Politicians Should Listen To Carl Sagan FAST!

Carl Sagan was an American astronomer who actively campaigned against nuclear weapons and pointed out the potential dangers, like a nuclear winter. Given that Israel and Iran are at war, while Russia and Ukraine have been going at it since years now, it is important for politicians to set aside their egos and read this wonderful, humanizing speech by Carl Sagan.

Background

The Pale Blue Dot is an image that was taken by NASA at Carl Sagan’s suggestion. The astonishing picture came from Voyager 1, a spacecraft launched in 1977 to study the outer solar system. When Voyager was about to exit the solar system, it turned around one last time to take a farewell photo. Earth appears as a very small stage in a vast cosmic arena, Sagan quipped.

The picture is evidence enough of our tininess in the universe. The enormity of space cannot be comprehended from our comfortable air conditioned rooms, but when you look at a picture like Pale blue dot, something moves you from the inside. That yearning to find our place in the Cosmos and persistent urge to "make it big" in Earth lingo, are challenged by this point of pale light.

Significance

Sagan used this image to challenge arrogance and nationalism. He pointed out that there is no hope that help will come from elsewhere to save us from ourselves. We have to protect our fragile planet, which is the only place we know of in the universe that supports life in all its glory.

In gaming terms, Earth is a checkpoint, a reminder that life happened here. The problem is, our intelligence has become quite dangerous in modern times. Blinded by power and ego. Therefore, politicians must find a few seconds from their busy schedules and take a look at Pale blue dot.

According to Carl Sagan, astronomy is a humbling experience and presents a possibility of peace. When we recognize how small our disputes look from the perspective of the universe and that earth is the only home we will ever know we will cherish it more perhaps. Sagan once said: "If a human disagrees with you, let him live. In a hundred billion galaxies, you will not find another."

Technicals

Pale blue dot was taken in February, 1990 from a staggering distance of 6 billion km. Of the 640,000 individual pixels in the image, Earth appears as a tiny pixel suspended in a ray of sunlight. A narrow angle camera aboard Voyager 1 was used to capture Earth's location. Earth looks blue in the photograph primarily because of Rayleigh scattering of sunlight in its atmosphere.

Excerpt

Here is a small excerpt from pale blue dot speech by Carl Sagan which every politician should read: The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.

There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

Where Are Wormholes: Shortcuts In Space?

Just like there are clever shortcuts on Earth to beat the traffic, what if there were "shortcuts in space" to bypass the enormous distances in the universe? That’s basically what a wormhole is - a theoretical tunnel through space and time.

Wormhole history

Technically, a wormhole is called Einstein-Rosen bridge.

The concept began with Albert Einstein and Nathan Rosen in 1935. They discovered that theory of general relativity made strange structures to link distant places in the universe possible. The term wormhole for such a structure was coined by physicist John Wheeler in the 1950s.

Physicists were fascinated. Wormholes soon became a favorite tool in science fiction. But the only problem with Einstein-Rosen bridge or wormhole is that the kind of wormhole described by Einstein and Rosen equations would collapse too soon for anything to pass through.

Picturing wormhole

Imagine space as a giant flat sheet of paper. If you draw two dots on opposite sides, the shortest way to connect them is a straight line, right? But what if you could fold the paper in half so the dots touched? Now you can connect the dots instantly - no long journey needed. That’s the basic idea behind a wormhole.

Wormhole literally

Now the wild thing is wormholes do not just connect space. They are also portals in time. If one end of a wormhole moves faster than the other, time would pass differently at each end. Therefore it is theoretically possible to use wormhole for time travel.

Math of wormhole

The math behind wormholes comes from Einstein’s field equations, which describe how mass and energy shape space and time. Massive objects bend space and time — like a bowling ball on a trampoline. If space can bend, maybe it can also fold too — bringing two distant points closer.

When scientists solve Einstein's equations under special conditions, wormholes are one possible result. Most solutions show wormholes collapsing before anything can use them. To keep wormhole open for long time, we need to create matter with negative energy, which is not quite possible.

Wormhole in media

Writers are fascinated by wormholes as they allow characters to hop across galaxies in seconds, which keeps stories moving without spending 1,000 years in a spaceship. Shows like "Dark" and "Doctor Who" have made use of wormholes in their plot.

Movies like Interstellar, Contact and Thor use wormholes in their storylines. Interstellar uses a scientifically inspired wormhole near Saturn to allow humans to explore other galaxies. In Contact, an alien-built machine creates a wormhole for interstellar communication and travel.

Do wormholes exist?

Have we ever discovered a wormhole, like we discovered a black hole? Math allows wormhole existence but astronomers have yet to identify one. Some scientists believe that wormholes might be hidden inside black holes. Others say they probably don’t exist at all.

Wormholes sit at the intersection of science and imagination. Wormholes offer a hopeful vision of overcoming the vastness of space — or even time. Whether practical or not, wormholes inspire stories, dreams, and real scientific questions.

Who knows? Maybe someday, wormholes will go from sci-fi fantasy to part of our cosmic travel plans. Until then we will have to thank Einstein and Rosen for empowering our writers community.

10 Fantastic Ways In Which Snails Use Physics

Nowadays, courtesy of early monsoon in Delhi, snails big and small, fast and slow, greeted the lawns of India Habitat Center one evening. In some cultures, observation of snails in abundance represents slow but steady progress and good luck. Furthermore, snails are also bio monitors and indicate the quality of environment - temperature, pollution, etc.

What I was more fascinated by was the physics of a snail. How snail was defying gravity and climbing up the wall without second thoughts. How the mucus left behind by Snail's muscular foot must have helped it reduce friction, but also slowed it down and so on.

It was a magical day to say the least and more than a dozen snails showing up was no less than a happy serendipity. Snails might seem simple, but they rely on a surprising range of physical principles in their everyday life. Following are 10 ways in which a snail uses physics for its survival:

1. Surface tension: Snails secrete a mucus to create a slimy track. Because of surface tension, the mucus acts like elastic membrane. The snails use wave like muscle movements to glide forward efficiently.

2. Friction control: The mucus is a non Newtonian fluid. Its viscosity or thickness changes depending on the stress applied to it. This allows snails to control friction on surfaces as per their wish.

3. Adhesion: Snails can also move vertically and upside down, like a spider. This is possible due to adhesive force between their mucus and and surfaces.

4. Stress distribution: Shells of snails are logarithmic spirals. The shell closely resembles Fibonacci sequence and is a thing of mathematical beauty. The structure distributes stress and protects snail's life.

5. Thermal regulation: Snails also use their skin and shells for heat transfer. Surface of the shell and skin is highly reflective and shiny and reduces absorption of heat, keeping snails cool.

6. Moisture retention: In dry conditions, the mucus of snail is useful in controlling evaporation of water. Snails drink water by absorbing it through their slimy skin.

7. Vibration sensitivity: Snails do not have ears but respond to vibrations quickly. Snails detect external threat by vibrations as they are firmly attached to the surfaces.

8. Optics: Snails do not have very sharp eyes. Snails can only distinguish between bright and dark. Snails cannot see colors and only use elementary optics for movement.

9. Torsion: Snail's shell is coiled in such a way that it helps the snail stay balanced while moving. Some shells can grow very large and heavy over time, but the center of mass is shifted gradually keeping the snail perfectly healthy.

10. Viscoelasticity: Snail mucus is not just slippery, it is viscoelastic. Thus, the mucus can be used both as liquid and solid. This allows snails to hold on to surfaces, and defend itself against attack.

What Is the Twin Paradox? A Simple Guide to Einstein’s Theory of Relativity

Did you know that NASA conducted a study of the effects of spaceflight on twins. This was done to test Einstein's famous twin paradox experiment which is a result of relativity. Identical twins Scott Kelly and Mark Kelly were chosen and while Mark stayed on Earth, Scott spent a year aboard the international space station. You can read the results here.

What exactly is twin paradox? Let us understand Einstein's original idea first.

Time machine

Surely the idea of time machine takes our mind on a wild imaginary ride when we attempt to understand it. Time travel is a kind of travel not in space (which we know has three dimensions, length, width and height) but it is the travel in the fourth time dimension. Is it possible to travel in the past or in the future?

In non-relativistic or classical physics, the concept of time is that of absolute time, which is independent of any observer and is same throughout the universe. Same time flow on Jupiter as on Earth. This was thought of first by English scientist Sir Isaac Newton back in the day... who proposed that time progressed at consistent pace for everyone everywhere and is essentially imperceptible and mathematical in nature.

But in Einstein's relativity, time is not absolute. Meaning that time is perceivable and is not the same everywhere and for everyone. And we now know that the rates of time actually run differently depending on relative motion for different observers; time effectively passes at different paces so it might not be the same flow of time on Jupiter.

So, making a time machine might be possible if we can control the flow of time.

Twin paradox

There are two types of time travel: to the future and to the past. We already are moving into the future all the time at the tick of the seconds hand, but we're doing so at a regular rate. Could we make it so that this pace of time going forwards is increased, such that we go into the unseen future?

There is a way. Sending elementary particles on round trips in a particle accelerators at 99% of light speed is routine. The result is that the inner clock of such a travelling particle, say electron, runs much slower than that of a particle of the same species that remains at rest. Time slows for the fast moving particle.

Can this result from subatomic particles extend to larger human bodies? Einstein thought so... in his famous experiment "twin paradox" while he was working on the theory of relativity. In this, a hypothetical astronaut returns from a near-light speed voyage in space only to find his stay-at-home twin many years older than him, because travelling at high speeds has allowed the astronaut to experience only, let's say, one year of time, while ten years have gone by on the Earth.

The real paradox happens from the fact that there is "no favourable reference frame" in relativity. Why can’t the twin in the spaceship define himself as being at rest, let's say? And everyone on Earth is moving in that frame, oppositely. The Earth moves away at high speeds before returning to the still spaceship.

And if that is the frame, couldn’t the travelling twin apply time-dilation to everyone who stay on the Earth? By that argument, shouldn’t it be the humans of earth that remain younger once the twins are reunited? We all must eventually agree though that only one of the twins' perspective has to be the correct one. Which one is it then? So this is the actual "twin" or "dual" paradox of time dilation as put forth by Einstein in the 20th century.

Mind bending.

From general relativity, we can say that time passes more slowly for objects in strong gravitational fields than for the objects which stay far from such fields. There are all kinds of space and time distortions near black holes, where the gravity can become very intense. Thus if one of the twins is orbiting around a black hole and the other's orbiting around the earth the question of the paradox, "which twin is older" is answerable.

Back to the past

We have all watched "Back to the Future" and wondered how messed up it could get if we too did actually move backwards in time? And many scientists say the very premise of pushing a button and going back to yesterday violates the law of causality. However there are also some who think otherwise. Professor Michio Kaku has said, "Time is a river. It speeds up, meanders, and slows down. It can also have whirlpools and even fork into two rivers."

That last bit, "fork into two rivers," is important because then moving backwards in time could become at least thinkable. Because as soon as we push the button we go back into an alternate world or reality. We do not cause harm to our previous reality as in the case of "grandfather paradox". The idea was first proposed by British physicist David Deutsch who used the terminology of multiple universes to solve the grandfather paradox. Deutschian time travel involves the time traveler emerging in a different universe other than his own but very similar to his own.

Time travel will remain only conceptual and debatable except if we are able to develop enough advanced technology for it to become achievable. Until then we will use our earth bound telescopes as time machines. Because when you look into one you'd actually be looking into the past stages of the universe.. meaning that the star you observe today might not even exist in the first place. Turns out that if aliens knew exactly where to point their telescopes they could see dinosaurs at least in principle.

What Physics Tells Us About a Hypothetical Nuclear War Between India and Pakistan

India and Pakistan were recently involved in fresh tensions resulting in military actions by both countries. World leaders called for maintaining peace as any further escalation could potentially lead to a nuclear war in south Asia.

What impacts would a hypothetical nuclear war between India and Pakistan have on the world? Let us explore the physics behind the potential consequences of nuclear war in South Asia.

1. Blast destruction: Nuclear explosions release immense energy (E=mc²), causing blast waves and thermal radiation that kill millions instantly. The explosion can release energy as much as ~10²³ joules, causing a shockwave, flattening structures.

2. Underground or surface detonations release energy as mechanical waves, causing artificial localized earthquakes (seismic waves).

3. Thermal radiation from the fireball (~several million °C) ignites flammable materials, leading to large-scale fires. Shockwaves (pressure >10 psi) destroy buildings and critical infrastructure.

4. Radioactive isotopes (e.g., Cs-137, Sr-90) from fission reactions decay, emitting gamma rays and contaminating air, water, and soil. Post nuclear war, it would be impossible for any species to survive in the place.

5. High-altitude detonations produce gamma rays that ionize the atmosphere, generating electromagnetic pulses (EMPs) that disable electronics.

6. Soot from the explosions absorbs sunlight, reducing surface temperatures by 5-10°C for years due to aerosol scattering. This would lead to an unbearable nuclear winter.

7. Nitrogen oxides from high-temperature explosions catalyze ozone breakdown, increasing UV radiation exposure. This would not only impact the south Asia region but also the rest of the world for decades to come.

8. Reduced sunlight and temperature from nuclear winter disrupt photosynthesis, leading to crop failures.

9. Radiation sickness follows. Ionizing radiation (alpha, beta, gamma) disrupts cellular structures and DNA, causing acute and chronic health effects.

10. The nuclear war would speed up global disarmament efforts. Countries would volunteer to destruct their nuclear arsenal because people around the world could clearly see how dangerous nuclear weapons are.

credit: Geralt on pixabay

Why Was Albert Einstein Not Religious?

Science without religion is lame and religion without science is blind. This popular quote of Albert Einstein has been repeatedly used, particularly in science versus religion debates. But from this statement alone can one say that Einstein was arguing for religion? A large number of believers definitely think so, referring to this adage and thus claiming the greatest scientist of the 20th century as one of their own.

However, Einstein had also famously written: "The idea of a personal God is a childlike one," in a letter to a friend dated 28 September 1949.

Einstein even went on to say, "You may call me an agnostic but I do not share the crusading spirit of the professional atheist whose fervor is mostly due to a painful act of liberation from the fetters of religious indoctrination received in youth."

From this saying alone, we can conclude that Einstein was neither a religious man in the usual sense nor was he a staunch atheist. Einstein was agnostic in belief. If you think about it, agnosticism really is the essence of science, whether ancient or modern.

Being an agnostic simply means that a man shall not say he knows or believes that which he has "no scientific grounds" for professing to know or believe.

Does God play dice? (Einstein's most famous quote)

Einstein was expected to make many statements on the origin of life, the universe and existence of God. Some of the views resonated with religious groups, but that does not make Einstein a believer. Albert Einstein was in fact one of the most famous agnostics in America, others being Edwin Hubble, Carl Sagan, John Bardeen, etc. and yet Einstein's name and his quotes are selectively chosen as merely "tools" by debaters to silence an opposition.

What had Einstein meant really, when he said: Science without religion is lame and religion without science is blind?

Actually, he was making a reference to a large part of human history in which science and religion were intertwined or interdependent. He put it like this, indicating that the interdependency still existed in the modern society.

This does not suggest in any way that Einstein was a deeply religious person and nor does it provide any surface to anyone to interpret it in such a way. If truth be told, Einstein had strongly asserted in one of his statements - "The word god is for me nothing more than the expression and product of human weaknesses."

So if Einstein wasn't even religious in the most ordinary sense, why his name is often dragged in trivial debates? Because it is assumed by a large number of people that in science "Einstein" is the authority. But they are wrong, because in actuality there is no authority in science. Feynman said: You can be the most amazing minds, if your ideas do not agree with experiment it is wrong. No matter who you are.

This is precisely how science progresses, by challenging, by having no authority, by questions and doubts; whereas religion has not progressed for hundreds and thousands of years.

Einstein's views were simply, that nature is not nurtured. That nature itself is nurturing. This is the ultimate essence of Spinozism a philosophical system which was largely advocated by Einstein. Spinoza belief is the unbounded admiration for the structure of the world, the universe, so far as our science can reveal it.

Just a year before his death, Einstein had replied to a fan in a letter, "It was of course a lie what you read about my religious convictions, a lie which is being systematically repeated. I do not believe in a personal God and I have never denied this but have expressed it clearly."