Category: einstein

This Is Why Time Has To Be A Dimension

This Is Why Time Has To Be A Dimension

“But even two different objects with the same exact three-dimensional spatial coordinates might not overlap. The reason is easy to understand if you start thinking about the chair you’re sitting in right now. It can definitely have its location accurately described by those three spatial coordinates familiar to us: x, y, and z. This chair, however, is occupied by you right now, at this exact moment in time, as opposed to yesterday, an hour ago, next week, or ten years from now.

In order to completely describe an event in spacetime, you need to know more than just where it occurs, but also when it occurs. In addition to x, y, and z, you also need a time coordinate: t. Although this might seem obvious, it didn’t play a large role in physics until the development of Einstein’s relativity, when physicists started thinking about the issue of simultaneity.”

When you describe where you are in the Universe, you typically think of the coordinates you’d need to give to describe your location. This includes an x, y, and z-direction: the three spatial coordinates corresponding to where we live in our three spatial dimensions. But this doesn’t fully tell you everything you’d need to know, because your location is defined not only by your spatial location but when you’re located there: you need a time coordinate, too. If we take a deep look into the relationship between space and time, first put forth by Einstein over a century ago, we’d find that it isn’t even enough to put in an additional coordinate. Time is more than a separate value; it’s every bit as much a dimension as any of the three spatial dimensions.

If you’ve ever wondered why we say that time is the fourth dimension, come read this. It couldn’t be any other way.

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The 5 Lessons Everyone Should Learn From Ein…

The 5 Lessons Everyone Should Learn From Einstein’s Most Famous Equation: E = mc^2

“3.) Einstein’s E = mc2 is responsible for why the Sun (like any star) shines. Inside the core of our Sun, where the temperatures rise over a critical temperature of 4,000,000 K (up to nearly four times as large), the nuclear reactions powering our star take place. Protons are fused together under such extreme conditions that they can form a deuteron — a bound state of a proton and neutron — while emitting a positron and a neutrino to conserve energy.

Additional protons and deuterons can then bombard the newly formed particle, fusing these nuclei in a chain reaction until helium-4, with two protons and two neutrons, is created. This process occurs naturally in all main-sequence stars, and is where the Sun gets its energy from.”

Even if you don’t know any physics at all, there’s a good chance that there’s at least one equation you know of: Einstein’s E = mc^2. It tells us that energy and mass are equivalent quantities, and that c^2 (the speed of light squared) is the constant that enables you to convert from one to the other. Along for the ride, we learn some amazing things, including that mass is not conserved, that bound objects have less mass than the same objects when they’re not bound, and that you can spontaneously create matter/antimatter pairs if you have enough available energy under the right conditions.

Einstein may be synonymous with “this is too hard for most people to understand,” but it doesn’t have to be this way. Get the 5 lessons everyone should know about E = mc^2 today!

General Relativity Rules: Einstein Victorious …

General Relativity Rules: Einstein Victorious In Unprecedented Gravitational Redshift Test

“The most interesting part of this result is that it clearly demonstrates the purely General Relativistic effect of gravitational redshift. The observations of S0-2 showcase an exact agreement with Einstein’s predictions, within the measurement uncertainties. When Einstein first conceived of General Relativity, he did so conceptually: with the idea that acceleration and gravitation were indistinguishable to an observer.

With the validation of Einstein’s predictions for the orbit of this star around the galactic center’s black hole, scientists have affirmed the equivalence principle, thereby ruling out or constraining alternative theories of gravity that violate this cornerstone of Einsteinian gravity. Gravitational redshifts have never been measured in environments where gravity is this strong, marking another first and another victory for Einstein. Even in the strongest environment ever probed, the predictions of General Relativity have yet to lead us astray.”

If you want to test Einstein’s General Relativity, you’ll want to look for an effect that it predicts that’s unique, and you’ll want to look for it in the strongest-field regime possible. Well, there’s a black hole at the center of our galaxy with 4 million times the mass of the Sun, and there’s a star (S0-2) that passes closer to it, during closest approach, than any other. In May of 2018, it made this closest approach, coming within 18 billion km (about twice the diameter of Neptune’s orbit) of the black hole, and zipping around at 2.7% the speed of light.

Did Einstein’s predictions for gravitational redshift come out right? You bet they did: 5-sigma, baby! Come get the full, amazing story here!

How To Prove Einstein’s Relativity In Th…

How To Prove Einstein’s Relativity In The Palm Of Your Hand

“If you ever doubted relativity, it’s hard to fault you: the theory itself seems so counterintuitive, and its effects are thoroughly outside the realm of our everyday experience. But there is an experimental test you can perform right at home, cheaply and with just a single day’s efforts, that allow you see the effects for yourself.

You can build a cloud chamber, and if you do, you will see those muons. If you installed a magnetic field, you’d see those muon tracks curve according to their charge-to-mass ratio: you’d immediately know they weren’t electrons. On rare occasion, you’d even see a muon decaying in mid-air. And, finally, if you measured their energies, you’d find that they were moving ultra-relativistically, at 99.999%+ the speed of light. If not for relativity, you wouldn’t see a single muon at all.

Time dilation and length contraction are real, and the fact that muons survive, from cosmic ray showers all the way down to Earth, prove it beyond a shadow of a doubt.”

Hold out the palm of your hand and turn it upwards to face the sky. Congratulations: right now, approximately 1 muon per second is passing through your hand! You might not be a very sensitive particle detector, but you can build one, in the form of a cloud chamber, for less than $100 with off-the-shelf materials. If you did, you’d be able to see these muons individually. With a little extra work, and a bit of physics, you can prove to yourself that without Einstein’s relativity, these muons wouldn’t exist!

And yet, they’re real, you can observe them yourself, and they can help you prove the truth of relativity itself. Come find out how to do it for yourself!

This Is How, 100 Years Ago, A Solar Eclipse Pr…

This Is How, 100 Years Ago, A Solar Eclipse Proved Einstein Right And Newton Wrong

“Today, May 29, 2019, marks the 100th anniversary of the day, the event, and the expedition that validated Einstein’s General Relativity as humanity’s leading theory of how gravitation works. Newton’s laws are still incredibly useful, but only as an approximation to Einstein’s theory with a limited range of validity.

General Relativity, meanwhile, has gone on to successfully predict everything from frame-dragging to gravitational waves, and still has yet to encounter an observation that conflicts with its predictions. Today marks a full century of General Relativity’s demonstrated validity, with not even a hint of how it might someday break down. Although we certainly don’t know everything about the Universe, including what a quantum theory of gravity might actually be like, today is a day for celebrating what we do know. 100 years after our first critical test, our best theory of gravity still shows no signs of slowing down.”

Happy 100th anniversary to the critical observations that demonstrated Einstein was right and Newton was wrong when it came to gravitation. There’s an incredible story to how this all occurred, and you won’t want to miss a drop of what it all means.

It took one of the longest solar eclipses in modern history for us to get there, but oh, was it worth it. Come find out why and how for yourself.

Messing around with people once more :p (can’t…

Messing around with people once more :p (can’t swear it will be the last omegle chat log)

How Far Could A Human Travel In A Constantly-A…

How Far Could A Human Travel In A Constantly-Accelerating Rocket Ship?

“Imagine that we could constantly accelerate at the same rate as Earth’s gravitational pull, 9.8 m/s2, indefinitely. While you’d initially speed up, you’ll rapidly approach the speed of light.

Owing to Einstein’s Special Relativity, time will dilate and lengths will contract. As you continue to accelerate, the distances and travel times to faraway destinations will plummet.

At the halfway mark, simply reverse your thrust to accelerate in the opposite direction for the remaining journey.

If you wanted to travel to a star that was 100 light-years away, you might think it would take you at least 100 years to get there. That might be true from the perspective of someone who remains on Earth, but for an astronaut who journeyed there at close to the speed of light, Einstein’s Special Relativity tells you that it would take far less than a century of travel. In fact, if you could accelerate at a constant rate, you could pretty much reach anywhere you wanted within 15 billion light-years of us within a human lifetime.

I even went and did the math for you here. Don’t be afraid to see how far a human could travel if we had the dream technology to get us there!

How Far Could A Human Travel In A Constantly-A…

How Far Could A Human Travel In A Constantly-Accelerating Rocket Ship?

“Imagine that we could constantly accelerate at the same rate as Earth’s gravitational pull, 9.8 m/s2, indefinitely. While you’d initially speed up, you’ll rapidly approach the speed of light.

Owing to Einstein’s Special Relativity, time will dilate and lengths will contract. As you continue to accelerate, the distances and travel times to faraway destinations will plummet.

At the halfway mark, simply reverse your thrust to accelerate in the opposite direction for the remaining journey.

If you wanted to travel to a star that was 100 light-years away, you might think it would take you at least 100 years to get there. That might be true from the perspective of someone who remains on Earth, but for an astronaut who journeyed there at close to the speed of light, Einstein’s Special Relativity tells you that it would take far less than a century of travel. In fact, if you could accelerate at a constant rate, you could pretty much reach anywhere you wanted within 15 billion light-years of us within a human lifetime.

I even went and did the math for you here. Don’t be afraid to see how far a human could travel if we had the dream technology to get us there!

Relativity Wasn’t Einstein’s Mirac…

Relativity Wasn’t Einstein’s Miracle; It Was Waiting In Plain Sight For 71 Years

“If the Universe had a frame of reference that was distinct from all the others, then there should be some measurement you could make that revealed to you how the laws of nature were different when you moved at one particular speed in one particular direction. But that is inconsistent with the Universe we have. No matter how fast you move or what direction you move in, the laws of physics are the same, and any physical experiment you can perform will give the same measurable results and result in the same physical phenomena.”

When we think about Einstein and the principle of relativity, we normally talk about the Michelson-Morley experiment, which showed that the speed of light remained constant whether it was aligned with or at an angle to Earth’s motion. We might think about the Lorentz transformations like time dilation or length contraction. Certainly, those results played a role, but Einstein himself was thinking about a puzzle that came to light much earlier: about what’s physically occurring to cause Faraday’s law of induction. If you move a bar magnet into a stationary coil of wire, you generate an electric current. If you move a coil of wire onto or off of a stationary bar magnet, you also generate an equal intensity electric current. But the physics of how is entirely different!

Why are they equivalent? How can we reason our way into this? It was thinking about this that led Einstein to relativity. Come see how he got there, from a result 71 years in the making.