Weird And Wonderful Irregular Galaxies

What is the weirdest thing you had to account for when building the perseverance rover?

Gravitational Waves in the Space-Time Continuum

Einstein's Theories of Relativity

Einstein has two theories of relativity. The first is The Theory of Special Relativity (1905). This is a theory of mechanics that correctly describes the motions of objects moving near the speed of light. This theory predicts that mass increases with velocity. The equation is E=MC^2 or Energy = Mass × Speed of Light ^2.

In 1916, Einstein proposed the Theory of General Relativity, which generalized his Theory of Special Relativity and had the first predictions of gravitational waves. It implied a few things.

Space-Time is a 4-Dimensional continuum.

Principle of equivalence of gravitational and inertial mass.

This suggests that Mass-Energy distorts the fabric of space-time in a predictable way (gravitational waves). It also implies

Strong gravitational force makes time slow down.

Light is altered by gravity

Gravity in strong gravitational fields will no longer obey Newton's Inverse-Square Law.

What is Newton's Inverse-Square Law?

Newton's Inverse-Square Law suggests that the force of gravity between any two objects is inversely proportional to the square of the separation distance between the two centers.

Stephen Hawking's Theory of Everything

Stephen Hawking's Theory of Everything is the solution to Einstein's equation in his Theory of General Relativity. It says that the mass density of the universe exceeds the critical density.

Critical Density: amount of mass needed to make a universe adopt a flat geometry.

This theory states that when the universe gets too big it will crash back into its center in a "Big Crunch" creating giant black hole. The energy from this "Big Crunch" will rebound and create a new "Big Bang".

Big Crunch: hypothetical scenario for the end of the known universe. The expansion of the universe will reverse and collapse on itself. The energy generated will create a new Big Bang, creating a new universe.

Big Bang: Matter will expand from a single point from a state of high density and matter. This will mark the birth of a new universe.

Basic Facts about Gravitational Waves

Invisible "ripples" in the Space-Time Continuum

Travel at the speed of light

186,000 miles per second / 299,337.984 Kilometers per second

11,160,000 miles per minute / 17,960,279.04 Kilometers per minute

669,600,000 miles per hour / 1,077,616,742.4 Kilometers per hour

There are four (4) defined categories

Continuous

Stochastic

Burst

Compact Binary Inspiral

What is LIGO?

The first proof of the existence of gravitational waves came in 1974. 20+ years after Einstein's death.

The first physical proof came in 2015, 100 years after his theory was published. The waves were detected by LIGO.

LIGO- Laser Interferometer Gravitational-Wave Observatory

The waves detected in 2015 came from 2 black holes that collided 1.3 billion years ago in the constellation Hydra. 1.3 billion years ago multicellular life was just beginning to spread on Earth, it was before the time of the dinosaurs!

Continuous Gravitational Waves

Produced by a single spinning massive object.

Caused by imperfections on the surface.

The spin rate of the object is constant. The waves are come at a continuous frequency.

Stochastic Gravitational Waves

Smalles waves

Hardest to detect

Possibly caused by remnants of gravitational radiation left over from the Big Bang

Could possibly allow us to look at the history of the Universe.

Small waves from every direction mixed together.

Burst Gravitational Waves

Never been detected.

Like ever.

Never ever.

Not once.

Nope

No

N E V E R

We don't know anything about them.

If we learn about them they could reveal the greatest revolutionary information about the universe.

Compact Binary Inspiral Gravitational Waves

All waves detected by LIGO fall into this category.

Produced by orbiting pairs of massive and dense objects. (Neutron Stars, Black Holes)

Three (3) subclasses

Binary Neutron Star (BNS) // Two (2) Neutron Stars colliding

Binary Black Hole (BBH) // Two (2) Black Holes colliding

Neutron Star- Black Hole Binary (NSBH) // A black hole and a neutron star colliding

Each subclass creates its own unique wave pattern.

Waves are all caused by the smae mechanism called an "inspiral".

Occur over millions of years.

Over eons the objects orbit closer together.

The closer they get, the faster they spin.

Sources Used:

On The Shoulders Of Giants by Stephen Hawking

Oxford Astronomy Encyclopedia

LIGO Lab | Caltech

LIGO Lab | Caltech | MIT

The Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two widely separated installations within the United States — one

nationalgeographic.com

National Geographic: Stories of Animals, Nature, and Culture

Explore National Geographic. A world leader in geography, cartography and exploration.

NASA

National Aeronautics and Space Administration

NASA.gov brings you the latest news, images and videos from America's space agency, pioneering the future in space exploration, scientific d

@watch-out-idiot-passing-through @nasa

In Roman mythology, the god Jupiter drew a veil of clouds around himself to hide his mischief. It was only Jupiter’s wife, the goddess Juno, who could peer through the clouds and reveal Jupiter’s true nature. ⁣ ⁣ Our @NASAJuno spacecraft is looking beneath the clouds of the massive gas giant, not seeking signs of misbehavior, but helping us to understand the planet’s structure and history…⁣ ⁣ Now, @NASAJuno just published its first findings on the amount of water in the gas giant’s atmosphere. The Juno results estimate that at the equator, water makes up about 0.25% of the molecules in Jupiter’s atmosphere — almost three times that of the Sun. An accurate total estimate of this water is critical to solving the mystery of how our solar system formed. 

The JunoCam imager aboard Juno captured this image of Jupiter’s southern equatorial region on Sept. 1, 2017. The bottom image is oriented so Jupiter’s poles (not visible) run left-to-right of frame.

Image credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill ⁣ ⁣

bRuH

i may not be beautiful but at least i know a lot of useless information

A small question:

Would anybody want me to do lessons? Like if you send in an ask like 'Hey, what do you know abt *science topic*?' I could do some research and make it a post with links and videos? (Like my Gravitational Waves in the Space-Time Continuum post [link below, and pinned to my acct])

Space Boii

Einstein's Theories of Relativity

Gravitational Waves in the Space-Time Continuum Einstein has two theories of relativity. The first is The Theory of Special Relativity (1905

Would anybody send in asks???

Who Was Mary W. Jackson?

On June 24, 2020, NASA announced the agency’s headquarters building in Washington, D.C., was to be named after Mary W. Jackson, the first African American female engineer at NASA.

Jackson’s story — along with those of her colleagues Katherine Johnson, Dorothy Vaughan, and Christine Darden — was popularized with the release of the “Hidden Figures” movie, based on Margot Lee Shetterly’s book by the same name.

Today, as the accomplishments of these women are brought to light, we celebrate them as Modern Figures — hidden no longer. Despite their recent recognition, we cannot forget the challenges that women and BIPOC faced and continue to face in the STEM fields.

Background

Jackson showed talent for math and science at an early age. She was born in 1921 in Hampton, Virginia, and attended the all-Black George P. Phenix Training School where she graduated with honors. She graduated from Hampton Institute (now Hampton University) in 1942 with a bachelor of science degree in both mathematics and physical sciences.

Jackson worked several jobs before arriving at the National Advisory Committee on Aeronautics (NACA), the precursor organization to NASA. She was a teacher, a receptionist, and a bookkeeper — in addition to becoming a mother — before accepting a position with the NACA Langley Aeronautical Laboratory’s segregated West Area Computers in 1951, where her supervisor was Dorothy Vaughan.

Accomplishments 

After two years in West Computing, Jackson was offered a computing position to work in the 4-foot by 4-foot Supersonic Pressure Tunnel. She was also encouraged to enter a training program that would put her on track to become an engineer — however, she needed special permission from the City of Hampton to take classes in math and physics at then-segregated Hampton High School.

She completed the courses, earned the promotion, and in 1958 became NASA’s first African-American female engineer. That same year, she co-authored her first report, “Effects of Nose Angle and Mach Number on Transition on Cones at Supersonic Speeds.” By 1975, she had authored or co-authored 12 NACA and NASA technical publications — most focused on the behavior of the boundary layer of air around an airplane.

Legacy

Jackson eventually became frustrated with the lack of management opportunities for women in her field. In 1979, she left engineering to become NASA Langley’s Federal Women’s Program Manager to increase the hiring and promotion of NASA’s female mathematicians, engineers, and scientists.

Not only was she devoted to her career, Jackson was also committed to the advancement of her community. In the 1970s, she helped the students in the Hampton King Street Community Center build their own wind tunnel and run experiments. She and her husband Levi took in young professionals in need of guidance. She was also a Girl Scout troop leader for more than three decades.  

Jackson retired from Langley in 1985. Never accepting the status quo, she dedicated her life to breaking barriers for minorities in her field. Her legacy reminds us that inclusion and diversity are needed to live up to NASA’s core values of teamwork and excellence.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

I still haven’t gotten over the fact that Hampshire College in Massachusetts has the worlds first non-human resident scholar.

THIS IS REAL

HOW IS THIS REAL

The Stellar Buddy System

Our Sun has an entourage of planets, moons, and smaller objects to keep it company as it traverses the galaxy. But it’s still lonely compared to many of the other stars out there, which often come in pairs. These cosmic couples, called binary stars, are very important in astronomy because they can easily reveal things that are much harder to learn from stars that are on their own. And some of them could even host habitable planets!

The birth of a stellar duo

New stars emerge from swirling clouds of gas and dust that are peppered throughout the galaxy. Scientists still aren’t sure about all the details, but turbulence deep within these clouds may give rise to knots that are denser than their surroundings. The knots have stronger gravity, so they can pull in more material and the cloud may begin to collapse.

The material at the center heats up. Known as a protostar, it is this hot core that will one day become a star. Sometimes these spinning clouds of collapsing gas and dust may break up into two, three, or even more blobs that eventually become stars. That would explain why the majority of the stars in the Milky Way are born with at least one sibling.

Seeing stars

We can’t always tell if we’re looking at binary stars using just our eyes. They’re often so close together in the sky that we see them as a single star. For example, Sirius, the brightest star we can see at night, is actually a binary system (see if you can spot both stars in the photo above). But no one knew that until the 1800s.

Precise observations showed that Sirius was swaying back and forth like it was at a middle school dance. In 1862, astronomer Alvan Graham Clark used a telescope to see that Sirius is actually two stars that orbit each other.

But even through our most powerful telescopes, some binary systems still masquerade as a single star. Fortunately there are a couple of tricks we can use to spot these pairs too.

Since binary stars orbit each other, there’s a chance that we’ll see some stars moving toward and away from us as they go around each other. We just need to have an edge-on view of their orbits. Astronomers can detect this movement because it changes the color of the star’s light – a phenomenon known as the Doppler effect.

Stars we can find this way are called spectroscopic binaries because we have to look at their spectra, which are basically charts or graphs that show the intensity of light being emitted over a range of energies. We can spot these star pairs because light travels in waves. When a star moves toward us, the waves of its light arrive closer together, which makes its light bluer. When a star moves away, the waves are lengthened, reddening its light.

Sometimes we can see binary stars when one of the stars moves in front of the other. Astronomers find these systems, called eclipsing binaries, by measuring the amount of light coming from stars over time. We receive less light than usual when the stars pass in front of each other, because the one in front will block some of the farther star’s light.

Sibling rivalry

Twin stars don’t always get along with each other – their relationship may be explosive! Type Ia supernovae happen in some binary systems in which a white dwarf – the small, hot core left over when a Sun-like star runs out of fuel and ejects its outer layers – is stealing material away from its companion star. This results in a runaway reaction that ultimately detonates the thieving star. The same type of explosion may also happen when two white dwarfs spiral toward each other and collide. Yikes!

Scientists know how to determine how bright these explosions should truly be at their peak, making Type Ia supernovae so-called standard candles. That means astronomers can determine how far away they are by seeing how bright they look from Earth. The farther they are, the dimmer they appear. Astronomers can also look at the wavelengths of light coming from the supernovae to find out how fast the dying stars are moving away from us.

Studying these supernovae led to the discovery that the expansion of the universe is speeding up. Our Nancy Grace Roman Space Telescope will scan the skies for these exploding stars when it launches in the mid-2020s to help us figure out what’s causing the expansion to accelerate – a mystery known as dark energy.

Spilling stellar secrets

Astronomers like finding binary systems because it’s a lot easier to learn more about stars that are in pairs than ones that are on their own. That’s because the stars affect each other in ways we can measure. For example, by paying attention to how the stars orbit each other, we can determine how massive they are. Since heavier stars burn hotter and use up their fuel more quickly than lighter ones, knowing a star’s mass reveals other interesting things too.

By studying how the light changes in eclipsing binaries when the stars cross in front of each other, we can learn even more! We can figure out their sizes, masses, how fast they’re each spinning, how hot they are, and even how far away they are. All of that helps us understand more about the universe.

Tatooine worlds

Thanks to observatories such as our Kepler Space Telescope, we know that worlds like Luke Skywalker’s home planet Tatooine in “Star Wars” exist in real life. And if a planet orbits at the right distance from the two stars, it could even be habitable (and stay that way for a long time).

In 2019, our Transiting Exoplanet Survey Satellite (TESS) found a planet, known as TOI-1338 b, orbiting a pair of stars. These worlds are tricker to find than planets with only one host star, but TESS is expected to find several more!

Want to learn more about the relationships between stellar couples? Check out this Tumblr post: https://nasa.tumblr.com/post/190824389279/cosmic-couples-and-devastating-breakups

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Bill Nye for most of his career: Imma do science for kids. Science without politics. Nice, tame science for the kiddos.

Bill Nye now: