Even though our universe is around 13.8 billion years old, it’s constantly growing, which is why most of us can barely keep up with all of its changes. Almost 95% of the cosmos still remains unknown to humankind, which makes it all the more mysterious and interesting.
Even though we laypeople might be in the dark about space, astronomers and cosmologists understand it so much better and are finally ready to reveal some of its secrets. Most of these facts about the universe might seem a bit baffling, so be prepared for a wild ride.
#21
Time didn't always exist. It's not a "brute fact".
And there is no single "true" time in the universe. It's different for all observers, depending on their movement through space.
And there is no single "true" time in the universe. It's different for all observers, depending on their movement through space.
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8points
Everyone might have dreamed of going to space one day, but astronauts are the people who have had the chance to explore the universe. Beyond their incredible travel experience, going to space can also make astronauts grow about 2 inches (5 cm) taller.
Researchers have studied this slight height boost extensively, and ultrasound technology found that when the spine isn't under Earth's gravity, its vertebrae can expand and relax, making astronauts a little taller. Unfortunately, this change is short-lived: once they return to Earth, their height returns to normal after a few months.
#22
We haven't found anywhere else in the universe that has fire. It's a uniquely Earth thing.
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7points
#23
I ain’t one but the fact that total solar eclipses are a super rare thing for a planet to have.
To specify: By “total solar eclipse” I meant how perfect they are here since you can see the corona.
To specify: By “total solar eclipse” I meant how perfect they are here since you can see the corona.
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7points
#24
Light that originates from the core of the sun from fusion takes like 30,000 years to make its way outside of the sun, then to take 8 and a half or so minutes to make its way from the sun to us.
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7points
Another interesting thing about astronauts is that they can’t burp in space, which might seem uncomfortable, but it’s because of the lack of gravity. This means that the air in their stomach doesn’t separate from ingested food and rise up and come out as it does for us.
Hearing this sound can be unpleasant for a lot of people, but for astronauts, if solids, liquids, and gases are all mixing around like that in their stomach, a burp could end up being vomit instead. This obviously would be an unpleasant experience for everyone, especially the unfortunate person who tried to burp.
#25
The fact that we have measured the size of galactic super structures at all without ever leaving near Earth is incredible.
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7points
#26
Every single planet in our solar system - including Jupiter, Saturn, Uranus, and Neptune - can easily fit in the space between Earth and the Moon at its apogee, with over 4,000 km to spare.
When we look at textbook illustrations, space feels crowded. In reality, the emptiness of the universe is horrifyingly massive.
When we look at textbook illustrations, space feels crowded. In reality, the emptiness of the universe is horrifyingly massive.
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7points
#27
Time dilation is real, measured, we even have to adjust satellites for it.
Relativity is weird, if you travelled at the speed of light to Proxima Centauri it would take 4.24 years for someone watching from Earth. For you, it would be instant. Time stops at the speed of light and time is causality.
Relativity is weird, if you travelled at the speed of light to Proxima Centauri it would take 4.24 years for someone watching from Earth. For you, it would be instant. Time stops at the speed of light and time is causality.
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7points
There’s still so much about space that we are yet to figure out and observe, but what we already seem to know sometimes feels too big for our little brains to hold. With ever-changing galaxies, nebulas, and even stars, it’s great that you were able to understand a little bit of the universe as it is today. Who knows what it might be like tomorrow?
We’d love to hear any space facts you might have, especially ones that might seem sun-believable. Do share any interesting things with us in the comments below.
#28
Conditions on the surface of Venus differ radically from those on Earth because its dense atmosphere is 96.5% carbon dioxide, causing an intense greenhouse effect, with most of the remaining 3.5% being nitrogen. The surface pressure is 9.3 megapascals (93 bars), and the average surface temperature is 737 K (464 °C; 867 °F), above the critical points of both major constituents and making the surface atmosphere a supercritical fluid of mainly supercritical carbon dioxide and some supercritical nitrogen.
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7points
#29
The further out you look in space the faster things appear to be moving away from us. Some objects are flying away from us faster than the speed of light because the space between is actually growing that fast. The furthest objects appear more and more red until the wavelengths vanish into the infrared. Anything beyond this cosmic horizon will never be seen again.
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7points
#30
Here's a crazy one: if you took all the DNA in your body and stretched it out end to end, it would be roughly 42 billion miles long. That's enough to go from Earth to the Sun and back more than 200 times. All of that DNA is packed inside microscopic cells. .
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6points
#31
There are more stars in the observable universe than there have been seconds since the big bang.
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6points
#32
In cosmology, there is a certain factor in the equations of the universe known as w. Right now, we believe that w = -1. But if it's less than -1, things could go very, VERY wrong with no warning.
The vacuum of space we now perceive could actually be a "false vacuum," and if a bubble of true vacuum suddenly appeared--and there's nothing to stop that from happening--then all matter would instantly fall apart inside that bubble...which expands outwards at the speed of light, so if it happened elsewhere, even a billion years ago (and a billion light years away), we could never see it coming. In an instant, we would just wink out of existence.
So, you know, sleep tight....
The vacuum of space we now perceive could actually be a "false vacuum," and if a bubble of true vacuum suddenly appeared--and there's nothing to stop that from happening--then all matter would instantly fall apart inside that bubble...which expands outwards at the speed of light, so if it happened elsewhere, even a billion years ago (and a billion light years away), we could never see it coming. In an instant, we would just wink out of existence.
So, you know, sleep tight....
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6points
#33
A **magnetar** is a highly magnetized neutron star. It is the ultra-dense core left behind when a massive star collapses.
A magnetar's magnetic field is roughly a trillion times stronger than Earth's. It is 100 million times stronger than the most powerful magnet engineered by humans.
If you came within 1,000 kilometers of a magnetar, the magnetic field would stretch your atoms into thin cylinders. Your basic chemistry would fail, and you would dissolve. If a magnetar were placed halfway to the moon, it would wipe all magnetic data on Earth.
Magnetars pack the mass of 1.5 suns into a sphere roughly 12 miles across. A single teaspoon of magnetar matter weighs about a billion tons.
A magnetar's solid crust is under severe magnetic stress. When the crust snaps, it causes a starquake. This releases a massive burst of gamma rays. In 2004, a blast from a magnetar 50,000 light-years away hit our solar system. The radiation physically compressed Earth's ionosphere and blinded several space satellites.
H/t to Phil Plait (“Bad Astronomy”) for introducing me to these monsters over a decade ago.
A magnetar's magnetic field is roughly a trillion times stronger than Earth's. It is 100 million times stronger than the most powerful magnet engineered by humans.
If you came within 1,000 kilometers of a magnetar, the magnetic field would stretch your atoms into thin cylinders. Your basic chemistry would fail, and you would dissolve. If a magnetar were placed halfway to the moon, it would wipe all magnetic data on Earth.
Magnetars pack the mass of 1.5 suns into a sphere roughly 12 miles across. A single teaspoon of magnetar matter weighs about a billion tons.
A magnetar's solid crust is under severe magnetic stress. When the crust snaps, it causes a starquake. This releases a massive burst of gamma rays. In 2004, a blast from a magnetar 50,000 light-years away hit our solar system. The radiation physically compressed Earth's ionosphere and blinded several space satellites.
H/t to Phil Plait (“Bad Astronomy”) for introducing me to these monsters over a decade ago.
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6points
#34
Not an astronomer, just a space nerd who falls down Wikipedia holes at 2am. The one that broke my brain: the observable universe is about 93 billion light-years across, but the universe is only 13.8 billion years old.
How? Nothing traveled faster than light. Space itself expanded between us while the light was traveling. So the light took 13.8 billion years to reach us, but the stuff that emitted it is now like 46 billion light-years away in every direction.
It’s like walking 10 miles on a moving walkway and ending up 20 miles from where you started. I still don’t fully accept it emotionally.
How? Nothing traveled faster than light. Space itself expanded between us while the light was traveling. So the light took 13.8 billion years to reach us, but the stuff that emitted it is now like 46 billion light-years away in every direction.
It’s like walking 10 miles on a moving walkway and ending up 20 miles from where you started. I still don’t fully accept it emotionally.
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6points
#35
We can tell how long ago the solar system formed by looking at ratios of radioactive isotopes in little glassy blobs called chondrules found inside meteorites.
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5points
#36
Due to quirks of speed, gravity, and space-time, If you could achieve constant acceleration, a young human could reach the edge of the observable universe within their lifetime. Meanwhile the sun would burn out during your trip.
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5points
#38
I always liked the one that goes: If you shrink the Milky Way down to the size of the United States of America, the center of it is roughly Kansas. Our solar system is roughly Denver, and the orbit of the planets around our sun is roughly the size of the swirls of your fingerprint.
EDIT: Denver is the location of our solar system in the same way that Kansas is the center of the Milky Way.
EDIT: Denver is the location of our solar system in the same way that Kansas is the center of the Milky Way.
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5points
#39
The interior of the sun, is enormously hot and high pressure. The massive pressure rattles hydrogen atoms so hard that they can bump into each other and fuse into helium, releasing a bit of energy.
The sun produces so ridiculously much energy that even here on earth 150 million km away it can be blazingly hot in the midday sun.
But if you took 1m^3 of the sun's core, and compared it to 1m^3 of human body, our human bodies actually output more energy per volume. It's just that the sun's core is unimaginably large. .
The sun produces so ridiculously much energy that even here on earth 150 million km away it can be blazingly hot in the midday sun.
But if you took 1m^3 of the sun's core, and compared it to 1m^3 of human body, our human bodies actually output more energy per volume. It's just that the sun's core is unimaginably large. .
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5points
#40
There are galaxies so far away that, because the universe’s expansion is accelerating, light they emit *today* will never reach us.
They are not outside the universe or hidden behind anything. They are simply receding so quickly that the gap grows faster than their future light can cross it.
They are not outside the universe or hidden behind anything. They are simply receding so quickly that the gap grows faster than their future light can cross it.
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5points