Thursday, October 22, 2020

Mask Physics

There is no controversy about the need to wear a mask to reduce the possibility of COVID-19 transmission. Every scientific research that I've read supports that.

Here are some more from the physics side of it. This is approaching it from purely the point of view of physics of fluids.

Visualizing droplet dispersal for face shields and masks with exhalation valves

Visualizing the effectiveness of face masks in obstructing respiratory jets

On respiratory droplets and face masks


Friday, October 16, 2020

Roger Penrose - Is Mathematics Invented or Discovered?

 Now that he has just be awarded the 2020 Nobel Prize in Physics .... :)

This is a video of a conversation with Roger Penrose on his opinion of mathematics and its ability to describe our world.


Eugene Wigner also had written a rather popular essay on what mathematics is and its "unreasonable effectiveness" in describing our world.


Tuesday, October 13, 2020

Death by Spaghettification

This is probably a rather unpleasant way to die, but it may also be the most spectacular way.

Astronomers have observed for the first time the ripping apart of a star as it got too close to a massive blackhole.

When an unlucky star wanders too close to a supermassive black hole in the centre of a galaxy, the extreme gravitational pull of the black hole shreds the star into thin streams of material,” explains study author Thomas Wevers, an ESO Fellow in Santiago, Chile, who was at the Institute of Astronomy, University of Cambridge, UK, when he conducted the work. As some of the thin strands of stellar material fall into the black hole during this spaghettification process, a bright flare of energy is released, which astronomers can detect.

What is even interesting is that the unfortunate star is about the same size as our sun. So you kinda feel a bit for the poor thing.

But of course, all of these happened quite some time ago. It is probably quiet now in that part of the universe.😁


Thursday, October 01, 2020

Total Amount of Matter in the Universe

We now have the most accurate measurement to date of the total amount of matter in our universe. A new paper published in The Astrophysical Journal[1] seems to indicate that our universe is composed of 31% matter, with the rest being dark energy.

And of that 31% of matter, 80% of that is dark matter, which we are still searching for. This means that the "ordinary matter" that is known within the Standard Model of elementary particle and that makes up you and I is only about 6.2% of the entire matter+energy of our universe. The remaining 93.8% are made up of "dark" stuff, i.e. dark energy and dark matter.

This means that we still do not know the nature of a huge portion of what makes up our universe. Would it be nice to be alive 50 or 100 years from now when we know more about these things then (hopefully!).