Ultimate space simulation software

 
User avatar
Watsisname
Science Officer
Science Officer
Posts: 2116
Joined: 06 Sep 2016
Location: Bellingham, WA

Science and Astronomy News

21 Mar 2021 18:01

A-L-E-X wrote:
Source of the post 140?!  I didn't even know we had names for elements that high!

Ah, sorry for using confusing terms. I should have said atomic mass, not 'atomic mass number'.

The r-process in neutron star mergers is the dominant way for nuclei with masses greater than about 140 to be synthesized, which corresponds roughly to element 45 and above. This process can get to atomic masses as high as 300, maybe even 330, which corresponds to elements 95 and above. Depending on the model, it may even make elements that we don't have names for, though of course there is much less of them produced, and they do not last very long.

A-L-E-X wrote:
Source of the post How common are neutron star mergers, Wat, are they much less common than supernova explosions?

Yes, by about an order of magnitude. First, most stars with at least 8 solar masses will go supernova, but not all of them result in a neutron star. Then there are type Ia supernovae involving accreting white dwarfs. So for every neutron star that forms, there are more than one supernovae of any type. Then for a neutron star merger, you need two of them in a sufficiently close binary. 

To put numbers to that, the estimated rate of supernovae (both core collapse and type Ia) in the universe is about 39,000 (+/- 18,000) per cubic Gpc per year.[1] Actually the true rate is higher than that because this estimate excludes the dense cores of spiral galaxies. The rate of neutron star mergers on the other hand, estimated from LIGO/Virgo, is about 1540 per cubic Gpc per year (though could be as high as 4700 or as low as 320.)[2]  For the outskirts of an average spiral galaxy, these rates correspond to about 25 supernovae per 10,000 years, and maybe just one neutron star merger during that time. Still, these rates are enough to give us all of the heavy elements we have on Earth. :)
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

21 Mar 2021 21:25

Watsisname wrote:
A-L-E-X wrote:
Source of the post 140?!  I didn't even know we had names for elements that high!

Ah, sorry for using confusing terms. I should have said atomic mass, not 'atomic mass number'.

The r-process in neutron star mergers is the dominant way for nuclei with masses greater than about 140 to be synthesized, which corresponds roughly to element 45 and above. This process can get to atomic masses as high as 300, maybe even 330, which corresponds to elements 95 and above. Depending on the model, it may even make elements that we don't have names for, though of course there is much less of them produced, and they do not last very long.

A-L-E-X wrote:
Source of the post How common are neutron star mergers, Wat, are they much less common than supernova explosions?

Yes, by about an order of magnitude. First, most stars with at least 8 solar masses will go supernova, but not all of them result in a neutron star. Then there are type Ia supernovae involving accreting white dwarfs. So for every neutron star that forms, there are more than one supernovae of any type. Then for a neutron star merger, you need two of them in a sufficiently close binary. 

To put numbers to that, the estimated rate of supernovae (both core collapse and type Ia) in the universe is about 39,000 (+/- 18,000) per cubic Gpc per year.[1] Actually the true rate is higher than that because this estimate excludes the dense cores of spiral galaxies. The rate of neutron star mergers on the other hand, estimated from LIGO/Virgo, is about 1540 per cubic Gpc per year (though could be as high as 4700 or as low as 320.)[2]  For the outskirts of an average spiral galaxy, these rates correspond to about 25 supernovae per 10,000 years, and maybe just one neutron star merger during that time. Still, these rates are enough to give us all of the heavy elements we have on Earth. :)

Thanks, I'm really interested in these superheavy elements.  I always thought that element 126 would be "special" because it should be exceptionally stable compared to the ones around it.  And element 118, the one you mentioned, should be the heaviest noble element (though maybe not a gas?)

Wat, have you seen this?

https://en.wikipedia.org/wiki/Extended_ ... ractinides

https://en.wikipedia.org/wiki/Przybylsk ... Hypotheses

That star is a treasure trove of "artificial elements" including technetium and promethium and a few transplutonium elements too!  Is this star in Space Engine? I wonder what it looks like!

This is also extremely interesting:

https://en.wikipedia.org/wiki/Continent_of_stability

an entire group of elements consisting of quark matter!

more extensive article

https://phys.org/news/2018-06-periodic-table.html
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

23 Mar 2021 23:38

Wat, could this be some exciting news coming out of CERN?

https://t.co/3WrDM5xcwe?amp=1

https://twitter.com/CERN/status/1374283651337355265

I know we've been "teased" by new results before, which only led to disappointment later on.

But if accurate, maybe the first hints of quantum gravity?
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

25 Mar 2021 01:07

https://www.sciencemag.org/news/2016/10 ... osmic-rays

A bizarre microbe found deep in a gold mine in South Africa could provide a model for how life might survive in seemingly uninhabitable environments through the cosmos. Known as Desulforudis audaxviator, the rod-shaped bacterium thrives 2.8 kilometers underground in a habitat devoid of the things that power the vast majority of life on Earth—light, oxygen, and carbon. Instead, this “gold mine bug” gets energy from radioactive uranium in the depths of the mine. Now, scientists predict that life elsewhere in the universe might also feed off of radiation, especially radiation raining down from space.
 
User avatar
Watsisname
Science Officer
Science Officer
Posts: 2116
Joined: 06 Sep 2016
Location: Bellingham, WA

Science and Astronomy News

31 Mar 2021 23:17

 
User avatar
midtskogen
Star Engineer
Star Engineer
Posts: 1258
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Science and Astronomy News

29 Apr 2021 00:30

We've been flooded by news of helicopter flights on Mars, which is fun, but I'm actually more excited about all the rest we've heard nothing about.  The rover has many interesting instruments.  Remote controlling a helicopter on Mars is more a technological feat than it gives new knowledge about Mars.  The only other thing that we've heard, is that oxygen has been produced from the atmosphere, but that was certainly well tested in a simulated atmosphere on Earth, so no new science really, just a field test.  When will the real science come, I wonder!
NIL DIFFICILE VOLENTI
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

29 Apr 2021 14:40

midtskogen wrote:
We've been flooded by news of helicopter flights on Mars, which is fun, but I'm actually more excited about all the rest we've heard nothing about.  The rover has many interesting instruments.  Remote controlling a helicopter on Mars is more a technological feat than it gives new knowledge about Mars.  The only other thing that we've heard, is that oxygen has been produced from the atmosphere, but that was certainly well tested in a simulated atmosphere on Earth, so no new science really, just a field test.  When will the real science come, I wonder!

Yes I am interested in that machine that converts CO2 to O2, do you think something like that scaled up could be used on Earth? As a way to remove some of the excess CO2?
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

29 Apr 2021 14:42

https://www.usnews.com/news/best-states ... -pesticide

Q&A: Why California Is Banning Chlorpyrifos, A Widely Used Pesticide

California growers will soon be barred from using the insecticide chlorpyrifos which has potential to cause developmental harm in children.

Editor's note: California, the top U.S. food-producing state, is ending use of chlorpyrifos, a pesticide associated with neurodevelopmental problems and impaired brain function in children. Gina Solomon, a principal investigator at the Public Health Institute, clinical professor at the University of California San Francisco and former deputy secretary at the California Environmental Protection Agency, explains the scientific evidence that led California to act.

 

Like other organophosphate insecticides, chlorpyrifos is designed to kill insects by blocking an enzyme called acetylcholinesterase. This enzyme normally breaks down acetylcholine, a chemical that the body uses to transmit nerve impulses. Blocking the enzyme causes insects to have convulsions and die. All organophosphate insecticides are also toxic and potentially lethal to humans.

Until 2000, chlorpyrifos was also used in homes for pest control. It was banned for indoor use after passage of the 1996 Food Quality Protection Act, which required additional protection of children's health. Residues left after indoor use were quite high, and toddlers who crawled on the floor and put their hands in their mouth were found to be at risk of poisoning.

 

Researchers published the first study linking chlorpyrifos to potential developmental harm in children in 2003. They found that higher levels of a chlorpyrifos metabolite – a substance that's produced when the body breaks down the pesticide – in umbilical cord blood were significantly associated with smaller infant birth weight and length.


Subsequent studies published between 2006 and 2014 showed that those same infants had developmental delays that persisted into childhood, with lower scores on standard tests of development and changes that researchers could see on MRI scans of the children's brains. Scientists also discovered that a genetic subtype of a common metabolic enzyme in pregnant women increased the likelihood that their children would experience neurodevelopmental delays.

Scientists working under contract for Dow Chemical, which manufactured chlorpyrifos, published a complex model in 2014 that could estimate how much of the pesticide a person would have to consume or inhale to trigger acetylcholinesterase inhibition. But some of their equations were based on data from as few as six healthy adults who had swallowed capsules of chlorpyrifos during experiments in the 1970s and early 1980s – a method that now would be considered unethical.

California scientists questioned whether risk assessments based on the Dow-funded model adequately accounted for uncertainty and human variability. They also wondered whether acetylcholinesterase inhibition was really the most sensitive biological effect.

In 2016 the U.S. EPA released a reassessment of chlorpyrifos's potential health effects that took a different approach. It focused on epidemiological studies published from 2003 through 2014 at Columbia University that found developmental impacts in children exposed to chlorpyrifos. The Columbia researchers analyzed chlorpyrifos levels in the mothers' cord blood at birth, and the EPA attempted to back-calculate how much chlorpyrifos they might have been exposed to throughout pregnancy.

 

On the basis of this analysis, the Obama administration concluded that chlorpyrifos could not be safely used and should be banned. However, the Trump administration reversed this decision in 2017, arguing that the science was not resolved and more study was needed.

 

Three new papers on prenatal exposures to chlorpyrifos, published in 2017 and 2018, broke the logjam. These were independent studies, conducted in rats, that evaluated subtle effects on learning and development.

The results were consistent and clear: Chlorpyrifos caused decreased learning, hyperactivity and anxiety in rat pups at doses lower than those that affected acetylcholinesterase. And these studies clearly quantified doses to the rats, so there was no uncertainty about their exposure levels during pregnancy. The results were eerily similar to effects seen in human epidemiological studies, vindicating health concerns about chlorpyrifos.

California reassessed chlorpyrifos using these new studies. Regulators concluded that the pesticide posed significant risks that could not be mitigated – especially among people who lived near agricultural fields where it was used. In October 2019, the state announced that under an enforceable agreement with manufacturers, all sales of chlorpyrifos to California growers would end by Feb. 6, 2020, and growers would not be allowed to possess or use it after Dec. 31, 2020.

Hawaii has already banned chlorpyrifos, and New York state is phasing it out. Other states are also considering action.

EPA did not mention the animal studies published in 2017 and 2018, but it legally must include them in its new assessment. When it does so, I believe EPA leaders will have great difficulty making a case that chlorpyrifos is safe.

In my view, we have consistent scientific evidence that chlorpyrifos threatens children's neurological development. We know what this pesticide does to people, and it is time to move to safer alternatives.

This article was written by Gina Solomon, clinical professor of medicine at University of California, San Francisco

 

https://earthjustice.org/news/press/202 ... lorpyrifos

 

over 100 farmworker, public health, and environmental organizations led by Earthjustice submitted a letter to the Environmental Protection Agency (EPA) urging the Biden administration to ban chlorpyrifos. In December, Trump’s EPA proposed that 11 food uses of the neurotoxic pesticide continue, prolonging harmful exposure to children, farmworkers, and endangered species.

On his first day in office, President Biden signed an executive order directing EPA to review the Trump administration decision to deny a 2007 petition to ban chlorpyrifos on food. But advocates say the harms of this pesticide have been documented for decades, therefore chlorpyrifos must be banned from food uses immediately. Chlorpyrifos is used on many different types of crops besides food, so farmworkers will continue to face additional exposure. We are asking the EPA to act quickly and cancel all non-food uses, as well.

Chlorpyrifos, which belongs to a class of nerve-agent pesticides called organophosphates, is acutely toxic and associated with neurodevelopmental harms in children, according to multiple studies. Chlorpyrifos is a widely used pesticide. It is sprayed on numerous crops, including apples, cherries, peaches, citrus, and wheat. Prenatal exposures to chlorpyrifos are linked to lower birth weight, reduced IQ, loss of working memory, attention disorders, and delayed motor development. It is also unsafe for workers even with the most protective equipment.

 

https://www.governor.ny.gov/news/govern ... lorpyrifos

 

DEC Will Take Immediate Action to Ban Aerial Use of Chlorpyrifos

Regulations to Ban Chlorpyrifos Will be in Effect by December 2020 for all Uses Except Spraying Apple Tree Trunks, Which Will be Banned by July 2021

New Restrictions on Pesticide Will Protect New Yorkers from Significant Adverse Public Health Impacts, Especially for Children

 

https://www.sciencedirect.com/science/a ... 5119300246

 

https://civileats.com/2019/02/11/can-ea ... esticides/

 

Much lower pesticide levels in the urine of those who consumed organic produce.
 
User avatar
midtskogen
Star Engineer
Star Engineer
Posts: 1258
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Science and Astronomy News

29 Apr 2021 22:31

A-L-E-X wrote:
Source of the post Yes I am interested in that machine that converts CO2 to O2, do you think something like that scaled up could be used on Earth? As a way to remove some of the excess CO2?

Something scaled up to, like, forests? Devices capturing carbon from the atmosphere are surely possible, but hardly practical.  The energy need is huge, and so are the building costs.  Capturing at the source, however, might be viable in many cases.
NIL DIFFICILE VOLENTI
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

30 Apr 2021 03:29

midtskogen wrote:
A-L-E-X wrote:
Source of the post Yes I am interested in that machine that converts CO2 to O2, do you think something like that scaled up could be used on Earth? As a way to remove some of the excess CO2?

Something scaled up to, like, forests? Devices capturing carbon from the atmosphere are surely possible, but hardly practical.  The energy need is huge, and so are the building costs.  Capturing at the source, however, might be viable in many cases.

I saw they are trying to expand forests in Poland and some other countries, but it was stated in the Nature documentary I saw on PBS that wouldn't be enough.  Capturing at the source is another story, as that should require less energy and resources, perhaps a mechanized way to do that would actually be the most cost effective and efficient way to do it.
 
User avatar
midtskogen
Star Engineer
Star Engineer
Posts: 1258
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Science and Astronomy News

30 Apr 2021 04:56

Tree planting is a big piece in carbon accounting, and there are all sorts of problems with that, besides not dealing with the carbon sources.  The fastest growing trees will be preferred, creating monocultures and reducing biodiversity.  I rank giving nature enough space to do its own things higher than fixing the climate, and we're currently doing more harm than good for nature in our fear for climate change.
NIL DIFFICILE VOLENTI
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

02 May 2021 21:52

we also have big problems with monoculture farming which leads to greater usage of toxic pesticides, it's a big problem.  I agree with the nature bit, we have some major land usage issues already because of conventional farming practices (including animal farming), and this will only make that problem worse.
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

16 May 2021 19:27

60 Minutes did a big report on this so I figured I would post this, even though we've discussed this before, it now includes air force and navy pilot accounts.

https://www.cbsnews.com/news/ufo-milita ... 021-05-16/

https://www.cbsnews.com/news/navy-ufo-s ... 021-05-16/

https://twitter.com/i/events/1395857752807854084

Looks like the Pentagon are "believers" according to that, doesn't mean that science should be.

I would like a better explanation for the "Tic Tac" incident from 2004 though.
Last edited by A-L-E-X on 21 May 2021 17:42, edited 1 time in total.
 
A-L-E-X
Galaxy Architect
Galaxy Architect
Posts: 3031
Joined: 06 Mar 2017

Science and Astronomy News

20 May 2021 15:31

https://www.newscientist.com/article/mg ... omes-from/

This is a pretty amazing discussion on the quantum nature of time and how to untie it to entropy (researchers into quantum gravity are also looking for a quantum nature of time, much more fundamental than the "space-time" concept.)
 
User avatar
midtskogen
Star Engineer
Star Engineer
Posts: 1258
Joined: 11 Dec 2016
Location: Oslo, Norway
Contact:

Science and Astronomy News

20 May 2021 22:53

A-L-E-X wrote:
Source of the post This is a pretty amazing discussion on the quantum nature of time

Possibly, but paywalled.
NIL DIFFICILE VOLENTI

Who is online

Users browsing this forum: No registered users and 1 guest