What are the strange objects that test our knowledge?

 1. I was in Florence with my wife. In one of the cafes, I noticed wooden sticks that looked like pointers. What are they used for?

The answer, to the surprise of many, is that these are newspaper headlines. The stick has a slot where the newspaper is inserted.

2. This isn't the first time I've noticed a gray metal box under the seat in a Dubai taxi. What's inside the box?

The answer to this question is simple: there's a piece of hardware that, by law, must be in a taxi in this city. For example, a GPS tracker or a receipt printer, which are already implemented in developed countries like Dubai.

3. If you look at the Libyan Desert on Google Maps, you can see that it's marked with an almost perfect grid. How and why is this done?

The answer is that these are seismic survey lines, which were made by special trucks.

4. Why did they add a ramp to this small window in the old hospital building?

The answer is that the coal was loaded through this window for the boiler room, which is probably in the basement; this way it was much easier to move it and put it down below.

5. The kitchen in my new apartment has a pull-out bar. Why is it necessary?

The answer is quite practical; this kitchen was fitted with a meat grinder or other similar devices for greater convenience when cooking.

6. Instead of the green traffic light, some type of device is installed.

The answer is that this is a new German traffic light, where there is no yellow signal and a loudspeaker is installed instead of a green one.

7. Why are there holes in the facade of this building built in 1700?

The answer is that these are ventilation ducts. It used to be a barn for drying tobacco.

8. Why do some old houses in London have the front door handle in the center?

The answer is that this arrangement is due to the design of old castles. When the handle was turned, the bolts were pushed back.

9. What is this box with round and oval holes for? I bought it as a decorative item for an apartment at a flea market.

The answer is that this is for an oxygen tank and mask, as part of a resuscitation kit in a fire department or ambulance.

10. I saw this in the luggage compartment of a Swiss train. What is it for?

The answer is that this is a ski rack.

If 2 objects are traveling directly away from each other at 99.999% light speed, what's the speed between the two?

 Basic math says two objects flying apart at 99.999% light speed separate at 199.998% light speed. Instead, the universe warps space and time to cap their relative speed at 99.999999995%.

When you drive down the highway at 60 mph, and a car drives away from you in the opposite direction at 60 mph, the distance between you grows at 120 mph. This Galilean velocity addition works perfectly for the slow speeds experienced on Earth.

But when you approach the speed of light ($c$), things get weird. In 1905, Albert Einstein realized that the speed of light is a strict universal constant for all observers. To protect that absolute limit, everyday measurements like distance and duration have to stretch or shrink.

From your perspective on one of those spaceships, time is moving normally and your ruler is the same length. But when you look at the other spaceship, you will see its clock ticking incredibly slowly, and its length compressed. Because time and space are warped, your measurement of their speed changes.

Einstein provided a new formula for adding velocities that takes this warping into account:

$v=\frac{v_1+v_2}{1+\frac{v_1\times v_2}{c^2}}$

If we plug in your numbers—where $v_1$ and $v_2$ are both 0.99999$c$—the top of the fraction is 1.99998$c$. But we must divide that by the bottom of the fraction, which is 1 + 0.9999800001, or 1.9999800001.

$1.99998÷1.9999800001=0.99999999995$

No matter what speeds you plug into this formula, as long as both objects are moving slower than light, the resulting relative speed will always be slower than light. The mathematics perfectly prevent you from ever crossing that threshold.

Physicists observe this reality every day inside particle accelerators like the Large Hadron Collider (LHC). When the LHC fires two protons in opposite directions, each one travels at 99.9999991% of the speed of light relative to the scientists standing in the laboratory. From the lab's perspective, the "closing speed" of the gap between the two particles is almost twice the speed of light.

But if you could strap a tiny radar gun to one of those protons and measure how fast the other proton is approaching it, the radar gun would never register a speed faster than $c$. Instead, it would measure a relative speed of 99.999999999999999% $c$.

A lead-ion collision at nearly the speed of light, as recorded by the ALICE detector at CERN's Large Hadron Collider. Photo by Pcharito is licensed under CC BY-SA 3.0.

Are there any objects in space that are smaller than stars but larger than planets, such as brown dwarfs?

 If you packed 70 times more mass into Jupiter, it wouldn't get any wider. It would become a brown dwarf—a "failed star" trapped in the cosmic middle ground between planets and true stars.

To understand what a brown dwarf is, it helps to look at the firm mass boundaries that define stars and planets:

• A star is an object massive enough that the crushing pressure and heat in its core ignite the sustained nuclear fusion of regular hydrogen (hydrogen-1). The absolute minimum mass required to do this is roughly 80 times the mass of Jupiter.
• A planet like Jupiter does not have enough mass to ignite any kind of nuclear fusion. It generates no internal fusion energy and simply cools down over time.

If an object forms with a mass between roughly 13 and 80 times that of Jupiter, it falls directly into this middle ground. Unlike true planets, brown dwarfs are massive enough that their core pressure ignites nuclear fusion—but only the fusion of deuterium, a heavy isotope of hydrogen. Because deuterium is scarce, a brown dwarf burns through its supply in a few million years, which is a blink of an eye in cosmic terms.

Once the fuel is gone, the fusion stops. For the rest of its long life, the brown dwarf glows faintly in the infrared spectrum from leftover heat, slowly fading and cooling until it turns pitch black.

This size paradox is one of the most unintuitive physical properties of brown dwarfs. Due to the quantum mechanics of electron degeneracy pressure, adding mass to a brown dwarf does not make it physically larger—it just makes it denser. Gravity pulls the extra mass inward so tightly that a heavy brown dwarf remains almost exactly the same diameter as Jupiter.

A size comparison showing a low-mass star, a brown dwarf, and Jupiter. Due to extreme density, a brown dwarf has roughly the same physical volume as Jupiter despite being up to 80 times more massive. Source: Wikimedia Commons.

For decades, these objects only existed in mathematical theories because they emit almost no visible light. Astronomers finally found undeniable proof in 1995 with the discovery of Gliese 229B. Spotted orbiting a red dwarf star, it glowed faintly in the infrared, and its atmosphere contained methane—a molecule that cannot survive the intense heat of a true star. At the very bottom of the brown dwarf temperature scale, astronomers have now even found Y-dwarfs, which have cooled down so much that their atmospheres match the temperatures of a warm summer day on Earth.

What is one of the most mysterious objects discovered in our universe?

 Hoag's Object is perhaps one of the most mysterious and at the same time most beautiful "objects" in our universe.

The latter is nothing more than a galaxy of unconventional appearance, known as a ring galaxy.

This galaxy, about 600 million light-years away, consists of a nearly perfect ring of hot, blue stars surrounding a yellow nucleus.

The diameter of the inner part of the galaxy is about 17,000 light-years, while the outer ring has an internal diameter of about 75,000 light-years.

The galaxy's total diameter is about 121,000 light-years, which is slightly larger than our own Milky Way!

The space separating the two stellar populations (center and ring) could contain some open clusters, but they are too faint to be observed.

Despite the incredible rarity of this type of galaxy, between the outer ring and the nucleus another galaxy with the same ring characteristics is visible, much more distant, and incredibly overlapping with each other for a rare perspective effect!

It is not known exactly how it formed, although some hypotheses indicate that it was crossed by another, much larger galaxy.

However, there is no sign of it.

It is worth noting that this type of ring galaxies represent less than 0.1% of all known galaxies!

What is the most mysterious object in Roman history?

 The dodecahedron .

This is a mysterious object probably dating back to the 2nd-3rd century AD, found in multiple specimens from Great Britain to Hungary, passing through France, Germany and Italy.

However, no written source that has reached us seems to mention it, and this instrument does not appear in any image , and so scholars can only speculate on how it worked and what it was used for.

These are small, hollow bronze or stone objects , composed of 12 flat pentagonal faces, each with a circular hole in the center. These enigmatic objects range in size from 4 to 11 centimeters.

Hypotheses of all kinds have been formulated, imagining functions linked to astronomy and the agricultural cycle or to religious or esoteric rites.

There are also those who think that they were toys , or tools to help technicians and engineers, perhaps to measure distances.

Finally, some hypothesize that they had a military use and in particular that they helped in the production of slingshot bullets.

All hypotheses formulated with care but lacking any evidence to confirm them.

Why do some everyday objects, like grains of salt or a strawberry's surface, look so amazing under a microscope?

 To the naked eye, a grain of table salt is just a jagged white speck. Under magnification, it reveals itself as a nearly perfect, interlocking cube.

Human eyes evolved to interpret the macroscopic world—to spot a predator in the brush or judge the ripeness of a fruit—completely ignoring the microscopic architecture that holds physical reality together. When a microscope bypasses that biological filter, it reveals that the most mundane objects are built from startling geometric and functional complexity.

This stark geometry occurs because salt is composed of sodium and chloride ions that naturally attract each other, locking together in a rigid, repeating 3D grid. The sharp corners and flat faces seen under a lens are the direct, scaled-up manifestation of salt's atomic lattice.

Biological objects look equally alien because magnification exposes the hidden mechanics of nature. A strawberry, for example, is not actually a true berry, but an "aggregate accessory fruit." The tiny specks on its surface, which people commonly call seeds, are actually individual dry fruits called achenes, each containing a single seed. Under a microscope, these achenes look like tough, textured armor plates embedded in a sweeping, fleshy landscape. Magnification reveals this complex reproductive strategy, stripping away the illusion of a simple, uniform red surface.

The technology used to view these objects also plays a massive role in why they look so captivating. Scanning electron microscopes (SEM) do not use visible light at all. Instead, they bounce beams of electrons off a sample's surface, creating images with incredible depth of field and stark shadowing. This process gives microscopic pollen grains, insect eyes, or woven fabrics a vivid, three-dimensional quality that traditional optical lenses cannot easily replicate.

Everyday objects look amazing under magnification because they are fundamentally engineered by physics and biology at a scale people were never meant to observe. A microscope simply grants temporary access to that hidden structural reality.

Why does the universe create objects as extreme as black holes?

 Here main player is gravity. When a massive star(>3 solar masses) collapse due to end of it’s fuel,then outward pressure is lower than the inward gravitational force and it creates a black hole.

According to GR, space time curvature bends heavily in case of a black hole. Thus we see that when gravity wins over expansion force,that creates high density region of mass so that nothing can escape from it nor even light. It is called black hole.

Now,unlike gravity creates star, galaxy, cluster ,it ,creates also black holes. In center of every galaxy there is a supermassive black hole.

The relationship is better described as mutual sculpting — the galaxy feeds the black hole, and the black hole regulates the galaxy. It's a deeply coupled system, not a one-way preservation mechanism(by Cormendy and Ho’s research paper).

Image credit: vox

What are some examples of astronomical objects?

 

We just discovered a new type of astronomical object. A galaxy in which gas outshines the stars it contains

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A billion years after the Big Bang, or 12.7 billion years ago, the universe was different than it is now. There were less heavy elements in nebulas from which new stars form. These atomic nuclei come to be in subsequent generations of stars that die as supernovas or, more calmly, spreading them around. At such a young age, the universe wasn’t old enough for many generations of stars to live and die. However, such gas nebulas that were heavy nuclei-poor allowed more massive and luminous stars to form than it is possible now. They lived short lives, exploded as supernovas, and illuminated nearby space and gas in young galaxies.

It turns out that one galaxy called 9422, 12.7 billion years ago, was unique because it had so many massive stars at once that they bombarded nebulas so much with their light that the gas in them shone more intensely than the stars themselves. These gigantic suns had temperatures of about 80,000 C/140,000 F. In comparison, the most massive stars in the contemporary universe have only temperatures around 45,000 C/80,000 F.

Gas shining more intensely than stars in young galaxies was already predicted in our models of the young universe, and this lucky discovery confirms our models. At 1 billion years old, galaxy 9422 doesn’t contain the very first stars called Population III anymore, which would be made almost entirely by hydrogen and helium that the universe was born with. The hot stars it contains are already some of the earliest, but subsequent generations formed from some ashes of earlier stars.

The fascinating discovery would not have been possible without the James Webb Telescope, which gives us an unprecedented view of the very old universe just after the Big Bang.

What Powers the Brightest Objects in the Universe?

 

The brightest object in the universe is a quasar. Now what is quasar? It is like headlight of a car (galaxy) where supermassive black hole(SMBH) is the engine of that car. It's the best simple way to analog galaxy, supermassive black hole and quasar. So that SMBH Powers the brightest object.

When matter infalling to a black hole, it spirals and forming an accretion disc. For friction and spinning property of black hole, this region's temperature goes to million to billion kelvin. At centre where quasar is, gravity turns into light and high velocity (nearly equal to velocity of light)relativistic jets are emerged. That quasar for milky Way galaxy is 1000 times brighter than that of milky way itself. It can shine whole galaxy.

So the answer is SMBH powers the brightest object (Quasar)in the universe.

Image source: google

Vishnu has 4 arms and holds 4 objects. What are those objects?

 The four objects in the 4 arms of Vishnu are Shankha, Chakra, Gada, Padma or in simplified English equivalents they are Conch, Discus, Mace and lotus.

Now, which arm of Vishnu holds which object? That is an interesting question. The Dwaita philosopher Madhvacharya lists out 24 ways ( i.e. 4X3X2X1) of holding these objects in 4 arms, in his Tantrasara Sangraha. Accordingly, each form (Roopa) holding the objects in a specific way is given a name and worshiped for a specific purpose. These 24 forms (Roopa) are

1. Keshava : Shankha, Chakra, Gada, Padma (clockwise starting from the top right hand)
2. NarayaNa: Padma, Gada, Chakra, Shankha
3. Madhava: Chakra, Shankha, Padma, Gada
4. Govinda: Gada, Padma, Shankha, Chakra
5. VishNu: Padma, Shankha, Chakra, Gada
6. Madhusoodhana: Shankha, Padma, Gada, Chakra
7. Trivikrama: Gada, Chakra, Shankha, Padma
8. Vaamana: CHakra, Gada, Padma, Shankha
9. Shreedhara: Chakra, Gada, Shankha, Padma
10. Hrsheekesha: Chakra, Padma, Shankha, Gada
11. Padmanaabha: Padma, Chakra, Gada, Shankha
12. DaamodaraL Shankha, Gada, Chakra, Padma
13. SankarShaNa: Shankha, Padma, Chakra, Gada
14. Vaasudeva: Shankha, Chakra, Padma, Gada
15. Pradyumna: Shankha, Gada, Padma, Chakra
16. Aniruddha: Gada, Shankha, Padma, Chakra
17. PuruShottama: Padma, Shankha, Gada, Chakra
18. AdhokShaja: Gada, Shankha, Chakra, Padma
19. Narasimha: Padma, Gada, Shankha, Chakra
20. Achyuta: Padma, Chakra, Shankha, Gada
21. Janaardhana: Chakra, Shankha, Gada, Padma
22. Upendra: Gada, Chakra, Padma, Shankha
23. Hari: Chakra, Padma, Gada, Shankha
24. KrShNa: Gada, Padma, Chakra, Shankha

Following image shows the 24 ways in which Udupi Krishna - the Krishna installed by Madhvacharya at Udupi - is decorated to illustrate the 24 forms of Vishnu as explained above.