I have witnessed bias in my work at university
Name and address supplied
You report on institutional racism in science (27 June, p 14). I am a white woman in a fairly senior support role at a university, but I have seen racism and sexism in my own institution.
It isn’t just the hurdles that BAME students have to overcome or the more obvious forms that discrimination can take, but also the daily small-scale occurrences of bias that can make life unbearable for both BAME people and women in science. It is even worse if you happen to be a BAME woman.
I am not a social scientist, so I don’t know how we might change these behaviours other than by challenging them when they happen in front of us. We have compulsory online training about unconscious bias, equality and diversity, but I suspect it needs something more personal and provocative. Consistent efforts to ensure a better attitude by senior staff, plus disciplinary action in some cases, will be required to bring about change. It is, however, the responsibility of those of us in the privileged groups to work for and aspire to real change.
Immunity may still have some benefits
When discussing why there hasn’t yet been another wave of the coronavirus in the UK, you say one explanation that can be ruled out is herd immunity as the level required for this virus has been estimated at 60 per cent, while studies suggest that “just 1 to 10 per cent of people have antibodies to the virus” (11 July, p 9).
This misses two critical points. Firstly, some parts of the UK have a much higher antibody prevalence than this 鈥� is close to 20 per cent, for example, and some boroughs presumably have even higher levels than this.
Logically, the places most vulnerable to a resurgence of the virus are those where it spread the fastest before 鈥� areas with high housing density and high use of public transport, for instance. These places are exactly where immunity is at its highest. Secondly, even at immunity levels well below 60 per cent, there could be a significant reduction of spread.
So while the main reasons for the lack of a second wave are probably the continuing precautionary behaviours and the remaining restrictions, as Clare Wilson suggests, the possible contribution from existing immunity shouldn’t be ignored.
We must do more about indoor airborne transfer
I share Peter Borrows’s feelings on inverse square laws applying to social distancing (Letters, 4 July). But there is another mechanism beyond direct transfer that is relevant to stopping the coronavirus. The question of indirect transfer 鈥� inhaling contaminated air that has been circulated from a distant person 鈥� seems relatively neglected.
In anything but still conditions, the respiratory plume from an infected person who is outdoors will quickly be carried away. Even in still outdoor conditions, the temperature difference between the plume and the ambient air should ensure that it is convected upwards away from head height.
This useful effect, which might also occur in large indoor spaces like supermarkets, can be nullified by ceiling fans. Even desk fans only serve to move virus-laden air laterally, rather than dilute it.
When investigating indoor air quality, it is common practice to monitor carbon dioxide levels. Since CO2 is also a respiratory product that responds to occupancy density and to dilution caused by ventilation, this could be used as a surrogate for microdroplets and as an indicator of risk. Advice for indoor gatherings should include “open all the windows, turn down the heating and turn off the fans”.
Reasons why distant oceans may be lifeless
Kevin Hand, in reference to moons in our solar system with ice-capped oceans, says the presence of microbial life in a range of extreme environments on Earth suggests that “if life emerges easily wherever the conditions are right, then these alien oceans beyond Earth should be inhabited” (20 June, p 40).
This would seem to conflate two things: where life can originate and where it can evolve and adapt to survive after it has originated. We don’t really know much about the beginnings of life, but it seems likely that the range of habitats in which life can originate is much narrower than the range it can subsequently adapt to. The oceans that Hand discusses may have never had conditions under which life could begin, even if it could have ultimately adapted to them.
We may be seeing the first TV signals of alien worlds
Jason Wright may not be able to think of a reason why the Odd Radio Circles (ORCs) recently found by astronomers might be created by aliens, but there may be one (11 July, p 14). We know that when our civilisation began broadcasting radio waves, these also spread out from our planet in an expanding sphere that, in theory, could be detected by alien civilisations. It seems to me that, seen from a great distance, such a sphere might look something like an ORC.
This would also account for the edges of the ORCs being brighter than their interiors. When we began broadcasting, we needed to use very highly powered transmitters to distribute the signal, but as technology improved, the same effect was achieved at lower power.
Recently, more and more signals have been distributed via cables rather than by broadcasting. This would result in a very radio-bright edge with a less bright interior. As these signals are only now coming within the sensitivity range of our telescopes, it could well be that we are making our first observations of the TV and radio signals from alien civilisations.
What happens to water-filled windows in a fire?
Regarding the use of water instead of argon in double-glazing, two thoughts come to mind (11 July, p 15). Firstly, wouldn’t water add a fair amount of weight to each window? This wouldn’t just be from the weight of water, but also from the frame and seals, which would have to be upgraded. Would building designs need to be modified to take this additional weight into account?
Secondly, how does this window react in the event of a serious fire? Is there a pressure release system? Otherwise, if the water has been heated to over 100掳C before the window breaks, this would result in an instantaneous (and possibly explosive) release of steam when the pressure is released 鈥� which is unlikely to please any firefighters in the vicinity.