South Demerdji, Crimea By Alexander Trashin

Left to right: Saturn V (Apollo), SLS (being built by ULA for NASA, in development, won’t fly until 2019 at the earliest), Falcon Heavy in the center, BFR (first flight 2022 if we are lucky), and Falcon 9 with Crew Dragon capsule on far right. The SLS is huge but likely will not be able to send as large a payload to Mars (I searched but can’t find a specific figure for SLS payload to the surface of Mars) as the BFR which Elon stated will be 100 metric tons. And the SLS will cost about $1 billion dollars per launch and is not reusable. The BFR cost per launch will be a small fraction of that price and it will be fully reusable. The SLS is nuts and US taxpayers are paying for it. SLS first planned flight to Mars is 2033. BFR first planned flight to Mars is 2022. Both will likely slip, but no question in my mind that SpaceX will be first to Mars by about a decade.

math aid

OK SO in the days leading up to the biggest maths exam I’ve ever written (also my 4th last one ever ) i’ve found this website. now, symbolab is different to mathaway and wolfram alpha (which are both great!) in that it shows you all the steps and it doesn’t do that thing where it’s “free” but if you want the explanation you have to sign up and pay. it’s AMAZING. know why?

it does everything. not baby everything, but everything. Calculus?

what’re you looking for? 

also, the interface is really easy to use, and it’s set out so well.

the website is https://www.symbolab.com and you will not be disappointed.

03.14.2017 // My notes geek.

Tips for Improving your Focus

1. Set yourself some goals at the start of the day – and make sure they are goals that are reasonable. Then check off each item, and keep going till the end.

2. Make sure you take plenty of regular breaks as these will increase your productivity. We can focus for around 20 minutes at a time - and then we need to get up and walk around.

3. Break larger tasks into lots of smaller tasks. That way you will receive constant reinforcement for making some progress, and finishing some tasks.

4. Use offline tools such as paper and pen as they make it easier to stick with the plan and to not get distracted by online stuff.

5. Notice the times when you tend to feel tired - then plan your breaks for around those times.

6. Give yourself some deadlines as these focus the mind, and give us something concrete to work towards.

Avocado-Egg Toast  #Breakfast Snack

If you are interested in self-studying physics

I found this amazing post that suggests some textbooks and supplemental reading based on big topics, as well as advice on how to structure your studying. A lot of these books, I’ve either used for my physics classes (University Physics by Young and Freedman), will use for future physics classes (Griffiths Electrodynamics and QM books), or are on my reading list (Student’s Guide to Lagrangians and Hamiltonians, Div, Grad, Curl, Feynman Lectures). 

So You Want to Learn Physics - Susan J. Fowler

I found this gem of a blog post while I was looking for ways to review Electrostatics and start reading up on Electrodynamics, Optics, and Relativity (my next physics class). 

There’s also some more reading suggestions in the comments at the bottom, however, feel free to add in if you have any suggestions as well!

6 Steps in Learning to Love Yourself

1.See the good in your past. There will always be things that we wish had never happened; there will always be bad memories and things that we regret. But they are part of who you are – so accept that they have happened and celebrate the person they’ve allowed you to become.

2. Invest time in the things that bring you happiness. It’s important to identify the things that you enjoy, and that make you come alive, and are all a part of “you”. Spending time on those things will help to raise your self-esteem, as you’re valuing yourself when you pursue happiness.

3. Forgive yourself for your mistakes. We all make mistakes - and when we think of them we cringe. But that doesn’t make you any worse than other people. Just learn what you can, and then move on with your life.

4. Stop criticising yourself. So often we’re really our own worst enemy. We look for our flaws, and we put ourselves down – instead of being understanding of our own limitations. It’s time to change that behaviour – so start loving yourself.

5. Listen to your instincts and your intuitions. If you want to love yourself, you must listen to yourself. Pay attention to those instincts and your instant gut reaction – and trust that you are right when you hear that inner voice.

6. Appreciate your life. Of course there are things that you wish that you could change. But some things are good, and are worth appreciating. So, focus on, appreciate, and make lots of your strengths.

hey guys! here is the requested biology note taking from textbook tutorial! I hope it helps, be sure to send me more requests, happy studying :-)

Five Famous Pulsars from the Past 50 Years

Early astronomers faced an obstacle: their technology. These great minds only had access to telescopes that revealed celestial bodies shining in visible light. Later, with the development of new detectors, scientists opened their eyes to other types of light like radio waves and X-rays. They realized cosmic objects look very different when viewed in these additional wavelengths. Pulsars — rapidly spinning stellar corpses that appear to pulse at us — are a perfect example.

The first pulsar was observed 50 years ago on August 6, 1967, using radio waves, but since then we have studied them in nearly all wavelengths of light, including X-rays and gamma rays.

Typical Pulsar

Most pulsars form when a star — between 8 and 20 times the mass of our sun — runs out of fuel and its core collapses into a super dense and compact object: a neutron star. 

These neutron stars are about the size of a city and can rotate slowly or quite quickly, spinning anywhere from once every few hours to hundreds of times per second. As they whirl, they emit beams of light that appear to blink at us from space.

First Pulsar

One day five decades ago, a graduate student at the University of Cambridge, England, named Jocelyn Bell was poring over the data from her radio telescope - 120 meters of paper recordings.

Image Credit: Sumit Sijher

She noticed some unusual markings, which she called “scruff,” indicating a mysterious object (simulated above) that flashed without fail every 1.33730 seconds. This was the very first pulsar discovered, known today as PSR B1919+21.

Best Known Pulsar

Before long, we realized pulsars were far more complicated than first meets the eye — they produce many kinds of light, not only radio waves. Take our galaxy’s Crab Nebula, just 6,500 light years away and somewhat of a local celebrity. It formed after a supernova explosion, which crushed the parent star’s core into a neutron star. 

The resulting pulsar, nestled inside the nebula that resulted from the supernova explosion, is among the most well-studied objects in our cosmos. It’s pictured above in X-ray light, but it shines across almost the entire electromagnetic spectrum, from radio waves to gamma rays.

Brightest Gamma-ray Pulsar

Speaking of gamma rays, in 2015 our Fermi Gamma-ray Space Telescope discovered the first pulsar beyond our own galaxy capable of producing such high-energy emissions. 

Located in the Tarantula Nebula 163,000 light-years away, PSR J0540-6919 gleams nearly 20 times brighter in gamma-rays than the pulsar embedded in the Crab Nebula.

Dual Personality Pulsar

No two pulsars are exactly alike, and in 2013 an especially fast-spinning one had an identity crisis. A fleet of orbiting X-ray telescopes, including our Swift and Chandra observatories, caught IGR J18245-2452 as it alternated between generating X-rays and radio waves. 

Scientists suspect these radical changes could be due to the rise and fall of gas streaming onto the pulsar from its companion star.

Transformer Pulsar

This just goes to show that pulsars are easily influenced by their surroundings. That same year, our Fermi Gamma Ray Space Telescope uncovered another pulsar, PSR J1023+0038, in the act of a major transformation — also under the influence of its nearby companion star. 

The radio beacon disappeared and the pulsar brightened fivefold in gamma rays, as if someone had flipped a switch to increase the energy of the system. 

NICER Mission

Our Neutron star Interior Composition Explorer (NICER) mission, launched this past June, will study pulsars like those above using X-ray measurements.

With NICER’s help, scientists will be able to gaze even deeper into the cores of these dense and mysterious entities.

For more information about NICER, visit https://www.nasa.gov/nicer

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