the expected time dilation via the schwarztchild metric was predicted and then found to be accurate; it is always better when it is this way around. 

Secondly, your wording is dubious - time is dilated, clocks which are running normally in their own frame, can tick slower or faster when viewed from a different frame which is in relative motion, at a different gravitational potential, or both in the case of an orbitting satellite.  You need to be very careful when using terms like travelling into the future - it is the marrying up of linguistic terms like that and the mathematical formalism of the physical theory which causes many of the problems of understanding.   Clocks at a higher gravitational potential tick faster when viewed from the persepective of a local frame at lower gravitational potential and vice versa.  Clocks in relative motion tick slower when viewed from the local frame which the observer deems to be at rest.  "Travelling into the future" does that mean the same?

42 minutes ago, swansont said:

It occurs to me that if filtering out the carrier is imperfect it could add a bias to the resulting signal

Any directly generated additional noise would have to be at a fraction of the carrier frequency (not sure if that is the correct terminology) the threashhold of human hearing is just under 30kHz for young adults (who I think have the best range) - whereas FM transmission is about 3000 times that frequency.  There is about 100kHz variation in the carrier frequency of  of about 100MHz..  You are much more likely to get annoyed at mains hum if you are an audio-phile audio-snob

For a decoding bias I just cannot envisage what happens to a 100MHz carrier modulated with a ~10-10000KHz signal when the carrier signal which is removed is actually 99MHz.  Just read that commonest form of demodulator is two rf transformers - #1 on a closed loop with fixed frequency of the carrier and #2 on the received signal; if the frequency is the same on signal and closed then no voltage difference between to transformers and no resulting output.  However if frequency is not the same then the difference will be expressed as a varying out put voltage which is proportional to the difference in frequency.  And that system was developed over 80 years ago and is still the basis of FM radios

On 04/08/2017 at 0:19 PM, swansont said:

Earthquakes. Melting snow from mountains, droughts. We're talking very small angles here. There are often stories after we've had a large earthquake discussing the effect on the movement of the rotational axis.

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edit:
http://content.usatoday.com/communities/sciencefair/post/2011/03/japan-earthquake-shifted-earth-axis-shorter-day-nasa/1#.WYRa3caZMc0
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I'm more familiar with rotational speed effects; moment of inertia varies as mr^2, so mass movement near the surface has the largest effect., but it would also have the largest effect on the orientation. Even weather patterns have an effect — a hurricane/typhoon has angular momentum, whose axis does not coincide with the earth's rotation, but angular momentum must be conserved. 

So again it was my inability to properly conceptualise how accurate our readings can be. 

On 8/3/2017 at 10:41 AM, swansont said:

 There are a number of different oscillation cycles present, as well as effects of redistributing mass on the earth.

 

What has enough mass and is moving to affect the orientation of the earth?  Surely the ocean's have reached a sort of synchrony after all this time and are one of the cycles.  I know I struggle to cope with how accurate your and your colleague's data are - but, even with this caveat, I cannot envisage anything other than the sloshing of the oceans which would be big enough to make a difference

1 Rather than answer the question directly - which would involve describing how the information is encoded - I will ask an analogous question.  Do you think that the meaning, import, and beauty of a Shakespeare sonnet is changed if it is printed in 12 point, or 72 point? 

2. The frequency of a radio band is where the radio "looks" for the signal - any signal can be encoded in the specific modulation chosen.  The signal, I believe, is encoded in a small change in the main ideal frequency

3. Note the frequency of the sound waves for middle C is about 261 hertz.  FM is broadcast at around 500 times higher frequency than that.  There is no necessary connection between the cycles per second of the soundwave produced by the speaker and the cycles per second of the carrier wave.

LT;DR

But to reiterate if y is whole number then answer will be whole number

1/(1/(x * y))= x * y

(x * y)/(x / y) = y(x * y)/x = (xy^2)/x = y^2

Sqrt[y^2] = y

this is what you are doing.  So please look at the simple algebra and realise what ever number you put in for y you will always get y out again. 

NB

1.  Perfect squares means whole numbers - you cannot have a perfect square which when rooted gives fractional answer by definition

2.  Factors are also whole numbers - there is little point looking for divisors with fractions as you will always always get one

excellent twitter thread/legal primer from Seth Abramson on the Fed GJ, its particular powers, and likely consequences in this case

https://t.co/4kKRDze2B5

5 hours ago, CharonY said:

But that being said, it should not be an either or situation. Human rights have to upheld for all citizens.

 

"Human rights have to upheld for all citizens."  Human rights have to be upheld for everyone, citizens or not - they spring from the belief in the importance of our shared humanity not from our nationality. 

I did a couple of courses in Quantum computation - but I think your paper is beyond me, but I will give it a go and congrats for getting it all down.