Speed of Light

Einstein’s special theory of relativity governs our understanding of both the flow of time and the speed at which objects can move. In special relativity, the speed of light is the ultimate speed limit to the universe. Nothing can travel faster than it. Every single moving object in the universe is constrained by that fundamental limit.

Speed of Light and Sound
This isn’t something like the speed of sound. Early scientists wondered if we could ever go faster than that speed, not because of some fundamental rule of the universe, but because we didn’t know if our engineering and materials science capabilities could withstand the extreme turbulence generated by moving at such speeds. But everyday objects already surpass the speed of sound. For example, the crack of a whip is caused by the tip creating a sonic boom as it travels faster than the sound speed.

The problem with trying to surpass the speed of light is that as you go faster, the more kinetic energy you have. But relativity tells us that energy is the same as mass, so the faster you go the more massive you become (and yes, this means that a moving baseball has more mass than one standing still, but that’s a tiny effect).

As you approach the speed of light, your mass balloons up to infinity. The closer you get to the speed of light, the more out of control your mass becomes. With higher masses, you must push yourself harder to accelerate, and you quickly find yourself in a position where it would take an infinite amount of energy to overcome light speed.

Exploring Light Speed
This isn’t just a matter of clever engineering or figuring out some trick – this is built into the fabric of the universe.

That said, there are proposals out there for designing specialized devices that could supposedly overcome this limit without outright breaking relativity. These concepts work because special relativity is a law of local physics: It tells you that you can never measure nearby motion going faster than light speed.  READ MORE...

Ending Civilization

TO A PHOTON, the sun is like a crowded nightclub. It’s 27 million degrees inside and packed with excited bodies—helium atoms fusing, nuclei colliding, positrons sneaking off with neutrinos. 

When the photon heads for the exit, the journey there will take, on average, 100,000 years. (There’s no quick way to jostle past 10 septillion dancers, even if you do move at the speed of light.) 

Once at the surface, the photon might set off solo into the night. Or, if it emerges in the wrong place at the wrong time, it might find itself stuck inside a coronal mass ejection, a mob of charged particles with the power to upend civilizations.

The cause of the ruckus is the sun’s magnetic field. Generated by the churning of particles in the core, it originates as a series of orderly north-to-south lines. But different latitudes on the molten star rotate at different rates—36 days at the poles, and only 25 days at the equator. 

Very quickly, those lines stretch and tangle, forming magnetic knots that can puncture the surface and trap matter beneath them. From afar, the resulting patches appear dark. They’re known as sunspots. Typically, the trapped matter cools, condenses into plasma clouds, and falls back to the surface in a fiery coronal rain. 

Sometimes, though, the knots untangle spontaneously, violently. The sunspot turns into the muzzle of a gun: Photons flare in every direction, and a slug of magnetized plasma fires outward like a bullet.  READ MORE...

Violating Speed of Light

Just 13.8 billion years after the hot Big Bang, we can see 46.1 billion light-years away in all directions. Doesn't that violate...something?

A visual history of the expanding Universe includes the hot, dense state known as the Big Bang and the growth and formation of structure subsequently. The full suite of data, including the observations of the light elements and the cosmic microwave background, leaves only the Big Bang as a valid explanation for all we see. (Credit: NASA/CXC/M. Weiss)

The cardinal rule of relativity is that there's a speed limit to the Universe, the speed of light, that nothing can break.And yet, when we look at the most distant of objects, their light has been traveling for no more than 13.8 billion years, but appears much farther away.Here's how that doesn't break the speed of light; it only breaks our outdated, intuitive notions of how reality ought to behave.

If there’s one rule that most people know about the Universe, it’s that there’s an ultimate speed limit that nothing can exceed: the speed of light in a vacuum. If you’re a massive particle, not only can’t you exceed that speed, but you’ll never reach it; you can only approach the speed of light. If you’re massless, you have no choice; you can only move at one speed through spacetime: the speed of light if you’re in a vacuum, or some slower speed if you’re in a medium. The faster your motion through space, the slower your motion through time, and vice versa. There’s no way around these facts, as they’re the fundamental principle on which relativity is based.

And yet, when we look out at distant objects in the Universe, they seem to defy our common-sense approach to logic. Through a series of precise observations, we’re confident that the Universe is precisely 13.8 billion years old. The most distant galaxy we’ve seen so far is presently 32 billion light-years away; the most distant light we see corresponds to a point presently 46.1 billion light-years away; and galaxies beyond about 18 billion light-years away can never be reached by us, even if we sent a signal at the speed of light today.

Still, none of this breaks the speed of light or the laws of relativity; it only breaks our intuitive notions of how things ought to behave. Here’s what everyone should know about the expanding Universe and the speed of light.  READ MORE...

Our Twisted Universe

A forgotten idea of Albert Einstein’s might just be the saviour of cosmology, plus the great man’s (vain) quest to undermine quantum weirdness and the question of why the universe looks “just right” for our existence.

Hello, and welcome to November’s Lost in Space-Time, the monthly physics newsletter that unpicks the fabric of the universe and attempts to stitch it back together in a slightly different way. To receive this free, monthly newsletter in your inbox, sign up here.

Einstein’s forgotten twisted universe
There’s a kind of inevitability about the fact that, if you write a regular newsletter about fundamental physics, you’ll regularly find yourself banging on about Albert Einstein. As much as it comes with the job, I also make no apology for it: he is a towering figure in the history of not just fundamental physics, but science generally.

A point that historians of science sometimes make about his most monumental achievement, the general theory of relativity, is that, pretty much uniquely, it was a theory that didn’t have to be. When you look at the origins of something like Charles Darwin’s theory of evolution by natural selection, for example – not to diminish his magisterial accomplishment in any way – you’ll find that other people had been scratching around similar ideas surrounding the origin and change of species for some time as a response to the burgeoning fossil record, among other discoveries.

Even Einstein’s special relativity, the precursor to general relativity that first introduced the idea of warping space and time, responded to a clear need (first distinctly identified with the advent of James Clerk Maxwell’s laws of electromagnetism in the 1860s) to explain why the speed of light appeared to be an absolute constant.  READ MORE...

Dead Reckoning

DEAD RECKONING is the navigational process of calculating
current position of some moving object by using a previously determined position, or fix, by using estimations of speed, heading direction and course over elapsed time.

ADVANTAGE:  it can be a highly accurate way of moving from one point to another if done carefully over short distances, even where few external cues are present to guide the movements.

In other words, we can forecast where we might be in 3 months by using the clues and cues of where we are now which has been determined by dead reckoning, but, if we were to push farther out into the future and even if our forecasted predictions were based and predicated upon the past for the last 20-50 years, there is still no guarantees that they will continue in the same direction forward unless the future has already been PREORDAINED or PREDETERMINED which we all know is simply not possible at all...  given our current levels of knowledge and technologies...  however, is that really true?

The speed of light is very fast and it takes about 8.5 minutes for sunlight to reach the earth... so, the light of our present is really from the sun's past.  And if, we were living on the sun, the earth would be 8.5 minutes ahead of us...  therefore, we could see into our future...  however, at this moment living on the sun is theoretically impossible and probably highly improbable given how hot it is.

But, the concept of seeing into our future is theoretically possible...  so, our future can be seen as being preordained and/or predetermined...  it is just that we are not in a position to take advantage of that.  Yet, if we could, then it would also be possible to see into our future more than 3 months, possibly more than 3 years, highly likely more than 3 decades, and quite feasible more than 3 centuries or more.

RIGHT NOW:  we are simply in a position where all we can do is make predictions like:

1.  China using its military and economy one day to control the world

2.  North Korea becoming a nuclear power and using it against South Korea and Japan

3.  Russia reclaiming all those countries that the USSR lost once its government dissolved

4.  Larger cities like SEATTLE, WA increasing and sustaining waves of crime and violence now that police department have been defunded

5.  Our country bordering on financial collapse (or printing up more money) due to the wealthy hiding their money so that it cannot be taxes to pay for everything

6.  Changing our government from being a Democratic Republic to that of a Socialist Nation

7.  To seeing race wars spread like wildfire across the continent when in reality they are wars between the wealthy and those who live in or close to poverty