Antimatter
Antimatter particles are mirrored versions of the particles that make up our world. All types of particles have antimatter versions of themselves, although there is very little antimatter left in the universe. These antimatter particles have opposite properties, such as the reverse electric charge. When the two meet they explode and destroy each other in a flash of energy. Writing for The Conversation website, Lars Eklund, Professor of Particle Physics at the University of Glasgow, explains a new development at CERN (the European Organization for Nuclear Research), that could shed light on antimatter particles.
For decades, scientists have been asking three key questions regarding antimatter:
- why equal amounts of antimatter and matter particles weren’t created at the big bang;
- why the two sets of particles didn’t annihilate each other; and
- why there is so little antimatter left in the universe.
The predominant theory amongst scientists is that during, and immediately after, the big bang there were processes that gave preference to matter over antimatter. This created a small surplus of matter, out of which all life and material were created. What this process is, and how it occurred, remains unclear.
Scientists at CERN, however, have recently made a discovery. In their Large Hadron Collider beauty experiment (LHCb), scientists studying B meson particles (particles which contain both matter and antimatter, that oscillate between the two identities), have published findings shedding light on the relationship between matter and antimatter.
Writing for Symmetry magazine, Sarah Charley explains the findings. The extent of the favouritism for matter over antimatter within these B meson particles depends on how the B mesons decay. In certain patterns of decay, this favouritism can be expressed as 55% favoured towards matter, and 45% towards antimatter. While this cannot fully explain missing antimatter in the universe, it does provide important new information on both particles’ existence.
Read the full articles:
- Lars Eklund, ‘CERN: discovery sheds light on the great mystery of why the universe has less ‘antimatter’ than matter’, The Conversation, 21 December 2020
- Sarah Charley, ‘LHCb finds more matter-antimatter weirdness in B mesons’, Symmetry, 17 December 2020
Vitamin D
The effectiveness of vitamin D supplementation has been a topic of debate in the medical community for decades. In this editorial for The Lancet: Diabetes and Endocrinology medical journal, the authors discuss this in the context of protecting the public against Covid-19.
The beneficial effect of vitamin D in bone growth and maintenance is proven by medical research. Studies have also been published arguing that the vitamin has beneficial effects on the immune system. The effect of vitamin D on other medical conditions, such as respiratory tract infections, however, remains unclear.
The Covid-19 pandemic has reignited the debate around the benefits of vitamin D. The editorial states that groups that traditionally exhibit vitamin D deficiency or insufficiency have been disproportionately impacted by Covid-19. Such groups include older adults, those from ethnic minority backgrounds, and nursing home residents. Government advice currently states:
Everyone is advised to take a supplement of vitamin D during winter months.
A rapid review study from the National Institute for Health and Care Excellence (NICE) and Public Health England evaluated the evidence around vitamin D supplements and Covid-19. While it supported the Government advice on vitamin D supplements, the study also concluded that:
There is not enough evidence to support taking vitamin D solely to prevent or treat Covid-19.
The study states that further research is required. However, others in the medical community have argued that as vitamin D is thought to be safe, any small benefit for Covid-19 patients would outweigh the costs.
Read the full article: Editorial, ‘Vitamin D and COVID-19: why the controversy?’, The Lancet: Diabetes and Endocrinology, 11 January 2021.