34587 About asthma, NYC and LA are particularly vulnerable because of the population density and the high number of people driving vehicles that add polluting NO2 to the air. I think that's a too simplistic conclusion.  I don't deny that city dwellers might be more vulnerable, but consider also lif...

34570 Perhaps all these extra precautions not only reduced COVID deaths but will also reduce seasonal flu deaths? Many spent less time outside their home in March and April, and visits to care homes were restricted. so this might have reduced the seasonal flu deaths.  But I can tell you that all th...

These numbers are more telling than the reported Covid deaths, since the latter depends on how much different countries have tested, and it's also very difficult to tell whether Covid-19 was the actual cause of death. I bet the Swedish numbers will be discussed.  Sweden did not shut down schools or ...

I collected some statistics on weekly deaths in Norway to compare 2020 with previous years.  Here's what I got: y.jpg The deaths around week 15 was higher than previous years (but much lower than around week 10 in 2018 - perhaps a bad flu year?), but nothing out of the ordinary.  For the rest of the...

34542 the radioactive waste problem That problem seems to me as a very manageable problem, one of the least worries.  The waste is contained, it takes up very little space, and we only need a safe place to store it.  The main issue is that it's toxic for a very long time, and the storage has to be ...

34532 the change in the photon's energy did not depend on the path it took around the black hole (that's what I mean earlier by the path independence due to gravity being a conservative force), but you are "driving into it" (invoking the driving in rain analogy for aberration), and becaus...

34517 Objects behind you will be aberrated into view ahead, but there won't be bands of color. Just a smooth transition from redshift behind to blueshift ahead, as illustrated here. The reason is that gravitation is a conservative force, even in general relativity with black holes. This means the c...

34513 Yes, the sky behind you will be redshifted, and the sky in front will be blueshifted. But approaching the black hole behind and in front get somewhat smeared out, so would there rather be bands of red and blue? The short duration could be compensated by making the hole larger. Maybe this is s...

Yes, I wondered if that would cancel each other out, but then I saw that the colours still were shifted, so I thought it wasn't that simple. If you were already approaching the black hole close to the speed of light, so stuff in front of you should be blue shifted and stuff behind you should be red ...

Everything goes red in that video just before the singularity, but are the colours accurate?  Since you would reach crazy speeds relative to the background stars before the event horizon is crossed, why don't we see any redshift?

A-L-E-X wrote:

Qr Bbpost did you know that lichen can exist on the outside of the ISS?

Exist maybe, but not grow, even less evolve.

I had to did a bit in the old forums.  Back in 2012 I wrote that I think life on Venus is more likely than on Mars (but I'd still say probably no life on either).  Mars is overrated, also for human settlements.  Floating settlements in Venus' atmosphere still sound better as a permanent thing than b...

How are the forests in arid California and Oregon managed?  Any firebreaks cleared?

34425 There was a study that came out a few weeks ago that showed there is at least three months of immunity.  That was the lower boundary. A lower boundary is something else than a general statement that the immunity is 3 months.  And there are limits how low you can go before you can't separate o...

A-L-E-X wrote:

Qr Bbpost About reinfection it seems that 3 months is the period for which you get immunity

Do you have any data to back up this claim?  This is basically saying that there is no immunity.