Astronomy

[Danik 2016]

Aboriginal Australians Observed Red Giant Stars’ Variability

By: Javier Barbuzano | October 13, 2017

New interpretations of oral accounts by Aboriginal Australians show that they included references to the variability of red giants Antares, Betelgeuse, and Aldebaran.

"European astronomers realized that red giants changed in brightness in 1596, when David Fabricius registered the variability of the star Mira. Johannes Hevelius went on to calculate the amplitude and periodicity of Mira’s changes in 1662. But the oral traditions of Australian Aborigines could go much further back in time: they have inhabited the fifth continent for more than 65,000 years. Research examining oral tradition for geological events, such as volcanic eruptions or meteorite impacts, have shown that such oral traditions can survive for thousands of years."
http://www.skyandtelescope.com/astro...t-variability/

[Dreamwoven]

Mars was this morning very bright, and its light steady, just above the horizon. Beautiful.

[Dreamwoven]

Modern astronomy tends to do that to our illusions. Sad but true.

[Dreamwoven]

There is a feeling that a new era is beginning in astronomy. Its best expressed in Astronomy Now: https://astronomynow.com/2017/10/16/...-of-astronomy/. I'm still not sure what this new era is. Perhaps it will gradually clear as more such colliding neutron stars become more frequent and more understood:

"A neutron star is formed when a massive star many times the size of our Sun explodes as a supernova, and what remains of the star’s core collapses under its own gravity. Neutron stars are only 20 or 30 kilometres across, but they pack the mass of an entire star inside them, with matter crushed so densely that all the protons and electrons merge to form neutron particles, hence their name. It’s often said that a teaspoon of neutron star material would weigh the same as Mount Everest. The estimated masses for the two neutron stars that merged in GW 170817 range between 0.86 and 2.26 times the mass of the Sun."

OK, Einstein predicted this almost exactly a century ago.

A kilonova is smaller and more concentrated than a supernova...

[Dreamwoven]

There are version of this across the astronomy pages. I chose Astronomy Now's version as being the least difficult to understand...

[Dreamwoven]

https://www.space.com/37988-did-life...ical-laws.html

This question about the origins of life suggests that it may emerge where sufficient elements are found together, like water, hydrogen, moderate temperatures, and other elements. I suspect that "life" - at least in unicellular bacterial form - many well be found to exist where such elements are found together.

[Danik 2016]

There is a feeling that a new era is beginning in astronomy. Its best expressed in Astronomy Now: https://astronomynow.com/2017/10/16/...-of-astronomy/. I'm still not sure what this new era is. Perhaps it will gradually clear as more such colliding neutron stars become more frequent and more understood:

"A neutron star is formed when a massive star many times the size of our Sun explodes as a supernova, and what remains of the star’s core collapses under its own gravity. Neutron stars are only 20 or 30 kilometres across, but they pack the mass of an entire star inside them, with matter crushed so densely that all the protons and electrons merge to form neutron particles, hence their name. It’s often said that a teaspoon of neutron star material would weigh the same as Mount Everest. The estimated masses for the two neutron stars that merged in GW 170817 range between 0.86 and 2.26 times the mass of the Sun."

OK, Einstein predicted this almost exactly a century ago.

A kilonova is smaller and more concentrated than a supernova...

I have the same feeling, DW. That´s what makes me so curious about astronomy. It is presently one of the fields that generates most futuristic fantasies and expectations and that what reminds me so much of the Renaissance. And we know the result of the Renaissance explorations.

[Danik 2016]

https://www.space.com/37988-did-life...ical-laws.html

This question about the origins of life suggests that it may emerge where sufficient elements are found together, like water, hydrogen, moderate temperatures, and other elements. I suspect that "life" - at least in unicellular bacterial form - many well be found to exist where such elements are found together.

And it seems that these researches aren´t limited by religious orientations.

[Dreamwoven]

Mars was this morning very bright, and its light steady, just above the horizon. Beautiful.

That was not Mars, it was Venus, its atmosphere reflects light back to the observer! It was there again early this morning, together with the moon showing a very narrow sliver...

[Dreamwoven]

I've been checking up on the general theory of relativity that Albert Einstein discovered some 100 years ago. You will find it here: https://www.space.com/17661-theory-g...elativity.html

[YesNo]

I just finished Sabine Hossenfelder's post in Backreaction about inflation solving the flatness problem: http://backreaction.blogspot.com/201...ion-never.html

I follow her blog because it gets me thinking. In this case it is experts saying things that aren't true at least by her assessment. Inflation is what is supposed to have happened immediately after the big bang.

[Dreamwoven]

https://www.universetoday.com/137535...g-hosted-life/

This is a bacterial life form that may have existed on Mars. It also shows how alien the Mars environment is to even bacterial life. Metal-eating bacteria sounds really bizarre.

[Danik 2016]

"According to a new study by a team of European researchers, extreme lifeforms that are capable of metabolizing metals could have existed on Mars in the past. The “fingerprints” of their existence could be found by looking at samples of Mars’ red sands.

For the sake of their study, which recently appeared in the scientific journal Frontiers of Microbiology, the team created a “Mars Farm” to see how a form of extreme bacteria might fare in an ancient Martian environment. This environment was characterized by a comparatively thin atmosphere composed of mainly of carbon dioxide, as well as simulated samples of Martian regolith."
https://www.universetoday.com/137535...g-hosted-life/

Bizarre indeed and I hope it doesn´t find it´s way to earth. Currently I am struggling against a very resistant sort of mites, I suppose they are bird mites. No disinfection seems to work with them. It made me think that one is surrounded by more invisible predators than one usually thinks.

[Danik 2016]

I just finished Sabine Hossenfelder's post in Backreaction about inflation solving the flatness problem: http://backreaction.blogspot.com/201...ion-never.html

I follow her blog because it gets me thinking. In this case it is experts saying things that aren't true at least by her assessment. Inflation is what is supposed to have happened immediately after the big bang.

I couldn´t follow the argument very well as it seems to be based on mathematical calculations. The one thing I suppose is that one probably must also have other kinds of evidence beside the mathematical one.

[YesNo]

I think Hossenfelder was trying to warn people to be wary of what one is being told even by experts. I may have misunderstood her post but I think one of her justifications was the use of probability claims (to make the claim sound mathematical and therefore authoritative) when there is no probability distribution justifying that claim.

I think those metal eating bacteria are on Earth. They are being used to see what traces they leave behind when in a simulated Martian environment on Earth. Given that information, one can look on Mars for similar traces and try to conclude, if those traces are found, that they were caused by some extinct Martian life form rather than an inanimate chemical reaction. I was hoping the current mission to Mars would have shown by now that there was life there, at least in the past. Apparently more study needs to be done.