Today’s Wonder of the Day was inspired by jonathan. jonathan Wonders, “what is the space time continuam ” Thanks for WONDERing with us, jonathan!

When you read today's Wonder of the Day question, what comes to mind? Do the words "space-time continuum" conjure up thoughts of light sabers from Star Wars and spaceships from Star Trek?

If so, that's understandable. Something called a "space-time continuum" certainly sounds like it would be out of this world. In reality, though, it's far from science fiction. It's actually a theoretical scientific construct that could help explain the very fabric of our existence.

The idea of a space-time continuum comes from the groundbreaking work of Albert Einstein. Through the process of developing his special and general theories of relativity, Einstein examined the laws of physics as they related to the speed of light.

Einstein concluded that space and time, rather than separate and unrelated phenomena, are actually interwoven into a single continuum (called space-time) that spans multiple dimensions. So how many dimensions are there in the space-time continuum?

The space-time continuum consists of four dimensions: the three dimensions of space (length, width, and height…or up/down, left/right, and forward/backward, depending upon how you wish to think of them) plus the fourth dimension of time. Einstein's theories of relativity spurred other scientists to investigate the relationships between space and time.

Does all this still seem a bit confusing? Don't worry if it does! The space-time continuum and Einstein's theories of relativity are advanced scientific ideas that even scientists sometimes have trouble grasping the meaning and significance of. Without going into confusing detail, let's take a look at a couple of interesting ideas that stem from the space-time continuum.

One way of envisioning the space-time continuum is to think of a large piece of fabric, such as a sheet. Einstein realized that objects with mass, such as a person or Planet Earth, create a distortion in space-time.

Imagine placing a bowling ball in the middle of the sheet. The area around the bowling ball would be pressed down, creating a dimple in the sheet. These dimples represent curvatures in the fabric of the space-time continuum. Einstein identified these curves in the space-time continuum as gravity.

Are these curves real, though? Although scientists can't see or measure space-time, they have been able to confirm certain phenomena predicted by Einstein. For example, light should bend when traveling around massive objects. This phenomenon, known as gravitational lensing, has been observed by astronomers who use it to study galaxies and stars otherwise hidden behind massive objects.

Einstein also theorized that the relative nature of space and time would mean that an object in motion would experience time at a slower rate than one at rest. On Earth, we move too slowly to notice this phenomenon. Scientists have, however, confirmed its truth.

Every day, the satellites that make up the Global Positioning System gain about 38 microseconds compared to Earth clocks. This would affect their location accuracy by several miles if it weren't for built-in calibrations that keep their clocks synced with Earth. So the next time you use a GPS device to go geocaching, you can tell your friends that your location information is coming from just slightly into the future!

#### Wonder What's Next?

Tomorrow, we take our hats off (and maybe put our caps on!) to people who wear the subject of our WONDERing–kippot and yarmulkes!