How To Prepare To Go Stargazing

just added a new place to my bucket list

Aurora Borealis dancing in Southern Ontario l Jason O'Young

Kind of reminds me of the inside of a marble...art really does imitate life!

Orion Nebula in visible & infrared

Messier 101 : Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier’s famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way. M101 was also one of the original spiral nebulae observed by Lord Rosse’s large 19th century telescope, the Leviathan of Parsontown. Assembled from 51 exposures recorded by the Hubble Space Telescope in the 20th and 21st centuries, with additional data from ground based telescopes, this mosaic spans about 40,000 light-years across the central region of M101 in one of the highest definition spiral galaxy portraits ever released from Hubble. The sharp image shows stunning features of the galaxy’s face-on disk of stars and dust along with background galaxies, some visible right through M101 itself. Also known as the Pinwheel Galaxy, M101 lies within the boundaries of the northern constellation Ursa Major, about 25 million light-years away. via NASA

Modeling the merger of a black hole with a neutron star and the subsequent process in a single simulation

Using supercomputer calculations, scientists at the Max Planck Institute for Gravitational Physics in Potsdam and from Japan show a consistent picture for the first time: They modeled the complete process of the collision of a black hole with a neutron star. In their studies, they calculated the process from the final orbits through the merger to the post-merger phase in which, according to their calculations, high-energy gamma-ray bursts may occur. The results of their studies have now been published in the journal Physical Review D. Almost seven years have passed since the first detection of gravitational waves. On September 14, 2015, the LIGO detectors in the U.S. recorded the signal of two merging black holes from the depths of space.

Since then, a total of 90 signals have been observed: from binary systems of two black holes or neutron stars, and also from mixed binaries. If at least one neutron star is involved in the merger, there is a chance that not only gravitational-wave detectors will observe the event, but also telescopes in the electromagnetic spectrum.

When two neutron stars merged in the event detected on August 17, 2017 (GW170817), about 70 telescopes on Earth and in space observed the electromagnetic signals. In the two mergers of neutron stars with black holes observed so far (GW200105 and GW200115), no electromagnetic counterparts to the gravitational waves were detected. But when more such events are measured with the increasingly sensitive detectors, the researchers expect electromagnetic observations here as well. During and after the merger, matter is ejected from the system and electromagnetic radiation is generated. This probably also produces short gamma-ray bursts, as observed by space telescopes.

For their study, the scientists chose two different model systems consisting of a rotating black hole and a neutron star. The masses of the black hole were set at 5.4 and 8.1 solar masses, respectively, and the mass of the neutron star was set at 1.35 solar masses. These parameters were chosen so that the neutron star could be expected to be torn apart by tidal forces.

“We get insights into a process that lasts one to two seconds—that sounds short, but in fact a lot happens during that time: from the final orbits and the disruption of the neutron star by the tidal forces, the ejection of matter, to the formation of an accretion disk around the nascent black hole, and further ejection of matter in a jet,” says Masaru Shibata, director of the Department of Computational Relativistic Astrophysics at the Max Planck Institute for Gravitational Physics in Potsdam. “This high-energy jet is probably also a reason for short gamma-ray bursts, whose origin is still mysterious. The simulation results also indicate that the ejected matter should synthesize heavy elements such as gold and platinum.”

What happens during and after the merger?

The simulations show that during the merger process the neutron star is torn apart by tidal forces. About 80% of the neutron star matter falls into the black hole within a few milliseconds, increasing its mass by about one solar mass. In the subsequent about 10 milliseconds, the neutron star matter forms a one-armed spiral structure. Part of the matter in the spiral arm is ejected from the system, while the rest (0.2–0.3 solar masses) forms an accretion disk around the black hole.

When the accretion disk falls into the black hole after the merger, this causes a focused jet-like stream of electromagnetic radiation, which could ultimately produce a short gamma-ray burst.

Seconds-long simulations

It took the department’s cluster computer “Sakura” about 2 months to solve Einstein’s equations for the process that takes about two seconds. “Such general relativistic simulations are very time-consuming.

That’s why research groups around the world have so far focused only on short simulations,” explains Dr. Kenta Kiuchi, group leader in Shibata’s department, who developed the code. “In contrast, an end-to-end simulation, such as the one we have now performed for the first time, provides a self-consistent picture of the entire process for given binary initial conditions that are defined once at the beginning.”

Moreover, only with such long simulations the researchers can explore the generation mechanism of short gamma-ray bursts, which typically last one to two seconds.

Shibata and the scientists in his department are already working on similar but even more complex numerical simulations to consistently model the collision of two neutron stars and the phase after the merger.

Newton's Three Laws of Motion

What are they?

Generally speaking, Newton's Three Laws of Motion are some of the most important laws in science. They are the fundamentals, and they are necessary for basic physics. They may seem complicated and jargon-y at first, but they are actually very understandable once broken down. So let's go over them!

Law of Inertia

Newton's Law of of Inertia states that "An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force." 

First, let's go over inertia, which this law is about. Inertia is the tendency of objects to remain the same. So basically, what this law is saying is that an object that is not moving, will stay not moving, and an object that is moving will continue moving in the same direction and speed that it is going. The last phrase in this law, "unless acted on by an unbalanced force" is basically just saying that due to inertia, objects will remain the same unless another force (eg. gravity, friction, air resistance, etc.) changes/affects the object. 

For example: a marble rolling on the floor will continue rolling in the same direction and at the same speed. Common sense says this makes no sense because obviously, the marble would eventually stop rolling. This is because although it may not seem as obvious, there actually is a force acting on the marble--friction from the floor. The friction acting on the marble slows it down until it eventually comes to a stop. 

Law of Acceleration

Newton's Law of Acceleration states that "The acceleration of an object depends on the mass of the object and the amount of force applied."

Most times Newton's Second Law is summarized as the equation F = ma, where F = net force in a system, m = mass of object(s), and a = acceleration of object(s). This law is pretty simple, it mostly is just saying that the force applied to an object depends on the acceleration of the ojbect and the mass of the object, or any other variation of this statement. In practice, you just need to input the necessary information into this equation to solve for the unknown variable. One lovely thing about F = ma is its simplicity; it only requires basicaly algebra to solve and is easy to remember. It also merits a mention that of all the equations you need to memorize for school, this is one of the most important ones (especially for physics), it should be up there in your brain with c^2 = a^2+b^2 and the quadratic formula. 

Here's an example: If a 5 kg bowling ball is rolling down the bowling alley with an acceleration of 2 m/s^2, what is the force being applied to the bowling ball? To solve this simple problem, you can input the mass and acceleration of the bowling ball into F = ma, so F = 5 kg * 2 m/s^2, meaning the force applied to the bowling ball is 10 kg m/s^2, or 10 N.

(Note: Force is usually in N, or newtons, and kg m/s^2 = N)

Law of Action and Reaction

Newton's Law of Action and Reaction states that "Whenever one object exerts a force on another object, the second object exerts an equal and opposite on the first."

You've probably have heard the saying "What goes up must come down" before. Well, this law isn't too far off from that, and the concept is pretty similar. This law is actually pretty self-explanatory; it's basically saying that for every action force, there will be an opposing reaction force that is the same strength and in the opposite direction. The law also stipulates that the two objects in the action/reaction force pair are acting on two DIFFERENT objects (so an object won't exert a reaction force unto itself). It's pretty simple when put in words, but this law is best explained using examples. 

For instance: If you jump off a skateboard, you will go forward (the skateboard is pushing you), and the skateboard will go backwards (you are pushing the skateboard). 

Another example: When you jump on a trampoline, you go up and you will notice that the trampoline will (temporarily) go down. 

Summary

This graphic from Owlcation.com describes Newton's Laws quite well: 

Worm Saliva Breaks Down Tough Plastic

Polyethylene, a durable plastic, is widely considered one of the worst forms of plastic pollution, but chemicals found the saliva of the wax worm may hold the key to breaking it down. One hours worth of exposure to the saliva breaks down the plastic by the equivalent of years worth of weathering.

There are two enzymes responsible for this degradation, and it’s believed that they are the first effective agents found in nature.

Polyethylene comprises 30% of production of a wide range of materials such as pipes, flooring, and bottles. Its hardiness comes from its resistance to oxygen. In order to get oxygen into the plastic, it has to be treated with UV light, but, the wax worms saliva seems to have a similar, if not improved, effect.

Wax worms are well known for destroying honey bee hives, and researchers say that its this ability to destroy hives that may hold the key to their ability to degrade plastics.

The study, published in the journal, Nature, is led by a team of Spanish researchers, who now want to research further into the degradation of polyethylene by wax worm saliva, and hope that one day, people may be able to have a home kit that they can use to breakdown the polyethylene at home.

Source: BBC News, written by Matt Magrath , and, Sanluis-Verdes, A., et al., (2022). Wax worm saliva and the enzymes therein are the key to polyethylene degradation by Galleria mellonella. Nature Communications, 13(1). Available at: https://www.nature.com/articles/s41467-022-33127-w (Accessed: 5th October 2022)

Psychology 😂

Physics: i mean you could technically lick a pulley (might be harder if it's moving) jkjk

Software engineering hits a little bit too close to home

Astronomy...why can i not disagree with this statement 😂

Astronomy I-

can't tell which is more confusing: random names that don't really follow a pattern but are relatively easy to learn and remember OR random set of numbers and letters that sometimes make sense but is impossible to remember

Cosmic Witch Head © Utkarsh Mishra