MigL

I suggest doing your analysis of the two observers in a gravity well, with EM waves instead of photons. The peaks and troughs of a wave are in effect signal pulses, and frequency of a particular EM emission is, in effect a clock. Now consider a specific emission deep in a gravity well, as observed by an observer much higher in the gravity well. Using your same logic ( as you previously applied to the photons ) the higher up observer will see the peaks and troughs of that specific emission arriving slower, and more separated. IOW, lower frequency and longer wavelength ( otherwise known as red-shift ), and if you multiply the two together, you still get c . Alternatively, an observer lower in the gravity well will see waves from that same specific emission ( but now higher up in the well ) arriving with peaks and troughs at a faster rate, or more closely spaced. IOW, higher frequency and shorter wavelength ( also known as blue-shift ). In both cases, the frequency/wavelength shifts are not observed at the same depth in the gravity well, but only at differing depths. That is a 'comparison' and what is meant by relative, certainly not 'absolute'. And in neither case is c measured to be different from the speed of light by any observer. Its amazing how much confusion you can avoid, by using the right model for the circumstances.

Welcome. We are all good, but some are better than others. ( or just more opinionated ) Join in the fun.

Having had Kawasaki does not put you at higher risk. But this affliction, very similar to Kawasaki, has been linked ( in UK, Italy and US ) to Covid-19

It may act as a systemic inflammatory agent. Other than the respiratory tract, GI tract and kidneys, it also seems to inflame blood vessels, leading to a thickening ( gelling ? ) of blood. There is also the systemic inflammation that has been affecting children, and linked to Covid-19.

Uummm… You think you've been drinking for only an hour, but actually, it's been 4 hours. Then you stumble.

Well, there goes the invariance of c .

That would lead to a lot of Marilyn Monroe, skirt blown up around the waist, type incidents. Is this thread becoming a little silly ?

All observers also agree on the invariance of c ; something has to change. Frequency, or wavelength, of the signal. Hence, red or blue shift. That was simple, wasn't it ?

How do you know it ticks more slowly until you bring them together to compare ? Frequency and wavelength are a 'signal', and are used as 'timing', or a clock, if you will.

Gravitational time dilation is relative. It is only apparent when comparing the emission ( frequency/wavelength ) from two differing depths of the Gravitational potential well. IOW, one 'signal' has to climb/descend to the height/depth of the other for the comparison to be made. You cannot circumvent that ( no mixed frames ).

An opinion piece on the response, successes and failures, of two similar countries, the US and Canada, to the Covid-19 pandemic https://www.msn.com/en-ca/news/canada/canada-succeeded-on-coronavirus-where-america-failed-why/ar-BB13A2OT?ocid=msedgntp Makes for interesting reading, and places the large majority of blame, for the US's inadequate response, on its polarized political system, and lack of a universal heath care system. How many Americans need to die before you Democrats and Republicans learn to work together, and everyone has access to national health care ? ( Oh wait... Didn't I ask this same question regarding gun control ? ) Seems even Republicans can't work together... G W Bush has become the latest target of President D Trump after the former president released a video calling for people and their government to work together. The President 'slammed' G W Bush, questioning his absence during the impeachment trials. ( Maybe G W was embarrassed to be associated with what passes for presidential behavior today )

That's a problem with all democratic political systems. Political leaders only govern four years down the road, and can't see past the next election. But I'll take that over a dictatorship, or one-party system, any day.

Definitely. I can certainly agree that D Trump is dancing as fast as he can to try and divert blame for the many failures, from himself, in an attempt to secure re-election. That's been his MO for the last 3 1/2 years.

If you want to blame D Trump for the stupid advice he gives ( Hydroxychloroquine, UV light and disinfectants, etc. ), fine. If you want to blame D Trump for squabbling with medical professionals, instead of listening to their advice, fine. If you want to blame D Trump for worrying about his re-election more than mitigating the pandemic, and associated death toll, that's fine too. But in 2009, during the H1N1 epidemic, the CDC estimate for the death toll is between 9000 and 18000. "During the pandemic, CDC provided estimates of the numbers of 2009 H1N1 cases, hospitalizations and deaths on seven different occasions. Final estimates were published in 2011. These final estimates were that from April 12, 2009 to April 10, 2010 approximately 60.8 million cases (range: 43.3-89.3 million), 274,304 hospitalizations (195,086-402,719), and 12,469 deaths (8868-18,306) occurred in the United States due to pH1N1. These final estimates are available at: Estimating the burden of 2009 pandemic influenza A (H1N1) in the United States (April 2009-April 2010), " From https://www.cdc.gov/h1n1flu/estimates_2009_h1n1.htm Who do we blame for those deaths ? Seems B Obama prepared his pandemic response playbook a little late ? ( hey, it's my duty to stir up controversy ) PS: ( and generate discussion )

I would have thought you'd give him a white hood ( KKK ) mask, INow, not a 'gimp' ( Pulp Fiction ) mask.

To clarify, CY, The exposure has to be large enough to overwhelm the immune system for serious outcomes. 'Large enough', is obviously different for different people, according to their age or comorbidities.

I would agree. And thanks for the info, INow.

There does seem to be continuing confusion about aerosol spreading of SARS-COV2 virus, with reports out of Wuhan, of detectable traces of virus RNA in cramped, non-ventilated areas of hospitals, markets, and even open air. But you would have to breathe for 15 min or more, to inhale a single fragment of virus, in open air. Whether these fragments are viable whole virions, or not, is debatable, as the testing is not that specific ( only looks for certain markers ), and no-one has yet attempted to 'culture', and grow these fragments to check for viability. Also , viral load comes into play at these small concentrations; how many virus are needed for an infection ? Indications are that low viral loads result in mild to no infections, that may still test positive. Larger exposures are needed for serious,symptomatic cases. A recent case in BC, Canada, had a woman undergo testing 4 times, two positives, one negative, and one inconclusive, so she was diagnosed of having been infected. After quarantine, she was subsequently re-infected, and medical professionals are left wondering if there is no acquired immunity to the virus. I would first look at the testing procedures, to see what determines an active, viable virus. And the minimum number of viable virions that determine infection.

Iowan daily new case number does seem kind of high for the total number of cases ( all depending on testing of course ). I can't get a history of Iowa's daily case numbers, but yesterday's single data point, would indicate new cases are still climbing rapidly. Most places will wait until new case numbers decline for a period of time before considering partial lifting of the lockdown.

I'm only familiar with semiconductor clean rooms, which are not sterile as they are only concerned with particulate contaminants.

Laminar flow simply means without ( or minimal ) turbulence. Top-down flow is a method to minimize turbulence and horizontal flows ( which may spread contaminants )

Didn't think social distancing would be much of a problem in the wide-open spaces of Iowa . Stay safe.

I would think so. Spinning separators work on density, to separate cream from milk, for example. Knock-out pots ( or cyclonic filters ) work on the same principle as a snow fence. Air has to accelerate to go over it, and the heavier snow drops out on the windward side. For this same reason I wouldn't think ventilation systems would spread virus droplets. Going through a high speed fan will get rid of most virus droplets. ( usually the knock-out pot or cyclonic separator is just ahead of the fan to collect dust, liquid or whatever you're separating out of the airstream )

What about this vaccine being developed at Oxford, which has been able to skip several stages of testing. as it uses the same mechanism used for a MERS vaccine previously developed. They say if final testing proves successful, they could have 3 million units ready by the fall.

Droplets tend to fall out of suspension very quickly if the airflow is passed through a 'knock-out pot' ( engineering speak ). In Physics terms, airflow is directed into a large chamber, where it is quickly decelerated, and then accelerated again. The liquid droplets have much more inertia than air molecules, and cannot 'keep-up'; they drop out of suspension.